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Human amniotic membrane (hAM) has been extensively used for several decades as a bioactive scaffold for regenerative medicine. In its cryopreserved form—one of the main storage formats—the presence of viable cells has often been questioned. Furthermore, there is little published evidence of the role of endogenous amniotic cells from cryopreserved hAM in tissue repair.Some technologies, often patented and combined, have facilitated the use of hAM. Decellularization and devitalization processes have been developed to ensure its safety and prevent immune rejection. Lyophilization and dehydration methods have had a significant impact on clinical practices by enabling storage at room temperature in the operating room and making handling and cutting easier. Consequently, the commercialization of hAM has expanded, initially in the USA, and now in Europe.In the last decade, there has been growing interest in new perinatal tissues in clinical medicine. Similar processes have been adapted for these tissues to prevent immune or inflammatory reactions, and to improve storage and make them easier to use. For example, in the USA, many products marketed for wound healing undergo lyophilization, sometimes in combination with decellularization.Given our expertise, we wanted to highlight the potential of decellularized/devitalized and lyophilized perinatal tissues in regenerative medicine, particularly for bone repair. In this opinion paper, we discuss why these tissues represent the future of regenerative medicine, their potential drawbacks and strategies to overcome these challenges.

Purpose: To report a case of scleral melting noted within weeks after symblepharon release and pterygium excision with peri-operative adjuvant topical Mitomycin C (MMC) that was salvaged with in-office cryopreserved membrane. Observations: A 61-year-old Hispanic gentleman with history of pterygium excision many years prior underwent right nasal pterygium excision and symblepharon release using bare sclera technique followed by topical MMC 0.1 % for a week, 16 years ago. He was noted to have a right nasal scleral thinning. He was successfully treated conservatively with in-office cryopreserved amniotic membrane without further progression of the scleral melting or surgical intervention required. Conclusions and Importance: Short-term complication of pterygium excision with adjuvant topical MMC may occur. This case shows that early detection and recognition of the complication can be sight-saving with in-office cryopreserved amniotic membrane.

Purpose: Idiopathic macular holes are rare in children. The optimal management and surgical technique have not been fully investigated in chronic pediatric macular holes. Observations: Here we report a pediatric patient with leukemia who presented with non-clearing vitreous hemorrhage and intraoperative identification of a full thickness macular hole. After pars plana vitrectomy and internal limiting membrane peeling, a human amniotic membrane transplant (AMT) was fashioned and tucked under the retina at the edge of macular hole. Silicone oil was used to provide sufficient tamponade to the graft as the patient lived at high elevation. At follow up the graft was properly incorporated in the retina with successful anatomic closure of the macular hole without graft displacement, intraocular inflammation, or retinal detachment. One month after surgery visual acuity was 3/100 with subsequent improvement to 20/70 at final follow up. The graft remained well integrated in the retina after silicone oil removal. Optical coherence tomography demonstrated restoration of foveal contour with disruption in outer retinal layers. Conclusion and importance: Unlike idiopathic senile macular holes, application of AMT for idiopathic macular holes in children has not been investigated. Our case suggests amniotic membrane graft as an adjunctive tool in management of pediatric macular holes.

Objective: To determine the efficacy of latelet-rich fibrin (PRF) and Amniotic membrane (AM) along with the coronally advanced flap (CAF) technique in treating Miller’s class I gingival recession (GR) defects. Material and methods: A total of 32 sites with Miller’s class I GR defects were distributed into Group A (CAF + PRF, n = 16) and Group B (CAF + AM, n = 16). Clinical parameters like gingival index (GI), plaque index (PI), gingival bleeding index (GBI), gingival sulcus depth (GSD), relative attachment level (RAL), and gingival marginal level (GML) were measured at baseline and at 3, 6 and 9 months after surgical intervention. Results: PRF and AM with CAF were effective treatment modalities for treating Miller’s class I GR defects, with an average root coverage value of 2.00 ± 0.75 mm in Group A and 1.5 ± 0.3 mm in Group B. Complete coverage (100 %) was obtained in 57 % sites of group A and 49 % sites of group B. At the 9-month follow-up, there was a significant increase in relative attachment levels in both groups when compared to baseline. Conclusion: In the present study it was observed that there was a clinically and statistically significant improvement in root coverage with both groups. PRF-treated sites showed > 50 % complete coverage and hence were superior. AM showed comparable results to PRF and could be used as an alternative.

