Amnion Membrane in Diabetic Foot Wounds: A Meta-analysis

Systematic Review of Cellular, Acellular, and Matrix-like Products and Indirect Treatment Comparison Between Cellular/Acellular and Amniotic/Nonamniotic Grafts in the Management of Diabetic Foot Ulcers

Significance: This Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant review focuses on the efficacy of cellular, acellular, and matrix-like products (CAMPs) in the management of diabetic foot ulcers (DFUs) based on published randomized controlled trials (RCTs). Recent Advances: Although CAMPs have been incorporated into the clinical algorithm for chronic wounds, evidence is lacking to comparatively evaluate the efficacy of these products. Critical Issues: Level 1 RCT studies are the gold standard to evaluate the efficacy of different treatment approaches; however, due to differences in surgical techniques, patient demographics, and compliance, standard-of-care (SOC) outcomes in the wound care space can vary significantly between different RCTs, making it difficult to compare them against each other. Future Directions: To mitigate variability between different RCTs, wound closure outcomes can be reported as risk ratios (RRs). This review of all the currently published RCTs (with a similar trial design) in patients with DFU and RRs confirms that CAMPs adjunct to SOC result in statistically superior wound closure outcomes in DFUs, when compared with SOC alone, with a RR of 1.72 [1.56, 1.90], p < 0.00001. Enough evidence is still lacking to determine a statistical difference between broad categories of cellular/acellular and amniotic/nonamniotic CAMPs, and hence, decision makers should consider published head-to-head comparative studies, real-world evidence, and cost-effectiveness evidence between individual CAMPs to decide on which to use in practice.

Dehydrated Amnion Chorion Membrane versus standard of care for diabetic foot ulcers: a randomised controlled trial

OBJECTIVE

Diabetic foot ulcers (DFUs) continue to challenge wound care practitioners. This prospective, multicentre, randomised controlled trial (RCT) evaluated the effectiveness of a dehydrated Amnion Chorion Membrane (dACM) (Organogenesis Inc., US) versus standard of care (SoC) alone in complex DFUs in a challenging patient population.

METHOD

Subjects with a DFU extending into dermis, subcutaneous tissue, tendon, capsule, bone or joint were enrolled in a 12-week trial. They were allocated equally to two treatment groups: dACM (plus SoC); or SoC alone. The primary endpoint was frequency of wound closure determined by a Cox analysis that adjusted for duration and wound area. Kaplan-Meier analysis was used to determine median time to complete wound closure (CWC).

RESULTS

The cohort comprised 218 patients, and these were split equally between the two treatment groups with 109 patients in each. A Cox analysis showed that the estimated frequency of wound closure for the dACM plus SoC group was statistically superior to the SoC alone group at week 4 (12% versus 8%), week 6 (22% versus 11%), week 8 (31% versus 21%), week 10 (42% versus 27%) and week 12 (50% versus 35%), respectively (p=0.04). The computed hazard ratio (1.48 (confidence interval: 0.95, 2.29) showed a 48% greater probability of wound closure in favour of the dACM group. Median time to wound closure for dACM-treated ulcers was 84 days compared to 'not achieved' in the SoC-treated group (i.e., ≥50% of SoC-treated DFUs failed to heal by week 12; p=0.04).

CONCLUSION

In an adequately powered DFU RCT, dACM increased the frequency, decreased the median time, and improved the probability of CWC when compared with SoC alone. dACM demonstrated beneficial effects in DFUs in a complex patient population.

DECLARATION OF INTEREST

This study was funded by Organogenesis Inc., US. JC serves as a consultant and speaker for Organogenesis. RDD serves as a speaker for Organogenesis. OMA and MLS serve as consultants for Organogenesis. The authors have no other conflicts of interest to declare.

Bioengineering Skin Substitutes for Wound Management-Perspectives and Challenges

Non-healing wounds and skin losses constitute significant challenges for modern medicine and pharmacology. Conventional methods of wound treatment are effective in basic healthcare; however, they are insufficient in managing chronic wound and large skin defects, so novel, alternative methods of therapy are sought. Among the potentially innovative procedures, the use of skin substitutes may be a promising therapeutic method. Skin substitutes are a heterogeneous group of materials that are used to heal and close wounds and temporarily or permanently fulfill the functions of the skin. Classification can be based on the structure or type (biological and synthetic). Simple constructs (class I) have been widely researched over the years, and can be used in burns and ulcers. More complex substitutes (class II and III) are still studied, but these may be utilized in patients with deep skin defects. In addition, 3D bioprinting is a rapidly developing method used to create advanced skin constructs and their appendages. The aforementioned therapies represent an opportunity for treating patients with diabetic foot ulcers or deep skin burns. Despite these significant developments, further clinical trials are needed to allow the use skin substitutes in the personalized treatment of chronic wounds.

Cost effectiveness analysis for commonly used human cell and tissue products in the management of diabetic foot ulcers

Background and Aims

This study considers the cost-effectiveness of commonly used cellular, acellular, and matrix‑like products (CAMPs) of human origin also known as human cell and tissue products (HCT/Ps) in the management of diabetic foot ulcers.

Methods

We developed a 1-year economic model assessing six CAMPs [cryopreserved placental membrane with viable cells (vCPM), bioengineered bilayered living cellular construct (BLCC), human fibroblast dermal substitute (hFDS), dehydrated human amnion chorion membrane (dHACM), hypothermically stored amniotic membrane (HSAM) and human amnion membrane allograft (HAMA) which had randomized controlled trial evidence compared with standard of care (SoC). CAMPs were compared indirectly and ranked in order of cost-effectiveness using SoC as the baseline, from a CMS/Medicare's perspective.

