Placental Membrane Provides Improved Healing Efficacy and Lower Cost Versus a Tissue-Engineered Human Skin in the Treatment of Diabetic Foot Ulcerations

Exploring the Efficacy of Selected Allografts in Chronic Wound Healing: Evidence from Murine Models and Clinical Data for a Proposed Treatment Algorithm

SIGNIFICANCE

Chronic wounds can lead to poor outcomes for patients, with risks including amputation and death. In the United States, chronic wounds affect 2.5% of the population and cost up to $28 billion per year in primary healthcare costs.

RECENT ADVANCES

Allograft tissues (dermal, amnion, and amnion/chorion) have shown efficacy in improving healing of chronic, recalcitrant wounds in human patients, as evidenced by multiple clinical trials. Their mechanisms of actions have been relatively understudied, until recently. Research in murine models has shown dermal allografts promote re-epithelialization, amnion allografts promote granulation tissue formation and angiogenesis, and amnion/chorion allografts support all stages of wound healing. These findings not only confirm effectiveness, but they shed light on mechanisms of action responsible for their therapeutic utility in patients.

CRITICAL ISSUES

Despite the promise of allografts in chronic wound care, a gap exists in understanding which allografts are most effective during each wound healing stage. The variable efficacy among each type of allograft suggests a mechanistic approach towards a proposed clinical treatment algorithm, based on wound characteristics and patient's needs, may be beneficial.

FUTURE DIRECTIONS

Recent advances in allografts provide a framework for further investigations on how allograft selection can be based on specific needs of individual patients. This requires additional research to identify which allografts support the best outcomes during each stage of the wound healing process as well as utility in specific wound types. Longitudinal human studies investigating the long-term impacts of allografts, particularly in the remodeling phase, are also essential to developing a deeper understanding of their role in sustained wound repair and recovery.

A purified reconstituted bilayer matrix shows improved outcomes in treatment of non-healing diabetic foot ulcers when compared to the standard of care: Final results and analysis of a prospective, randomized, controlled, multi-centre clinical trial

As the incidence of diabetic foot ulcers (DFU) increases, better treatments that improve healing should reduce complications of these ulcers including infections and amputations. We conducted a randomized controlled trial comparing outcomes between a novel purified reconstituted bilayer membrane (PRBM) to the standard of care (SOC) in the treatment of non-healing DFUs. This study included 105 patients who were randomized to either of two treatment groups (n = 54 PRBM; n = 51 SOC) in the intent to treat (ITT) group and 80 who completed the study per protocol (PP) (n = 47 PRBM; n = 33 SOC). The primary endpoint was the percentage of wounds closed after 12 weeks. Secondary outcomes included percent area reduction, time to healing, quality of life, and cost to closure. The DFUs that had been treated with PRBM healed at a higher rate than those treated with SOC (ITT: 83% vs. 45%, p = 0.00004, PP: 92% vs. 67%, p = 0.005). Wounds treated with PRBM also healed significantly faster than those treated with SOC with a mean of 42 versus 62 days for SOC (p = 0.00074) and achieved a mean wound area reduction within 12 weeks of 94% versus 51% for SOC (p = 0.0023). There were no adverse events or serious adverse events that were related to either the PRBM or the SOC. In comparison to the SOC, DFUs healed faster when treated with PRBM. Thus, the use of this PRBM is an effective option for the treatment of chronic DFUs.

Bioengineered Skin for Diabetic Foot Ulcers: A Scoping Review

Diabetic foot ulcers (DFUs) pose a significant threat to individuals with diabetes mellitus (DM), such as lower limb amputation and severe morbidity. Bioengineered skin substitutes (BSS) are alternatives to traditional interventions for treating DFUs, but their efficacy compared to standard wound care (SWC) or other treatment types, such as allografts, remains unknown. A scoping review of human studies was conducted to identify current approaches in the treatment of DFUs using BSS as compared with other treatment options. Systematic searches in PubMed, Cochrane Library, and Web of Science were conducted to identify comparative studies that enrolled 10 or more patients and evaluated wound healing outcomes (closure, time-to-healing, and area reduction). Database searches isolated articles published from 1 December 2012 to 1 December 2022 and were conducted in accordance with PRISMA-ScR guidelines. The literature search yielded 1312 articles, 24 of which were included for the qualitative analysis. Findings in these studies demonstrated that BSS outperformed SWC in all measured outcomes, suggesting that BSS may be a superior treatment for DFUs. Of the 24 articles, 8 articles compared human amniotic membrane allografts (hAMA) to BSS. Conflicting evidence was observed when comparing BSS and hAMA treatments, highlighting the need for future research.