Purpose: We present two cases of fungal keratitis following amniotic membrane transplantation, including Sistotrema biggsiae and Fusarium keratitis. Observations: A 76-year-old female with a history of anterior basement membrane dystrophy referred for reduced vision and left eye pain ten days following AMT at an outside facility. Despite topical management, the patient continued to worsen clinically, with a recalcitrant course of Fusarium keratitis requiring conjunctival flap, cryotherapy, and intracameral and intrastromal injection. The second case involved a 46-year-old male with a history of recurrent corneal erosions referred for blurry vision and pain in his left eye seven days following AMT. He was found to have Sistotrema biggsiae keratitis and had remarkable visual improvement with topical management. Conclusions: Fungal keratitis following amniotic membrane placement has not been reported presenting within ten days after transplantation. This is the first report of Sistotrema biggsiae infection in humans. This case series highlights the risk of severe recalcitrant microbial keratitis presenting within days after AMT placement and recognizing fungal etiologies not previously reported in literature. The risk of keratitis following AMT should be considered with close patient follow up, especially in patients with monocular vision.

Amniotic membrane (AM) is an effective and widely used dressing in ocular injuries to reconstruct the cornea. Due to its low mechanical strength, high biodegradation rate, and difficult handling, its usage in medical interventions remains challenging. In this study, decellularized AM was covered with an ultrathin layer of Polydimethylsiloxane (PDMS) through a spinning method, which in turn resulted in an ultrathin (less than 80 µm in thickness) bilayer corneal wound dressing membrane with improved mechanical behavior and transparency. The biomechanical, biological, and antibacterial properties of the bilayer membranes were measured both in vitro and in vivo. The optimized microsized membrane was applied on a corneal defect wound created in a rabbit model to evaluate the corneal healing. The results demonstrated a significant decrease in degradation rate, improved mechanical properties, and AM/PDMS transparency compared with AM. The corneal transparency improved until 21 days post-surgery in AM/PDMS group. Histological evaluations revealed that AM/PDMS had better epithelial delaminated cell morphology. The results of the RT-PCR showed a significant increase in MMP9, a significant decrease in Col1A1, TGF-β1, TNF-α and IL-6 in both AM and AM/PDMS compared with control wounds. This study suggessts AM/PDMS membrane as an excellent corneal wound dressing.

Purpose: To investigate the efficiency of amniotic membrane transplantation (AMT) combined with conjunctival flap covering surgery (CFCS) for patients with corneal perforations in fungal keratitis (FK). Methods: In this non-comparative, retrospective case series, 16 participants of corneal perforation in FK were successfully treated by a combination of multilayer AMT and bipedicle conjunctival flap with partial tenon's capsule. Corneal healing, recurrence of FK, visual acuity, and relevant complications were reported as outcome measures. Results: Sixteen patients (13 male, 3 female) had a mean age of 58.8 ± 10.3 (range 29–72) years. The mean diameter of corneal perforation was 1.9 ± 0.7 (range 0.5–2.8) mm. Corneal perforations healed and all the patients preserved their eyeballs. During the 11.0 ± 4.4 (range 6–18) months of follow-up, there was no recurrence of FK in any of these cases. Visual acuity improved in 15 eyes (93.8 %) and remained unchanged in 1 patient (6.3 %) who had no light perception when first admitted. All 6 patients who accepted secondary keratoplasty showed improved best corrected visual acuity of more than 4 lines. The most frequently found fungi were Aspergillus species (6 of 16, 37.5 %) and Fusarium species (4 of 16, 25.0 %), followed by 1 Scedosporium apiospermum (1 of 16, 6.3 %). Conclusions: Combination AMT with CFCS is a safe and effective surgery for patients with corneal perforations in FK, particularly where eye banks and fresh corneas are not available. This surgery could preserve the integrity of the eyeball and avoid the recurrence of FK. Besides, it provides a greater opportunity for further optical keratoplasty.

