Tag Archives: Wound healing

Collagen in Wound Healing: Are We Onto Something New or Just Repeating the Past?

by Ryan H. Fitzgerald, DPM1 , John S. Steinberg, DPM2

The Foot and Ankle Online Journal 2 (9): 3

Lower extremity amputations in patients living with diabetes have significant morbidity and mortality. Given the obvious link between lower extremity amputations and the ulcerations that precede them, it is incumbent upon the wound care provider to become familiar with advanced wound care products. The importance of re-establishing a functional extracellular matrix (ECM) in chronic wounds has led to a renewed interest in collagen-based wound healing products. These products can be applied either in the surgical or clinical setting. An intact functional ECM will seek to promote normal progression through the stages of wound healing. This article presents several representative collagen-based advanced wound care products utilized in wound healing, discusses their mechanism of action, and the appropriate indication for each product’s usage.

Key Words: Collagen, wound, diabetes, matrix metalloproteases, bioengineering, alternative tissue.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.  It permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©The Foot and Ankle Online Journal (www.faoj.org)

Accepted: July, 2009
Published: September, 2009

ISSN 1941-6806
doi: 10.3827/faoj.2009.0209.0003

Chronic lower extremity wounds demonstrate a considerable health care dilemma and substantial health care cost in the United States. [1,2] Chronic wounds and diabetic ulcerations represent a large component of this cost, with nearly one million new lesions diagnosed each year. [3,4,5] Furthermore, greater than 60% of non-traumatic amputations in the western world are performed on persons with diabetes [6] and the majority of these amputations are preceded by some form of infected ulceration. Therefore we can surmise that aggressive efforts at ulcer healing will have a direct influence on amputation rates. The risk is obvious; the relationship between diabetic foot ulcerations and subsequent amputation has been well documented and is well understood. [7]

There is significant morbidity and mortality at five years following amputation in this patient population. [8] This staggering data has prompted further research into the science of wound healing in an attempt to reduce diabetic foot ulcerations and their life changing sequelae.

Many of today’s wound care concepts have developed from research associated with burn therapies. [9] More recent research has focused on the wound environment, and on both the cellular and extracellular components necessary to promote wound healing. A better understanding of vasculopathy, infection, and poor nutritional status have enabled industry to target the failing biology of wounds with new products including many new collagen derivatives.

The Science

Throughout the four phases of wound healing, the extracellular matrix (ECM) provides a significant role in regulating and providing a framework for the many processes of healing. The ECM is the largest component of the dermal skin layer and is composed of a variety of polysaccharides, water and collagen proteins. [10] Collagens make up the largest fibrous components of the ECM; in the dermal matrix, the majority of collagen is type I and type III. These collagens demonstrate a fibrillar or rod shape and are composed of three triple-helix protein chains arranged in a linear fashion. This linear orientation provides much of the tensile strength of skin. In addition to longitudinal strength, bundles of collagen molecules in the ECM cross link with adjacent collagen molecules to provide additional strength and stability against shearing forces. [11]

Acute wounds create a provisional wound matrix which contains fibrin and fibronectin, which act as chemical mediators to direct cells to the site of injury and to motivate cells to proliferate and to differentiate into new, provisional matrix structures. [4,6] However, in chronic wounds, increased levels of inflammatory cells and proteases degrade the ECM components which are essential for healing. [8,12] Among these proteases, matrix metalloproteases (MMPs) play an important role in damaging the ECM and the extracellular growth factors present in a chronic wound. These MMPs are synthesized by multiple cell types, including neutrophils, fibroblasts and macrophages at the direction of chemical mediators such as inflammatory cytokines. [6] In normal healing, the MMPs function to debride away denatured elements of the ECM, thus exposing areas of intact functional matrix that are needed for wound healing. This process is highly regulated and controlled via tissue inhibitors of metalloproteases (TIMPs). [12] In chronic wounds, however, in addition to an excess number of MMPs, there is a failure in the regulation of protease activity between the MMPs and TIMPs which can result in further degradation of the ECM. This is followed by the destruction of growth factors, inhibition of angiogenesis, and breakdown of granulation tissue. [13]

For wound healing to occur, a balance is needed between the protein degrading activities of MMPs and other cellular activity that synthesizes and deposits protein components of granulation tissue. Many new collagen based wound care products aim to reduce excessive protease levels and reestablish balance in the wound environment. In addition, these products serve to contribute functional ECM proteins to stimulate the healing process. [1] Research has demonstrated that topically placed collagen can initiate wound healing by activating inflammatory cells and promoting increased vascularization of the healing tissue. [14] Other research has demonstrated that the physical three-dimensional structure of collagen has the ability to induce fibroblastic growth, which is essential in the formation of granulation tissue. [1]

The Products

There are an abundance of collagen-based products on the market today. These products can be loosely divided into groups based upon the setting in which they are applied (either in the clinic setting or in the operating room). In addition to differences in the application process, these collagen-based products can be combined with other treatment modalities, such as the addition of an alginate to manage exudate or the addition of silver to provide antimicrobial effects (See attached table).

Attached Table:  Collagen based products and their properties.

Below is a detailed discussion of several representative topical collagen products that are intended for use in the outpatient dressing setting:

FIBRACOL PLUS® (Systagenix Wound Management) combines the structural support of collagen with the exudate management of an alginate. In this way, the alginate component maintains a moist wound environment while the collagen component allows for cellular and vascular in-growth, which promotes formation of granulation tissue and neo-epithelialization at the wound site.

Promogran® (Systagenix Wound Management) combines oxidized regenerated cellulose (ORC) and collagen. This bioactive collagen product binds to and neutralizes destructive proteases in chronic wound fluid. [14]

Once bound, MMPs are rendered inactive due to alteration of their protein structure. Reduction of MMP burden in the chronic wound allows endogenous ECM protein cells to proceed to the formation of granulation tissue and normal wound healing.

PRISMA® (Systagenix Wound Management) is the next generation in the Promogran® line. This product provides the MMP binding function of Promogran® in the form of ORC and collagen with the addition of silver to provide antibiosis, thus lowering the bioburden in chronically colonized wounds. [14] PRISMA® provides a biodegradable cellular matrix that promotes cellular migration and neo-vascularization while helping to maintain bacterial balance at the wound site and to create an optimal wound healing environment.

PURACOL PLUS® (Medline Industries, Inc) is a bovine derived collagen matrix, which utilizes a native, triple-helical structure to stimulates fibroblastic activity in the wound bed to promote ECM formation and thus stimulate local wound healing. Additionally, this product controls moisture in the wound environment by converting to soft, gel-like sheet that maintains intimate contact with wound bed as it absorbs exudate. PURACOL PLUS® is most commonly utilized in chronic, partial thickness wounds which demonstrate light to heavy exudate and are non-infected and non-ischemic.

Biostep® and Biostep Ag® (Smith & Nephew) are two new collagen products which are demonstrating a great deal of success in the treatment of chronic wounds. The semi-denatured porcine collagen in Biostep® attracts and bind excess MMPs present in the chronic wound environment, and the EDTA component in the product irreversibly deactivates MMPs by binding to their zinc ions. In this way the collagen in Biostep®, coupled with EDTA, functions as a competitive substrate for the MMPs and thus allows endogenous collagen matrix formation to progress undeterred as granulation tissue forms. In addition, the product contains carboxy methyl cellulose and alginate which helps to provide moisture management in an actively draining wound environment.

Biostep Ag® provides similar anti-MMP activity, while the addition of silver ions helps to maintain bacterial balance in the wound site.