Results

The mean cost, healed wounds (hw) and QALYs per patient for vCPM is $10,907 (0.914 hw, 0.783 QALYs), for HAMA $11,470 (0.903 hw, 0.780 QALYs), for dHACM $15,862 (0.828 hw, 0.764 QALYs), for BLCC $18,430 (0.816 hw, 0.763 QALYs), for hFDS $19,498 (0.775 hw, 0.757 QALYs), for SoC $19,862 (0.601 hw, 0.732 QALYs) and $24, 214 (0.829, 0.763 QALYs) for HSAM respectively. Over 1 year, vCPM results in cheaper costs overall and better clinical outcomes compared to other CAMPs. Following probabilistic sensitivity analysis, vCPM has a 60%, HAMA 40% probability of being cost-effective then dHACM, hFDS, BLCC, and lastly HSAM using a $100,000/healed wound or QALY threshold.

Conclusions

All CAMPs were shown to be cost-effective when compared to SoC in managing DFUs. However, vCPM appears to be the most cost-effective CAMP over the modelled 52 weeks followed by HAMA, dHACM, hFDS, BLCC, and HSAM. We urge caution in interpreting the results because we currently lack head-to-head evidence comparing all these CAMPs and therefore suggest that this analysis be updated when more direct evidence of CAMPs becomes available.

Use of amniotic membrane in hard-to-heal wounds: a multicentre retrospective study

OBJECTIVE

Hard-to-heal (chronic) wounds negatively impact patients and are a source of significant strain on the healthcare system and economy. These wounds are often resistant to standard of care (SoC) wound healing approaches due to a diversity of underlying pathologies. Cellular, acellular, and matrix-like products, such as amniotic membranes (AM), are a potential solution to these challenges. A growing body of evidence suggests that AM may be useful for treatment-resistant wounds; however, limited information is available regarding the efficacy of dehydrated amniotic membrane (DHAM) on multi-aetiology, hard-to-heal wounds. Therefore, we analysed the efficacy of DHAM treatment in reducing the size of hard-to-heal diabetic and venous leg ulcers (VLUs) that had failed to improve after SoC-based treatments.

METHOD

In this multicentre retrospective study, we analysed wound size during clinic visits for patients being treated for either diabetic or VLUs. During each visit, the treatment consisted of debridement followed by application of DHAM. Each wound was measured after debridement and prior to DHAM application, and wound volumes over time or number of DHAM applications were compared.

RESULTS

A total of 18 wounds in 11 patients were analysed as part of this study. Wounds showed a significant reduction in volume after a single DHAM application, and a 50% reduction in wound size was observed after approximately two DHAM applications. These findings are consistent with reports investigating DHAM treatment of diabetic ulcers that were not necessarily resistant to treatment.

CONCLUSION

To our knowledge, this study is the first to directly compare the efficacy of standalone DHAM application to hard-to-heal diabetic and venous leg ulcers, and our findings indicate that DHAM is an effective intervention for resolving these types of wounds. This suggests that implementing this approach could lead to fewer clinic visits, cost savings and improved patient quality of life.

DECLARATION OF INTEREST

This research was supported in part by Merakris Therapeutics, US, and facilitated access to deidentified patient datasets, which may represent a perceived conflict of interest; however, the primary data analysis was performed by FSB who is unaffiliated with Merakris Therapeutics. TCB is a founder, employee of and shareholder in Merakris Therapeutics; WSF is a co-founder of, consultant for, and shareholder in Merakris Therapeutics, and was also supported by the National Institutes of Health National Center for Advancing Translational Sciences Clinical and Translational Science Awards Grant KL2 Scholars Program (KL2TR001441). The research was also supported through endowments to WSF from the University of Texas Medical Branch Mimmie and Hallie Smith Endowed Chair of Transplant Research and the John L Hern University Chair in Transplant Surgery.

An in situ forming gelatin-based hydrogel loaded with soluble amniotic membrane promotes full-thickness wound regeneration in rats

Objectives

Early effective treatment and appropriate coverage are vital for full-thickness wounds. Amnion membrane-derived products have recently emerged in tissue engineering. However, the optimal concentration, carrier for controlled release, and handling have remained challenges. This study aims to develop and optimize an in situ forming, amniotic-based hydrogel for wound healing.

Materials and Methods

Here, a composite matrix was fabricated with gelatin hydrogel modified with methacrylate functional group conjugated (GelMA) and keratose (wt.1%), loaded with mesenchymal stem cells (MSCs, 1×105 cell/ml) and optimized soluble amniotic membrane (SAM, 0.5 mg/ml). The physicochemical properties of the final subject were evaluated in vitro and in vivo environments.

Results

The results of the in vitro assay demonstrated that conjugation of the methacryloyl group with gelatin resulted in the formation of GelMA hydrogel (26.7±1.2 kPa) with higher mechanical stability. Modification of GelMA with a glycosaminoglycan sulfate (Keratose) increased controlled delivery of SAM (47.3% vs. 84.3%). Metabolic activity (93%) and proliferation (21.2 ± 1.5 µg/ml) of MSCs encapsulated in hydrogel improved by incorporation of SAM (0.5 mg/ml). Furthermore, the migration of fibroblasts was facilitated in the scratched assay by SAM (0.5 mg/ml)/MSCs (1×105 cell/ml) conditioned medium. The GelMA hydrogel groupes revealed regeneration of full-thickness skin defects in rats after 3 weeks due to the high angiogenesis (6.3 ± 0.3), cell migration, and epithelialization.

Conclusion

The results indicated in situ forming and tunable GelMA hydrogels containing SAM and MSCs could be used as efficient substrates for full-thickness wound regeneration.