Tendon adhesion is a common complication after tendon surgery. The inflammatory phase of tendon healing is characterized by the release of a large number of inflammatory factors, whose mediated excessive inflammatory response is an important cause of tendon adhesion formation. Nonsteroidal anti-inflammatory drugs(NSAIDs) were used to prevent tendon adhesions by reducing the inflammatory response. However, recent studies have shown that the NSAIDs partially impairs tendon healing. Therefore, optimizing the anti-adhesive membrane loaded with NSAIDs to mitigate the effects on tendon healing requires further in-depth study. Amniotic membranes(AM) are natural polymeric semi-permeable membranes from living organisms that are rich in matrix, growth factors, and other active ingredients. In this study, we used electrostatic spinning technology to construct multifunctional nanofiber membranes of the PCL membrane loaded with celecoxib and AM. In vitro cellular assays revealed that celecoxib-loaded PCL membranes significantly inhibited the adhesion and proliferation of fibroblasts with increasing concentrations of celecoxib. In a rabbit tendon repair model, biomechanical tests further confirmed that the PCL membrane loaded with celecoxib had better anti-adhesion effects. Further experimental studies revealed that the PCL/AM membrane improved the inflammatory microenvironment by downregulating the expression of pro-inflammatory factors such as COX-2, IL-1β, and TNF-α proteins; and inhibiting the synthesis of COL I and COL Ⅲ. The PCL/AM membrane can continuously release celecoxib to reduce the inflammatory response and deliver growth factors to the damaged area to build a suitable microenvironment for tendon repair, which provides a new direction to improve the repair efficiency of tendon.

Umbilical cord-derived mesenchymal stem cells (UC-MSC) are promising candidates for wound healing. However, the low amplification efficiency of MSC in vitro and their low survival rates after transplantation have limited their medical application. In this study, we fabricated a micronized amniotic membrane (mAM) as a microcarrier to amplify MSC in vitro and used mAM and MSC (mAM-MSC) complexes to repair burn wounds. Results showed that MSC could live and proliferate on mAM in a 3D culture system, exhibiting higher cell activity than in 2D culture. Transcriptome sequencing of MSC showed that the expression of growth factor-related, angiogenesis-related, and wound healing-related genes was significantly upregulated in mAM-MSC compared to traditional 2D-cultured MSC, which was verified via RT-qPCR. Gene ontology (GO) analysis of differentially expressed genes (DEGs) showed significant enrichment of terms related to cell proliferation, angiogenesis, cytokine activity, and wound healing in mAM-MSC. In a burn wound model of C57BL/6J mice, topical application of mAM-MSC significantly accelerated wound healing compared to MSC injection alone and was accompanied by longer survival of MSC and greater neovascularization in the wound.

In human body, biomaterials can be used to accelerate the wound healing process. Amniotic membrane-derived secretory leukocyte protease inhibitor (SLPI) is one of the biomaterials which able to accelerate the wound healing process by its several functions such as protease inhibition, leukocytes activity control, growth factor regulation such as transforming growth factor β (TGF-β), and its anti inflammatory, anti bacterial also anti retroviral properties. Objectives: To analyzed the SLPI effect on the TNF-α expression and the quantity of new blood vessel in the incisional wound healing. SLPI are produced from Essericea coli TOP10 as the cloning host, BL21 (DE3) strains as the expression host and pET30a plasmids were used for the expression system construction. The incision wound was made in dorsal skin area, then treated with SLPI dose 0.03 cc, 0.45 cc, 0.06 cc. After treatment, the wound covered with hypafix. The control group only covered with hypafix. In the next four days, the dorsal skin area is biopsied, then the quantity of TNF-α expression and blood vessels was analyzed with hematoxylin eosin and immunohistochemistry staining. The SLPI 0.045 cc showed the higher quantity of new blood vessel compared the SLPI 0.03 cc and control group (p

Purpose: To describe the microscopic epithelial changes and the clinical outcomes of a patient treated with amniotic membrane eye drops (AMED) because of a persistent epithelial defect (PED) and a partial limbal stem cell deficiency (LSCD) after simple limbal epithelial transplantation (SLET) and deep anterior lamellar keratoplasty (DALK). Observations: A 72-year-old patient, who had previously undergone SLET and DALK due to a total LSCD, presented with a PED related to a partial LSCD, and was treated with AMED for one month. We evaluated the patient's visual acuity, the Oxford grading scale, the Wong-Baker Pain Rating Scale, and in vivo confocal microscopy, both at baseline and 3 months after the end of treatment. Visual acuity improved from 0.5 to 0.4 LogMAR, the Oxford grading scale changed from grade III to grade I and the Wong-Baker Pain Rating Scale from grade 4 to grade 1. The corneal surface, which initially showed conjunctival characteristics over approximately 50% of the whole area, consisted mainly (75%) of mature corneal epithelium 3 months after the end of treatment. Conclusions and importance: While improving symptoms and clinical characteristics, AMED was also able to restore the normal corneal epithelium's morphology in a case of partial LSCD after SLET and DALK.