OASIS® Wound Matrix (HealthPoint) is a biologically derived extracellular matrix-based wound product which is derived from porcine small intestine submucosa. Indicated in the management of partial and full thickness wounds, this product provides intact acellular collagen scaffold that allows promotes a favorable host tissue response and stimulates cellular migration, leading to restoration of tissue structure and promotion of wound healing.

Integra® Matrix (Integra Life Sciences) consists of a cross-linked bovine tendon collagen and glycosaminoglycan matrix which is available with and without a semi-permeable polysiloxane layer. [2] Glycosaminoglycans are large saccharide polymers that are important elements of the ECM; these proteins aid in cellular adhesion to the matrix, as well as playing a role in cell and tissue differentiation necessary for wound healing. [9] The semi-permeable polysiloxane membrane of the bilayer matrix functions as a temporary epidermis by protecting the deeper collagen graft tissue and wound while also controlling water vapor loss. Below the silicone layer, the collagen-glycosaminoglycan biodegradable matrix provides a scaffold for cellular invasion and capillary growth. As the graft is incorporated, the silicone layer peels away to expose new granulation tissue formation and neo-epithelialization. Additionally, this product is available in a “flowable” or injectable form that can be utilized to provide collagen and glycosaminoglycan matrix to difficult to manage wounds with tunneling or tracking components. Often this modality can be used in conjunction with the conventional graft to provide three dimensional reconstruction at complex wound sites.

GraftJacket® Regenerative Tissue Matrix (Wright Medical), which is a collagen based graft processed from donated cadaveric skin. As an allograft, this product contains components of normal skin including collagen, elastin, hyaluronan, fibronectin, and blood vessel channels. [8]

In this way, GRAFTJACKET® provides soft tissue coverage over deep structures, functions as a scaffold for new cellular in-growth. It preserves the vascular channels in the donor graft and allows for rapid revascularization necessary for wound healing.

In the operating room setting, collagen-containing products are often applied to provide coverage over a soft tissue deficit following surgical debridement or serve as a scaffold initiate the filling of a void. As with the clinically applied products described above, these collagen grafts were originally designed to be used in the treatment of partial and full thickness burns. These surgically applied collagen products, such as Integra® Matrix and GraftJacket® Regenerative Tissue Matrix, are not specifically designed to neutralize proteases as several of the previously described products. Instead, they provide a functional cellular scaffold that promotes cellular in-growth and formation of granular tissue while also providing soft tissue coverage over bone, tendons, and other deep structures. As a result, it reduces the risk of contamination and subsequent infection.

To reduce MMP burden in a wound site prior to application of these surgically applied collagen grafts, it is recommended that the wounds be debrided sharply to promote local bleeding and to remove any nonviable and necrotic soft tissue and bone that will further stagnate a wound site. Localized bleeding following debridement stimulates influx of alpha-2-macroglobin (A2M), which is a chemical agent that acts as a protease inhibitor, thus reducing proteolytic destruction of the graft. [1,11]


In discussion of collagen products in wound healing, it is important to understand the underlying etiologies of wound chronicity. Vascular and nutritional status, the presence of an infection or colonization, and the microenvironment present in the wound bed all combine to affect healing. Each barrier must be addressed to ensure that the wound progresses through the normal stages of healing. [1]

Research has demonstrated the importance of re-establishing a functional ECM in chronic wounds and this has led to a renewed interest in collagen based wound healing products. [8] These products seek to provide a functional ECM as well as to reduce MMP levels present in the wound bed and seek to promote normal progression through the stages of wound healing. In addition, these products can be combined with other modalities, such as alginates or heavy metals to provide additional effects to the wound environment such as management of exudate or bacterial load.

The collagen-based surgical grafting materials, such as Integra Matrix® and GraftJacket® have filled a niche that have allowed for significant increases in salvage options due to the ability to provide collagen ECM to the wound site, following sharp debridement. These surgically applied collagen wound fillers can provide soft tissue coverage over deeper structures to reduce the risk of infection. Pioneered in the burn community, much of these techniques are now being utilized to preserve limb length in partial foot amputations, which is important as the costs of health care spiral and the annual incidence of foot ulcerations continue to climb. [2]

Considering the significant morbidity and mortality associated with lower extremity amputations, and the obvious link between lower extremity amputations and the ulcerations that precede them, it is incumbent upon the clinician involved in wound care to become familiar with these advanced wound care products in order to provide patients with the greatest possibility for successful outcomes in the treatment of chronic wounds.


1. Schultz GS, Sibbald RG, Falanga V, Ayello EA, Dowsett C, Harding K et al: Wound bed preparation: a systematic approach to wound management. Wound Repair Regen, 2003. 11 (suppl 1): S1 – 28, 2003.
2. Voigt DPC, Edwards P: Economic study of collagen-
glycosaminoglycan biodegradable matrix for chronic wounds. Wounds 18 (1): p. 1 – 7, 2006.
3. Physicians AAoF: Clinical guidelines on diabetic foot disorders. J Foot Ankle Surgery 63 (5): 290 – 295, 2001.
4. Greiling DCR: Fibronectin provides a conduit for fibroblast transmigration from collagenous stroma into fibrin clot provisional matrix. J cell science 110 (7): 861 – 870, 1997.
5. Gordois A, Scuffham P, Shearer A, Oglesby A: The health care costs of diabetic nephropathy in the United States and the United Kingdom. J Diabetes Complications 18 (1): 18 – 26, 2004.
6. Ovington L: Overview of matrix metalloprotease modulation and growth factor protection in wound healing. Wounds 14(5): 3 – 7, 2002.
7. Moulik PK, Mtonga R, Gill GV: Amputation and mortality in new-onset diabetic foot ulcers stratified by etiology. Diabetes Care 26 (2): 491 – 494, 2003.
8. Loots MA, Lamme EN, Zeegelaar J, Mekkes JR, Bos JD, Middelkoop E: Differences in cellular infiltrate and extracellular matrix of chronic diabetic and venous ulcers versus acute wounds. J Invest Dermatol 111 (5): 850 – 857, 1998.
9. Ehrenreich RZ, Ruszczak Z: Update on tissue-engineered biological dressings. Tissue Engineering 12 (9): 2407 – 2424, 2006.
10. Dalla Paola L, Faglia E: Treatment of diabetic foot ulcer: an
overview strategies for clinical approach. Curr Diabetes Rev 2 (4): 431 – 447, 2006.
11. Kainulainen V, Wang H, Schick C, Bernfield M: Syndecans, heparan sulfate proteoglycans, maintain the proteolytic balance of acute wound fluids. J Biol Chem 273 (19): 11563 -11569, 1998.
12. Trengove NJ, Stacey MC, MacAuley S, Bennett N, Gibson J, Burslem F, Murphy G, Schultz G: Analysis of the acute and chronic wound environments: the role of proteases and their inhibitors. Wound Repair Regen 7 (6): p. 442 – 452, 1999.
13. Ladwig GP, Robson MC, Liu R, Kuhn MA, Muir DF, Schultz GS: Ratios of activated matrix metalloproteinase-9 to tissue inhibitor of matrix metalloproteinase-1 in wound fluids are inversely correlated with healing of pressure ulcers. Wound Repair Regen 10 (1): 26 – 37, 2002.
14. Cullen B, Watt PW, Lundqvist C, Silcock D, Schmidt RJ, Bogan D, Light ND: The role of oxidised regenerated cellulose/collagen in chronic wound repair and its potential mechanism of action. Int J Biochem Cell Biol 34 (12): 1544 – 1556, 2002.