Protecting human amnion and chorion matrices during processing: Performance enhancement in a diabetic mouse model and human co-culture system

Recent evidence suggests that protecting human amnion and chorion matrices (HACM) during processing enhances the performance of HACM for wound repair and tissue regeneration. We utilised a diabetic (db/db) delayed wound healing mouse model. Treatment of db/db full-thickness excisional wounds with HACM, processed with a polyampholyte preservative accentuated the proliferative phase of wound healing that decreased the time necessary to heal wounds. Polyampholyte protection improved the preservation of growth factors and cytokines during room temperature storage following E-beam sterilisation and improved its function in wound healing applications. Our findings indicate protected HACM tissue up-regulated MIP2, NF-kB, TNF-α, KI-67, and Arg1 (0.6-fold to 1.5-fold) but those changes were not statistically significant. Immunofluorescent assessment identifying cell activity illustrated an induction of the proliferative phase of wound healing and a switch from an inflammatory macrophage phenotype (M1) to a pro-regenerative macrophage phenotype (M2a). Genomic profiling of 282 genes was performed using Nanostring from co-cultures of human macrophages and fibroblasts. The polyampholyte + HACM-treated group, compared with the HACM or polyampholyte alone groups, had a statistically significant up-regulation (32-368 fold) of 12 genes primarily involved in macrophage plasticity including CLC7, CD209, CD36, HSD11B1, ICAM1, IL1RN, IL3RA, ITGAX, LSP1, and PLXDC2 (adj. p-value < 0.05). The polyampholyte alone group demonstrated statistically significant down-regulation of four genes ADRA2, COL7A1, CSF3, and PTGS2 (adj. p < 0.05). The HACM alone group up-regulated four genes ATG14, CXCL11, DNMT3A, and THBD, but the results were not statistically significant. Biomechanical measurements indicated that wounds treated with polyampholyte-protected HACM had more tensile integrity compared with wounds treated with HACM alone. These findings indicate that better protection of HACM during processing stabilises the HACM matrix, which may lead to improved wound healing outcomes.

HOXA3 accelerates wound healing in diabetic and aged non-diabetic mammals

Chronic wounds are characterized by a persistent, hyper-inflammatory environment that prevents progression to regenerative wound closure. Such chronic wounds are especially common in diabetic patients, often requiring distal limb amputation, but occur in non-diabetic, elderly patients as well. Induced expression of HoxA3, a member of the Homeobox family of body patterning and master regulatory transcription factors, has been shown to accelerate wound closure in diabetic mice when applied topically as a plasmid encased in a hydrogel. We now provide independent replication of those foundational in vivo diabetic wound closure studies, observing 16% faster healing (3.3 mm wounds vs 3.9 mm wounds at Day 9 post original injury of 6 mm diameter) under treatment with observable microscopic benefits. We then expand upon these findings with minimal dose threshold estimation of 1 μg HoxA3 plasmid delivered topically at a weekly interval. Furthermore, we observed similarities in natural wound healing rates between aged non-diabetic mice and young diabetic mice, which provided motivation to test topical HoxA3 plasmid in aged non-diabetic mice. We observed that HoxA3 treatment achieved complete wound closure (0 mm diameter) at 2 weeks whereas untreated wounds were only 50% closed (3 mm wound diameter). We did not observe any gross adverse effects macroscopically or via histology in these short studies. Whether as a plasmid or future alternative modality, topical HoxA3 is an attractive translational candidate for chronic wounds.

The Use of a Dehydrated Complete Human Placental Membrane Allograft for Mohs Surgical Defects of the Nose

BACKGROUND

Repair options for Mohs surgical defects include primary closure, flap or graft, or healing by second intention. These options may not be optimal in all cases. A dehydrated complete human placental membrane (dCHPM) allograft may serve as an alternative repair option.

OBJECTIVE

To assess the aesthetic and functional outcomes of an alternative repair technique for Mohs surgical defects of the nose.

METHODS

Twenty patients with Mohs surgical defects of the nose repaired with a dCHPM allograft were retrospectively identified. Photographs were used to demonstrate surgical technique and outcomes. Two blinded observers evaluated final outcomes using the Patient and Observer Scar Assessment Scale.

RESULTS

Observers rated the scar outcome a combined mean score of 8.4 ± 3.2 (scale 5-50). Patients rated their outcomes a mean of 12.6 ± 7.4 (scale 6-60). The mean "Overall Opinion score" was 2.5 ± 1.8 by patients and 1.9 ± 1.3 by observers (scale 1-10).

LIMITATIONS

This was a single institution study with a small sample size.

CONCLUSION

Our study demonstrates that dCHPM allografts are a viable alternative repair option for Mohs surgical defects of the nose.

The importance of inflammation control for the treatment of chronic diabetic wounds

Diabetic chronic wounds cause massive levels of patient suffering and economic problems worldwide. The state of chronic inflammation arises in response to a complex combination of diabetes mellitus-related pathophysiologies. Advanced treatment options are available; however, many wounds still fail to heal, exacerbating morbidity and mortality. This review describes the chronic inflammation pathophysiologies in diabetic ulcers and treatment options that may help address this dysfunction either directly or indirectly. We suggest that treatments to reduce inflammation within these complex wounds may help trigger healing.

Comparing the standard surgical dressing with dehydrated amnion and platelet-derived growth factor dressings in the healing rate of diabetic foot ulcer: A randomized clinical trial

AIMS

The management of diabetic foot ulcers is a challenging issue due to the pathophysiological background, delay in healing, and prevalence of diabetes. The purpose of this study was to compare the therapeutic effects of the three methods of diabetic wound care: surgical debridement and dressing, dressing with dehydrated amnion powder, and dressing with platelet-derived growth factor gel.