Objective: To evaluate the published literature on the efficacy of amniotic membrane grafting (AMG) in the management of acute chemical and thermal ocular surface burns with respect to the rate of corneal re-epithelialization and improvement of visual acuity or corneal clarity., Methods: Literature searches were conducted in the PubMed database in May 2023 and updated in January 2024 and were limited to the English language without date restrictions. The searches yielded 474 citations; 58 were reviewed in full text, and 9 met the inclusion criteria. Four studies were rated level II, and 5 studies were rated level III. This assessment focuses on 3 level II articles that provided consistent primary and secondary outcomes but demonstrated suboptimal study design with respect to power calculations and lacked a priori sample-size calculations., Results: Amniotic membrane grafting significantly improved corneal re-epithelialization compared with medical therapy alone in eyes with moderate-grade burns. For severely burned eyes, AMG demonstrated no advantage over medical therapy. Additionally, AMG demonstrated no significant advantage over medical therapy for improved visual acuity or corneal clarity for moderate or severe ocular surface burns., Conclusions: The best available level II evidence suggests that AMG in the setting of acute ocular surface burns has efficacy in hastening re-epithelialization in moderate burns. As an adjuvant to medical therapy, it did not demonstrate a benefit in improving re-epithelialization in severe burns or visual acuity or corneal clarity in either moderate or severe burns., Financial Disclosure(s): Proprietary or commercial disclosure may be found after the references., (Copyright © 2024 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Human amniotic membrane (hAM) and collagen nerve wraps are biomaterials that have been investigated as therapies for improving outcomes of peripheral nerve regeneration; however, their efficacy has not been compared. The purpose of this study is to compare the efficacy of collagen and human amniotic membrane nerve wraps in a rodent sciatic nerve reverse autograft model. Lewis rats (n = 29) underwent sciatic nerve injury and repair in which a 10-mm gap was bridged with reverse autograft combined with either no nerve wrap (control), collagen nerve wrap or hAM nerve wrap. Behavioral analyses were performed at baseline and 4, 8 and 12 weeks. Electrophysiological studies were conducted at 8, 10 and 12 weeks. Additional outcomes assessed included gastrocnemius muscle weights, nerve adhesions, axonal regeneration and scarring at 12 weeks. Application of both collagen and hAM nerve wraps resulted in improvement of functional and histologic outcomes when compared with controls, with a greater magnitude of improvement for the experimental group treated with hAM nerve wraps. hAM-treated animals had significantly higher numbers of axons compared to control animals (p

Purpose: To report the use of cryopreserved amniotic membrane from the umbilical cord (UC) in the reconstruction of a dehisced wound with the additional ability to increase orbital volume, expand superior and inferior fornices, and improve cosmesis following evisceration of a blind, painful, atrophic, sunken eye with ptosis. Observations: Patient developed conjunctival wound dehiscence without implant exposure following evisceration. One month later, reconstruction was performed with UC to cover the defect, increase the orbital volume, and expand orbital fornices to allow placement of a large ocular prosthesis with superior lip for ptosis elevation. Post-operatively, at the 6th week, the socket was healthy and the globe had good movement. At the 7th week, the ocular prosthesis was sized and fitted. At the 8th month, the structural integrity of the socket was maintained with deep fornices, and the patient had excellent cosmetic result with natural appearance and movement of the prosthetic eye. Conclusions and importance: This case highlights the successful utilization of UC graft to augment soft tissue volume, restore socket structural integrity and increase socket volume, and achieve good cosmesis and ocular motility following evisceration.

Objective: Inflammation, catabolism, and hypertrophy in chondrocytes play a central role in osteoarthritis (OA). The Wnt/β-catenin and NF-κβ pathways contribute to these degradative processes. This in vitro study evaluates the inhibitory effect of a novel therapeutic, micronized dehydrated human amnion/chorion membrane (μdHACM), as a potential treatment to offset elevated Wnt/β-catenin and NF-κβ signaling. Design: Three-dimensional human articular chondrocyte pellets were stimulated with an inflammatory cocktail to induce a degenerative phenotype. Treatments included varying doses of μdHACM. Protein and gene expression were analyzed using qRT-PCR, immunoblotting, and immunofluorescence to assess changes in the major constituents of Wnt/β-catenin and NF-κβ signaling. Regulation of catabolic activity was evaluated using enzymatic assays that detect MMP-13 and aggrecanase-mediated degradation products in conditioned media. Results: Confirmation of the model was established through the expression of specific markers and extracellular matrix genes, verifying a chondrogenic phenotype was maintained. Inflammatory stimulation elicited a change in the chondrocyte proteome and secretome, elevating Wnt/β-catenin and NF-κβ signaling and downstream expression of inflammatory, proteolytic, and hypertrophic markers, while decreasing primary cartilage matrix components, ACAN and COL2A1. μdHACM reversed these inflammatory-induced changes, suppressing phospho-GSK-3β, β-catenin expression/nuclear localization of the Wnt signaling axis and inhibiting IKKβ, phospho-IκBα, and phospho-p65 in the NF-κβ signaling cascade. Additionally, μdHACM altered expression of direct downstream targets, namely MCP1, MMP3, MMP13, ADAMTS4, ADAMTS5, RUNX2 and COL10A1. Moreover, μdHACM reduced MMP-13 and aggrecanase-mediated substrate degradation. Conclusion: μdHACM ameloriated the effects of inflammatory-induced degeneration in chondrocytes through Wnt/β-catenin and NF-κβ inhibition, subsequently downregulating key inflammatory, hypertrophic and catabolic mediators in vitro.