Address correspondence to: Ryan H. Fitzgerald, DPM, AACFAS. Hess Orthopaedics & Sports Medicine, PLC
4165 Quarles Court, Harrisonburg, Virginia 22801.

Attending physician, Hess Orthopaedics & Sports Medicine, Harrisonburg Virginia.
Assistant Professor, Department of Plastic Surgery, Georgetown University School of Medicine.

© The Foot and Ankle Online Journal, 2009

EBMR: Comparison of Negative Pressure Wound Therapy using Vacuum-Assisted Closure with Advanced Moist Wound Therapy in the Treatment of Diabetic Foot Ulcers

Evidence Based Medicine Review

Blume P., Walters J., Payne W., Ayala J., and Lantis J.

Diabetes Care 31:631-636, 2008

Michael Turlik, DPM

The Foot & Ankle Journal 1 (12): 5

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.  It permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©The Foot & Ankle Journal (www.faoj.org)


This was a multi-center randomized controlled efficacy trial of 342 diabetic subjects who were followed for a minimum of 112 days. The study was performed across 37 diabetic foot clinics and hospitals principally in the United States. The primary outcome was complete ulcer closure. There was a thorough description of the method of randomization as well as, concealment allocation. Subjects and investigators were not blinded and it was unclear if data collectors and analysts were blinded. Safety and effectiveness analysis was conducted by the company sponsoring the study.


A sample size calculation was carried out with the expectation of a 20% difference between groups (Absolute Risk Reduction). Enough subjects were enrolled in the study to satisfy the sample size calculation. Baseline data examination reveals no difference between groups. Data from the primary outcome were analyzed as intention to treat as well as, per protocol. Efficacy of the intervention was reported as statistically significant both for intention to treat and per protocol analysis favoring the vacuum assisted closure method. Point estimates were reported for the primary outcome but 95% confidence intervals were not reported.


The manufacturer of the wound closure vacuum assisted device (KCI) supported the study. It was not indicated if the study was registered. The primary author has received payments from the manufacturer for speaking engagements. No other disclosures were noted for other authors or investigators. The article has been marked as an advertisement by the publisher.


The study contains several well described methodological techniques to limit bias, randomization, concealment allocation, and intention to treat analysis. However, due to the nature of the study investigators and subjects were unable to be blinded.

Although unblinded studies are associated with an increased treatment effect this is less likely when the primary outcome is objective such as resolution of an ulcer as opposed to soft measurements such as patient reported outcomes. [1] However, no mention was made regarding blinding of data collectors and analyzers.

The data from the study was analyzed by the company funding the study. This may be perceived as a potential source of bias, it is more reassuring to the reader when the data is analyzed by a neutral third party. The results of the primary outcome were presented as intention to treat and per protocol. It appears the author chose to assign the worst case scenario for the data lost to follow-up for the ITT analysis. Both methods were statistically significant however differed in their point estimate. Was this study clinically significant? The authors expected a 20% difference (ARR) between groups when they calculated their sample size. If the 20% difference is to be accepted as a clinically significant result then the result of the primary outcome using the intention to treat analysis was not clinically significant but only statistically significant. The per protocol analysis was both clinically and statistically significant. Furthermore, it is difficult to analyze the results with only point estimates and not 95% confidence intervals (CI). Why 95% CI were reported for secondary measures and not the primary outcome was unclear.

There appears to be a fairly high loss to follow-up in both arms of the study (approximately 30% per treatment arm). The prognosis for subjects lost to follow-up is thought to be different than the patients who remain in the study. [2] This loss of data may compromise the randomization sequence. Did the loss of follow-up effect the results of the study? The strength of the inference drawn from the study is modified by the magnitude of the difference between the intention to treat and per protocol analysis. It would have been instructive for the reader if the authors addressed this point during their discussion of the results.

Interpretation the study’s results would be better understood with a clear clinically important difference stated by the authors and with 95% CI reported about the point estimate of the primary outcome.

Using the data from this study 95% CI can be calculated for the Absolute Risk Reduction (ARR) and Number Needed to Treat (NNT) for both the intention to treat and per protocol analysis. [3] (table 1)

Table 1

The ARR only exceeds 20% during the per protocol analysis. The lower end of the 95% CI for both ITT and PP is greater than 0 which is consistent with a statistically significant result. Although the point estimate (ARR) for the intention to treat analysis is less than 20% , a risk reduction of more than 20% cannot be ruled out by evaluating the upper end of the 95% CI and would suggest a larger study is necessary or less loss of follow-up.

The NNT is a more clinician friendly metric to access efficacy in studies with dichotomous outcomes. The NNT for both are similar 5 (PP) and 8 (ITT) however, the upper limit of the 95% CI or worse case scenario is 12 (PP) and 24 (ITT). This appears to be a large difference.

Although the use of the vacuum assisted closure appears to be more efficacious the magnitude of the effect is unclear and the inference reduced. It is up to the reader to determine if the loss to follow-up, lack of blinding and lack of clinical significance reduces the inference of the results of this study.

In addition, since the study was designed as an efficacy rather than an effectiveness study, generalizing the results to clinical practice should be undertaking with caution.

The safety data were presented as treatment related rates at six months. However, the trial evaluated treatment until day 112 or ulcer closure by any means. It would be informative to the reader to review the data on safety prior and post intervention termination. There have been two meta-analysis published this year for vacuum assisted closure and diabetic foot ulcers this year. [4,5]


1. Woods L, Egger M, Lotte Gluud L, Schulz KF, Jüni P, Altman DG, Gluud C, Martin RM, et al. Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study. BMJ 336 (March): 601 – 605, 2008.
2. Montori VM, Guyatt GH. Intention-to-treat principle. Can Med Assoc J 165 (10): 1339 – 1341, 2001.
3. Graphpad. http://www.graphpad.com/quickcalcs/NNT1.cfm Accessed 11/3/2008.
4. Gregor S, Maegle M, Sauerland S, Krahn JF, Peinemann F, Lange S. Negative pressure wound therapy a vacuum of evidence? Arch Surg 143 (2): 189 – 196, 2008.
5. Bell G, Forbes A. A systematic review of the effectiveness of negative pressure wound therapy in the management of diabetes foot ulcers. Int Wound J 5 (2): 233 – 242, 2008.

© The Foot & Ankle Journal, 2008

The Use of Marigold Therapy for Podiatric Skin Conditions

by Robert A. Hadfield, BS1, Tracey C. Vlahovic, DPM2 , M. Tariq Khan, PhD (Lond), BSc (Pod Med), BSc (Hons), MChS, DFHom (Pod), FBAHChP PFLS3

The Foot & Ankle Journal 1 (7): 1

Marigold therapy has been used for over 30 years in the United Kingdom and has been evaluated by numerous randomized double-blind placebo-controlled studies for various skin issues on the lower extremity. Various species of marigold are naturally anti-viral, keratolytic, and anti-inflammatory when applied topically to the affected area. Marigold therapy offers a non-invasive and gentle treatment for difficult to treat plantar verruca, painful hyperkeratotic lesions, and inflamed bursa secondary to hallux abducto valgus.

