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

Hybrid thermosensitive hydrogel/amniotic membrane structure incorporating S-nitrosothiol microparticles: potential uses for controlled nitric oxide delivery

Insufficient levels of nitric oxide may lead to chronic and acute wounds. Additionally, it is crucial that nitric oxide is prepared in a controlled-release manner due to its gaseous nature and short half-life. To address this issue, utilizing nitric oxide donors, particularly S-nitrosothiols such as S-nitrosoglutathione (GSNO), could efficiently overcome instability and aid in biomedical applications. Decellularized human amniotic membranes are also best known for their anti-inflammatory, angiogenic, and antimicrobial properties to promote wound epithelization. In this study, a novel nitric oxide-generated wound dressing based on an amniotic membrane was investigated. This construct consisted of a chitosan/β-glycerophosphate thermosensitive hydrogel covered with a decellularized human amniotic layer embedded with GSNO-loaded polylactic acid microparticles. The structure of GSNO was confirmed by spectrometric, elemental, and chemical analyses. The GSNO-loaded microparticles had a diameter of 40.66 ± 6.92 µm, and an encapsulation efficiency of 45.6 ± 6.74%. The hybrid construct and GSNO-loaded microparticles enhanced the long-term stable release of GSNO compared to free GSNO. The construct released nitric oxide ranging from 24 to 68 nM/mg during 7 days. The thermosensitive hydrogel was formed at 32.7 ± 1 °C and had a porous structure with a pore size of 41.76 ± 9.76 µm. The MTT and live/dead assays performed on human dermal fibroblast cells demonstrated suitable cell viability and adhesion to the final construct. Further, hemolysis analysis revealed less than a 5% hemolysis rate due to negligible blood cell adhesion. Overall, the prepared hybrid construct demonstrated suitable characteristics as a potential active wound dressing capable of controlled nitric oxide delivery.

Combined therapeutic use of umbilical cord blood serum and amniotic membrane in diabetic wounds

Diabetic wounds are hard-to-heal due to complex multifactorial dysregulation within the micro-environment, necessitating the development of novel regenerative approaches to stimulate healing. This study investigated whether the combined therapeutic application of two novel cellular tissue products, namely a decellularized collagen-rich amniotic membrane (AmR) and growth factor-rich umbilical cord blood serum (UCBS) could have a positive synergistic effect on long-term healing outcomes by stimulating both superficial wound closure and wound bed regeneration. Full thickness excisional wounds were induced on obese diabetic mice (B6.Cg-lepob/J, ob/ob, n = 23) and treated with either: 1) Standard wound care (control); 2) UCBS; 3) AmR or 4) UCBS + AmR. Macroscopic wound closure was assessed on days 0, 3, 7, 10 and 14 post wounding. To determine the potential impact on wound recurrence, endpoint analysis was performed to determine both the overall quality of healing histologically as well as the molecular state of the wounds on day 14 via proteomic analysis. The data demonstrated the presence of both healers and non-healers. Re-epithelization took place in the healers of all treatment groups, but underlying tissue regeneration was far more pronounced following application of the combined treatment (UCBS + AmR), suggesting improved quality of healing and potentially a reduced change of recurrence long term. In non-healers, wounds failed to heal due to excessive slough formation and a reduction in LTB4 expression, suggesting impaired antimicrobial activity. Care should thus be taken since the cellular tissue product therapy could pose an increased risk for infection in some patients.

Amniotic Membrane Transplantation: Clinical Applications in Enhancing Wound Healing and Tissue Regeneration

Chronic wounds and non-healing tissue defects pose significant clinical challenges, necessitating innovative therapeutic approaches. A comprehensive literature review of amniotic membrane transplantation for wound healing and tissue repair evaluates the efficacy and safety of amniotic membrane transplantation in enhancing wound healing and tissue repair. Amniotic membranes promote wound closure and reduce inflammation and scarring via abundant growth factors, cytokines, and extracellular matrix components, which foster conducive environments for tissue regeneration. Amniotic membrane transplantation is effective in various medical disciplines, including ophthalmology, dermatology, and orthopedics. Low immunogenicity and anti-microbial properties ensure their safe application. Amniotic membrane transplantation offers a promising therapeutic approach for wound healing and tissue repair, and further research is warranted to explore its regenerative potential fully.

Application of Fetal Membranes and Natural Materials for Wound and Tissue Repair

The human fetal membrane is a globally accepted biological biomaterial for wound and tissue repair and regeneration in numerous fields, including dermatology, ophthalmology, and more recently orthopedics, maxillofacial and oral surgery, and nerve regeneration. Both cells and matrix components of amnion and chorion are beneficial, releasing a diverse range of growth factors, cytokines, peptides, and soluble extracellular matrix components. Beside fetal membranes, numerous natural materials have also been reported to promote wound healing. The biological properties of these materials may potentiate the pro-healing action of fetal membranes. Comparison of such materials with fetal membranes has been scant, and their combined use with fetal membranes has been underexplored. This review presents an up-to-date overview of (i) clinical applications of human fetal membranes in wound healing and tissue regeneration; (ii) studies comparing human fetal membranes with natural materials for promoting wound healing; and (iii) the literature on the combined use of fetal membranes and natural pro-healing materials.

Homogenized and Lyophilized Amniotic Membrane Dressings for the Treatment of Diabetic Foot Ulcers in Ambulatory Patients

BACKGROUND

Diabetic foot ulcers (DFUs) constitute a complication that occurs in 19% to 34% of patients with diabetes mellitus (DM). The aim of this study is to describe median days to healing, average velocity of wound closure, and percentage of wound surface closed at 3, 6, and 12 weeks through the use of homogenized and lyophilized amniotic membrane (hAMpe) dressings for the treatment of DFUs in ambulatory patients.