Updates on Recent Clinical Assessment of Commercial Chronic Wound Care Products

Impaired wound healing after trauma, disorders, and surgeries impact millions of people globally every year. Dysregulation in orchestrated healing mechanisms and underlying medical complications make chronic wound management extremely challenging. Besides standard-of-care treatments including broad spectrum antibiotics and wound-debridement, novel adjuvant therapies are clinically tested and commercialized. These include topical agents, skin substitutes, growth factor delivery, and stem cell therapies. With a goal to overcome factors playing pivotal role in delayed wound healing, researchers are exploring novel approaches to elicit desirable healing outcomes in chronic wounds. Although recent innovations in wound care products, therapies, and devices are extensively reviewed in past, a comprehensive review summarizing their clinical outcomes is surprisingly lacking. Herein, this work reviews the commercially available wound care products and their performance in clinical trials to provide a statistically comprehensive understanding of their safety and efficacy. The performance and suitability of various commercial wound care platforms, including xenogeneic and allogenic products, wound care devices, and novel biomaterials, are discussed for chronic wounds. The current clinical evaluation will provide a comprehensive understanding of the benefits and drawbacks of the most-recent approaches and will enable researchers and healthcare providers to develop next-generation technologies for chronic wound management.

A Prospective Multicenter Study of a Weekly Application Regimen of Viable Human Amnion Membrane Allograft in the Management of Nonhealing Diabetic Foot Ulcers

Background

Diabetic foot ulcers (DFUs) pose a significant clinical challenge for providers and patients, and often precede devastating complications such as infection, hospitalization, and amputation. Therefore, advanced treatment options are needed to facilitate the healing of chronic DFUs and improve outcomes in this high-risk population. Cryopreserved viable human amnion membrane allograft (vHAMA) has shown great promise in the treatment of recalcitrant DFUs as a supplement to standard of care (SOC). Placental grafts are rich in extracellular matrix proteins, growth factors, and cytokines, which can induce angiogenesis and dermal fibroblast proliferation, resulting in accelerated healing.

Methods

In this prospective, multicenter single arm trial, 20 patients with nonhealing DFUs received weekly application of vHAMA, in addition to SOC, for up to 12 weeks. The primary study endpoint was proportion of healed wounds at 12 weeks. Secondary endpoints included proportion of wounds healed at 6 weeks, time to heal, and percentage area wound reduction. Subjects were evaluated for ulcer healing and assessed for adverse events at every treatment visit.

Results

At study conclusion, 85% of patients receiving vHAMA healed. Ten wounds healed (50%) by 6 weeks, and 17 wounds (85%) healed by 12 weeks. The mean time to heal was 46.6 days (95% CI: 35.1-58.0), and the average number of vHAMAs used was 5.4 (SD: 3.25). The mean PAR was 86.3% (SD: 40.51).

Conclusions

Aseptically processed, cryopreserved vHAMA should be considered as a safe and effective option for DFUs refractory to SOC therapy.

Application of Amniotic Membrane in Skin Regeneration

Amniotic membrane (AM) is an avascular structure composed of three different layers, which contain collagen, extracellular matrix, and biologically active cells (stem cells). Collagen, a naturally occurring matrix polymer, provides the structural matrix/strength of the amniotic membrane. Tissue remodeling is regulated by growth factors, cytokines, chemokines, and other regulatory molecules produced by endogenous cells within AM. Therefore, AM is considered an attractive skin-regenerating agent. This review discusses the application of AM in skin regeneration, including its preparation for application to the skin and its mechanisms of therapeutic healing in the skin. This review involved collecting research articles that have been published in several databases, including Google Scholar, PubMed, Science Direct, and Scopus. The search was conducted by using the keywords ‘amniotic membrane skin’, ‘amniotic membrane wound healing’, ‘amniotic membrane burn’, ‘amniotic membrane urethral defects’, ‘amniotic membrane junctional epidermolysis bullosa’, and ‘amniotic membrane calciphylaxis’. Ultimately, 87 articles are discussed in this review. Overall, AM has various activities that help in the regeneration and repair of damaged skin.