Key words: Phytotherapy, Marigold, verrucae, foot ulcer, Tagetes species, Calendula species, hyperkeratotic lesions, bunion, bursitis

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.  It permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©The Foot & Ankle Journal (www.faoj.org)

Accepted: May 2008
Published: July 2008

ISSN 1941-6806
doi: 10.3827/faoj.2008.0107.0001

Two marigold species, Tagetes and Calendula, have been used for centuries as herbal remedies for various ailments. (Figs.1ab) Phytotherapy, or the use of plants for their medicinal properties, is the basis for most pharmaceutical products. In particular, the marigold has an interesting history as both a topical and an oral remedy.


Figures 1ab  The Tagetes (a) and Calendula (b)  marigold species.

Marigold therapy was first described in the podiatric literature as a treatment for plantar hyperkeratotic lesions in 1980. [1] The Tagetes species of marigold has been found to be strongly keratolytic. The keratolytic and anti-inflammatory properties of Tagetes in the treatment of verrucae and hyperkeratotic lesions have been well documented in the literature. [2-8] Tagetes has also been described as a treatment for carbuncles and eye infection in India as well as for joint pain and muscular spasms in Brazil and Mexico. [9,10] In addition to being a treatment for verruca, this species has also been used in the treatment of allergic contact dermatitis as well as radiation dermatitis associated with breast cancer therapy. [11,12]

In contrast, the English pot Marigold (Calendula species) has been described in the treatment of cuts, wounds and ulcerations as early as 1838. [13] More recently, anti-tumor and anti-oxidant properties of Calendula species have been established and utilized in researching treatments for various cancers. [14,15] This species has also been found to have hepatocytoprotective properties in the treatment of CCI4 poisoning as well as anti-microbial properties.16-18 In recent years, investigators outside the United States have studied the properties of the Calendula species in healing diabetic foot ulcerations. [19,20]

This article will review the literature for the use of Tagetes and Calendula species on the most common podiatric conditions treated and will show their usefulness as an effective and non-invasive therapy. The chemicals found in the multiple Tagetes species described will demonstrate keratolytic, anti-viral, and anti-inflammatory properties. The use of the Calendula species of marigold will be described, including a case study demonstrating its use in non-healing ulcerations.

Hyperkeratotic Lesions

Painful hyperkeratotic lesions, arising from both mechanical stressors and boney deformity, are extremely common podiatric conditions. Treatments range from conservative debridement, change of shoe gear, orthotics, and topical keratolytics to surgical correction of the underlying deformity.

A marigold based paste has been used successfully as topical therapy for these lesions for many years in the United Kingdom. (Figs. 2, 3)

Figure 2   Painful plantar hyperkeratotic lesions prior to marigold therapy.

Figure 3  Clearance of lesions after four treatments; one month after initial therapy.

Davidson reported M. Taufiq Khan’s work with the Tagetes species and its ability to inhibit cell activity in the stratum corneum. [1] A chemical analysis of Tagetes isolated tagetone, d-limonene, acimene, linalyl-acetate, linalol 9.8%, and other terpenes. [21] Tagetone acts as a catalyst to inhibit the rapid production and transmission of keratinocytes. [22,23]

Tagetes’ effect on podiatric skin, bone, and nail conditions was further described by Khan and White followed by numerous randomized, double-blind placebo controlled studies on those conditions. [24]

In 1996, Tagetes erecta was used for a double blind placebo controlled study for thirty patients with painful plantar hyperkeratotic lesions. [4] They were separated into three groups: marigold therapy with an aperture pad, marigold therapy without an aperture pad, and placebo marigold therapy with aperture pad. The placebo paste was formulated to look and feel identical to the active paste but with no active chemical ingredients. In the semi-compressed felt aperture pad, a paste of fresh plant combined with isopropyl alcohol was applied by the podiatric practitioner once a week for four weeks over the painful lesions. The patients wore the poultice dressing for a week and returned weekly for lesion debridement by the practitioner. At the end of the treatment period, patients received either active or placebo tincture and ointment to use on the test area at home for four weeks.

The active paste group with a pad showed a significant decrease in hyperkeratotic lesion width, length, and pain when compared to the placebo group.

The active paste group with pad versus the active paste group without pad also had a significant difference in width, length and pain showing that the aperture pad had helped to offload the lesions as well as compartmentalize the marigold paste to the affected area. Reducing the trauma at the painful hyperkeratosis site is believed to decrease cytokine production thus decreasing kertinocyte production. This coupled with the natural keratolytic property of Tagetes (containing tagetone among other chemicals) proved to be a promising therapy, which could be used prior to custom molded orthotic therapy or as an alternative to surgical correction.

The keratolytic property of Tagetes was further explored in several published case studies. [5,13,25] Patients receiving a similar therapy as previously described reported pain relief after 48 hours of the first dressing application. Interestingly, the patients who used the home therapy and orthotic control after the initial eight week period had no recurrence of the lesions after one year.

Plantar Verrucae

Plantar verrucae cause patients to seek treatment when the lesions become painful or do not resolve on their own. Treatments range from topical to surgical and are typically painful. Marigold therapy can also be added to the many topical treatments for verrucae. (Figs. 4,5)

Figure 4  Recalcitrant plantar verruca prior to marigold therapy.

Figure 5  Clearance of the lesion after four treatments.

Forty patients were randomly placed into one of four groups; active, placebo, active with pad, and pad only with no paste. [26] Patients were treated twice a week for two weeks and then used home therapy consisting of the tincture and ointment for four weeks. The lesion surface area pre-treatment and post-treatment was analyzed with a wound mapping system. Results showed that the active group had a significant difference in appearance, pain, and size compared with the placebo group.

Additionally, the proposed antiviral property of Thuja occidentalis, a member of the conifer tree family, was studied using thirty randomly selected patients. [27] Patients were chosen with lesions older than eighteen months. An extract containing T. occidentalis was applied daily for three weeks and followed for six months after initial treatment. Ninety percent of patients had resolution of their lesion after one month from the initial treatment. At six months, the same number of patients had no recurrence. After the assessment, a double blind placebo controlled study was done. Results showed 80% of the active group had resolution while the placebo group had just 33% resolution. [27]

A combination of the Tagetes and Thuja into a paste has been used extensively since the separate controlled studies were completed. A small case study showed the usefulness of the paste in immunocompromised patients with mosaic type verrucae. [28] All of the patients were HIV positive with detectable viral loads and verrucae that did not respond to conventional treatment. Four applications of the combination paste eradicated the verrucae in two of the three patients. (Figs. 6,7) Although further research is warranted in this population, it is a hopeful outcome for a non-invasive treatment.

Figure 6    Immunocompromised patient with mosaic plantar verruca prior to therapy.

Figure 7  Clearance of mosaic verruca after four treatments.

Soft Tissue Inflammation Associated with Hallux Valgus

The tissue underlying the prominent medial eminence seen in hallux valgus can become inflamed and be the source of a patient‘s discomfort. This bursitis is often treated with injections, padding, and shoe gear change. For patients that do not want surgery to correct the underlying boney deformity, marigold offers a gentle alternative to decrease inflammation and pain associated with hallux valgus. (Figs. 8,9) There is strong evidence that a particular species of Tagetes exerts anti-inflammatory action towards acute and chronic conditions. [29]

Figure 8  Patient with significant bursitis pain over bunion prior to marigold therapy.

Figure 9  Decrease of erythema and inflammation at bunion site after therapy.

