Comparison of cryopreserved amniotic membrane and umbilical cord tissue with dehydrated amniotic membrane/chorion tissue

Clinical Outcomes and Indications of In-Office Sutureless Dried Gamma Ray-Sterilized Human Amniotic Membrane Transplantation With Bandage Contact Lenses in Various Ocular Surface Disorders

PURPOSE

The purpose of this study was to investigate the efficacy and indications of using dried gamma ray-sterilized amniotic membrane (AM) transplantation with bandage contact lenses for the in-office sutureless treatment of various ocular surface diseases.

METHODS

This study retrospectively included 56 eyes of 52 patients with various ocular surface diseases treated with sutureless dehydrated AM-assisted therapeutic contact lenses. The patients were followed up and assessed 1, 2, and 4 weeks after the treatment, and the therapeutic contact lenses were removed after 1 or 2 weeks. The size of the corneal lesion and the degree of pain experienced by each patient before and after the procedure were measured. Corneal re-epithelization rate and clinical aspects related to re-epithelialization were evaluated.

RESULTS

Complete corneal re-epithelialization of the epithelial defect was observed in 40 eyes. The complete re-epithelialization rates of persistent epithelial defect caused by infectious ulcers, neurotrophic ulcers, ulcers due to burn, toxic keratopathy, previous penetrating keratoplasty or other corneal surgeries, and severe dry eye disease were 69.2%, 80.0%, 77.8%, 100%, 75.0%, and 100%, respectively. Five patients with uncontrolled infectious ulcers, neurotrophic ulcer, bullous keratopathy, and ulcers associated with rheumatic disease did not show significant improvement. Patient pain scores significantly decreased after the procedure.

CONCLUSIONS

Dehydrated AM transplantation with a bandage contact lens is minimally invasive and easily applicable through in-office procedures. This approach is expected to be more actively applied in various ocular surface disorders, not only in severe corneal diseases but also in relatively mild corneal surface diseases.

Wharton's jelly of the umbilical cord serves as a natural biomaterial to promote osteogenesis

Various factors can contribute to bone damage or loss, presenting challenges for bone regeneration. Our study explores the potential clinical applications of two processed forms of Wharton's jelly of the human umbilical cord for treating bone loss. Wharton's jelly from fresh umbilical cords underwent two distinct processes: (1) frozen Wharton's jelly (WJF), preserved with cryoprotective agents, and (2) decellularized Wharton's jelly matrix (WJD), prepared only via lyophilization without cryoprotectants. Both WJD and WJF are rich in collagen, hyaluronan, and polysaccharide proteins. Notably, WJD exhibited a porous structure lacking nuclei from human umbilical cord mesenchymal stem cells, unlike WJF. In direct contact experiments, WJD stimulated osteoblast migration, enhanced osteoblast maturation, and promoted calcium deposition for bone formation when administered to cultured rat osteoblasts. Furthermore, in transwell co-culture experiments, both WJD and WJF increased the rat osteoblast expression of RUNX2 and OPN genes, elevated alkaline phosphatase levels, and enhanced extracellular calcium precipitation, indicating their role in osteoblast maturation and new bone formation. Hyaluronic acid, one of the ingredients from WJD and WJF, was identified as a key component triggering osteogenesis. In vivo experiments involved creating circular bone defects in the calvarias of rats, where WJD and WJF were separately implanted and monitored over five months using micro-computerized tomography. Our results demonstrated that both WJD and WJF enhanced angiogenesis, collagen formation, osteoblast maturation, and bone growth within the bone defects. In summary, WJD and WJF, natural biomaterials with biocompatibility and nontoxicity, act not only as effective scaffolds but also promote osteoblast adhesion and differentiation, and accelerate osteogenesis.

Dr. Scheffer C.G. Tseng: A Pioneer in Cryopreserved Amniotic Membrane for Regenerative Medicine

Dr. Scheffer Chuei-Goong Tseng is widely recognized as a pioneer in the development and application of cryopreserved amniotic membrane therapy. Dr. Tseng has completely revolutionized the management of ocular and various diseases through the success in the study of regenerative medicine, specifically through the human amniotic membrane. He has turned innovative scientific discoveries into products that contribute to many medical fields, including ophthalmology, orthopedics, oral and maxillofacial surgery, dermatology, and wound care. This review article explores Dr. Tseng's background, career, and significant contributions to regenerative medicine, with a particular focus on the impact of cryopreserved amniotic membrane technology.

Etiopathology, Epidemiology, Diagnosis, and Treatment of Fungal Keratitis

Fungal keratitis (FK) is a severe ocular condition resulting from corneal infection that is prevalent in tropical countries, particularly in developing regions of Asia and Africa. Factors like corneal lens misuse, inappropriate steroid use, and diagnostic challenges have provoked the epidemic. FK causes significant vision impairment, scarring, and ocular deformities. Accurate pathological diagnosis is crucial for effective therapeutic intervention. Topical antifungal therapy with surface healing medications proves effective in preventing fungal-borne ulcers. Managing FK requires a comprehensive understanding of fungal pathogenesis, guiding formulation strategies and preventive measures to curb global ocular blindness. This review provides in-depth insights into FK, covering etiology, epidemiology, pathogenesis, therapeutic interventions, antifungal resistance, limitations, prevention, and future perspectives on ocular surface disease management.

The current alternative for ocular surface and anophthalmic socket reconstruction, cryopreserved umbilical amniotic membrane (cUAM)

PURPOSE

This report presents the results of using cryopreserved umbilical amniotic membrane (cUAM) as an alternative mucosal graft for ocular surface reconstruction in cases of anophthalmic socket contracture (ASC), cicatricial entropion (CE), and conjunctival-scleral defects.

METHODS

The study included patients who underwent non-commercial implantation of cUAM grafts (prepared by corneal banking methods) for ASC, CE, conjunctival defect, and scleral melting. The main success criteria for this study were the comfortable fitting of the ocular prosthesis in ASC patients, the natural eyelid position in CE patients, and the degree of conjunctivalisation in melting patients.

RESULTS

cUAM transplantation was performed in 2 patients who could not use a prosthetic eye due to conjunctival contracture, 2 patients with CE, and 1 patient with conjunctival defect and 1 patient with conjunctival-scleral melting. The primary outcome was achieved in 83.3% (5/6) of patients. In one patient with CE, partial healing was achieved due to the persistence of CE in the medial upper eyelid.

CONCLUSIONS

cUAM is a viable alternative to mucosal grafting for reconstructing the bulbar and palpebral conjunctival surface, fornix, and orbit, with reduced donor morbidity and shorter surgical time. Its regenerative ability allows for tissue defect healing and improves cosmetic appearance through epithelialization within weeks.

Exosomes for the Management of Low Back Pain: A Review of Current Clinical Evidence

Low back pain affects millions of people, creating an enormous financial burden on the global healthcare system. Traditional treatment modalities are short-lived and have shortcomings. Recently, orthobiologics, including extracellular vesicles or exosomes derived from mesenchymal stem cells, have markedly increased for managing musculoskeletal conditions. Here, the primary aim is to review the outcomes of clinical studies using extracellular vesicles or exosomes for treating low back pain. Numerous databases (Scopus, PubMed, Web of Science, Embase, and Google Scholar) were searched using terms for the intervention 'exosomes' and the treatment 'low back pain' for studies published in English to March 18, 2024. Articles utilizing exosomes for the management of low back pain were included. Articles not utilizing exosomes, not explicitly stating the presence of exosomes in their formulation, or not targeting low back pain were excluded. Two articles that met our pre-defined criteria were included in this review. The results showed that administering extracellular vesicles or exosomes is safe and potentially effective in patients suffering from low back pain. Yet, more sufficiently powered, multi-center, prospective, randomized, and non-randomized trials with longer follow-up are essential to assess the long-term safety and efficacy of extracellular vesicles or exosomes derived from various sources and to support its routine clinical use for managing low back pain.