Background: The amniotic membrane (AM) is used in ocular surface reconstruction and is effective at promoting epithelialization and preventing corneal perforation in cases of acute microbial keratitis. Here, we report a case of isolated AM infection after AM transplantation for a persistent epithelial defect following tectonic penetrating keratoplasty. Case presentation: A 47-year-old man with poorly controlled type 2 diabetes mellitus presented to the emergency department with a referral for perforated microbial keratitis. After ophthalmic examination, corneal scraping was performed, and corneal gluing was attempted and failed. Hence, the patient underwent tectonic penetrating keratoplasty. After keratoplasty, the patient developed a persistent epithelial defect that required AM transplantation as an overlay. Thirty days post-AM transplant, the patient presented with signs and symptoms resembling granular microbial infection of the cornea. After two days, the granular findings began dislodging from the corneal surface and were sent for culture, sensitivity, and histopathological identification. Histological analysis of the granular material indicated it to be a small piece of AM stroma infiltrated with mixed-type inflammatory cells. Corneal scraping cultures indicated Streptococcus mitis and Streptococcus oralis. Conclusion: The infiltrate was localized to the basement membrane of the AM as, despite the anti-inflammatory effects of AM, it can also act as a barrier against polymorphonuclear leukocyte infiltration from the tear film and microbial invasion into the cornea.

Canonical Wnt signaling is a major pathway known to regulate diverse physiological processes in multicellular organisms. Signaling is tightly regulated by feedback mechanisms; however, persistent dysregulation of this pathway is implicated in the progression of multiple disease states. In this study, proteomic analysis identified endogenous Wnt antagonists in micronized dehydrated human amnion/chorion membrane (μdHACM); thereby, prompting a study to further characterize the intrinsic properties of μdHACM as it relates to Wnt activity, in vitro. A TCF/LEF reporter cell line demonstrated the general ability of μdHACM to inhibit β-catenin induced transcription activity. Furthermore, in vitro systems, modeling elevated Wnt signaling, were developed in relevant cell types including tenocytes, synoviocytes, and human dermal fibroblasts (HDFs). Stimulation of these cells with Wnt3A resulted in translocation of β-catenin to the nucleus and increased expression of Wnt related genes. The subsequent addition of μdHACM, in the continued presence of Wnt-stimulus, mitigated the downstream effects of Wnt3A in tenocytes, synoviocytes, and HDFs. Nuclear localization of β-catenin was abated with corresponding reduction of Wnt related gene expression. These data demonstrate the in vitro regulation of canonical Wnt signaling as an inherent property of μdHACM and a novel mechanism of action.

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.