A randomized double-blind placebo controlled study utilized sixty patients with either bilateral or unilateral inflammation was performed. [30] Twenty patients with bilateral inflammation were randomly placed into one of two groups: active paste with aperture pad and placebo paste with protective pad. Forty patients with unilateral bursitis were randomly placed into similar groups with an identical treatment plan. All patients followed the paste and pad therapy with either an active or placebo home therapy consisting of tincture and ointment spray to use on the area daily. Soft tissue swelling at the medial eminence of the bunion was assessed using calipers pre and post treatment. Patients in both of then active groups had complete relief of pain after eight weeks and a 35% reduction in soft tissue swelling at the bursitis site. In the placebo group showed minor reduction in pain which was most likely due to the presence of the aperture pad. However, their original symptoms returned at a week 4 when the patients started the placebo home therapy.

Marigold’s ability to reduce bursitis inflammation was further studied in a group of 45 patients with unilateral pain. [22] Patients were randomly placed into five groups: six groups with active marigold paste (each group had various extracts in organic solvents) and aperture pad and three groups with placebo without aperture pad.

After a similar treatment plan described in the previous study, Group A (active paste in ethanolic extract with pad) had 100% in level of pain (using the visual analogue pain scale) while Group G had 30% reduction in their level of pain.

Both of these studies support the combined use of marigold therapy with a protective aperture pad for patients with painful medial eminence bursitis who are not surgical candidates or do not wish to undergo surgical correction.

Superficial Ulceration

Khan states, in his 1982 publication in World Medicine on the uses of various species of marigolds, that Calendula species promote healthy granulation tissue. [13] There are currently clinical projects underway at the School of Pharmacy at the University of London on these properties of Calendula. There was a single reported case of use in a diabetic ulcer, by Khan in the United Kingdom, using the formulation that was utilized in the following case study.

A larger study, by Duran, et al., was published in Serbia in 2005, using Calendula extract on 34 venous stasis ulcerations. [20]

They reported a statistically significant difference in reduction of total wound area compared with the control (p<0.05), showing an overall decrease of 41.71% in the experimental group compared with 14.52% in the control group. They conclude that application of Calendula extract significantly increases epithelization in chronic venous ulcerations.

This study by Duran, et al., lends scientific credence to the use of Calendula extract as a treatment to decrease the healing time of chronic ulcerations. However, randomized control studies have to yet to be completed.

Case Study

A thirty year old Caucasian male presented with concern of an ulcer on the anterior right leg. The superficial wound was over the site of an external fixator pin tract scar, which had occurred fifteen years earlier. The injury was a result of a blunt blow on a coffee table, shearing off the hypertrophic scar. The patient reported bleeding globally across the lesion at the time of injury. He denied a personal or family history of family diabetes, hypertension, coagulopathy and peripheral vascular disease.

Treatment initiated by the patient consisted of triple antibiotic ointment and a bandage. The patient reported that approximately one week after the injury, in the course of cleansing the wound, eschar that had previously formed self-debrided, and the wound appeared as it did on the day it was sustained. The same treatment was resumed, with a similar course of routine healing. Two weeks following the injury, a similar loss of eschar was duplicated. The second event led the patient to seek treatment.

On initial examination, the patient had a 2.5 cm x 2 cm x 0.5 cm circular lesion over the crest of the anterior tibia in the central one third of the leg. The lesion had a mixed granular and fibrotic base, with mild surrounding erythema and no edema (Figure 10).

Figure 10  Anterior leg ulcer on intital presentation prior to marigold therapy.

No undermining was present, and there was no maceration of the wound edges. There was no purulence or malodor. The scars from the other pin tract sites were also examined and were labeled hypertrophic.

The patient received a regimen of marigold therapy for the wound. The medication used was the HTS 087 Tincture and Ointment. (Marigold Footcare Ltd, UK) The therapy regimen consisted of a combination of the tincture and ointment placed in an aperture pad which was then covered with medical tape and gauze over the lesion for three consecutive days. The same regimen was followed every other day after the initial three day period for two weeks.

The patient related no pain or discomfort for the duration of the treatment. Reduction in wound size (approximately 25%) was noted 48 hours after marigold therapy was initiated. (Fig. 11)

Figure 11  The lesion with decreased erythema and increased granulation tissue 48 hours after therapy.

Eschar information with a decrease in wound size was noted on subsequent dressing changes for six days afterwards. The directions for application were followed until epithelization was noted, which was accomplished in eight days. Complete resolution was obtained in approximately four weeks. (Fig. 12)

Figure 12  The resolved lesion.

The complex nature of this wound, having formed over a pre-existing scar and in a traditionally difficult-to-heal area anatomically, caused a delay in wound healing despite the patient’s uncomplicated medical history. The wound’s recalcitrance in healing warranted additional therapy than just antibiotic ointment and patience.


It should be noted that over the counter and/or health food store creams and preparations of marigold do not have the same effect as the previously discussed studies show. The extracts used for the controlled and case studies were researched and developed by M Taufiq Khan and M Tariq Khan over thirty years. They developed specific extracts that are directly applied by the podiatric physician to the patient: an anti-viral paste (for verruca), an anti-inflammatory paste (for bursitis and tendonitis), a keratolytic paste (for hyperkeratosis), and an anti-fungal paste (for nails). The patients then continue with home therapy that consists of tinctures and ointments with the same properties. These products were only recently introduced to the United States. The second author was the first United States podiatric physician to become certified in the use of the marigold products from Marigold Footcare, Ltd., and the Royal London Homeopathic Hospital, London, UK and will be able to certify (in conjunction with the Hospital) other podiatric physicians in the future. In order to ensure appropriate use of the extracts, certification will only be available to podiatric physicians and is required for both the usage and purchasing of the products. Further research will continue into using the extracts on genodermatoses, onychomycosis, and other podiatric conditions.


The superficial ulceration case study and immunocompromised patients with verruca case study combined with studies performed outside of the United States show the promise of the continued investigation of marigold therapy as a treatment for various podiatric conditions. Marigold therapy has consistently been shown to provide gentle, non-invasive treatment that allows patients a painless alternative treatment.