Comparison of the effects of preservation methods on structural, biological, and mechanical properties of the human amniotic membrane for medical applications

Amniotic membrane (AM), the innermost layer of the placenta, is an exceptionally effective biomaterial with divers applications in clinical medicine. It possesses various biological functions, including scar reduction, anti-inflammatory properties, support for epithelialization, as well as anti-microbial, anti-fibrotic and angio-modulatory effects. Furthermore, its abundant availability, cost-effectiveness, and ethical acceptability make it a compelling biomaterial in the field of medicine. Given the potential unavailability of fresh tissue when needed, the preservation of AM is crucial to ensure a readily accessible and continuous supply for clinical use. However, preserving the properties of AM presents a significant challenge. Therefore, the establishment of standardized protocols for the collection and preservation of AM is vital to ensure optimal tissue quality and enhance patient safety. Various preservation methods, such as cryopreservation, lyophilization, and air-drying, have been employed over the years. However, identifying a preservation method that effectively safeguards AM properties remains an ongoing endeavor. This article aims to review and discuss different sterilization and preservation procedures for AM, as well as their impacts on its histological, physical, and biochemical characteristics.

Evaluation on the efficacy of processed hydrated and dehydrated amnion chorion membrane on the proliferation of periodontal ligament fibroblasts

The purpose of the present study was to process and assess the effect of hydrated amnion chorion membrane and dehydrated amnion chorion membrane on proliferation of periodontal ligament (PDL) fibroblast cells. The amnion chorion membrane (ACM) from placenta of 18 systemically healthy patients was obtained from the Department of Obstetrics and Gynaecology. They were processed as hydrated and dehydrated based on different processing methods. The Periodontal ligament cells were obtained from periodontal ligament of freshly extracted premolars of systemically healthy patients, due to orthodontic reasons. The PDL cells were further cultured in laboratory and were exposed to hydrated and dehydrated amnion chorion membrane. The MTT assay was performed to assess the proliferation of PDL fibroblast cells after 24 and 48 h. The hydrated and dehydrated amnion chorion membrane showed proliferation of PDL fibroblasts after 24 and 48 h. The proliferation of PDL fibroblasts in hydrated (p = 0.043) and dehydrated (p = 0.050) amnion chorion membrane was statistically significant at the end of 24 and 48 h respectively. On inter-group comparison dehydrated ACM showed significant proliferation of PDL fibroblasts after 24 (p=0.014) and 48 h (p=0.019). Within the limits of the present study, it can be concluded: both hydrated and dehydrated amnion chorion membrane showed proliferationof PDL fibroblast cells. However, dehydrated ACM showed significant proliferation of PDL fibroblasts.

Outcomes of transforaminal epidural injection of amniotic membrane/umbilical cord particulate for lumbar radiculopathy: a case series

Background

Radiculopathy can be a debilitating condition. Amniotic membrane/umbilical cord (AM/UC) particulate is a relatively new injectable treatment modality. Herein we report the outcomes of epidural injection of AM/UC particulate in managing lumbar radiculopathy.

Methods

Consecutive patients with lumbar radiculopathy who received epidural injection of AM/UC particulate for lumbar radiculopathy were included. Primary outcome was change in pain as measured by the 11-point numerical rating scale. Safety was assessed by AM/UC- and procedure-related complications. Paired t-tests were used to determine statistical significance.

Results

A total of 12 patients with a mean age of 56.7 ± 21.0 years were included in the analysis. The patients were previously treated with physical therapy (91.7%), chiropractic corrective measures (16.7%), epidural steroid injection (83.3%), and radiofrequency ablation (8.3%). Two patients (16.7%) were taking opioids for chronic pain syndrome. After AM/UC injection, the average pain score decreased from 6.6 ± 1.5 to 5.2 ± 1.9 at 1-3 months, 2.0 ± 1.4 at 6 months, and 2.9 ± 1.4 at last mean follow-up of 21.3 ± 11.1 months (p < 0.001). No patients required subsequent treatment or surgery. There were also no complications.

Conclusion

This case series supports the preliminary safety and shows potential benefit of epidural AM/UC particulate injection in this cohort of patients with lumbar radiculopathy pain.

Dehydrated human amnion/chorion membrane allograft with spongy layer to significantly improve the outcome of chronic non-healing wounds

We investigated the healing effect of a new dehydrated amnion/chorion membrane with a spongy layer over a 30-month period in 32 patients with 53 chronic non-healing wounds of different aetiologies. Wounds with <40% surface reduction after 4 weeks of best wound treatment underwent weekly allograft application by a certified wound specialist based on national guidelines and a standardised protocol until complete healing or definite treatment interruption. The main outcome measure was the percentage of wound surface reduction from baseline calculated using digital planimetry follow-up photographs. Overall, 38 (71.7%) wounds presented a favourable outcome (70%-100% area reduction), with 35 (66%) completely healing over a median time of 77 days (range 29-350 days). Favourable outcomes were observed in 75% of traumatic wounds, surgical wounds, venous leg ulcers and pressure injuries, as well as in 50% of ischaemic wounds. Wounds being present <12 months were significantly more likely to have a favourable outcome than more long-standing wounds (χ2  = 7.799; p = 0.005; OR = 3.378; 95% CI, 1.410-8.092). Thus, treatment with dehydrated amnion/chorion membrane with a spongy layer improves the outcome of non-healing wounds of different aetiologies and, therefore, has to be considered early in the management of refractory wounds.

Retention of Key Characteristics of Unprocessed Chorion Tissue Resulting in a Robust Scaffold to Support Wound Healing

Placental membranes have been widely studied and used clinically for wound care applications, but there is limited published information on the benefits of using the chorion membrane. The chorion membrane represents a promising source of placental-derived tissue to support wound healing, with its native composition of extracellular matrix (ECM) proteins and key regulatory proteins. This study examined the impact of hypothermic storage on the structure of chorion membrane, ECM content, and response to degradation in vitro. Hypothermically stored chorion membrane (HSCM) was further characterized for its proteomic content, and for its functionality as a scaffold for cell attachment and proliferation in vitro. HSCM retained the native ECM structure, composition, and integrity of native unprocessed chorion membrane and showed no differences in response to degradation in an in vitro wound model. HSCM retained key regulatory proteins previously shown to be present in placental membranes and promoted the attachment and proliferation of fibroblasts in vitro. These data support the fact that hypothermic storage does not significantly impact the structure and characteristics of the chorion membrane compared to unprocessed tissue or its functionality as a scaffold to support tissue growth.

The Preparation and Clinical Efficacy of Amnion-Derived Membranes: A Review

Biological tissues from various anatomical sources have been utilized for tissue transplantation and have developed into an important source of extracellular scaffolding material for regenerative medicine applications. Tissue scaffolds ideally integrate with host tissue and provide a homeostatic environment for cellular infiltration, growth, differentiation, and tissue resolution. The human amniotic membrane is considered an important source of scaffolding material due to its 3D structural architecture and function and as a source of growth factors and cytokines. This tissue source has been widely studied and used in various areas of tissue repair including intraoral reconstruction, corneal repair, tendon repair, microvascular reconstruction, nerve procedures, burns, and chronic wound treatment. The production of amniotic membrane allografts has not been standardized, resulting in a wide array of amniotic membrane products, including single, dual, and tri-layered products, such as amnion, chorion, amnion-chorion, amnion-amnion, and amnion-chorion-amnion allografts. Since these allografts are not processed using the same methods, they do not necessarily produce the same clinical responses. The aim of this review is to highlight the properties of different human allograft membranes, present the different processing and preservation methods, and discuss their use in tissue engineering and regenerative applications.

Amniotic membrane and/or umbilical cord tissue for treatment of facet joint syndrome: a narrative review

Musculoskeletal spine disorders, especially low back pain, induce enormous amounts of stress and financial burden on individuals and healthcare systems throughout the world. Disorders of the facet joints in the lumbar spine are the most predominant cause of back pain, resulting in facet joint syndrome (FJS). Conventional treatments for FJS are short-lived and have limitations and side effects. Thus, safer and more effective alternatives that can reduce pain and improve patient-reported outcomes are needed. Recently, the utilization of biologics, including the ones derived from perinatal tissue such as amniotic membrane (AM) and umbilical cord (UC), has significantly increased for regenerative medicine applications. This manuscript summarizes the outcomes of preclinical and clinical studies utilizing AM and/or UC for FJS. We identified no preclinical studies and 3 retrospective studies utilizing the search terms "amniotic membrane" and/or "umbilical cord" and "facet joint syndrome". The administration of AM + UC is safe and potentially efficacious for patients with FJS. However, more preclinical studies and appropriately powered, multi-center, prospective non-randomized and randomized controlled studies with longer follow-up are warranted to further evaluate the efficacy of AM + UC to justify its clinical use.