METHODS

In this multi-arm parallel-group randomized trial, 243 patients with a minimum 4-week medical history of diabetic foot ulcers with Wagner's grades 1 and 2, no infection, and adequate tissue blood flow were randomly assigned to one of three 81-person groups: surgical debridement (the standard method), dehydrated amnion dressing, or platelet-derived growth factor dressing. The follow-up period lasted 12 weeks. The percentage area reduction (PAR) was measured as the final target. SPSS version 25 was used to perform statistical analysis on the data.

RESULTS

All three study groups were comparable in terms of the type of ulcer, the area of ulcer, Wagner's grade, the period, and the ulcer's size. The PAR in the surgical debridement, platelet-derived growth factor, and dehydrated amnion groups were 7.4%, 14.8%, and 49.3% in week 4; 20.1%, 35.8%, and 79% in week 6; 43.7%, 56.8%, 86.4% in week 8; and 50%, 61.7%, and 87.6% in weeks 10 and 12, respectively. The observed differences were statistically significant (p < 0.05) over the entire period.

CONCLUSION

The study concluded that dehydrated amnion dressing, when compared to platelet-derived growth factor dressing and surgical debridement, resulted in better-improved healing in diabetic foot ulcer patients.

A regenerative approach to the pharmacological management of hard-to-heal wounds

A wound is considered hard-to-heal when, despite the appropriate clinical analysis and intervention, the wound area reduces by less than a third at four weeks and complete healing fails to occur within 12 weeks. The most prevalent hard-to-heal wounds are associated with underlying metabolic diseases or vascular insufficiency and include arterial, venous, pressure and diabetic foot ulcers. Their common features include an abnormal immune response and extended inflammatory phase, a subdued proliferation phase due to cellular insufficiencies and finally an almost non-existent remodeling phase. Advances in wound care technology, tested in both pre-clinical models and clinical trials, have paved the way for improved treatment options, focused on regeneration. These interventions have been shown to limit the extent of ongoing inflammatory damage, decrease bacterial load, promote angiogenesis and deposition of granulation tissue, and stimulate keratinocyte migration thereby promoting re-epithelialization in these wounds. The current review discusses these hard-to-heal wounds in the context of their underlying pathology and potential of advanced treatment options, which if applied promptly as a standard of care, could reduce morbidity, promote quality of life, and alleviate the burden on a strained health system.

Using of Amniotic Membrane Derivatives for the Treatment of Chronic Wounds

Amniotic membrane grafts have some therapeutic potential for wounds healing. Early application of amniotic membrane turned out as beneficial in healing ulcers, burns, and dermal injuries. Since the second half of the 20th century, the autotransplants of amniotic/chorion tissue have been also used for the treatment of chronic neuropathic wounds, cornea surface injuries, pterygium and conjunctivochalasis, and dental and neurosurgical applications. The aim of this publication is to prepare a coherent overview of amniotic membrane derivatives use in the field of wound healing and also its efficacy. In total 60 publications and 39 posters from 2000-2020 were examined. In these examined publications of case studies with known study results was an assemblage of 1141 patients, and from this assemblage 977 were successfully cured. In case of posters, the assemblage is 570 patients and 513 successfully cured. From the investigated data it is clear that the treatment efficacy is very high-86% and 90%, respectively. Based on this information the use of the amniotic membrane for chronic wounds can be considered highly effective.

Healing Effects of Human Amniotic Membrane and Burned Wool on the Second-degree Burn in Rats

Background:

This study aimed to compare sheep burnt wool and human amniotic membrane (AM) on second-degree burn wound healing in rats.

Materials and Methods:

Seventy-two adult male rats of Sprague Dawley underwent general anesthesia, and a deep second-degree burn was created on their skin by a hot iron plate. Afterward, human AM, silver sulfadiazine ointment (SSD), and sheep burned wool were used on wound area for burn treatment. On days 7, 14, and 21 of the experiment, the rats were sacrificed, and histopathological assessments were done.

Results:

Human AM, in comparison with other groups, significantly (P<0.05) showed better improvement in all pathologic variables. Burned wool showed significant improvement compared to the control group on day 7 in the angiogenesis, on day 14 in granulation tissue formation and epithelial formation, and on day 21 in new epithelial formation (P<0.05). Burned wool compared with SSD ointment in granulation tissue formation improved significantly (P<0.05) on days 7 and 14. Also, SSD ointment in comparison with the control group significantly improved (P<0.05) granulation tissue formation and macrophage on day 7.

Conclusion:

Human AM has a significant effect on the treatment of second-degree burn. Burned wool has a better effect on wound healing than SSD ointment and negative control group without treatment in terms of granulation tissue and epithelium formation.

Use of a dual-layer amniotic membrane in the treatment of diabetic foot ulcers: an observational study

BACKGROUND

Despite advances in the treatment, fewer than half of diabetic foot ulcers (DFUs) heal in 12 weeks and 85% of non-traumatic amputations follow the development of a DFU. The search for treatment options continues. Placental-derived products have shown promise in the treatment of DFUs. This study investigates Artacent (Tides Medical, US), a unique amniotic patch containing two layers of amnion and its potential to increase growth factor delivery.

METHOD

This observational analysis included patients with DFUs with documented failure to heal by >50% after the protocol-defined run-in period (either two or four weeks) of standard of care (SOC), and who had been randomised in a larger clinical trial that had been discontinued earlier for logistical reasons. Patients were randomised to either weekly or biweekly application of the dual-layer amniotic membrane (DLAM) plus SOC and were included in per-protocol effectiveness analyses. Descriptive statistics were chosen for this analysis. Primary endpoint was complete closure at 12 weeks.

RESULTS

A total of 26 patients were included in the analysis. Examination of baseline patient characteristics revealed that the ulcers were larger than in most DFU clinical trials (4.65±4.89cm²). For the primary endpoint, 17/26 (65%, 95% CI: 44-83%) of the combined treatment arms achieved complete closure. The small sample size precluded a meaningful comparison of healing between weekly and biweekly DLAM applications.