1. Davidson L., “Marigold rediscovered: a cure for callosities,” Therapy. Pg 1, 1980.
2. Khan M., et al., “Homeopathic treatment of common foot conditions,” British Journal of Dermatology Nursing. 1: 20-23, 2003.
3. Khan M., et al., “Marigold Treatment of foot conditions,” Dermatology in Practice. 10 (3): 28-30, 2002.
4. Khan M., et al.,“Podiatric Treatment of hyperkeratotic plantar lesions with marigold Tagetes erecta,” Phytotherapy Research. 10: 211-14, 1996.
5. Khan, et al., “Treatment of plantar hyperkeratosis with homeopathic podiatry,” Podiatry Now. Dec. 502-505, 2000.
6. Talhouk R., et al., “Anti-inflammatory bioactivities in plant extracts,” J Med Food. 10 (1): 1-10, Mar 2007.
7. Herold A., et al., “Antioxidant Properties of some hydroalcoholic plant extracts with anti-inflammatory activity,” Roum Arch Microbiol Immunol. 62(3-4): 217-227, 2003.
8. Fuchs S., et al., “Protective effects of different marigold (Calendula officinalis L.) and rosemary cream preparations against sodium-lauryl-sulfate-induced irritant contact dermatitis, “ Skin Pharmacol Physiol. May 20, 2005.
9. Hernandez F. “Historia de las plantas de nueve Espana.” Mexico Irmenta Universitaria. 1: 90-91, 1942.
10. Caius J. “The Medical and Poisonous Compsoitae of India, “ J Bombay Natural History Society. 41: 90-91, 1940.
11. Pommier P., et al., “Phase III randomized trial of Calendula officinalis compared with trolamine for the prevention of acute dermatitis during irradiation for breast cancer, “ J Clin Onco.l 22 (8) ; 1447-1453, Apr 15, 2004.
12. Pirker C., et al., “Cross-reactivity with Tagetes in Arnica contact eczema,” Contact Dermatitis. 26 (4): 217-219, Apr 1992.
13. Khan M. “Why marigolds can be a corny treatment: A pilot study of the effects of marigold in the treatment of painful corns,” World Medicine. 42-43, Feb 1982.
14. Jimenez-Medina E., et al., “A new extract of the plant Calendula officinalis produces a dual in vitro effect: cytotoxic anti-tumor and activity and lymphocyte activation,” BMC Cancer. 6: 119, 2006.
15. Wang M., et al., “Antioxidant activity, mutagenicity/anti-mutagenicity, and clastogenicity of lutein from marigold flowers,” Food Chem Toxicol Epub Sp; 44(9) : 1522-1529, Apr 25, 2006.
16. Barajas-Farias L., et al., “A dual and opposite effect of Calendula officinalis flower extract: chemoprotector and promoter in a rat hepatocarcinogenesis model” Planta Med. 72(3) 217-221, Feb 2006.
17. Rusu M., et al., “The hepatoprotective action of ten herbal extracts in CCl4 intoxicated liver,” Phytother Res. 19(9): 744-749, Sep 2005.
18. Radioza S., et al., “Antimicrobial activity of Calendula L. plants,” Ukranian Journal of Microbiology. 21-25, 2007.
19. Khan M., et al., “Treatment of Diabetic foot ulcer with Homeopathic Podiatry,” Poster Presentation, Symposium on Advances in Skin and Wound Care, Las Vegas, 2005.
20. Duran V., et al., “Results of the clinical examination of an ointment with marigold (Calendula officinalis) extract in the treatment of venous leg ulcers,” Int J Tissue React. 27(3) ; 101-6, 2005.
21. Leung A Encyclopedia of Common Natural Ingredients, Used in Food, Drugs and Cosmetics. Academic Press, New York, 1980.
22. Khan M. “Phytochemical and biologic studies of Tagetes erecta and its clinical evaluation in the treatment of hallux abducto valgus and its associated condition bunion,” PhD Thesis, Faculty Medicine, Centre for Pharmacognosy, School of Pharmacy, University of London, 1999.
23. Sharma A. “Tagetes genus,” Wealth of India. Vol X, SP W p 109, 1961.
24. Khan M., et al., “Comparative clinical studies of Calendula offcinalis and Tagetes varieties of marigold,” 35th LMHH Congress, Sussex, 488-492, 1982.
25. Khan M., et al., “Clinical evaluation of Tagetes erecta in the treatment of parakeratosis,” Phytotherapy Res. 10: 186-188, 1996.
26. Khan M. Jnr. “Tagetes signata in the treatment of verruca pedis,” J British Pod Med. 51: 118b, 1996.
27. Khan M., et al., “A double blind placebo study of topical Thuja occidentalis on verruca pedis in children and adults,” JEADV. 1: S251, 1999.
28. Vlahovic T., et al., “The Use of Marigold Therapy on Mosaic Verrucae in the HIV population,” Presented at AAD, San Antonio, TX 2008. JAAD. 58(2): AB34, 2008.
29. Kasahara Y., et al., “Effect of methanol extract from flower petals of Tagetes patula L. on acute and chronic inflammation model,” Phytother Res. 16(3): 217-222, 2002.
30. Khan M. “The podiatric treatment of hallux abducto valgus and its associated condition bunion with Tagetes patula,” J Pharm Pharmacol. 48: 768-770, 1996.

Address correspondence to: Tracey C. Vlahovic, DPM
Associate Professor, Temple University School of Podiatric Medicine, Philadelphia, Pa. 19107
email: traceyv@tample.edu

1Fourth year student, Temple University School of Podiatric Medicine, Philadelphia, Pa. 19107.
2Associate Professor, Temple University School of Podiatric Medicine, Philadelphia, Pa. 19107.
3Deputy Director of Moeopathic Podiatry, The Marigold Clinic, Royal London Homeopathic Hospital, London, UK.

© The Foot & Ankle Journal, 2008

The BRAIN Principle: Managing Wounds After Application of Bioengineered Alternative Tissues to Maximize Incorporation and Wound Healing

by Jonathan Moore, DPM, MS1

The Foot & Ankle Journal 1 (5): 3

The efficacy of bioengineered alternative tissue (BAT) for lower extremity ulcers (diabetic and non-diabetic) is well described in the literature. What is not present in the literature is a concise description of how to manage these fragile biological tissues after application. This paper introduces the BRAIN principle for adjuvant management of wounds after application of bioengineered alternative tissues. Based on the experience of the author, utilizing the principles found in the BRAIN protocol have not only demonstrated improved BAT incorporation rates, it also increased the rate of wound closure.

Key words: Diabetic wounds, bioengineered alternative tissues, wound healing

This is an Open Access article distributed under the terms of the Creative Commons Attribution License.  It permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ©The Foot & Ankle Journal (www.faoj.org

Accepted: April 1, 2008
Published: May 1, 2008

ISSN 1941-6806
doi: 10.3827/faoj.2008.0105.0003

Bioengineered Alternative Tissues (BAT’s) have revolutionized the science of wound healing. These new technologies offer the wound care specialist an important tool in the battle to prevent nearly 90,000 amputations that occur annually among diabetic patients. [7] However, this technology is of little value when not used as a part of a comprehensive approach to wound healing. This includes assessing nutrition, metabolic status, vascular status, off loading options, and choosing the right wound healing product.

As new bioengeenered alternative tissue products enter the market it is important to consider patient expectations and treat the patient with the best product available for their specific wound. While there are procedures described for many of the better-known BAT’s on the market, they differ in many respects. The table in the study demonstrates the differing protocols for “after-care” following applications of these products. (Table 1)

Table 1 Application and Aftercare Instructions to Providers from the Manufacturer.

Choosing the right BAT along with the appropriate topical wound care agent is critical not only to improve healing times, but to also lower costs.

It has been estimated that 15 to 20 percent of individuals with diabetes will suffer from lower extremity ulceration during their lifetime. [8] Furthermore, half of the diabetic patients who have had a leg amputated will loose the other leg in three to five years. In 1997 it was estimated that total costs for both direct and indirect health care for the persons with diabetes was $98 billion. Of this total, direct medical costs including hospitalization, medical care, and dressing supplies, accounts for $44.1 billion. [9] What is more startling is the annual $5 billion dollar price tag estimated for the cost of dressings for these conditions. With the increased cost of wound care, the wound care specialist should consider using protocols that not only maximize wound healing, but also minimize the risk of BAT failure by providing the best tools to maintain the optimum environment for the wound.

While it is not the purpose of this paper to review every type of BAT on the market, it is vital to understand the characteristics of these products in order to understand how they work and how they should be adjunctively managed after application.

For purposes of defining terms, BAT’s are products that have been produced artificially or modified in some way that alters the biology and its interaction with the wound bed with the goal of creating an optimal environment to stimulate healing.

These tissues include both allograft, xenografts and manufactured/engineered biologic products like Apligraf® (Organogenesis, Inc., Canton, MA). The purpose of these tissues has been well established in the medical literature. However, the primary goal in using a BAT is to stimulate granulation of a chronic wound and augment the wound’s intrinsic healing pathway, thus creating a bridge to epithelialization of the wound.