Umbilical Cord Graft for Refractory Neurotrophic Keratopathy

PURPOSE

The purpose of this study was to evaluate whether an umbilical cord tissue graft (UCG) could promote reepithelialization in refractory cases of neurotrophic keratopathy, which failed traditional treatment modalities including amniotic membrane grafts.

METHODS

This retrospective case series included 3 eyes of 3 patients who underwent UCG placement for refractory stage 3 neurotrophic keratopathy. Records were reviewed to evaluate the clinical course including previous treatments, time to UCG dissolution, time to corneal epithelialization, and recurrence of epithelial defects.

RESULTS

The time of a nonhealing epithelial defect before UCG placement ranged from 7.7 to 30 weeks (mean 21.0). UCG dissolution time ranged from 1.7 to 8.1 weeks (mean 5.0) compared with the previous failed amniotic membrane dissolution time of 0.3 to 1.6 weeks (mean 0.95). The time to complete epithelialization after UCG placement was 7.7 and 8.1 weeks, respectively, for the first 2 cases, whereas the third case did not fully epithelialize. Only 1 eye did not have recurrence of an epithelial defect. The maximum time of maintained epithelialization without recurrence ranged from 5 to 86 weeks (mean 42.7). Follow-up time was 37 to 108.1 weeks (mean 62.2) after first UCG placement.

CONCLUSIONS

UCG may allow for longer retention time of tissue grafts, provide a mechanical barrier for protection, and aid in regeneration of the ocular surface. UCG may be an option for re-epithelialization in recalcitrant cases of neurotrophic keratopathy, after conventional treatments such as amniotic membrane grafts have failed.

Placental-Derived Biomaterials and Their Application to Wound Healing: A Review

Chronic wounds are associated with considerable patient morbidity and present a significant economic burden to the healthcare system. Often, chronic wounds are in a state of persistent inflammation and unable to progress to the next phase of wound healing. Placental-derived biomaterials are recognized for their biocompatibility, biodegradability, angiogenic, anti-inflammatory, antimicrobial, antifibrotic, immunomodulatory, and immune privileged properties. As such, placental-derived biomaterials have been used in wound management for more than a century. Placental-derived scaffolds are composed of extracellular matrix (ECM) that can mimic the native tissue, creating a reparative environment to promote ECM remodeling, cell migration, proliferation, and differentiation. Reliable evidence exists throughout the literature to support the safety and effectiveness of placental-derived biomaterials in wound healing. However, differences in source (i.e., anatomical regions of the placenta), preservation techniques, decellularization status, design, and clinical application have not been fully evaluated. This review provides an overview of wound healing and placental-derived biomaterials, summarizes the clinical results of placental-derived scaffolds in wound healing, and suggests directions for future work.

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.

Preparation of human amniotic membrane for transplantation in different application areas

The human amniotic membrane (hAM) is the inner layer of the placenta and plays protective and nutritional roles for the fetus during pregnancy. It contains multiple growth factors and proteins that mediate unique regenerative properties and enhance wound healing in tissue regeneration. Due to these characteristics hAM has been successfully utilized in ophthalmology for many decades. This material has also found application in a variety of additional therapeutic areas. Particularly noteworthy are the extraordinary effects in the healing of chronic wounds and in the treatment of burns. But hAM has also been used successfully in gynecology, oral medicine, and plastic surgery and as a scaffold for in vitro cell culture approaches. This review aims to summarize the different graft preparation, preservation and storage techniques that are used and to present advantages and disadvantages of these methods. It shows the characteristics of the hAM according to the processing and storage methods used. The paper provides an overview of the currently mainly used application areas and raises new application possibilities. In addition, further preparation types like extracts, homogenates, and the resulting treatment alternatives are described.

Application of Amniotic Membrane in Skin Regeneration

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

Initial Clinical Outcomes Using Umbilical Cord-Derived Tissue Grafts to Repair Anovaginal Fistula

BACKGROUND

Perianal fistula is a debilitating disease and challenging condition to treat. Recently, the use of stem cells has been shown to improve healing of fistulas.

OBJECTIVE

The aim was to examine the use of an umbilical cord-derived stem cell graft in a pilot study as a novel scaffold/stem inlay implanted into fistula repairs for anovaginal fistula to examine healing rates.

DESIGN

This was a pilot study.

SETTINGS

This study took place in a colorectal surgery practice.

PATIENTS

Patients with anovaginal fistula consented to participate. Cryopreserved umbilical cord tissue graft with viable cells was incorporated as an inlay using a previously reported technique by the authors. Demographic data including history of previous repairs and IBD were included. All patients were followed for a minimum of 6 weeks.

MAIN OUTCOME MEASURES

The primary measures were safety and efficacy of novel stem cell graft in the treatment of anovaginal fistula.

RESULTS

From September 2017 to September 2019, 15 patients underwent anovaginal fistula repair. Three of these patients underwent a second repair, for a total of 18 repairs. No patient was intentionally diverted, but 3 patients presented for repair with a preexisting stoma. The majority of repairs were previous repair failures (12; 67%), and 7 repairs were performed on 5 patients with IBD. Median follow-up was 30 (6-104) weeks. The safety profile for cryopreserved umbilical cord tissue graft was excellent as no adverse events occurred. Overall complete healing rate was 39%, and 12 (67%) repairs resulted in improvement of symptoms.

LIMITATIONS

This was a small pilot study.

CONCLUSIONS

This is the largest series using cryopreserved umbilical cord graft for anovaginal fistula repair. The use of umbilical cord was safe and effective at closing defects. Randomized studies are necessary to determine added benefits over current standard of care. See Video Abstract at http://links.lww.com/DCR/B896 .

RESULTADOS CLNICOS INICIALES DEL USO DE INJERTOS DE TEJIDO DERIVADO DE PLACENTA PARA REPARACIN DE FSTULAS ANOVAGINALES

ANTECEDENTES:La fístula perianal es una enfermedad debilitante y una afección difícil de tratar. Recientemente, se ha demostrado que el uso de células madre mejora la curación de las fístulas.OBJETIVO:Deseamos examinar el uso de un injerto de células madre derivadas de cordón umbilical en un estudio piloto como una nueva matriz/injerto de células madre implantado en reparaciones de fístula para fístula anovaginal para examinar las tasas de curación.DISEÑO:Este fue un estudio piloto.ESCENARIO:Este estudio se llevó a cabo en una clínica de cirugía colorrectal.PACIENTES:Se obtuvo consentimiento informado de pacientes con fístula anovaginal. El injerto de tejido de cordón umbilical criopreservado con células viables se incorporó como incrustación utilizando una técnica previamente informada por los autores. Se incluyeron datos demográficos que incluían antecedentes de reparaciones previas y enfermedad inflamatoria intestinal. Todos los pacientes fueron seguidos durante un mínimo de 6 semanas.PRINCIPALES MEDIDAS DE RESULTADO:Las principales medidas fueron la seguridad y la eficacia del nuevo injerto de células madre en el tratamiento de la fístula anovaginal.RESULTADOS:Desde 9/2017-9/2019, 15 pacientes fueron sometidas a reparación de fístula anovaginal. Tres de estos pacientes fueron sometidos a una segunda reparación, para un total de 18 reparaciones. Ningún paciente fue derivado intencionalmente mientras que 3 pacientes se presentaron para reparación con un estoma preexistente. La mayoría de las reparaciones fueron fallas de reparaciones previas (12, 67%) y se realizaron siete reparaciones en 5 pacientes con enfermedad inflamatoria intestinal (EII). La mediana de seguimiento fue de 30 semanas (6-104). El perfil de seguridad del injerto de tejido de cordón umbilical criopreservado fue excelente ya que no se produjeron efectos adversos. La tasa general de curación completa fue del 39% y 12 (67%) reparaciones dieron como resultado una mejoría de los síntomas.LIMITACIONES:Este fue un pequeño estudio piloto.CONCLUSIÓNES:Ésta es la serie más grande de utilización de injerto de cordón umbilical criopreservado para la reparación de una fístula anovaginal. La utilización del cordón umbilical resultó segura y eficaz para cerrar defectos. Se necesitan estudios aleatorizados para determinar los beneficios adicionales sobre el estándar de atención actual. Consulte Video Resumen en http://links.lww.com/DCR/B896 . (Traducción-Dr. Jorge Silva Velazco ).