CONCLUSION

The observations taken from the discontinued clinical trial suggest that the DLAM promotes healing of DFUs. The healing rates are similar to those in other placental-based tissue studies. In addition, the relatively larger size of the ulcers suggests that the DLAM may be effective in ulcers that are more resistant to standard of care. In the future, a revised clinical trial with a greater sample size is planned.

Skin Substitutes for Adults With Diabetic Foot Ulcers and Venous Leg Ulcers: A Health Technology Assessment

BACKGROUND

Wounds may be caused in a variety of ways. Some wounds are difficult to heal, such as diabetic foot ulcers and venous leg ulcers. We conducted a health technology assessment of skin substitutes for adults with neuropathic diabetic foot ulcers and venous leg ulcers, which included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding skin substitutes, and patient preferences and values.

METHODS

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Cochrane risk-of-bias tool for randomized studies (version 2), and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-utility analysis with a 26-week time horizon from a public payer perspective. We also analyzed the budget impact of publicly funding skin substitutes in adults with diabetic foot ulcers and venous leg ulcers in Ontario. We explored the underlying values, needs, and priorities of those who have lived experience with diabetic leg ulcers and venous leg ulcers, as well as their preferences for and perceptions of skin substitutes.

RESULTS

We included 40 studies in the clinical evidence review. Adults with difficult-to-heal neuropathic diabetic foot ulcers who used dermal (GRADE: High) or multi-layered (GRADE: Moderate) skin substitutes as an adjunct to standard care were more likely to experience complete wound healing than those whose who used standard care alone. Adults with difficult-to-heal venous leg ulcers who used dermal (GRADE: Moderate) or multi-layered (GRADE: High) skin substitutes as an adjunct to standard care were more likely to experience complete wound healing than those who used standard care alone. The evidence for the effectiveness of epidermal skin substitutes was inconclusive for venous leg ulcers because of the small size of the individual studies (GRADE: Very low). We found no studies on epidermal skin substitutes for diabetic foot ulcers. We could not evaluate the safety of skin substitutes versus standard care, because the number of adverse events was either very low or zero (because sample sizes were too small).In our economic analysis, the use of skin substitutes as an adjunct to standard care was more costly and more effective than standard care alone for the treatment of difficult-to-heal diabetic foot ulcers and venous leg ulcers. For diabetic foot ulcers, the incremental cost-effectiveness ratio (ICER) of skin substitutes plus standard care compared with standard care alone was $48,242 per quality-adjusted life-year (QALY), and the cost per ulcer-free week was $158. For venous leg ulcers, the ICER was $1,868,850 per QALY, and the cost per ulcer-free week was $3,235. At the commonly used willingness-to-pay of $50,000 per QALY, the cost-effectiveness of skin substitutes plus standard care versus standard care alone was uncertain (47% probability of being cost-effective) for diabetic foot ulcers and highly unlikely (0% probability of being cost-effective) for venous leg ulcers. At the commonly used willingness-to-pay of $100,000 per QALY, the cost-effectiveness of skin substitutes plus standard care versus standard care alone was moderately likely (71% probability of cost-effectiveness) for people with diabetic foot ulcers and highly unlikely (0% probability of being cost-effective) for people with venous leg ulcers. The annual budget impact of publicly funding skin substitutes in Ontario over the next 5 years would range from an additional $0.17 million in year 1 to $1.2 million in year 5 for people with diabetic foot ulcers, and from $1 million in year 1 to $7.7 million in year 5 for people with venous leg ulcers.Direct patient engagement consisted of three participants for this assessment and 51 from previous health technology assessments that addressed interventions for diabetic foot ulcers and venous leg ulcers. Participants spoke of the negative impact on their quality of life with regard to mobility, employment, social activities, and emotional and mental health. No participants had direct experience using skin substitutes, but participants were open to this treatment option. Barriers to access included the limited use of skin substitutes across Ontario, lack of knowledge of skin substitutes among people with diabetic foot ulcers and venous leg ulcers, and cost.

CONCLUSIONS

Dermal and multi-layered skin substitutes, when used as an adjunct to standard care, were more effective than standard care alone in completely healing difficult-to-heal neuropathic diabetic foot ulcers and venous leg ulcers in adults. Using skin substitutes as an adjunct to standard care was more costly and more effective than standard care alone for the treatment of difficult-to-heal neuropathic diabetic foot ulcers and venous leg ulcers. For adults with diabetic foot ulcers, the likelihood of skin substitutes being cost-effective compared with standard care depends on the willingness to pay. The likelihood of skin substitutes being cost-effective compared with standard care is uncertain at $50,000 per QALY and moderately likely at $100,000 per QALY. For adults with venous leg ulcers, skin substitutes were highly unlikely to be cost-effective compared with standard care. We estimated that publicly funding skin substitutes in Ontario would result in additional costs of $3 million and $20 million over the next 5 years for people with diabetic foot ulcers and venous leg ulcers, respectively. The people with diabetic foot ulcers and venous leg ulcers we spoke with were open to using skin substitutes as a treatment option.

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.