Cellular Therapeutics for Chronic Wound Healing: Future for Regenerative Medicine

Chronic wounds are associated with significant morbidity and mortality, which demand long-term effective treatment and represent a tremendous financial strain on the global healthcare systems. Regenerative medicines using stem cells have recently become apparent as a promising approach and are an active zone of investigation. They hold the potential to differentiate into specific types of cells and thus possess self-renewable, regenerative, and immune-modulatory effects. Furthermore, with the rise of technology, various cell therapies and cell types such as Bone Marrow and Adipose-derived Mesenchymal Cell (ADMSC), Endothelial Progenitor Cells (EPCs), Embryonic Stem Cells (ESCs), Mesenchymal Stem Cell (MSCs), and Pluripotent Stem Cells (PSCs) are studied for their therapeutic impact on reparative processes and tissue regeneration. Cell therapy has proven to have substantial control over enhancing the quality and rate of skin regeneration and wound restoration. The literature review brings to light the mechanics of wound healing, abnormalities resulting in chronic wounds, and the obstacles wound care researchers face, thus exploring the multitude of opportunities for potential improvement. Also, the review is focused on providing particulars on the possible cell-derived therapeutic choices and their associated challenges in healing, in the context of clinical trials, as solutions to these challenges will provide fresh and better future opportunities for improved study design and therefore yield a substantial amount of data for the development of more specialized treatments.

A Multicenter, Randomized, Controlled, Clinical Trial Evaluating Dehydrated Human Amniotic Membrane in the Treatment of Venous Leg Ulcers

BACKGROUND

This randomized controlled trial evaluated the safety and effectiveness of weekly and biweekly applications of dehydrated human amnion and chorion allograft (dHACA) plus standard of care compared to standard of care alone on chronic venous leg ulcers.

METHODS

This open-label randomized controlled trial included patients with chronic venous leg ulcers at eight wound care centers across the United States. The primary endpoint was the proportion of healed ulcers at 12 weeks. Secondary endpoints included the proportion of ulcers achieving 40 percent closure at 4 weeks and the incidence of adverse events.

RESULTS

Among 101 patients screened for eligibility, 60 were eligible and enrolled. At 12 weeks, significantly more venous leg ulcers healed in the two dHACA-treated groups (75 percent) than in the standard-of-care group (30 percent) ( p = 0.001) even after adjustment for wound area ( p = 0.002), with an odds ratio of 8.7 (95 percent CI, 2.2 to 33.6). There were no significant differences in the proportion of wounds with percentage area reduction greater than or equal to 40 percent at 4 weeks among all groups. The adverse event rate was 63.5 percent. Among the 38 adverse events, none were graft or procedure related, and all were resolved with appropriate treatment.

CONCLUSIONS

dHACA and standard of care, either applied weekly or biweekly, significantly healed more venous leg ulcers than standard of care alone, suggesting that the use of aseptically processed dHACA is advantageous and a safe and effective treatment option in the healing of chronic venous leg ulcers.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