METHODS

An observational, descriptive, longitudinal study was performed. Patients presenting with granulation-based DFU, after proper debridement, were included from August 19, 2021, until July 14, 2023. hAMpe dressings placed every 3 days were used for the treatment of these ulcers.

RESULTS

Sixteen patients were included with a mean age of 52.38 (8.07) years. The analyzed lesions were postsurgical ulcers in 15 of the 16 included patients. Median ulcer size was 19.5 cm2 (6.12-36). The median ABI was 1.10 (1-1.14). The median days to healing was 96 (71-170). The median percentage closure of the wound at 3 weeks was 41% (28.9%-55.3%), at 6 weeks it was 68.2% (48.6%-74.2%), and at 12 weeks it was 100% (81%-100%). The average velocity closure was 1.04% per day (95% CI 0.71%-1.31%). It was higher during the closure of the first 50% of the ulcer, 2.12% per day (95% CI 0.16%-4.09%), and decreased from 50% to 25% of the ulcer size to 0.67% per day (95% CI 0.23%-1.10%) and from 25% to closure to 0.47% per day (95% CI 0.14%-0.80%), P < .001.

CONCLUSION

These results are difficult to compare to other studies given the higher surface area of the ulcers included in our sample. The development of hAMpe dressings enables patients to apply them without requiring assistance from health care teams and was not associated with any recognized complications.

Amnion membranes support wound granulation in a delayed murine excisional wound model

Chronic or delayed healing wounds constitute an ever-increasing burden on healthcare providers and patients alike. Thus, therapeutic modalities that are tailored to particular deficiencies in the delayed wound healing response are of critical importance to improve clinical outcomes. Human amnion-derived viable and devitalized allografts have demonstrated clinical efficacy in promoting the closure of delayed healing wounds, but the mechanisms responsible for this efficacy and the specific wound healing processes modulated by these tissues are not fully understood. Here, we utilized a diabetic murine excisional wound model in which healing is driven by granulation and re-epithelialization, and we applied viable (vHAMA) or devitalized (dHAMA) amnion-derived allografts to the wound bed in order to determine their effects on wound healing processes. Compared to control wounds that were allowed to heal in the absence of treatment, wounds to which vHAMA or dHAMA were applied demonstrated enhanced deposition of granulation tissue accompanied by increased cellular proliferation and increased de novo angiogenesis, while vHAMA-treated wounds also demonstrated accelerated re-epithelialization. Taken together, these data suggest that both vHAMA and dHAMA facilitate wound healing through promoting processes critical to granulation tissue formation. Further understanding of the cellular and tissue mechanisms underlying the effects of tissue-derived matrices on wound healing will enable tailored prescription of their use in order to maximize clinical benefit.

Application of amniotic membranes in reconstructive surgery of internal organs-A systematic review and meta-analysis

Amniotic membrane (AM) has great potential as a scaffold for tissue regeneration in reconstructive surgery. To date, no systematic review of the literature has been performed for the applications of AM in wound closure of internal organs. Therefore, in this systematic review and meta-analysis, we summarize the literature on the safety and efficacy of AM for the closure of internal organs. A systematic search was performed in MEDLINE-PubMed database and OVID Embase to retrieve human and controlled animal studies on wound closure of internal organs. The Cochrane Risk of Bias tool for randomized clinical trials and the SYRCLE risk of bias tool for animal studies were used. Meta-analyses (MAs) were conducted for controlled animal studies to assess efficacy of closure, mortality and complications in subjects who underwent surgical wound closure in internal organs with the application of AM. Sixty references containing 26 human experiments and 36 animal experiments were included. The MAs of the controlled animal studies showed comparable results with regard to closure, mortality and complications, and suggested improved mechanical strength and lower inflammation scores after AM application when compared to standard surgical closure techniques. This systematic review and MAs demonstrate that the application of AM to promote wound healing of internal organs appears to be safe, efficacious, and feasible.

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.

Novel therapeutic targets for diabetes-related wounds or ulcers: an update on preclinical and clinical research

INTRODUCTION

Diabetes-related wounds, particularly diabetes-related foot ulcers, are mainly caused by lack of foot sensation and high plantar tissue stress secondary to peripheral neuropathy, ischemia secondary to peripheral artery disease, and dysfunctional wound healing. Current management of diabetes-related wounds involves the offloading of high foot pressures and the treatment of ischemia through revascularization. Despite these treatments, the global burden of diabetes-related wounds is growing, and thus, novel therapies are needed. The normal wound healing process is a coordinated remodeling process orchestrated by fibroblasts, endothelial cells, phagocytes, and platelets, controlled by an array of growth factors. In diabetes-related wounds, these coordinated processes are dysfunctional. The past animal model and human research suggest that prolonged wound inflammation, failure to adequately correct ischemia, and impaired wound maturation are key therapeutic targets to improve diabetes-related wound healing.

AREAS COVERED

This review summarizes recent preclinical and clinical research on novel diabetes-related wound treatments. Animal models of diabetes-related wounds and recent studies testing novel therapeutic agents in these models are described. Findings from clinical trials are also discussed. Finally, challenges to identifying and implementing novel therapies are described.

EXPERT OPINION

Given the growing volume of promising drug therapies currently under investigation, it is expected within the next decade, that diabetes-related wound treatment will be transformed.