Managing Diabetic Foot Ulcers: Pharmacotherapy for Wound Healing

Historically, there has been a scarcity of evidence-based topical therapy to hasten the healing of diabetic foot ulcers. But recently new evidence-based treatments have emerged from multicentre, randomised, controlled trials. This article highlights those trials, and describes the current pharmacological management of the diabetic foot ulcer and the advances that have been made in wound therapy to date. It provides an overview of topical and systemic pharmacotherapies in current use and those in development for future use in managing the diabetic foot. For each treatment, proposed mechanisms of action and evidence available to support their clinical use are presented. There is supporting randomised, controlled evidence for sucrose octasulfate in the treatment of neuro-ischaemic ulcers, and multi-layered patch of autologous leucocytes, platelets and fibrin in ulcers with or without ischaemia. There is also evidence for placentally derived products and for topical and systemic oxygen therapy in the healing of diabetic foot ulcers. Growth factors, bio-engineered tissues, stem cell therapy, gene therapy and peptide therapy also have some supporting evidence in the healing of diabetic foot ulcers. Nonsurgical debriding agents may be useful when the optimum approach of sharp debridement is not possible, and immunomodulators may be helpful for their antimicrobial effects, but robust data is still required to strengthen the case for general use. The review does not cover antimicrobials as their primary role are as anti-infectives and not in wound healing. The development of nanotechnology has created a means of prolonging the bioavailability of target molecules at the wound site, with the use of glass/hydrogel nanoparticles, polyethylene glycol and hyaluronic acid. Looking forward, novel therapies, including traction force-activated payloads, local delivery of short-interfering RNA and finally hydrogels incorporating bioactive agents or cells may provide possibilities for pharmacotherapy in the future.

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.

Lyopreserved amniotic membrane is cellularly and clinically similar to cryopreserved construct for treating foot ulcers

We compared cellular viability between cryopreserved and lyopreserved amniotic membranes and clinical outcomes of the lyopreserved construct in a prospective cohort study of 40 patients with neuropathic foot ulcers. Patients received weekly application of lyopreserved membrane for 12 weeks with standard weekly debridement and offloading. We evaluated the proportion of foot ulcers that closed, time to closure, closure trajectories, and infection during therapy. We used chi-square tests for dichotomous variables and independent t-tests for continuous variables with an alpha of α = .10. Cellular viability was equivalent between cryo- and lyopreserved amniotic tissues. Clinically, 48% of subjects' wounds closed in an average of 40.0 days. Those that did not close were older (63 vs 59 years, P = .011) and larger ulcers at baseline (7.8 vs 1.6 cm² , P = .012). Significantly more patients who achieved closure reached a 50% wound area reduction in 4 weeks compared with non-closed wounds (73.7% vs 47.6%, P = .093). There was no difference in the slope of the wound closure trajectories between closed and non-closed wounds (0.124 and 0.159, P = .85), indicating the rate of closure was similar. The rate of closure was 0.60 mm/day (SD = 0.47) for wounds that closed and 0.50 mm/day (SD = 0.58) for wounds that did not close (P = .89).

Comparison between Cryopreserved and Dehydrated Human Amniotic Membrane Graft in Treating Challenging Cases with Macular Hole and Macular Hole Retinal Detachment

Purpose

To evaluate the surgical outcomes of cryopreserved and dehydrated human amniotic membrane (hAM) graft transplantation for macular hole (MH) and macular hole retinal detachment (MHRD) repair.

Materials and Methods

This retrospective, interventional case series was conducted in two hospitals. Two types of hAM grafts, namely, the dehydrated form (AmnioGen, HCT Regenerative, Taiwan) and the cryopreserved form (AmnioGraft, Bio-Tissue, Miami, FL), were consecutively used in MH surgeries. Anatomical and functional outcomes between the 2 types of hAM grafts were compared.

Results

Seventeen patients (mean age: 62.1 ± 10.0 years, 9 (52.9%) males) were enrolled. Of them, 11 patients had persistent MH, 3 had MH without prior surgery, and 3 had MHRD. A cryopreserved hAM graft was used in 10 patients, and a dehydrated hAM graft was used in 8 patients. One patient used a cryopreserved hAM in the first MH surgery and a dehydrated hAM in the second surgery for extramacular hole with retinal detachment. After a 6-month follow-up, 13 (76.5%) patients had sealed MHs. The average visual acuity (VA) of cases with sealed MHs improved from 1.38 ± 0.62 to 1.12 ± 0.47 logMAR (p=0.03). In the other 4 cases with persistent MH, 3 had graft dislocation and 1 had a reopened MH with graft contraction. There were no significant differences in closure rate (80.00% vs. 71.43%, p=0.68) or VA improvement (0.19 ± 0.37 logMAR vs. 0.15 ± 0.41 logMAR, p=0.85) between the 2 kinds of hAM graft.

Conclusion

This preliminary case series showed that both cryopreserved hAM and dehydrated hAM are feasible alternative grafts for either persistent or recurrent MH. Both approaches have similar anatomical and functional outcomes.

One-year safety, healing and amputation rates of Wagner 3-4 diabetic foot ulcers treated with cryopreserved umbilical cord (TTAX01)

An open label, multicenter 16‐week trial of cryopreserved human umbilical cord (TTAX01) was previously undertaken in 32 subjects presenting with a Wagner grade 3 or 4 diabetic foot ulcer, with 16 (50%) of these having confirmed closure following a median of one product application (previous study). All but two subjects (30/32; 94%) consented to participate in this follow‐up study to 1‐year postexposure. No restrictions were placed on treatments for open wounds. At 8‐week intervals, subjects were evaluated for adverse events (AEs) and wound status (open or closed). Average time from initial exposure to end of follow‐up was 378 days (range 343‐433), with 29 of 30 (97%) subjects completing a full year. AEs were all typical for the population under study, and none were attributed to prior exposure to TTAX01. One previously healed wound re‐opened, one previously unconfirmed closed wound remained healed, and nine new wound closures occurred, giving 25 of 29 (86.2%) healed in the ITT population. Three of the new closures followed the use of various tissue‐based products. Three subjects whose wounds were healed required subsequent minor amputations due to osteomyelitis, one of which progressed to a major amputation (1/29; 3.4%). One additional subject underwent two minor amputations prior to healing. Overall, the study found TTAX01 to be safe in long‐term follow‐up and associated with both a low rate of major amputation and a higher than expected rates of healing.