UTILIZAÇÃO DA PLACENTA HUMANA NA CICATRIZAÇÃO DE ÚLCERAS NOS PÉS DE PESSOAS COM DIABETES: REVISÃO INTEGRATIVA

Objetivo:Identificar na literatura as contribuições da utilização da placenta humana na cicatrização de úlceras nos pés de pessoas com diabetes. Método: Estudo de revisão integrativa realizado por meio da busca de artigos na Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scientific Electronic Library Online (SciELO), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, National Library of Medicine (PubMed), Web of Science e Scopus, com a utilização das estratégias de busca: Placenta AND “Pé diabético” e Placenta AND “Diabetic foot”. Resultados: A busca inicial resultou em 148 artigos. Após aplicação dos critérios de inclusão e exclusão, obteve-se amostra final de 12 artigos. Observou-se que a placenta tem potencial de promover a melhora do tecido de granulação e a circulação periférica, maior repitelização, redução na área da ferida, com uso majoritário de aloenxerto de membranas placentária e amniótica criopreservadas. Conclusão: A placenta humana é um material biológico rico em nutrientes que apresentou potencial para contribuir com o reparo tecidual de úlceras nos pés de pessoas com diabetes em menor período de tempo.

USE OF THE HUMAN PLACENTA IN THE HEALING OF FOOT ULCERS IN PEOPLE WITH DIABETES: INTEGRATIVE REVIEW

Objective: To identify in the literature the contributions of the use of the human placenta in the healing of foot ulcers in people with diabetes. Method: An integrative review study carried out by searching articles in Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scientific Electronic Library Online (SciELO), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, National Library of Medicine (PubMed), Web of Science and Scopus, using the search strategies: Placenta AND “Diabetic foot” and Placenta AND “Diabetic Foot”. Results: The initial search resulted in 148 articles. After applying the inclusion and exclusion criteria, a final sample of 12 articles was obtained. It was observed that the placenta has the potential to promote the improvement of granulation tissue and peripheral circulation, greater epithelialization, and reduction in the wound area, with the majority use of cryopreserved placental and amniotic membrane allograft. Conclusion: The human placenta is a nutrient-rich biological material that has the potential to contribute to the tissue repair of foot ulcers in people with diabetes in a shorter period of time.

Use of a purified reconstituted bilayer matrix in the management of chronic diabetic foot ulcers improves patient outcomes vs standard of care: Results of a prospective randomised controlled multi-centre clinical trial

Diabetic foot infections continue to be a major challenge for health care delivery systems. Following encouraging results from a pilot study using a novel purified reconstituted bilayer matrix (PRBM) to treat chronic diabetic foot ulcers (DFUs), we designed a prospective, multi‐centre randomised trial comparing outcomes of PRBM at 12 weeks compared with a standard of care (SOC) using a collagen alginate dressing. The primary endpoint was percentage of wounds closed after 12 weeks. Secondary outcomes included assessments of complications, healing time, quality of life, and cost to closure. Forty patients were included in an intent‐to‐treat (ITT) and per‐protocol (PP) analysis, with 39 completing the study protocol (n = 19 PRBM, n = 20 SOC). Wounds treated with PRBM were significantly more likely to close than wounds treated with SOC (ITT: 85% vs 30%, P = .0004, PP: 94% vs 30% P = .00008), healed significantly faster (mean 37 days vs 67 days for SOC, P = .002), and achieved a mean wound area reduction within 12 weeks of 96% vs 8.9% for SOC. No adverse events (AEs) directly related to PRBM treatment were reported. Mean PRBM cost of healing was $1731. Use of PRBM was safe and effective for treatment of chronic DFUs.

Clinical and cost efficacy of advanced wound care matrices in the treatment of venous leg ulcers: a systematic review

BACKGROUND

Venous leg ulcers (VLUs) are hard-to-heal, recurrent and challenging to treat. Advanced wound care matrices (AWCMs) have been developed to supplement conventional therapies. These costly AWCMs warrant careful comparison as healthcare expenditures are subjected to increasing scrutiny.

AIM

This study was designed to compare AWCMs in their ability to heal VLUs and their cost efficacy through a systematic review of randomised controlled trials (RCTs).

METHOD

An organised search of Medline, Cochrane Library, Central and CINAHL databases identified RCTs that compared AWCMs to standard compression therapy in the healing of VLUs. Bias was assessed using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies. Eight studies analysing bilayered skin substitute (BSS) (Apligraf), dehydrated human amnion/chorion membrane (dHACM) (Epifix), human fibroblast-derived dermal substitute (HFDDS) (Dermagraft), extracellular wound matrix (ECM) (Oasis), advanced matrix (AM) (Talymed) and matrix wound dressing (MWD) (Promogran) met the inclusion criteria.

