A single-centre, retrospective study of cryopreserved umbilical cord/amniotic membrane tissue for the treatment of diabetic foot ulcers

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.

LEVEL OF EVIDENCE

Level IV, case series.

Contemporary Review: The Use of Human Placental Tissues in Foot and Ankle Surgery

The use of fetal tissues in regenerative medicine has long been a source of both promise and controversy. Since the turn of the century, their utilization has expanded because of antiinflammatory and analgesic properties, which have been theorized to act as an avenue for treating various orthopaedic conditions. With increased recognition and use, it is essential to understand the potential risks, efficacy, and long-term effects of these materials. Given the substantial body of literature published since 2015 (the date of the most recent review of fetal tissues in foot and ankle surgery), this manuscript provides an updated reference on the topic. Specifically, we evaluate the recent literature regarding the role of fetal tissues in wound healing, hallux rigidus, total ankle arthroplasty, osteochondral defects of the talus, Achilles tendinopathy, and plantar fasciitis.

Decellularization of Wharton’s Jelly Increases Its Bioactivity and Antibacterial Properties

The field of regenerative medicine has recently seen an emerging trend toward decellularized extracellular matrix (ECM) as a biological scaffold for stem cell-delivery. Human umbilical cord represents a valuable opportunity from both technical and ethical point of view to obtain allogenic ECM. Herein, we established a protocol, allowing the full removal of cell membranes and nuclei moieties from Wharton’s jelly (WJ) tissue. No alterations in the ECM components (i.e., collagen, GAG content, and growth factors), physical (i.e., porosity and swelling) and mechanical (i.e., linear tensile modulus) properties were noticed following WJ processing. Furthermore, no effect of the tissue processing on macromolecules and growth factors retention was observed, assuring thus a suitable bioactive matrix for cell maintenance upon recellularization. Based on the in vitro and in vivo biodegradability and stromal cell homing capabilities, decellularized WJ could provide an ideal substrate for stromal cells adhesion and colonization. Interestingly, the tissue processing increased the antibacterial and antiadhesive properties of WJ against Staphylococcus aureus and Staphylococcus epidermidis pathogens. Altogether, our results indicate that decellularized WJ matrix is able to limit Staphylococcus-related infections and to promote stromal cell homing, thus offering a versatile scaffold for tissue regenerative medicine.

Antibacterial and Immunomodulatory Properties of Acellular Wharton’s Jelly Matrix

Of all biologic matrices, decellularized tissues have emerged as a promising tool in the field of regenerative medicine. Few empirical clinical studies have shown that Wharton’s jelly (WJ) of the human umbilical cord promotes wound closure and reduces wound-related infections. In this scope, we herein investigated whether decellularized (DC)-WJ could be used as an engineered biomaterial. In comparison with devitalized (DV)-WJ, our results showed an inherent effect of DC-WJ on Gram positive (S. aureus and S. epidermidis) and Gram negative (E. coli and P. aeruginosa) growth and adhesion. Although DC-WJ activated the neutrophils and monocytes in a comparable magnitude to DV-WJ, macrophages modulated their phenotypes and polarization states from the resting M0 phenotype to the hybrid M1/M2 phenotype in the presence of DC-WJ. M1 phenotype was predominant in the presence of DV-WJ. Finally, the subcutaneous implantation of DC-WJ showed total resorption after three weeks of implantation without any sign of foreign body reaction. These significant data shed light on the potential regenerative application of DC-WJ in providing a suitable biomaterial for tissue regenerative medicine and an ideal strategy to prevent wound-associated infections.

Biomechanical tensile behavior of human Wharton's jelly

Wharton's jelly (WJ) is a mucous connective tissue of the umbilical cord. It shows high healing capabilities, mainly attributed to the chemical composition and to the presence of stem cells, growth factors and peptides. Although WJ biological properties are well documented in vitro and in vivo, there is still a lack of mechanical data on this tissue, which is paramount for its use as a biomaterial for medical applications. In this study, mechanical responses of ten WJ samples within close physiological conditions were registered undergoing quasi static cyclic tensile tests followed by a load up to failure. This protocol aimed on one hand to provide biomechanical data to feed predictive numerical models and on the other hand increase WJ knowledge in view of its potential use in biomedical field. In spite of the WJ harvest, the resulting viscous nonlinear elastic response obtained is fully in tune with the literature confirming the database quality. A side of the knowledge improvement on WJ mechanical response, this paper provides accurate data that will enhance predictive simulation work such as finite element analysis. The mechanical step-through brought by the analytical nonlinear characterization over cyclic and ultimate loads is to predict WJ behavior. Actually, principal component analysis highlighted its quality while pointing out indicators, such as failure or hydration criteria, as well as models' limitations.