Amniotic membrane (AM) is an attractive source for bone tissue engineering because of its low immunogenicity, contains biomolecules and proteins, and osteogenic differentiation properties. Hydroxyapatite is widely used as bone scaffolds due to its biocompatibility and bioactivity properties. The aim of this study is to design and fabricate scaffold based on hydroxyapatite-coated decellularized amniotic membrane (DAM-HA) for bone tissue engineering purpose. So human amniotic membranes were collected from healthy donors and decellularized (DAM). Then a hydroxyapatite-coating was created by immersion in 10X SBF, under variable parameters of pH and incubation time. Hydroxyapatite-coating was characterized and the optimal sample was selected. Human adipose-derived mesenchymal stem cell behaviors were assessed on control, amniotic membrane, and coated amniotic membrane. The results of the SEM, MTT assay, and Live-Dead staining showed that DAM and DAM-HA support cell adhesion, viability and proliferation. Osteogenic differentiation was evaluated by assessment of alkaline phosphatase activity and expression of osteogenic markers. Maximum gene expression values compared to control occurred in 14 days for alkalin phosphatase, while the highest values for osteocalcin and osteopontin in 21 days. These gene expression values in DAM and DAM-HA for alkalin phosphatase is 6.41 and 8.47, for osteocalcin is 3.95 and 5.94 and for osteopontin is 5.59 and 9.9 respectively. The results of this study indicated DAM supports the survival and growth of stem cells. Also, addition of hydroxyapatite component to DAM promotes osteogenic differentiation while maintaining viability. Therefore, hydroxyapatite-coated decellularized amniotic membrane can be a promising choice for bone tissue engineering applications., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Purpose: To report successful management of acute ocular graft-versus-host disease (oGVHD) by self-retained cryopreserved amniotic membrane (AM). Observations: A 69-year-old male developed acute oGVHD following hematopoietic stem cell transplantation (HSCT) with severe dryness, pain, photophobia, and blurred vision, the right eye worse than the left eye. Despite topical artificial tears, corticosteroids, and bandage contact lens (BCL) for two weeks, his right eye deteriorated with increasing redness and blurred vision and presented with diffuse conjunctival inflammation, severe superficial punctate keratitis, and corneal and limbal epithelial defect. Hence, self-retained cryopreserved AM was applied in the right eye while conventional therapy was continued in the left eye. Placement of self-retained AM for 3-days resulted in resolution of symptoms, reduction in inflammation, and complete re-epithelialization of the corneal and limbal defect with the visual acuity improving from 20/500 to 20/70 in the right eye. In contrast, the visual acuity improved from 20/300 to 20/150 and remained inflamed with conventional therapy in the left eye. One-month post-AM placement, the right eye remained asymptomatic with the visual acuity improved to 20/30 without any additional therapy, whereas the left eye improved to 20/70 with conventional treatment of BCL, loteprednol, and artificial tears. Conclusions and Importance: This case suggests application of self-retained AM can be an effective treatment to accelerate the restoration of vision and corneal surface health for acute oGVHD.

Unlike other tissue types, the nervous tissue extends to a wide and complex environment that provides a plurality of different biochemical and topological stimuli, which in turn defines the advanced functions of that tissue. As a consequence of such complexity, the traditional transplantation therapeutic methods are quite ineffective; therefore, the restoration of peripheral and central nervous system injuries has been a continuous scientific challenge. Tissue engineering and regenerative medicine in the nervous system have provided new alternative medical approaches. These methods use external biomaterial supports, known as scaffolds, to create platforms for the cells to migrate to the injury site and repair the tissue. The challenge in neural tissue engineering (NTE) remains the fabrication of scaffolds with precisely controlled, tunable topography, biochemical cues, and surface energy, capable of directing and controlling the function of neuronal cells toward the recovery from neurological disorders and injuries. At the same time, it has been shown that NTE provides the potential to model neurological diseases in vitro, mainly via lab-on-a-chip systems, especially in cases for which it is difficult to obtain suitable animal models. As a consequence of the intense research activity in the field, a variety of synthetic approaches and 3D fabrication methods have been developed for the fabrication of NTE scaffolds, including soft lithography and self-assembly, as well as subtractive (top-down) and additive (bottom-up) manufacturing. This article aims at reviewing the existing research effort in the rapidly growing field related to the development of biomaterial scaffolds and lab-on-a-chip systems for NTE applications. Besides presenting recent advances achieved by NTE strategies, this work also delineates existing limitations and highlights emerging possibilities and future prospects in this field.

Purpose: To report the outcome of self-retained amniotic membrane after debridement in recurrent dendritic keratitis. Observations: A 70-year-old female with a recurrent dendritic corneal ulcer received debridement followed by placement of self-retained amniotic membrane. Five days after treatment, the patient experienced a complete resolution of symptoms, marked reduction of inflammation, complete re-epithelialization of the cornea and improvement of visual acuity. The corneal surface remained stable for 18 months despite noncompliance in using antiviral therapy. Conclusions and importance: Self-retained amniotic membrane after debridement appears effective in treating dendritic keratitis. While early debridement is crucial to remove the infected corneal epithelium, amniotic membrane was shown to enhance the healing without scarring or recurrence. Besides the known anti-inflammatory and anti-scarring effects of the amniotic membrane, it may have a potential topical antiviral effect that warrants further investigation.