RESULTS

Four studies reported significant improvement over standard therapy: BSS, dHACM, ECM and AM. Incremental cost per additional successful treatment was determined for each trial, ranging from $2593 (MWD) to $210,800 (HFDDS).

CONCLUSION

Our consolidated analysis of eight major RCTs of AWCMs in the treatment of VLUs revealed a great variation in clinical and cost efficacy among these products. The included trials were inconsistent in methodology, and these limitations should be noted, but, in the absence of RCTs to compare these products, our systematic review may serve as a guide for practitioners who seek to optimise wound healing while considering cost efficacy.

3D Bioprinting of Functional Skin Substitutes: From Current Achievements to Future Goals

The aim of this review is to present 3D bioprinting of skin substitutes as an efficient approach of managing skin injuries. From a clinical point of view, classic treatments only provide physical protection from the environment, and existing engineered scaffolds, albeit acting as a physical support for cells, fail to overcome needs, such as neovascularisation. In the present work, the basic principles of bioprinting, together with the most popular approaches and choices of biomaterials for 3D-printed skin construct production, are explained, as well as the main advantages over other production methods. Moreover, the development of this technology is described in a chronological manner through examples of relevant experimental work in the last two decades: from the pioneers Lee et al. to the latest advances and different innovative strategies carried out lately to overcome the well-known challenges in tissue engineering of skin. In general, this technology has a huge potential to offer, although a multidisciplinary effort is required to optimise designs, biomaterials and production processes.

Human Amnion Chorion Membrane Allografts in the Treatment of Chronic Diabetic Foot Ulcers: A Literature Review

OBJECTIVE

To discuss human amnion chorion (placental) membrane allograft (HACMA) use for the treatment of chronic diabetic foot ulcers (DFUs) and to evaluate the effectiveness, cost, and product waste of this therapy.

DATA SOURCES

PubMed, Cochrane, and OVID databases.

STUDY SELECTION

Twenty-four articles pertaining to HACMA and DFUs published from 2016 to 2020 were selected.

DATA EXTRACTION

The data collected included type of wound care product, study design, study size, baseline size of DFU, cost, product wastage, number of applications, and wound healing outcomes.

DATA SYNTHESIS

Human amnion chorion membrane allografts in the treatment of chronic DFUs have led to a reduction in healing time and increased the overall percentage of healing, making them more effective in treating DFUs compared with standard of care. These products are offered in multiple sizes with various shelf lives and methods of storage, making them accessible, easy to use, less wasteful, and lower in cost compared with other commercially available products. Promising evidence demonstrates that HACMAs are beneficial in treating complex, high-grade DFUs with exposed tendon or bone.

CONCLUSIONS

Human amnion chorion membrane allografts are effective in treating chronic DFUs with a greater percentage of complete wound closure and a reduction in healing time versus standard of care.

Efficacy of Dehydrated Human Amnion Chorion Membrane in the Treatment of Diabetic Foot Ulcers: A Review

Studies have been conducted to evaluate the efficacy of dehydrated human amnion chorion membrane (dHACM) in treating recalcitrant diabetic foot ulcers. A literature search was performed to review the data collected from the use of dHACM allografts. Two products were explicitly named in these publications, EpiFix and AmnioBand Membrane. Relevant results included the healing rate, number of wounds healed, and number of grafts used. Data had supported the potential of lowering the overall cost to manage a wound despite a relatively higher cost per dressing. However, discrepancy was observed in the rate of healing between several of the studies. Nonetheless, dHACM had demonstrated improvement in healing of recalcitrant diabetic foot ulcers compared to standard of care alone. These results provide grounds for more inclusive research on dHACM in the future.