Implantation of cryopreserved umbilical cord allograft in hard-to-heal foot wounds: a retrospective study

OBJECTIVE

The objective of this study was to assess the clinical effectiveness of surgically implanted cryopreserved human umbilical cord allograft in treating hard-to-heal wounds with and without osteomyelitis.

METHOD

In this single-centre, retrospective investigation, wounds (average size 6.9±10.1cm²) were included for analysis that had failed prior standard wound care for an average of 14.4±8.0 weeks.

RESULTS

After surgical implantation of cryopreserved umbilical cord between the deep tissue planes, 20 (95%) of the 21 wounds included in the study achieved complete closure in a median time of 7.8 weeks (range: 1-68) despite presence of residual osteomyelitis in 15 cases. A total of 12 wounds (57.1%) healed by 12 weeks, and 16 (76.2%) wounds healed by 24 weeks. A patient who presented with a limb-threatening calcaneal ulcer that was complicated by osteomyelitis at the time of treatment required subsequent amputation. No adverse events or complications related to cryopreserved umbilical cord were observed.

CONCLUSION

The results suggest that surgical implantation of cryopreserved umbilical cord allograft may be a safe and effective treatment in improving healing of hard-to-heal wounds. Further prospective, randomised controlled trials are warranted.

Systematic review on the rational use of amniotic membrane allografts in diabetic foot ulcer treatment

Background

Diabetic foot ulcer is a complication with multiple aetiological factors which has a significant impact to patients’ lives and costs to the healthcare system. The potential of human amniotic membrane to act as an allograft has been studied in relation to this condition. Aim of this study is to evaluate the current scientific evidence on its effectiveness in healing diabetic foot ulcers.

Methods

Pubmed, Cochrane library, and Google scholar were searched using the search terms, “Amnion” OR “Placenta” AND “Diabetic foot”. (MeSH terms) in the title or the abstract field from 1st of January 2000 to 30th March 2020. The quality of published reports was assessed using standard methods. We searched for experimental and observational studies in terms of randomized control trials, prospective cohort, retrospective cohort studies and case series.

Results

When searched with Mesh terms, 12 citations in PubMed, 22 citations in Cochrane library and 30 in other data bases were found. After screening the studies and their reference lists, 12 studies met the inclusion criteria and the others were excluded. There were 8 randomized control trials (RCTs), 2 prospective studies and 2 retrospective studies employing different preparation methods of the amniotic membranes. A wide variation in study end points were noted. Majority of the RCTs (n = 7) were concluded with significantly higher wound closure rate compared to the conventional treatment groups. In prospective and retrospective studies, it was shown that large chronic ulcers which were resistant to closure with standard therapy achieved wound closure with amniotic membrane allografts. A meta-analysis could not be performed due to study heterogeneity, and publication bias was not assessed due to the small number of available studies which was not sufficient for accurate comparison.

Conclusion

Even though, the studies had some inherent heterogeneity due to different preparation methods, different study end points and outcome measurements. According to our review the current studies using amniotic membrane allografts give reliable evidence of reduction in healing time over conventional methods.

Umbilical amnion and amniotic membrane transplantation for infectious scleritis and scleral melt: A case series

Purpose

To report the outcomes of two cases of infectious scleritis with severe scleral thinning managed using combined mechanical debridement, cryopreserved umbilical amnion (UA) and amniotic membrane (AM) grafts, and antimicrobial therapy.