Clinical Outcomes of Amniotic Membrane/Umbilical Cord Particulate in Spinal Disorders: A Retrospective Study

Background

Musculoskeletal spinal disorders significantly impact patient populations from everyday workers to military soldiers. Effective treatment is critical to minimize the time between injury and returning to work and daily activities. Injection of amniotic membrane/umbilical cord (AMUC) tissue has demonstrated great potential in reducing patients' pain and has become an increasingly popular treatment option for painful orthopedic disorders.

Methods

A single-center, retrospective study was conducted on patients diagnosed with musculoskeletal spinal disorders and subsequently treated with AMUC via epidural and facet injections. Demographics and outcomes related to pain were assessed. Pain was verbally reported by the patient on a scale of 0-10 where 0 indicated no pain and 10 indicated worst imaginable pain. Complications and adverse events were also reported.

Results

A total of 52 patients (average age 40.8 ± 9.6 years) were included in the analysis with diagnoses of spondylosis (n = 44), intervertebral disc degeneration (n = 31), radiculopathy (n = 18), stenosis (n = 2), or other conditions. The cohort's average baseline pain score was 4.9 ± 2.2 with a mean duration of symptoms for 54.2 months (range: 1-300 months). After AMUC injection, pain significantly decreased to 3.4 ± 2.3 at two weeks (p < 0.0001) and 3.5 ± 2.2 at 3-4 weeks (p = 0.0023). For the mean follow-up period of 10.6 ± 5.4 weeks, pain was reduced to 2.8 ± 2.1 (p < 0.0001 vs baseline). No significant complications or adverse events were reported.

Conclusion

Use of an injectable AMUC, such as CLARIX FLO, may alleviate pain in patients with painful spinal indications of various pathologies. This study provides further evidence of its safety and efficacy in epidural and facet injections. Further studies are warranted to verify these promising results.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

Amniotic Membrane Scaffolds Support Organized Muscle Regeneration in A Murine Volumetric Muscle Defect Model

Current treatment for volumetric muscle loss is limited to muscle transfer or acellular collagen scaffold (ACS) therapies that are associated with donor site morbidity and nonfunctional fibrosis, respectively. The aim of this study is to assess the utility of amniotic membrane scaffold (AMS) for volumetric muscle loss treatment.

Methods

Murine quadriceps defects were created and randomized to three groups (n = 5/group): untreated controls, ACS, and AMS. In vivo muscle regeneration volume was quantified by MRI and microcomputed tomography. Muscle explants were analyzed using standard histology and whole-mount immunofluorescence at 8 weeks.

Results

The cross-sectional muscle regeneration ratio was 0.64 ± 0.3 for AMS, 0.48 ± 0.07 for ACS, and 0.4 0 ± 0.03 for controls as assessed by MRI (P = 0.09) and 0.61 ± 0.28 for AMS, 0.50 ± 0.06 for ACS, and 0.43 ± 0.04 for controls as assessed by microcomputed tomography (P = 0.2). Histologically, AMS demonstrated significantly higher cellular density (900 ± 2 70 nuclei/high powered field) than ACS (210 ± 36) and control (130 ± 4) groups (P = 0.05). Immunofluorescence for laminin (AMS 623 ± 11 versus ACS 339 ± 3 versus control 115 ± 7; P < 0.01) and myosin heavy chain (AMS 509 ± 7 versus ACS 288 ± 5 versus control 84 ± 5; P = 0.03) indicated greater organized muscle fiber formation with AMS.

Conclusion

AMS mediated muscle healing was characterized by increased cellular infiltration and organized muscle formation when compared with controls and ACS.

Pilot study of a glue-less, suture-less amniotic membrane for pterygium excision

PURPOSE

Pterygium is a non-cancerous, fibrovascular growth of the bulbar conjunctiva that can cause visual disturbance, ocular pain, and cosmetic concerns. Surgical management is required in certain cases, which consists of excising the pterygium and associated Tenon's, then overlaying the bare sclera with an autograft or amniotic membrane using glue or sutures. The purpose of this study is to assess outcomes of pterygium repair using a newly developed self-adhesive amniotic membrane that does not require glue or sutures for fixation.

METHODS

Chart review of pterygium excision using a new self-adhesive amniotic membrane from a single surgical practice from 2012-2018. Descriptive statistics from 51 primary cases of pterygium excision were included.

RESULTS

Pterygium recurrence occurred in 3 of the 51 self-adhesive amniotic membrane cases studied, resulting in a recurrence rate of 5.9%. Pterygium excision with the self-adhesive amniotic membrane had high rate of pyogenic granuloma formation of 27%. Self-adhesive amniotic membranes were found to perform comparably to more widely used techniques for pterygium excision, namely amniotic membranes and conjunctival autographs with glue or sutures. However, the self-adhesive grafts are associated with substantially more pyogenic granuloma formation.

CONCLUSION

Self-adhesive amniotic membranes offer comparable efficacy for preventing pterygium recurrence in comparison to other amniotic membranes and the conjunctival autograft. The incidence of pyogenic granuloma formation is higher in self-adhesive grafts compared to other widely used options.

Use of Cryopreserved Human Umbilical Cord for Wound Healing of the Nose after Mohs Micrographic Surgery

Mohs micrographic surgery (MMS) is microscopically controlled surgery used to treat common skin cancers including primary and recurrent basal cell carcinoma (BCC). Unfortunately, postexcisional MMS wounds, particularly down to periosteum or perichondrium, are susceptible to potentially poor cosmetic outcomes, including wound contracture, hypopigmentation and hyperpigmentation, and contour mismatch. Herein, we report a case to show how adjunctive application of human cryopreserved umbilical cord tissue (UC) may expedite wound healing with improved aesthetic outcome. A 53-year-old Caucasian female with a slight natural lifelong depression between her lower nasal tip alar cartilages suffered from a recurrent BCC mostly of the right nasal tip. After MMS down to the perichondrium, UC was immediately applied to the surgical wound. Prolific granulation developed at one week followed by rapid reepithelialization at two weeks. This resulted in complete closure at four weeks and a pleasing aesthetic nasal tip at 6 weeks. At one year and 5 months after MMS, there continued to be excellent aesthetic outcome as evaluated by surrounding skin color, contour, and texture with a minimal residual scar. In this case, the adjunctive use of cryopreserved human UC accelerated the postsurgical MMS wound healing in the nasal tip particularly in patients with significant comorbidities or are unwilling to undergo a formal surgical reconstruction. This encouraging finding warrants further controlled studies in the future.

Human Amnion/Chorion Membrane May Reduce Transient Recurrent Laryngeal Nerve Injury During Thyroid Surgery

Recurrent laryngeal nerve (RLN) damage is a significant and prevalent complication of thyroid surgery. Based on the beneficial role of a human amnion/chorion membrane (HACM) allograft in wound management and nerve regeneration, we investigated whether placement of a commercially available HACM allograft on dissected RLN could reduce the occurrence and/or duration of RLN injury during thyroidectomy. Among 67 patients undergoing thyroidectomy, 100 at-risk nerves (exposure of at least 3 cm of RLN) received intraoperative placement of HACM; 205 at-risk RLNs without HACM in 134 matched patients served as controls. Patient-reported vocal analysis, physician-assessed vocal analysis, and laryngoscopic assessment of vocal-fold dysfunction were performed before and after surgery. At 24 h after surgery, 17 patients in the control group (12.5%) had documented voice changes; these changes persisted for at least 3 weeks in seven patients (5%). Only one patient (1.5%) in the HACM group had vocal changes at 24 h after surgery, which resolved within 1 week (P < 0.01). Intraoperative placement of the HACM allograft over at-risk RLNs during thyroidectomy may reduce the incidence, severity, and/or duration of intraoperative RLN injury, which could address a significant complication of head and neck surgery. A larger prospectively designed clinical study is warranted to further investigate a possible benefit of the HACM allograft in thyroid surgery and to begin to understand the mechanisms through which a clinical benefit might be mediated.

Allografts for Skin Closure during In Utero Spina Bifida Repair in a Sheep Model

OBJECTIVES

Use of off-label tissue graft materials, such as acellular dermal matrix (ADM), for in utero repair of severe spina bifida (SB), where primary skin layer closure is not possible, is associated with poor neurological outcomes. The cryopreserved human umbilical cord (HUC) patch has regenerative, anti-inflammatory, and anti-scarring properties, and provides watertight SB repair. We tested the hypothesis that the HUC is a superior skin patch to ADM for reducing inflammation at the repair site and preserving spinal cord function.