Periodontal disease is a chronic inflammatory process that potentially leads to alveolar bone destruction and tooth loss. Tissue engineering combined with stem cell therapy is a potential effective treatment for periodontal bone loss. Amniotic membrane (AM) is a potential scaffold enriched with multiple growth factors. It has the effects of anti-inflammation, antiangiogenesis, and immunosuppression. Herein, we used adipose-derived stem cells (ADSCs) and an AM co-cultured system to study bone regeneration in a rat periodontal defect model in vivo. Methods: Human ADSCs were isolated from the infrapatellar fat pad, and characterized by flow cytometry, reverse transcription-polymerase chain reaction, and multipotent differentiation assays. The co-culture system was applied in the periodontal two-wall osseous defect in a rat model, and computed tomography was used to measure the effect. Results: Human ADSCs isolated from the infrapatellar fat pad showed spindle-like morphology. Flow cytometry results demonstrated that ADSCs expressed a high level of CD90 and CD105, but not CD31, CD34, and CD45. ADSCs strongly expressed stemness genes, including SOX2, OCT4, NANOG, and KLF4 on different passages. Furthermore, ADSCs were able to differentiate into osteogenic, chondrogenic, and adipogenic cells. In the periodontal osseous defect rat model, ADSCs and the AM co-culture system significantly increased bone regeneration. Conclusion: This study provides the basis for using ADSCs with an AM co-culture system as stem cell therapy and scaffold transplantation in clinical periodontology.

Introduction: Amniotic membranes (AM) have shown its great potential in reconstructive surgery due to their regenerative capacity. However, AM is regarded to be relatively weak when applied for load-bearing purposes. This study aims to produce an AM-based scaffold that can withstand the mechanical loads applied in vesicovaginal fistula repair. Different strategies are investigated to improve the mechanical characteristics of AM., Methods: Single and multilayered AM, and composite constructs of AM with electrospun poly-4-hydroxybutyrate (P4HB) or bovine pericardial tissue combined with the use of fibrin glue, were mechanically tested in this study. Suture retention strength and mechanical characteristics (tensile stress, elongation, tangent modulus and maximum load) were assessed by uniaxial testing. The effect of degradation of the composite constructs on the mechanical characteristics was determined by uniaxial testing after 4 and 8 weeks., Results: Single and multilayered AM could not provide the mechanical requirements needed for surgical implantation (>2N load). AM was combined successfully with electrospun P4HB and bovine pericardium with the use of fibrin glue and were able to exceed the 2N load., Conclusion: The composite constructs with AM showed sufficient mechanical characteristics for surgical implantation. Electrospun P4HB combined with AM seemed the most promising candidate since the mechanical characteristics of P4HB can be further modified to meet the requirements of the application site and the degradation of the P4HB allows a gradual transfer of load. Eventhough the scaffold is intended for fistula repair, it can potentially be applied in surgical reconstruction of other hollow organs by modifying the mechanical characteristics., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: J.P.W.R. Roovers reports that financial support was provided by the Amsterdam Reproduction and Development research institute. L.P. Maljaars reports that equipment, drugs, or supplies were provided by Baxter SA. L.P. Maljaars reports that equipment, drugs, or supplies were provided by The University of Utah School of Medicine. D. Bezuidenhout reports a relationship with Strait Access Technologies that includes board membership. J.P.W.R. reports that financial support (unrestricted research grant) was provided by Tepha Inc., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The human amniotic membrane (hAM) surrounds and protects the fetus. It mainly consists of a thick basement membrane and an avascular stromal matrix. The structural, physical, and biological properties of AM make it a wonderful choice to use in regenerative medicine applications. This review discusses recent applications of hAM in skin transplantation and wound healing, ophthalmology, orthopedics, cell culture matrix, cell delivery system, cardiac injury, male and female reproductive systems, and liver. Moreover, an overview is presented on the advantages and disadvantages of using hAM and some methods to systematically refine and standardize hAM preparation., Competing Interests: Declaration of competing interest The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2022. Published by Elsevier Inc.)