Observations

Two patients presented with severe infectious scleritis with progressive scleral melts secondary to Pseudomonas aeruginosa subsequent to pterygium surgery and intravitreal injection, respectively. Surgical debridement was followed by UA grafting, AM transplantation, and antimicrobial therapy. Epithelialization and vascularization were seen within 1-4 weeks post-operatively. At last follow up of 5-6 months, the structural integrity of the sclera remained preserved with no infection recurrence, graft necrosis, or wound dehiscence.

Conclusions and importance

This case series highlights the utilization of UA grafting along with AM transplantation and topical and systemic antibiotics to preserve the globe in cases of severe infectious scleritis.

Use of Cryopreserved Human Umbilical Cord and Amniotic Membrane Allograft and Portable Negative Pressure Therapy in Dehisced Giant Omphalocele Repair: A Case Study

BACKGROUND

A giant omphalocele is a rare congenital abdominal wall defect that measures more than 6 to 8 cm in any dimension. The child's abdominal visceral contents as well as the liver which are both covered by the amniotic sac protrude outside the abdomen through the umbilicus. Consequently, closing this defect is extremely challenging due to the risk for wound dehiscence.

CASE

Baby C, a 1-year-old male infant, developed a dehisced abdominal wound after secondary repair of a giant omphalocele. Escharification of the amniotic sac was achieved with silver products, followed by intra-abdominal tissue expansion and skin closure. A conservative approach was undertaken with the use of cryopreserved human umbilical cord and amniotic membrane allograft in conjunction with portable negative pressure therapy.

CONCLUSIONS

To the best of our knowledge, this is the first case study to evaluate the effect of cryopreserved human umbilical cord and amniotic membrane allograft in a dehisced neonatal abdominal wound due to a giant omphalocele or, in fact, neonatal wounds in general. Our experience with this case suggests that cryopreserved human umbilical cord and amniotic membrane allograft may create a superior healing trajectory and regeneration, avoidance of surgical intervention, and an early hospital discharge. Wound-supporting properties of amniotic allograft, in addition to lack of immunologic reactivity, offer an attractive option for a variety of pediatric and neonatal wounds.

Use of Human Umbilical Cord and Its Byproducts in Tissue Regeneration

The fresh or cryopreserved human umbilical cord (HUC) and its byproducts, such as cells and extracts, have different uses in tissue regeneration. Defining what HUC byproduct is more effective in a particular application is a challenge. Furthermore, the methods of isolation, culture and preservation, may affect cell viability and regenerative properties. In this article, we review the HUC and its byproducts' applications in research and clinical practice. We present our results of successful use of HUC as a patch to treat gastroschisis and its potential to be applied in other conditions. Our in vitro results show an increase in proliferation and migration of human fibroblasts by using an acellular HUC extract. Our goal is to promote standardization of procedures and point out that applications of HUC and its byproducts, as well as the resulting advances in regenerative medicine, will depend on rigorous quality control and on more research in this area.

Therapeutic Potential of Wharton's Jelly Mesenchymal Stem Cells for Diabetes: Achievements and Challenges

Diabetes mellitus (DM) is an alarming metabolic disease in which insulin secreting β-cells are damaged to various extent. Unfortunately, although currently available treatments help to manage the disease, however, patients usually develop complications, as well as decreased life quality and increased mortality. Thus, efficient therapeutic interventions to treat diabetes are urgently warranted. During the past years, mesenchymal stem cells (MSCs) have made their mark as a potential weapon in various regenerative medicine applications. The main fascination about MSCs lies in their potential to exert reparative effects on an amazingly wide spectrum of tissue injury. This is further reinforced by their ease of isolation and large ex vivo expansion capacity, as well as demonstrated multipotency and immunomodulatory activities. Among all the sources of MSCs, those isolated from umbilical cord-Wharton's jelly (WJ-MSCs), have been proved to provide a great source of MSCs. WJ-MSCs do not impose any ethical concerns as those which exist regarding ESCs, and represent a readily available non-invasive source, and hence suggested to become the new gold standard for MSC-based therapies. In the current review, we shall overview achievements, as well as challenges/hurdles which are standing in the way to utilize WJ-MSCs as a novel efficient therapeutic modality for DM.