METHODS

In timed-pregnant ewes with twins, on gestational day (GD) 75, spina bifida was created without a myelotomy (functional model). On GD 95, repair was performed using HUC vs. ADM patches (randomly assigned) by suturing them to the skin edges. Additionally, full thickness skin closure as a primary skin closure (PSC) served as a positive control. Delivery was performed on GD 140, followed by blinded to treatment neurological assessments of the lambs using the Texas Spinal Cord Injury Scale (TSCIS) for gait, proprioception, and nociception. Lambs without spina bifida were used as controls (CTL). Ex vivo magnetic resonance imaging of spines at the repair site were performed, followed by quantitative pathological assessments. Histological assessments (blinded) included Masson's trichrome, and immunofluorescence for myeloperoxidase (MPO; neutrophils) and for reactive astrocytes (inflammation) by co-staining vimentin and GFAP.

RESULTS

The combined hind limbs' TSCIS was significantly higher in the HUC group than in ADM and PSC groups, p = 0.007. Both ADM and PSC groups exhibited loss of proprioception and mild to moderate ataxia compared to controls. MRI showed increased pathological findings in the PSC group when compared to the HUC group, p = 0.045. Histologically, the meningeal layer was thickened (inflammation) by 2-3 fold in ADM and PSC groups when compared to HUC and CTL groups, p = 0.01. There was lower MPO positive cells in the HUC group than in the ADM group, p = 0.018. Posterior column astrocyte activation was increased in ADM and PSC lambs compared to HUC lambs, p = 0.03.

CONCLUSION

The HUC as a skin patch for in utero spina bifida repair preserves spinal cord function by reducing underlying inflammation when compared to ADM.

Cell-free stem cell-derived extract formulation for treatment of knee osteoarthritis: study protocol for a preliminary non-randomized, open-label, multi-center feasibility and safety study

Background

Musculoskeletal conditions are highly prevalent, and knee OA is most common. Current treatment modalities have limitations and either fail to solve the underlying pathophysiology or are highly invasive. To address these limitations, attention has focused on the use of biologics. The efficacy of these devices is attributed to presence of growth factors (GFs), cytokines (CKs), and extracellular vesicles (EVs). With this in mind, we formulated a novel cell-free stem cell-derived extract (CCM) from human progenitor endothelial stem cells (hPESCs). A preliminary study demonstrated the presence of essential components of regenerative medicine, namely GFs, CKs, and EVs, including exosomes, in CCM. The proposed study aims to evaluate the safety and efficacy of intraarticular injection of the novel cell-free stem cell-derived extract (CCM) for the treatment of knee OA.

Methods and analysis

This is a non-randomized, open-label, multi-center, prospective study in which the safety and efficacy of intraarticular CCM in patients suffering from grade II/III knee OA will be evaluated. Up to 20 patients with grade II/III OA who meet the inclusion and exclusion criteria will be consented and screened to recruit 12 patients to receive treatment. The study will be conducted at up to 2 sites within the USA, and the 12 participants will be followed for 24 months. The study participants will be monitored for adverse reactions and assessed using Numeric Pain Rating Scale (NPRS), Patient-Reported Outcomes Measurement Information System (PROMIS) Score, Knee Injury and Osteoarthritis Outcome Score Jr. (KOOS Jr.), 36-ietm short form survey (SF-36), Single Assessment Numeric Evaluation (SANE), physical exams, plain radiography, and magnetic resonance imaging (MRI) with Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score for improvements in pain, function, satisfaction, and cartilage regeneration.

Discussion

This prospective study will provide valuable information into the safety and efficacy of intraarticular administration of cell-free stem cell-derived extract (CCM) in patients suffering with grade II/III knee OA. The outcomes from this initial study of novel CCM will lay the foundation for a larger randomized, placebo-controlled, multi-center clinical trial of intraarticular CCM for symptomatic knee OA.

Trial registration

Registered on July 21, 2021. ClinicalTrials.gov NCT04971798

Concentrations of tissue inhibitor of matrix metalloproteinase-1 and hyaluronic acid in canine amniotic membranes cryopreserved for different time points and its effects in dogs with complicated corneal ulcers

OBJECTIVES

To determine the concentrations of total protein (TP), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and hyaluronic acid (HA) in amniotic membranes (AMs) harvested from placentas of bitches of different ages and cryopreserved for different time points. The outcomes of complicated corneal defects of dogs repaired with AMs stored for the same time points were also evaluated.

PROCEDURES

Ten cryopreserved canine AMs were stored for short term (2-50 days), middle term (92-210 days), or long term (256-357 days). TP was quantified by Bradford's test, whereas TIMP-1 and HA were quantified by ELISA. Twenty-one dogs that had an AM transplantation to restore deep or perforating corneal wounds were selected.

RESULTS

TIMP-1 levels were lower in AMs cryopreserved for middle term (p = .02) and long term (p = .0009), when compared to AMs stored for short term. TP (p = .39) and HA (p = .18) concentrations in AMs did not differ among the storage time. TIMP-1 concentration in AMs correlated with storage time (R = -.65, p < .0001), while TP (R = -.33, p = .07) and HA concentrations did not (R = -.15, p = .41). The age of donors did not correlate with the components evaluated in the AMs. Corneal defects repaired with AMs stored for short term healed sooner than the ones repaired with AMs stored for middle (p < .01) and long term (p = .02). Additionally, TIMP-1 levels in AMs correlated negatively with the epithelization time (R = -.62, p = .002). Graft opacity was severe in 55% of cases. However, the HA levels in AMs correlated negatively with the opacification score (R = -.47, p = .03). Vision was observed in more patients who presented deep ulcers and descemetoceles, than in the ones with perforations (p = .004).

CONCLUSIONS

TIMP-1 concentration in canine AMs significantly decreased over a year storage time, while TP and HA concentrations did not change during the same period. The age of donors did not correlate with the components evaluated in the AMs. Complicated corneal defects repaired with AMs cryopreserved for short term healed sooner and tended to be less opaque; however, satisfactory to optimal outcomes were achieved even in the eyes repaired with AMs stored for up to a year.

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.

Arthroscopic Repair of Talar Osteochondral Defects With Umbilical Cord Allograft: A Prospective, Single-Center, Pilot Study

Cryopreserved umbilical cord (UC) allografts have been shown to promote postoperative wound healing by suppressing inflammation and reducing scar formation. The purpose of this study was to determine whether adjunctive use of UC may improve clinical and functional outcomes following arthroscopic repair of talar osteochondral defects (OCDs). A total of 10 patients with talar OCDs that failed nonoperative treatment were enrolled in this single-center, prospective, pilot study. Clinical and functional outcomes were assessed using the Ankle Osteoarthritis Scale (AOS), Foot and Ankle Ability Measure, and Visual Analog Scale (VAS) pain scale at 6, 12, 24, and 52 weeks postoperatively. Results showed a consistent improvement in all outcome measures. VAS pain scores significantly improved from 4.2 ± 2.9 to 1.3 ± 2.2 at 52 weeks (P = .015). AOS difficulty and pain scores nonsignificantly improved from 27.0 ± 24.6 and 33.1 ± 28.3 at baseline to 15.3 ± 20.5 and 14.8 ± 18.7 at 52 weeks, respectively. The clinical outcome improvement was accompanied by significant reduction in OCD defect size and associated bone marrow lesion. This pilot study suggests that adjunctive use of UC during arthroscopic repair of talar OCD may lead to clinical and functional improvement.Levels of Evidence: Level II: Prospective Cohort Study.

Prenatal Neural Tube Anomalies: A Decade of Intrauterine Stem Cell Transplantation Using Advanced Tissue Engineering Methods

Neural tube defects (NTDs) are among the most common congenital defects during neurulation. Spina bifida is a type of NTD that can occur in different forms. Since myelomeningocele (MMC) is the most severe form of spina bifida, finding a satisfactory treatment for MMC is a gold standard for the treatment of spina bifida. The Management of Myelomeningocele Study (MOMS) demonstrated that intrauterine treatment of spina bifida could ameliorate the complications associated with spina bifida and would also reduce the placement of ventriculoperitoneal (VP) shunt by 50%. Recently developed tissue engineering (TE) approaches using scaffolds, stem cells, and growth factors allow treatment of the fetus with minimally invasive methods and promising outcomes. The application of novel patches with appropriate stem cells and growth factors leads to better coverage of the defect with fewer complications. These approaches with less invasive surgical procedures, even in animal models with similar characteristics as the human MMC defect, paves the way for the modern application of less invasive surgical methods. Significantly, the early detection of these problems and applying these approaches can increase the potential efficacy of MMC treatment with fewer complications. However, further studies should be conducted to find the most suitable scaffolds and stem cells, and their application should be evaluated in animal models. This review intends to discuss advanced TE methods for treating MMC and recent successes in increasing the efficacy of the treatment.