The literature has well described the process of preparing the wound bed for application of a BAT. The TIME acronym as proposed by the International Wound Bed Preparation Advisory Board provides an exceptional framework for the physician to improve the opportunity for wounds to heal. The TIME principle in essence describes an approach to remove the barriers to the wound-healing process in order to optimize wound repair and healing. Removal of these barriers will not only help to establish a well-vascularized wound bed, but they will also be vital for the incorporation and success of a BAT. (Table 2). [10]

Table 2   International Wound Bed Preparation Advisory Board – TIME principles.

While the principles of TIME described above remains important a new set of principles are needed to assure the BAT has the best chance of incorporation and healing the wound in a timely manner.

Thus, the following acronym called BRAIN is proposed. (Table 3)

Table 3   The BRAIN principles to maximize BAT incorporation and wound healing.

The BRAIN Principle

B (Bioburden)

Despite having properly prepared the wound bed before application of the bioengineered tissue through debridement, among other modalities, maintenance of the bioburden after BAT application remains important. Non-cytotoxic antimicrobials should be considered to prevent colonization after application of bioengineered tissues.

Proper assessment to the needs of the wound is vital after application of the BAT in order to reduce the chances of infection. In the event of a clinical infection of a chronic wound, aggressive treatment is recommended to prevent limb loss. The following are recommendations that should be considered after application of a BAT for the prevention of infection:

1. Sharp debridement is the fundamental component in preparing the chronic wound for the BAT, whether it is an allograft or a bioengineered skin equivalent, like Apligraf®. Sharp debridement too early after application of the BAT may result in destruction of the bioengineered tissue or disruption of the materials the BAT was able to establish in the wound bed. Debridement post BAT application should only be considered if there is necrotic or infected tissue present.

2. Application of a topical antimicrobial agent for use on the wound bed prior to application of the BAT (at least 2 weeks prior), in order to decrease bacterial colonization, should be considered for both cellular engineered tissues and allografts. Use of a silver containing antimicrobial agent, as a part of wound bed preparation should not be a problem, as the silver will be inactivated by wound fluid among other wound components. Application of a topical antimicrobial agent post application of a BAT remains controversial

Living skin equivalents like Apligraf® should not be used in conjunction with any silver-based topical antimicrobial agent as these can be, at certain levels, cytotoxic to keratinocytes and fibroblasts.11 While there is debate about other types of topical agents used on or with a living skin equivalent like Apligraf®, I have used Bacitracin ointment as well as AmeriGel®

Hydrogel Saturated Gauze Dressing (Amerx Health Care Corporation, Clearwater, FL) pre and post application of Apligraf® pose no adverse clinical effects. Agents that are known to be cytotoxic to living skin equivalents include: Dakin’s solution, Mafenide Acetate, Scarlet Red Dressing, Tincoban, Zinc Sulfate, Povidone-iodine solution, Polymyxin/Nystatin and Chlorhexidine.

3. Care must be taken to control swelling and edema with careful compression over the BAT site taking care not to compromise circulation. Edema can significantly compromise wound healing and incorporation of the BAT.

4. Systemic antibiotics should be considered in the presence of malodorous drainage, friable necrotic tissue, increased levels of wound exudate, increasing pain, surrounding cellulitis, crepitus, necrosis and lymphadenopathy. Fever, chills, malaise, leukocytosis, and an elevated erythrocyte sedimentation rate are also common systemic manifestations of wound infection. Superficial contaminants are not always representative of the wound status, as healing wounds will have some contamination. Macerated tissue culture or curettage is a reliable way to determine the etiology of a serious wound infection. Infected wounds will typically respond to aggressive debridement with appropriate systemic antibiotic therapy. Indiscriminate use of oral antibiotics will not decrease infection rates, but can result in resistance. Gram-negative bacterial infections can be severe and need to be treated aggressively. [12]

R (Reduction of pressure and shear force)

In order for incorporation of the BAT to take place in the chronic wound, excess pressure, motion and shearing must be eliminated. Unless the bioengineered tissue maintains adherence to the wound bed with proper pressure redistribution, BAT incorporation will fail. The medical literature is replete with articles that stress the importance of offloading during wound healing. [13]

Although there are many devices on the market that can be employed to remove plantar pressure {Bledsoe® Walker (Bledsoe Brace Systems, Grand Prairie, TX), DH Walker® (Royce Medical, Inc., Camarillo, CA) or total contact casting}, care must further be taken when applying the BAT to the wound site.

Although most BAT manufacturers recommend some type of anchoring of the bioengineered tissue to the wound (i.e. sutures, staples, etc.), specific protocols are lacking. The following are recommendations to consider for the development of your protocols:

1. Determine the best and the most secure application method based upon the quality of the tissues and the location of the BAT. Plantar pressures will deteriorate the BAT unless properly offloaded and secured. With dorsal wounds, anything creating pressure or shear over the site will also result in the failure of the BAT.

2. Although suturing the BAT to the wound bed is ideal, in cases of severe tissue atrophy or poor skin perfusion, Steri-Strips™ (3M, St Paul, MN) should be considered to prevent worsening of the wound site.

3. If sutures or staples are employed, be careful to make sure the bioengineered tissue has been adequately fenestrated in order to prevent hematoma or seroma formation under the BAT.

4. Plantar ulcers MUST be offloaded in order for the BAT to incorporate. Ideally, no pressure should be applied to the wound site, if possible. Surgical shoes with a Velcro®(Velcro Industries B.V., Manchester, NH) latch should be considered for dorsal foot wounds in order to prevent rubbing or shearing forces.

5. Regular shoes, flip-flops or any like footwear are contraindicated after application of any BAT and should NOT be employed.

A (Adapting to the moisture needs of the wound and the bioengineered tissue.)

Any BAT must stay hydrated in order to achieve wound incorporation. Early desiccation of the wound bed and the surrounding tissues will ultimately lead to BAT failure and subsequent slower healing times. The concept of keeping wounds moist in order to accelerate wound healing has been known now for over 50 years. [14,15] Contrary to conventional wisdom, keeping the wound site and the BAT moist does not increase the risk of infection. In fact, a moist wound environment has been shown to improve wound healing by up to 50% compared with exposure to air. [16]

Many factors will determine the amount of wound fluid present in the wound bed. Venous ulcers, for instance, are more likely to produce more moisture than an ulcer on the top of the foot. Close assessment of the moisture balance in the wound is critical for the success of the BAT. Fluid from chronic wounds will block cellular proliferation and angiogenesis, and will ultimately impair wound healing through the build up of excessive amounts of matrix metalloproteinases (MMPs) that break down critical matrix proteins. [17]

The dressing choice after the application of the BAT to the wound site is vital in order to properly adapt to the moisture needs of the wound. Here are some considerations:

1. Upon review of many bioengineered tissue dressing protocols, as provided by the manufacturers of the top BAT’s on the market, regular gauze is recommended as a secondary dressing in nearly all. (Table 1) Although the purpose of the gauze is understood to provide some level of absorption of drainage from the wound, this concept is not ideal for several reasons. No matter how much hydrogel or mineral oil you use under a regular piece of dry gauze, most of this will be absorbed by the gauze and thus provide minimal moisture to the wound bed over time.

Regular gauze alone, even with a nonadherent dressing of some sort, cannot provide consistent and long lasting moisture to the wound site. Hydrogels and hydrogel impregnated gauzes formulated with substrates allowing for longer and controlled moisture balance reduces the incidence of adhesion to the BAT and wound site. Saline or glycerin-based hydrogels or hydrogel impregnated gauzes frequently result in premature desiccation and should be avoided.