Updates on Bioengineered Alternative Tissues

Over the past quarter century, the management of diabetic wounds and their sequelae has improved dramatically. One of the greatest areas of advancement includes the development of bioengineered alternative tissues that act as adjuncts to the deficits of chronic wounds and accelerate healing. The use of bioengineered alternative tissues will likely only continue to dominate the outpatient and perioperative management of chronic, recalcitrant wounds as new additional products continue to cut costs and improve wound healing expectations. This article reviews common and novel bioengineered alternative tissue products, identifying their unique composition, function, and current published outcome data.

A single-center, retrospective review of robot-assisted laparoscopic prostatectomy with and without cryopreserved umbilical cord allograft in improving continence recovery

The objective of this study was to evaluate the safety and effectiveness of cryopreserved umbilical cord (UC) allograft as a nerve wrap around the neurovascular bundle (NVB) in accelerating return to continence after radical prostatectomy. A single-center, retrospective study was performed on 200 patients who underwent bilateral, nerve-sparing robot-assisted radical prostatectomy (RARP) with and without placement of UC around the NVBs (n = 100/group). Patients were excluded if they had previous simple or transurethral prostatectomy or history of pelvic radiation. Post-operative continence, defined as 0 or 1 safety pad, was analyzed between groups at 1, 3, 6, and 12 months. Complications, biochemical recurrence and adverse events were assessed to determine safety. Patients who underwent RARP with UC were significantly more likely to be continent at 1 month (65% vs. 44%, p = 0.018), 3 months (83% vs. 70%, p = 0.03), and 12 months (97% vs. 87%, p = 0.009). Sample stratification revealed that UC is beneficial for obese patients and those > 60 years, both of which are high risk for post-RARP incontinence. Biochemical failure was noted in 2 (UC) and 4 (control) patients. No adverse events or complications related to UC were observed. The results suggest that UC allograft is safe and accelerates continence recovery in post-RARP patients. Prospective, randomized trials are warranted.

Delivery systems of current biologicals for the treatment of chronic cutaneous wounds and severe burns

While wound therapy remains a clinical challenge in current medical practice, much effort has focused on developing biological therapeutic approaches. This paper presents a comprehensive review of delivery systems for current biologicals for the treatment of chronic wounds and severe burns. The biologicals discussed here include proteins such as growth factors and gene modifying molecules, which may be delivered to wounds free, encapsulated, or released from living systems (cells, skin grafts or skin equivalents) or biomaterials. Advances in biomaterial science and technologies have enabled the synthesis of delivery systems such as scaffolds, hydrogels and nanoparticles, designed to not only allow spatially and temporally controlled release of biologicals, but to also emulate the natural extracellular matrix microenvironment. These technologies represent an attractive field for regenerative wound therapy, by offering more personalised and effective treatments.

An update and review of cell-based wound dressings and their integration into clinical practice

Chronic wounds affect over 4 million individuals and pose a significant burden to the US healthcare system. Diabetes, venous stasis, radiation or paralysis are common risk factors for chronic wounds. Unfortunately, the current standard of care (SOC) has a high relapse rate and these wounds continue to adversely affect patients' quality of life. Fortunately, advances in tissue engineering have allowed for the development of cell-based wound dressings that promote wound healing by improving cell migration and differentiation. As the available options continue to increase in quantity and quality, physicians should have a user-friendly guide to reference when deciding which dressing to use. The objective of this review is to identify the currently available biologic dressings, describe their indications, and provide a framework for integration into clinical practice. This review included 53 studies consisting of prospective and retrospective cohorts as well as several randomized control trials. Three general categories of cell-based biologic dressings were identified and nine brands were included. Cell-based biologic dressings have shown efficacy in a broad range of scenarios, and studies examining their efficacy have improved our understanding of the pathophysiology of chronic wounds. Amniotic and placental membranes have the widest scope and can be used to treat all subtypes of chronic wounds. Human skin allografts and bioengineered skin substitutes can be used for chronic ulcers but generally require a vascularized wound bed. Autologous platelet rich plasma (PRP) has shown promise in venous stasis ulcers and decubitus ulcers that have failed conventional treatment. Overall, more research is necessary to determine if these novel therapeutic options will change the current SOC, but current studies demonstrate encouraging results in the treatment of chronic wounds.