Nano-Scale Modifications of Amniotic Membrane Induced by UV and Antibiotic Treatment: Histological, AFM and FTIR Spectroscopy Evidence

The efficiency of amniotic membrane (AM) transplantation in different types of ocular surface disorders is due to its outstanding properties such as antifibrotic, antibacterial, anti-inflammatory and antiangiogenic, working as a versatile scaffold to promote corneal tissue epithelialization. A proper preparation, preservation and clinical application are crucial for the best outcomes in the treatment of different severe ocular disorders, taking into account its fragility. In this context, by combining high-sensitivity tools such as atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy with histological and immunohistochemical examination, we aimed to investigate the ultrastructural modifications of the amniotic membrane (AM) upon UV exposure and/or antibiotic treatment, with relevance for clinical applications in ocular surface surgery. From the morphological point of view, we noticed a loss of cuboidal cells in the basal membrane, accompanied by the splitting of collagen fibers upon UV and/or gentamicin treatment, while structural alteration of proteins was evidenced by the FTIR quantitative analysis of the secondary structure. A decrease in α-helix and β-sheet content, accompanied by increased content in less ordered structures (turns, random and side chains), was noticed after all the treatments. At the nano-scale, AFM details showed modifications of collagen fibrils in terms of their thickness and network compaction upon gentamicin and/or UV treatment. The enzymatic digestion assay demonstrated that UV exposure significantly reduces the degradation rate of the AM, while gentamicin treatment promotes an accelerated enzymatic digestion upon UV exposure. In order to highlight the clinical impact of the research, a clinical case is presented showing the relevance of amniotic membrane transplantation in pterygium surgery.

Injectable Amniotic Membrane/Umbilical Cord Particulate for Knee Osteoarthritis: A Prospective, Single-Center Pilot Study

OBJECTIVE

To evaluate the short-term safety and effectiveness of amniotic membrane/umbilical cord particulate (AMUC) in managing pain in patients with various severities of knee osteoarthritis (OA).

DESIGN

Single-center, prospective, investigator-initiated pilot study.

SETTING

Private practice.

SUBJECTS

A total of 20 knee OA patients aged ≥18 years were enrolled with pain >40 mm, as determined by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)-A.

METHODS

Patients received an ultrasound-guided, intra-articular injection of 50 mg of AMUC particulate reconstituted in 2 mL of preservative-free saline. All patients were then monitored at six weeks, 12 weeks, and 24 weeks postinjection. Patients who did not show >30% reduction in pain received a second injection of AMUC at six weeks. WOMAC, Patient Global Assessment, medication usage, and magnetic resonance imaging (MRI) were assessed.

RESULTS

Knee OA pain significantly decreased from 74.3 ± 17.2 at baseline to 45.0 ± 25.4 at six weeks (P < 0.01), 35.4 ± 26.6 at 12 weeks (P < 0.001), and 37.4 ± 26.7 at 24 weeks (P < 0.001). This pain reduction was associated with a significant improvement in physical function (WOMAC-C) at all time points (P < 0.05) and stiffness (WOMAC-B) at 12 weeks (P = 0.01). Eleven patients received a second injection, which was significantly correlated with body mass index >30 kg/m2 (P = 0.025). MRI evaluation of the overall population revealed an improvement in the severity of bone marrow lesions in seven patients. No adverse events were observed.

CONCLUSIONS

AMUC particulate injection relieved pain and improved physical function in patients with symptomatic knee OA.

Amniotic membrane allografts maintain key biological properties post SCCO2 and lyophilization processing

Amniotic membrane (AM) has been shown to enhance corneal wound healing due to the abundance of growth factors, cytokines, and extracellular matrix (ECM) proteins inherent to the tissue. As such, AM has garnered widespread clinical utility as a biological dressing for a number of ophthalmic and soft tissue applications. The preparation, sterilization, and storage procedures used to manufacture AM grafts are extremely important for the conservation of inherent biological components within the membrane. Current processing techniques use harsh chemicals and sterilization agents that can compromise the fundamental wound healing properties of AM. Furthermore, commercially available cryopreserved AM products require specific storage conditions (e.g., ultra-low freezers) thereby limiting their clinical availability in austere environments. Supercritical carbon dioxide (SCCO₂) technology allows for the sterilization of biological tissues without the resulting degradation of integral ECM proteins and other factors often seen with current tissue sterilization processes. With this study we demonstrate that lyophilized AM, sterilized using SCCO₂, maintains similar biochemical properties and biocompatibility as that of commercially available AM products requiring specialized cold storage conditions.

Niche regulation of limbal epithelial stem cells: HC-HA/PTX3 as surrogate matrix niche

Homeostasis of the corneal epithelium is ultimately maintained by stem cells that reside in a specialized microenvironment within the corneal limbus termed palisades of Vogt. This limbal niche nourishes, protects, and regulates quiescence, self-renewal, and fate decision of limbal epithelial stem/progenitor cells (LEPCs) toward corneal epithelial differentiation. This review focuses on our current understanding of the mechanism by which limbal (stromal) niche cells (LNCs) regulate the aforementioned functions of LEPCs. Based on our discovery and characterization of a unique extracellular matrix termed HC-HA/PTX3 (Heavy chain (HC1)-hyaluronan (HA)/pentraxin 3 (PTX3) complex, "-" denotes covalent linkage; "/" denotes non-covalent binding) in the birth tissue, i.e., amniotic membrane and umbilical cord, we put forth a new paradigm that HC-HA/PTX3 serves as a surrogate matrix niche by maintaining the in vivo nuclear Pax6+ neural crest progenitor phenotype to support quiescence and self-renewal but prevent corneal fate decision of LEPCs. This new paradigm helps explain how limbal stem cell deficiency (LSCD) develops in aniridia due to Pax6-haplotype deficiency and further explains why transplantation of HC-HA/PTX3-containing amniotic membrane prevents LSCD in acute chemical burns and Stevens Johnson syndrome, augments the success of autologous LEPCs transplantation in patients suffering from partial or total LSCD, and assists ex vivo expansion (engineering) of a graft containing LEPCs. We thus envisage that this new paradigm based on regenerative matrix HC-HA/PTX3 as a surrogate niche can set a new standard for regenerative medicine in and beyond ophthalmology.

Amniotic Membrane Transplantation in Ophthalmology: An Updated Perspective

Aim

The aim of this paper is to provide a succinct literature review of the different clinical applications for AMT usage in an ophthalmic setting, ranging from commonly used applications to less mainstream approaches. The hope is that this review enables the reader to have a better understanding of the biological properties of amnion as well as the indications and scenarios in which AMT can be used, whilst presenting relevant evidence from within the literature which may be of interest. We also provide an update on the methods of preservation of amniotic membrane and the application methodologies.

Methods

Literature search. A PubMed search was performed using the search terms “amniotic membrane transplant”, “amnion AND cornea”, amnion AND ophthalmology”, “amnion AND ocular surface” and “Amnion AND eye”. A full review of the literature using the PubMed database was conducted up until 01/05/20. The articles used were written in English, with all articles accessed in full. Both review articles and original articles were used for this review. All full publications related to ophthalmology were considered.

Amniotic Umbilical Cord Particulate for Discogenic Pain

Context

Discogenic low back pain is the most common type of low back pain and is a major cause of morbidity worldwide. Current nonoperative treatment options are limited in efficacy and lack evidence of long-term pain relief; thus, there is an unmet clinical need for an effective treatment for patients with discogenic pain. Amniotic membrane and umbilical cord (AMUC) particulate may be useful in relieving pain and inhibiting the degenerative cascade in patients with discogenic pain by reducing inflammation.

Objective

To evaluate the effectiveness of AMUC particulate for discogenic pain.

Methods

Six months of conservative therapy failed in patients who had discogenic pain confirmed by magnetic resonance imaging and provocative discography. They subsequently received intradiskal injection of 50 to 100 mg of AMUC particulate for cervical, lumbar, and lumbosacral disks.