A dehydrated, aseptically-processed human amnion/chorion allograft accelerates healing in a delayed murine excisional wound model

Since chronic, non-healing wounds represent an increasing source of economic and temporal burden for patients who suffer from them and healthcare professionals that treat them, therapeutic modalities that promote closure of delayed and non-healing wounds are of utmost importance. Recent clinical results of allografts derived from amnion and chorion placental layers encourage further investigation of the mechanisms underlying clinical efficacy of these products for treatment of wounds. Here, we utilized a diabetic murine splinted excisional wound model to investigate the effects of a dehydrated human amnion/chorion-derived allograft (dHACA) on delayed wound healing, as well as the effects of dehydrated allograft derived solely from amnion tissue of the same donor. We examined wound healing by histological endpoint analysis, and we assessed other parameters relevant to functional wound healing in the wound bed including angiogenesis, macrophage phenotypes, proliferative activity, and gene expression. Herein we demonstrate that application of dHACA to a murine diabetic model of delayed wound progression results in better macroscale wound resolution outcomes, including rate of closure, compared to unaided wound progression, while dehydrated human amnion allograft (dHAA) fails to improve outcomes. Improved gross wound resolution observed with dHACA was accompanied by increased granulation tissue formation, proliferation and vascular ingrowth observed in the wound bed, early macrophage polarization towards anti-inflammatory phenotypes, and downregulation of pro-fibrotic gene expression. Overall, our data suggest that improvements in the rates of delayed wound closure observed from combined amnion/chorion allografts are associated with modulation of critical cellular and tissue processes commonly found to be dysregulated in delayed healing wounds, including proliferation, vascularization, inflammation, and re-epithelialization.

Effectiveness and safety of human amnion/chorion membrane therapy for diabetic foot ulcers: An updated meta-analysis of randomized clinical trials

Human amnion/chorion membrane therapy has shown advantages in the management of diabetic foot ulcers and its effectiveness has been evaluated in the systematic reviews and meta-analyses. However, the number of patients included in the previous literatures was small and the safety profile of human amnion/chorion membrane therapy was not concerned. Therefore, we conducted an updated meta-analysis to better understand the effectiveness and safety of human amnion/chorion membrane therapy for diabetic foot ulcers. The PubMed, Embase, Cochrane Library, and ClinicalTrial.gov databases were searched for any randomized clinical trials comparing human amnion/chorion membrane therapy and standard therapy in the treatment of diabetic foot ulcers. Ulcer healing rate was considered as the primary outcome and the secondary outcomes mainly included mean time to ulcer healing and adverse events. Nine RCTs with 541 patients were included. Compared with merely standard therapy, human amnion/chorion membrane therapy plus standard therapy improved the ulcer healing rates at 6 weeks (RR = 3.50, 95% CI: 2.35-5.21), 12 weeks (RR = 2.09, 95% CI: 1.53-2.85) and 16 weeks (RR = 1.70, 95% CI: 1.25-2.30), and also shortened the healing time (MD = -4.58, 95% CI: -5.70 to -3.46). Meanwhile, no significant difference was observed in the number of patients with adverse events (RR = 0.56, 95% CI: 0.31-1.03) between two groups. This meta-analysis suggests that human amnion/chorion membrane therapy as an adjuvant treatment could promote the healing of diabetic foot ulcers and has a safety profile. More evidence from large high-quality randomized clinical trials with long follow-up duration are in urgent need to further confirm our findings.

Nonpharmacological Management of Diabetic Foot Ulcers: An Update

Diabetic foot ulcers (DFUs) are a common and serious complication of diabetes mellitus that is associated with increased morbidity and mortality, as well as substantial economic burden for the health care system. The standard of care for DFUs includes pressure off-loading, sharp debridement, and wound moisture balance, along with infection control and management of peripheral arterial disease. A variety of advanced modalities that target distinct pathophysiological aspects of impaired wound healing in diabetes are being studied as possible adjunct therapies for difficult to heal ulcers. These modalities include growth factors, stem cells, cultured fibroblasts and keratinocytes, bioengineered skin substitutes, acellular bioproducts, human amniotic membranes, oxygen therapy, negative pressure wound therapy, and energy therapies. Additionally, the use of advanced biomaterials and gene delivery systems is being investigated as a method of effective delivery of substances to the wound bed. In the present narrative review, we outline the latest advances in the nonpharmacological management of DFUs and summarize the efficacy of various standard and advanced treatment modalities.