2. In those cases where excessive wound fluid is evident, more frequent dressing changes is recommended.

3. In cases of severe exudate and draining from the wound site, the presence of infection needs to be addressed and antibiotics should be prescribed.

4. The ideal wound dressing will remove the excess amounts of wound exudates while retaining a moist environment that accelerates wound healing.

Keep in mind that healing wounds are always characterized by high mitogenic activity, low inflammatory cytokines (less chronic wound fluid), low proteases, mitotically competent cells and a moist environment.

I ( Incorporation and Identification)

Successful incorporation of a BAT hinges upon the molecular environment of the wound. Incorporation of the acellular BAT into the wound bed through a collagen matrix allows for the recruitment of cells into the wound and facilitates the induction and expression of growth factors and cytokines necessary for wound healing. The balance between collagen degradation and synthesis can be disrupted by disease states like diabetes. This can result in defective collagen metabolism and disrupted wound healing.

In contrast, cellular BAT’s are designed to accelerate tissue regeneration by stimulating the recipient’s own wound bed derived skin cells. [18,19] Some authors have called the BAT an interactive “drug” delivery system by the transfer of MMPs and cytokines from the BAT into the wound. [20] Acellular BAT’s work by effectively providing a cover for the wound that prohibits desiccation and fluid loss within the wound, thus decreasing the bacterial burden and promoting angiogenesis and allowing vascular ingrowth into the dermal layer of the allograft.

Identification and correction of factors that can cause tissue damage is essential after application of a BAT. Keep in mind that cellular bioengineered alternative tissues work by biochemically balancing the wound environment to promote tissue regeneration. This provides the “primordial soup” of mediators and growth factors. [21]

Among the many things that can impair wound healing (systemic steroids, non-steroidal anti-inflammatories, immunosuppressive drugs), several other factors must be recognized:

1. Localized edema from venous insufficiency or lymphedema must be addressed before and after application of a BAT. Compression therapy or a referral to a certified lymphedema specialist should be considered.

2. Low albumin can have a significant impact on wound healing. A deficiency in serum albumin, which accounts for more than 50% of total serum proteins, impairs the inflammatory and proliferative stages of wound healing while also decreasing wound perfusion.22 A dietary or nutritional consult should be ordered to maximize the body’s own potential to heal.

3. Autonomic Neuropathy resulting in over drying of the wound and surrounding tissues will impair wound healing in many ways. Desiccation within the wound site will slow epithelial cell migration and thus prevent the incorporation of the BAT.

4. Infection within the wound site can present many challenges to the incorporation of the BAT. Infection must be treated without delay through either debridement, antibiotics, wound cleansing, or wound disinfection.

5. Hyperglycemia must be addressed in order to have successful incorporation of the BAT. Although the wound care specialist may not be able to directly influence this factor, all efforts need to be made to communicate with the primary care provider and patient to gain better control the patient’s blood sugar. Behavior modification regarding diet and exercise is always an immense challenge in the diabetic population. [23]

N ( Nonadherent Dressing)

It has been said that the choice of the wound dressing at one stage of the wound may well influence subsequent events in the later phases of healing. [24] In reviewing the protocols set forth by most BAT manufacturers, the one common denominator among all of them is the recommendation of a “nonadherent dressing” as the primary dressing to be used over the bioengineered tissue. (Table 1)

While the goal of the nonadherent dressing is to prevent trauma or adhesion of the secondary dressing to the BAT (or underlying tissues), few of these products possess the characteristics ideal for covering a bioengineered tissue. While it is possible for several different types of dressings to be employed over the BAT at once (i.e. petrolatum impregnated gauze, antibiotic cream, hydrogel, mineral oil followed by an absorptive 4” X 4” pad or a foam), this is impractical and expensive.

Ideal Characteristics of the Primary Dressing for Coverage over a BAT:

1. Nonadhesive
2. Antimicrobial
3. Ability to absorb exudate
4. Maintains moisture on the BAT and within the wound site
5. Non-cytotoxic
6. Cost-effective

Of the myriad of different dressing options available that meet some of the criteria mentioned above, the AmeriGel® Hydrogel Saturated Gauze Dressing is an excellent option that meets most if not all of the characteristics above.

Case Example using the BRAIN Principal

A 47 year-old diabetic patient with profound peripheral neuropathy developed a blister on the plantar aspect of her right heel that became recalcitrant to conservative treatment. The patient’s wound was debrided weekly and had Promogran™ (Johnson & Johnson Wound Management, Somerville, NJ) applied to the site until the wound developed a healthy granular base. Apligraf® was chosen to close the wound, secured in place by Steri-Strips™. AmeriGel® Hydrogel Saturated Gauze Dressing covered the BAT to provide an antimicrobial barrier. A dry sterile secondary dressing was then applied. The bioburden of the BRAIN principle had been accomplished. (Fig. 1)

Figure 1  The Bioburden of the wound has been addressed with debridement and diligent local wound care.

To achieve the reduction of pressure and shear force, a Bledsoe® boot was utilized along with a wheel chair. Due to the patient’s severe neuropathy, as well as other balance concerns, the patient could not use crutches. The primary and secondary dressings remained dry and intact for one week. (Fig. 2)

Figure 2  Reduction of pressure and shear force is essential for incorporation of the BAT.

Once the AmeriGel® Hydrogel Saturated Gauze Dressing was removed, the absorptive capability was evident as well as its ability to maintain a moist wound environment. (Fig. 3) This demonstrates adapting to the moisture needs of the BAT and of the wound.

Figure 3  Adapting to the moisture needs of the wound.  Here, a healthy moisture balance has been achieved using AmeriGel® Hydrogel Saturated Gauze Dressing after BAT application.

The patient returned at two weeks and Incorporation was achieved. The wound had already started to reduce in size and was considered to be a healthy granulating wound. There was no evidence of bleeding or absence of tissue caused by traumatic dressing changes. (Fig. 4)

Figure 4  Incorporation of the Apligraf®.  Reduction of wound size is already appreciated.

At 4 weeks and 4 days, after daily applications of the AmeriGel® Hydrogel Saturated Gauze Dressing and dry sterile gauze as the secondary dressing, the wound was healed.

The nonadherent secondary dressing played a significant role in healing this wound quickly and without the need for subsequent applications of the BAT. (Fig. 5)

Figure 5  Nonadherence of the surrounding secondary dressings will help ensure the viability of the BAT.  Using the AmeriGel® Hydrogel Saturated Gauze Dressing as a secondary dressing provides a non adherent and antimicrobial barrier to facilitate rapid wound healing.


Effective management of lower extremity ulcerations using bioengineered alternative tissues requires a multidisciplinary approach, patient involvement and the right use of the proper adjunctive tools available to the wound care specialist.

Diabetic foot ulceration is a limb and life threatening condition that requires the establishment of sound, evidence-based protocols. It is the hope of the author that protocols be established in every wound care clinic that are based upon patient outcomes, cost and ease of use for the wound care specialist and the patient.

A protocol as described above certainly may be modified depending on many factors that may or may not be present in the wound, however the core principles as presented in the acronym BRAIN should provide a road map to maximizing the effectiveness of bioengineered tissues before, during and after BAT application.


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Address correspondence to: Jonathan Moore, DPM, MS, Cumberland Foot & Ankle Center. 117 Tradepark Drive, Somerset, KY 42503

1Cumberland Foot & Ankle Center. 117 Tradepark Drive, Somerset, KY 42503.

© The Foot & Ankle Journal, 2008