Results

A total of 11 patients with 20 disks were included. Before treatment, all patients reported severe pain, and 10 patients took opioids daily. After treatment, the median reported pain relief was 40%, 50%, and 75% at 1-month (n=6), 3 months (n=8), and 6 months (n=5), respectively. Complete pain relief was noted in 1 patient; however, 2 patients (18%) reported no pain relief at 1 and 3 months. No adverse events, repeated procedures, or complications occurred.

Conclusion

This preliminary evidence suggests that a single intradiskal injection of AMUC particulate is safe and may provide symptomatic pain relief in some patients with discogenic pain.

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.

A Novel Use of Umbilical Perinatal Graft in Subungual Exostosis Resection

Nail pathologies have a broad range of origin and may sometimes be complicated in presentation or clinical course, specifically when the pathology remains recalcitrant after treatment. In this case report we discuss a pathologic disorder that was initially misdiagnosed as a pyogenic granuloma surrounding an ingrown nail but was later found to be a benign neoplastic bone growth, Dupuytren exostosis, also known as a subungual exostosis. Operative treatment was deemed appropriate for the patient, and the exostosis was resected, leaving a soft-tissue void at the distal toe. The remaining void was filled with a perinatal graft, the use of which has been deemed effective anecdotally in both chronic and acute lower-extremity wounds but has not been widely discussed in the lower-extremity literature. This graft was placed to aid in wound healing over a potentially difficult wound bed. As amniotic, chorionic, and umbilical grafts become more prevalent in lower-extremity surgery, its antitumor effects should be further explored and published. This is the first case report, to our knowledge, of the successful use of a perinatal graft in the setting of a bone tumor, and it demonstrates that certain benign neoplasms can be treated with resection and placement of a perinatal graft while helping to prevent chronic wounds at surgical sites.

Repeated Freezing Procedures Preserve Structural and Functional Properties of Amniotic Membrane for Application in Ophthalmology

For decades, the unique regenerative properties of the human amniotic membrane (hAM) have been successfully utilized in ophthalmology. As a directly applied biomaterial, the hAM should be available in a ready to use manner in clinical settings. However, an extended period of time is obligatory for performing quality and safety tests. Hence, the low temperature storage of the hAM is a virtually inevitable step in the chain from donor retrieval to patient application. At the same time, the impact of subzero temperatures carries an increased risk of irreversible alterations of the structure and composition of biological objects. In the present study, we performed a comprehensive analysis of the hAM as a medicinal product; this is intended for a novel strategy of application in ophthalmology requiring a GMP production protocol including double freezing–thawing cycles. We compared clinically relevant parameters, such as levels of growth factors and extracellular matrix proteins content, morphology, ultrastructure and mechanical properties, before and after one and two freezing cycles. It was found that epidermal growth factor (EGF), transforming growth factor beta 1 (TGF-β1), hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), hyaluronic acid, and laminin could be detected in all studied conditions without significant differences. Additionally, histological and ultrastructure analysis, as well as transparency and mechanical tests, demonstrated that properties of the hAM required to support therapeutic efficacy in ophthalmology are not impaired by dual freezing.

Successful treatment of painful chronic wounds with amniotic and umbilical cord tissue: A case series

Patients with chronic wounds may experience persistent, debilitating pain that cannot be adequately managed with analgesics and that negatively impacts their quality of life. In this case series, three painful chronic and ischemic wounds that were caused by polyarteritis nodosa vasculitis (n = 1) and peripheral arterial disease (PAD) (n = 2) were successfully treated with cryopreserved umbilical cord tissue and/or amniotic membrane and umbilical cord particulate, resulting in notable reduction in pain within 7 days followed by expedited wound closure. No adverse events related to these tissue products were observed. These preliminary data demonstrate its safety and efficacy in reducing pain and promoting wound healing in painful chronic and ischemic wounds.

Progesterone Prolongs Viability and Anti-inflammatory Functions of Explanted Preterm Ovine Amniotic Membrane

Amniotic membrane (AM) is considered an important medical device with many applications in regenerative medicine. The therapeutic properties of AM are due to its resistant extracellular matrix and to the large number of bioactive molecules released by its cells. An important goal that still remains to be achieved is the identification of cultural and preservation protocols able to maintain in time the membrane morphology and the biological properties of its cells. Recently, our research group demonstrated that progesterone (P₄) is crucial in preventing the loss of the epithelial phenotype of amniotic epithelial cells in vitro. Followed by this premise, it has been evaluated whether P₄ may also affect AM properties in a short-term culture. Results confirm that P₄ preserves AM integrity and architecture with respect to untreated AM, which showed alterations in morphology. Transmission electron microscopy (TEM) analyses demonstrate that P₄ also maintains unaltered cell-cell junctions, nuclear status, and intracellular organelles. On the contrary, an untreated AM experienced an extensive cell death and a strong reduction of immunomodulatory properties, measured in terms of anti-inflammatory cytokine expression and secretion. Overall, these results could open to new strategies to ameliorate the protocols for cryopreservation and tissue culture, which represent preliminary stages of AM application in regenerative medicine.

Cryopreserved human umbilical cord versus acellular dermal matrix patches for in utero fetal spina bifida repair in a pregnant rat model

OBJECTIVE

Despite significant improvement in spinal cord function after in utero spina bifida (SB) repair compared with traditional postnatal repair, over half of the children who undergo this procedure do not benefit completely. This lack of benefit has been attributed to closure methods of the defect, with subsequent spinal cord tethering at the repair site. Hence, a regenerative patch or material with antiinflammatory and anti-scarring properties may alleviate comorbidities with improved outcomes. The authors' primary objective was therefore to compare cryopreserved human umbilical cord (HUC) versus acellular dermal matrix (ADM) patches for regenerative repair of in utero SB lesions in an animal model.

METHODS

In vivo studies were conducted in retinoic acid-induced SB defects in fetuses of Sprague-Dawley rats. HUC or ADM patches were sutured over the SB defects at a gestational age of 20 days. Repaired SB defect tissues were harvested after 48-52 hours. Tissue sections were immunofluorescently stained for the presence of neutrophils, macrophages, keratinocytes, meningeal cells, and astrocytes and for any associated apoptosis. In vitro meningeal or keratinocyte cell coculture experiments with the ADM and HUC patches were performed. All experiments were scored quantitatively in a blinded manner.

RESULTS

Neutrophil counts and apoptotic cells were lower in the HUC-based repair group (n = 8) than in the ADM patch repair group (n = 7). In the HUC patch repair group, keratinocytes were present on the outer surface of the patch, meningeal cells were present on the inner surface of the patch adjacent to the neural placode, and astrocytes were noted to be absent. In the ADM patch repair group, all 3 cell types were present on both surfaces of the patch. In vitro studies showed that human meningeal cells grew preferentially on the mesenchymal side of the HUC patch, whereas keratinocytes showed tropism for the epithelial side, suggesting an inherent HUC-based cell polarity. In contrast, the ADM patch studies showed no polarity and decreased cellular infiltration.

CONCLUSIONS

The HUC patch demonstrated reduced acute inflammation and apoptosis together with superior organization in regenerative cellular growth when compared with the ADM patch, and is therefore likely the better patch material for in utero SB defect repair. These properties may make the HUC biomaterial useful as a "meningeal patch" during spinal cord surgeries, thereby potentially reducing tethering and improving on spinal cord function.

Basic science review of birth tissue uses in ophthalmology

The birth tissue is predominantly comprised of amniotic membrane (AM) and umbilical cord (UC), which share the same cell origin as the fetus. These versatile biological tissues have been used to treat a wide range of conjunctival and corneal conditions since 1940. The therapeutic benefits of the birth tissue stem from its anti-inflammatory and anti-scarring properties that orchestrate regenerative healing. Although the birth tissue also contains many cytokines, growth factors, and proteins, the heavy chain 1-hyaluronic acid/pentraxin 3 (HC-HA/PTX3) matrix has been identified to be a major active tissue component responsible for AM/UC's multifactorial therapeutic actions. HC-HA/PTX3 complex is abundantly present in fresh and cryopreserved AM/UC, but not in dehydrated tissue. In this review, we discuss the tissue anatomy, the molecular mechanism of action based on HC-HA/ PTX3 to explain their therapeutic potentials, and the various forms available in ophthalmology.

Histological Equivalence of a Hyper-Dry Amniotic Membrane and the Ambio2TM after Implantation in the Rabbit Conjunctiva

PURPOSE

A hyper-dry amniotic membrane (HDAM) has been used clinically for ocular surface reconstruction, but sufficient evidence of the histological dynamics and long-term safety have not been obtained. We examined the histological changes in an HDAM after its subconjunctival implantation in rabbit eyes, and we compared these changes to those in the Ambio2TM Amniotic Membrane Graft (IOP Ophthalmics, Costa Mesa, CA, USA) after the same surgery.