Human amniotic membrane allograft, a novel treatment for chronic diabetic foot ulcers: A systematic review and meta-analysis of randomised controlled trials

To evaluate the efficacy and safety of human amniotic membrane (HAM) allograft in treating chronic diabetic foot ulcers (DFUs), a comprehensive search of randomised controlled trials in MEDLINE, EMBASE, PubMed, CENTRAL and Web of Science was conducted to December 7, 2019. Two reviewers independently screened the studies, extracted data, and evaluated the quality of studies. The primary outcome was the proportion of complete healing. The secondary outcomes were mean time to complete healing and adverse events. Statistical analyses were performed using RevMan 5.3. We identified 257 articles, of which 7 articles (465 participants) were included in the meta-analysis. The proportion of complete wound healing in HAM plus standard of care (SOC) group was 3.88 times as high as that in SOC alone (RR: 3.88 [95% CI: 2.34, 6.44]) at 6 weeks, and 2.01 times at 12 weeks (RR: 2.01 [95%CI: 1.45, 2.77]). The intervention group had a significantly shorter time to complete healing (MD: -30.33 days, [95% CI: -37.95, -22.72]). The number needed to treat within 6 weeks was 2.3 ([95% CI: 1.8, 3.1]). No significant difference was shown in adverse events. Results were consistent in a sensitivity analysis. Hence, HAM plus SOC is effective and safe in treating chronic DFUs.

Preparation of Dried Amniotic Membrane for Corneal Repair

Amniotic membrane transplantation is an established therapeutic and biological adjunct for several clinical situations, including treatment of diabetic foot ulcers and ocular surface disease. However, poorly standardized and validated clinical preparation and storage procedures can render the final product highly variable and an unpredictable biomaterial. We have therefore developed a novel, standardized method for processing and dry-preserving amniotic membrane, minimizing biochemical, compositional, and structure damage to produce a potentially superior membrane suitable for clinical use. The intellectual property associated with this methodology was patented by the University of Nottingham and licensed to NuVision^® Biotherapies which formed the basis of the Tereo^® manufacturing process which is used to manufacture Omnigen^®.

A randomized controlled clinical trial of a hypothermically stored amniotic membrane for use in diabetic foot ulcers

Aim: Determine the effectiveness of hypothermically stored amniotic membrane (HSAM) versus standard of care (SOC) in diabetic foot ulcers (DFUs). Methods: A randomized controlled trial was conducted on 76 DFUs analyzed digitally. Results: Cox wound closure for HSAM (38 wounds) was significantly greater (p = 0.04) at weeks 12 (60 vs 38%), and 16 (63 vs 38%). The probability of wound closure increased by 75% (Hazard Ratio = 1.75; 95% CI: 1.16–2.70). HSAM showed >60% reductions in area (82 vs 58%; p = 0.02) and depth (65 vs 39%; p = 0.04) versus SOC. Conclusion: HSAM increased frequency and probability of wound closure in DFUs versus SOC.

Autologous amniotic membrane: An accelerator of wound healing for prevention of surgical site infections following Cesarean delivery

Cesarean delivery (CD) has been known as the most common surgery in the United States. This procedure might associate with different complications, the most important of which is surgical site infection (SSI). Among the major SSI categories, incisional type is more common than the others. Regardless of its notable expense, the use of prophylactic wound healing technics (such as negative pressure therapy) has been advised for the patients with high SSI risk. Herein, use of patient's own human amniotic membrane in an autologous form (as a free of charge treatment) would be suggested for prevention of SSI in CD wounds. Human amniotic membrane (hAM) has been used for treatment of acute and chronic wounds and shown to be able to reduce the infection and the pain along with accelerating the healing process. Moreover, it has been shown in a systematic review and meta-analysis that hAM could significantly improve the treatment rate in comparison to the standard of care dressing (RR 2.057-3.665, P < 0.001) during a set time of six weeks. Wound duration on the other hand, has been shown to negatively associate with SSI. Furthermore, there is data supporting the critical role of tissue perfusion in the acceleration of wound healing along with decreasing the rate of wound infection. Angiogenesis, the formation of new blood vessels from their existing capillaries, is among the most crucial pathways involved in increasing tissue perfusion and wound healing. Interestingly, hAM is a rich source of pro-angiogenic and other tissue growth factors with the ability of inducing angiogenesis as well as strong antibacterial peptides. Taken together, authors suggest autologous application of hAM in the high (even low) risk patients undergoing CD in order to decrease wound related complications such as SSI and accelerate the healing time as a free wound healer. However, further randomized clinical trials are necessary.

Allogeneic Skin Substitutes Versus Human Placental Membrane Products in the Management of Diabetic Foot Ulcers: A Narrative Comparative Evaluation of the Literature

Outcomes following standard wound care (SWC) for diabetic foot ulcers (DFUs) remain suboptimal. Supplementing SWC with tissue engineered allogeneic cellular wound therapies represents an emerging treatment strategy. This review aimed to evaluate the efficacy and safety of allogeneic skin substitutes and human placental membrane allografts in the management of DFUs. Ovid MEDLINE and Embase databases were searched from inception to October 2017. Any randomized controlled trial (RCT) with an allogeneic skin substitute or placental membrane allograft intervention group was included. Our primary outcome measure was the proportion of completely healed ulcers. Secondary outcome measures included time to complete wound healing and local adverse event rates. Each study was assessed for risk of bias and the quality of evidence was appraised using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Moderate quality evidence from 11 included RCTs demonstrated that both allogeneic cellular approaches improve the proportion of completely healed ulcers at 6 and 12 weeks. One RCT showed that a placental membrane allograft was superior to an allogeneic skin substitute, although this has yet to be repeated in other studies. The addition of allogeneic cellular wound products to SWC improves DFU outcomes. Further studies are required to conclusively establish if placental membrane allografts are superior to allogeneic skin substitutes.