DESIGN

A prospective controlled animal study.

METHODS

We used 27 rabbits in two groups: the HDAM group (36 eyes of 18 rabbits) and the Ambio2 group (18 eyes of 9 rabbits). The HDAM or Ambio2 was transplanted on the bare sclera and covered with a conjunctival autograft. The histological changes were determined by evaluating the amniotic membrane graft, inflammatory cells, and foreign body granulomas in hematoxylin/eosin-stained sections at 30 days, 93 days, and 184 days postoperatively.

RESULTS

In all cases, the amniotic membrane graft was completely absorbed without scarring at 184 days postoperatively. The positive rate of inflammatory cells was significantly higher in the HDAM group compared to the Ambio2 group at 30 days postoperatively. The positive rate of foreign body granulomas decreased with time, with no significant difference between the two groups.

CONCLUSIONS

Both the HDAM and Ambio2 were completely absorbed without scarring within 6 months after surgery. The two types of membranes showed histologically equivalent responses. Translational Relevance: Since the HDAM was completely absorbed without scarring within 6 months after surgery, we could confirm its long-term safety.

Cryopreserved amniotic membrane and umbilical cord for a radiation-induced wound with exposed dura: a case report

An 87-year old male received surgical excision of scalp melanoma and subsequent radiotherapy due to metastasis to the skull. A radiation-induced wound developed with osteoradionecrosis that required necrotic bone excision resulting in a 7.5x8.5cm wound over the exposed dura, which remained non-healing despite many attempts by local wound care management. Due to the refractory nature of the wound, strips of cryopreserved umbilical cord (cUC) allograft were applied over the exposed dura resulting in significant vascular granulation tissue formation in the central wound bed within four weeks. Re-epithelialisation around the wound perimeter was further promoted by injection of particulate amniotic membrane umbilical cord matrix (AMUC) at the 16th week, and completed by another application of cUC strips and injection of AMUC proximal to the necrotic bone at the 21st week. Vascularisation of the necrotic bone was further promoted by application of cUC and AMUC injection directly into the bony margins at 29 weeks and 34 weeks, respectively, followed by application with an AMUC-hydrogel paste, applied four times over an eight week interval. By 96 weeks, healthy re-epithelialised tissue had formed under the necrotic bony margins. This report highlights the unique regenerative capabilities of cUC and AMUC in promoting wound healing over exposed dura in a long-standing full-thickness, radiation-induced scalp and skull wound.

A cellular and proteomic approach to assess proteins extracted from cryopreserved human amnion in the cultivation of corneal stromal keratocytes for stromal cell therapy

Background

Human corneal stromal keratocytes propagated in culture media supplemented with human amnion extract (AME) can correct early corneal haze in an animal model. Clinical application of cultivated keratocytes is limited by infectious disease screening before amnion products can be used in humans. It remains unclear if AME from cryopreserved versus fresh human amnion can support human keratocyte propagation, and which components of the extract promote keratocyte growth.

Methods

Three placentas were collected for the preparation of fresh and cryopreserved amnion tissues followed by homogenization and protein extraction. AME protein profiles were studied using isobaric tagging for relative and absolute quantitation (iTRAQ) proteomics. Enriched gene ontology (GO) terms and functional classes were identified. Primary human keratocytes from 4 donor corneas were cultured in media supplemented with fresh AME (F-AME) or cryopreserved AME (C-AME). Cell viability, proliferation and keratocyte marker expression were examined by confocal immunofluorescence and flow cytometry.

Results

AME proteomics revealed 1385 proteins with similar expression levels (between 0.5- and 2-fold) between F- and C-AME, while 286 proteins were reduced (less than 0.5-fold) in C-AME. Enriched GO term and biological pathway analysis showed that those proteins with comparable expression between F-AME and C-AME were involved in cell metabolism, epithelial-mesenchymal transition, focal adhesion, cell-extracellular matrix interaction, cell stress regulation and complement cascades. Human corneal stromal keratocytes cultured with F-AME or C-AME showed similar morphology and viability, while cell proliferation was mildly suppressed with C-AME (P > 0.05). Expression of aldehyde dehydrogenase 3A1 (ALDH3A1) and CD34 was similar in both cultures.

Conclusion

AME from cryopreserved amnion had limited influence on keratocyte culture. It is feasible to use protein extract from cryopreserved amnion to propagate human keratocytes for potential translational applications.

How preparation and preservation procedures affect the properties of amniotic membrane? How safe are the procedures?

Human amniotic membrane (AM) has been widely used for tissue engineering and regenerative medicine applications. AM has many favorable characteristics such as high biocompatibility, antibacterial activity, anti-scarring property, immunomodulatory effects, anti-cancer behavior and contains several growth factors that make it an excellent natural candidate for wound healing. To date, various methods have been developed to prepare, preserve, cross-link and sterilize the AM. These methods remarkably affect the morphological, physico-chemical and biological properties of AM. Optimization of an effective and safe method for preparation and preservation of AM for a specific application is critical. In this review, the isolation, different methods of preparation, preservation, cross-linking and sterilization as well as their effects on properties of AM are well discussed. For each section, at least one effective and safe protocol is described in detail.

An open-label trial of cryopreserved human umbilical cord in the treatment of complex diabetic foot ulcers complicated by osteomyelitis

Clinical trials of potential new therapies for diabetic foot ulcers rarely enroll patients whose wounds extend to muscle, fascia, or bone with clinical and radiographic evidence of underlying osteomyelitis. An open‐label, multicenter trial of cryopreserved human umbilical cord (TTAX01) was undertaken in 32 subjects presenting with such complex wounds with a mean duration of 6.1 ± 9.0 (range: 0.2–47.1) months and wound area at screening of 3.8 ± 2.9 (range: 1.0–9.6) cm². Aggressive surgical debridement at baseline resulted in 17 minor amputations and an increase in mean wound area to 7.4 ± 5.8 (range: 1.1–28.6) cm². All subjects were placed on systemic antibiotics for at least 6 weeks in conjunction with baseline application of TTAX01. Repeat applications were made at no less than 4‐week intervals over the 16‐week trial. Initial closure occurred in 18 of 32 (56%) wounds, with 16 (50%) of these having confirmed closure in 16 weeks with a median of one‐product application. Cases with biopsy confirmed osteomyelitis (n = 20) showed initial closure in 12 (60%) wounds and confirmed closure in 10 (50%) wounds. Four of the five ulcers presenting as recurrences experienced confirmed closure. Mean overall time to healing was 12.8 ± 4.3 weeks. Mean wound area reduction from baseline was 91% for all wounds. Of the 16 wounds without confirmed closure during the 16‐week treatment period, five (31.3%) achieved 99–100% wound area reduction by their final visit. The product was well tolerated. Two minor amputations occurred during the study period due to recurrent or persistent osteomyelitis; however, there were no major amputations.

Use of cryopreserved umbilical cord with negative pressure wound therapy for complex diabetic ulcers with osteomyelitis

OBJECTIVE

The objective of this study was to evaluate the combined use of cryopreserved human umbilical cord (cUC) allograft and negative pressure wound therapy (NPWT) in treating complex diabetic foot ulcers (DFUs) with bone exposure and osteomyelitis. These types of wound are known to carry a high morbidity and mortality.

METHODS

A single-center, retrospective chart review was performed to assess the efficacy of the combined use of cUC with NPWT, by the same surgeon, to help promote the closure of complex DFUs presenting with biopsy-proven osteomyelitis. Change in wound size and volume, time to wound closure, and number of cUC applications were assessed.

RESULTS

We identified of 14 wounds in 13 patients, with an average initial wound area of (mean±standard devaition) 33.2±21.7cm² and wound volume of 52±26.2cm³. All achieved complete re-epithelialisation with an average time to closure of 24.0±10.9 weeks, using between 2-5 cUC applications. No adverse events were noted and none of the wounds required limb amputation during the a follow-up of 24 months for each patient.

CONCLUSION

The results suggest that combined use of cUC and NPWT may be effective in improving the healing of complex DFUs that present with osteomyelitis. Prospective, randomised controlled trials are warranted to confirm this efficacy as well as its potential applications in other chronic wounds.