Effectiveness of polypropylene mesh coated bovine amniotic membrane with adhesion barrier (polyethylene glycol) in repair of abdominal wall hernias in rats

This study was undertaken to investigate the effectiveness of polypropylene (PP) mesh coated bovine amniotic membrane (BAM) with 5% polyethylene glycol (PEG) 4000 as adhesion barrier in the repair of experimental 2 × 2 cm of abdominal hernias in rats. Rats (32) were divided into 4 groups. A 2 cm × 2 cm defect was created in the full thickness of abdominal muscle on the anterior abdominal wall. PP mesh was implanted in the abdominal cavity (Gr 1 to 4). BAM covered the abdominal face of the graft (Gr 3 and 4). It was given before the abdominal closure 5 ml of 5% PEG 4000 (Gr 2 and 4) and 5 ml of 0.9% NaCl (Gr 1 and 3). After 21 days following the operations, 32 rats were euthanized. Macroscopic and microscopic evaluations were performed according to the scoring systems. The differences between the groups was evaluated by Mann-Whitney U test and Kruskal Wallis analysis of variance. Highest adhesion percentage was observed in Gr 1 and lowest in Gr 4. Inflammatory reaction was observed in Gr 1 and 2. According to the results of this study, the combined use of BAM and 5% PEG 4000 was helpful to prevent the complications of PP mesh.

A confirmatory study on the efficacy of dehydrated human amnion/chorion membrane dHACM allograft in the management of diabetic foot ulcers: A prospective, multicentre, randomised, controlled study of 110 patients from 14 wound clinics

A randomised, controlled multicentre clinical trial was conducted at 14 wound care centres in the United States to confirm the efficacy of dehydrated human amnion/chorion membrane allograft (dHACM) for the treatment of chronic lower extremity ulcers in persons with diabetes. Patients with a lower extremity ulcer of at least 4 weeks duration were entered into a 2‐week study run‐in phase and treated with alginate wound dressings and appropriate offloading. Those with less than or equal to 25% wound closure after run‐in were randomly assigned to receive weekly dHACM application in addition to offloading or standard of care with alginate wound dressings, for 12 weeks. A total of 110 patients were included in the intent‐to‐treat (ITT) analysis, with n = 54 in the dHACM group and n = 56 in the no‐dHACM group. Of the participants, 98 completed the study per protocol, with 47 receiving dHACM and 51 not receiving dHACM. The primary study outcome was percentage of study ulcers completely healed in 12 weeks, with both ITT and per‐protocol participants receiving weekly dHACM significantly more likely to completely heal than those not receiving dHACM (ITT—70% versus 50%, P = 0.0338, per‐protocol—81% versus 55%, P = 0.0093). A Kaplan–Meier analysis was performed to compare the time‐to‐healing performance with/without dHACM, showing a significantly improved time to healing with the use of allograft, log‐rank P < 0.0187. Cox regression analysis showed that dHACM‐treated subjects were more than twice as likely to heal completely within 12 weeks than no‐dHACM subjects (HR: 2.15, 95% confidence interval 1.30–3.57, P = 0.003). At the final follow up at 16 weeks, 95% of dHACM‐healed ulcers and 86% of healed ulcers in the no‐dHACM group remained closed. These results confirm that dHACM is an efficacious treatment for lower extremity ulcers in a heterogeneous patient population.

Advances in perinatal stem cells research: a precious cell source for clinical applications

Perinatal tissues possess numerous types of stem (stromal) cells, which are considered effective candidates for cell therapy. These tissues possess common characteristics of both embryonic and adult stem cells, and cell therapists have begun to use perinatal stem cells to treat several diseases. Despite their benefits, these cells are considered biological waste and usually discarded after delivery. This review highlights the characteristics and potential clinical applications in regenerative medicine of perinatal stem cell sources - cord blood hematopoietic stem cells, umbilical cord mesenchymal stem cells, amniotic membrane stem cells, amniotic fluid stem cells, amniotic epithelial cells and chorionic mesenchymal stem cells.

Histopathological Alterations in Fetal Membranes of Women With Endometriosis

Previously, we reported endometriotic-like decidual lesions in contact with the fetal membranes (FMs) in 11 pregnant women with severe endometriosis. In this report, an extensive histomorphological analysis was performed on the FMs of 19 pregnant women with deep infiltrating endometriosis (DIE) at term pregnancy and who delivered by cesarean delivery before labor. On gross examination, all samples showed increased thickness, de novo microvessel formation, and small-size excrescences distributed along the membrane circumference. Histological examination of FM fragments sampled from the placenta edges or from the cesarean incision line showed fibrinoid necrosis and connective tissue accumulation in the amnion, chorion, and decidual layers in most of the 19 women with DIE. Papillary tufting and epithelial cell multilayering at the surface of the amnion layer were found in 3 of the 19 women with DIE. In 14 of the 19 women with DIE, the trophoblastic layer was disrupted by dense extracellular material, degenerative villi, and inflammatory infiltrates. Cystic gland-like structures were found in the decidual layer in all the 19 women with DIE, which were surrounded by irradiating small vessels and scattered inflammatory cells. The relationship between these peculiar histological changes and the endometriotic status of the pregnant women is still unclear. Sustained examination of FMs in women with DIE is needed to fully evaluate the defaults in these tissue structures and to establish whether these defaults have clinical impact on the pregnancy course.