Descemet's membrane endothelial keratoplasty (DMEK) may provide fast visual rehabilitation in the therapy of corneal endothelial disorders. However, due to shortage of donated corneas, how to construct a corneal endothelial substitute with powerful functions that can be used for DMEK is still unsolved. Herein, we introduced the method of corneal crosslinking (CXL) and conjugated the components of native Descemet's membrane (DM) to improve the mechanical properties and the biocompatibility of denuded amniotic membrane (dAM), further assessed their effects on cell adhesion, proliferation, YAP translocation, and metabolic activity in human corneal endothelial (HCE) cells. Using modified crosslinked dAM (mcdAM) and non-transfected HCE cells, we constructed a tissue-engineered HCE (TE-HCE) and evaluated its functions in cat and monkey models as well. Our results showed that the mechanical properties of mcdAM were improved effectively by CXL, and the adhesion, proliferation, and YAP translocation of HCE cells were dose-dependently improved after ECM modification. The combination of 0.01 mg/mL laminin with 0.1 mg/mL fibronectin showed the highest efficacy. Then, the TE-HCE was constructed in vitro, with a high density of 3612 ± 243 cells/mm 2 . Results of DMEK in animal models showed that corneal transparency was maintained, accompanied with normal morphology and histological structure of the regenerated corneal endothelium. Therefore, CXL combined with DM-mimic-coating methods could effectively improve the mechanical properties of dAM and enhance the biocompatibility with HCE cells. The constructed TE-HCE had normal histological structure and functioned well in animal models via DMEK, which could be used as a promising powerful equivalent of HCE. STATEMENT OF SIGNIFICANCE: Using high-quality corneal endothelium and an appropriate endothelial keratoplasty is the most effective way for the treatment of corneal endotheliopathy. Descemet's membrane endothelial keratoplasty (DMEK) which can provide better visual acuity, lower immunological rejection rates, and improved graft survival is an ideal surgery at present. However, due to the shortage of donated corneas, it is urgent to find an equivalent substitute of corneal endothelial donor which is suitable for the DMEK surgery to solve the problem of corneal endothelial regeneration. Herein, we introduced the clinical cornea-crosslinking and Descemet's membrane-mimic-coating methods to build the modified crosslinked denuded amniotic membrane scaffold and further constructed a high-quality corneal endothelial functional substitute that can be used in DMEK surgery., Competing Interests: Declaration of Competing Interest No conflicting relationship exists for any author. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

Spinal cord injury is a significant public health issue with high psychological and financial costs to both the family and the society. Effective treatment strategies are hence of immense value. Several reports have suggested application of amniotic membrane for treating injuries, and there is evidence that it may be used to treat spinal injuries. In this animal model study, we explore biochemical changes in amniotic membrane treated injured spinal cord with respect to untreated injured and uninjured spinal cord using Raman spectroscopy. Multivariate statistical analysis is able to classify control, untreated, and treated with 92%, 87%, and 80% efficiency, respectively; suggesting unique biochemical changes in each group. Such studies may lead to development of minimally invasive methodologies for spinal cord injury treatment monitoring., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Exfoliative cytology of human amniotic fluid (AF) has been extensively studied since 1940s, but no data exist in equine species. The AF compartment represents the environment in which the foetus grows and matures, and its composition changes, reflecting foetal well-being and development. The aim of this study was to describe for the first time the morphology of equine AF cells and amniotic membrane (AM) with light microscopy (LM) and transmission electron microscopy (TEM). AF was collected at parturition within 5 min after the appearance of the AM with a 60 mL syringe from 34 mares and samples of AM were collected from a subset of 7 mares with normal pregnancy hospitalized for attended parturition. For LM observation, a sample of cytocentrifuged fresh AF was stained with May-Grünwald Giemsa and AM sections were stained with H-E. For TEM observation, AF and AM were fixed, embedded in epoxy resins, then sectioned and stained with uranyl acetate and lead citrate solutions. Nucleated and anucleated squamous cells with basophilic cytoplasm, intensely basophilic cornified cells, polymorphonuclear cells, and clusters of eosinophilic amorphous substance were observed. Cells presumably derived from tracheal epithelium and small round nucleated cells with eosinophilic cytoplasm presumably derived from amniotic or urinary epithelium were occasionally found. Lamellar body-like structures (LBs) were present in some epithelial cells. In AM, epithelial, basal and mesenchymal layers were clearly visible with both techniques as previously described. Epithelial cells had several cytoplasmic vacuolization and microvilli were present on apical surface. The connective tissue presented fibroblasts, mesenchymal and rare polymorphonuclear cells, surrounded by abundant extracellular matrix, with distribution of collagen fibres. This is the first report about equine amniotic compartment description by LM and TEM. As recently reported in human medicine, the AM could be a second potential source of pulmonary surfactant, given the finding of LBs inside the cells which could have the same function as in humans. Further studies in samples collected at different gestational ages could increase the knowledge of AF cells and their modification during pregnancy, as well as a better comprehension of the role of AM as a secondary source of pulmonary surfactant in the horse. The diagnostic evaluation of AF cellular composition in high-risk pregnancies may also be investigated., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Stem cell-based therapy is known as a regenerative approach for a variety of diseases and tissue injuries. These cells exert their therapeutic effects through paracrine secretions namely extracellular vesicles. To achieve higher therapeutic potential, a variety of delivery routes have been tested in clinical and preclinical studies. Direct cell injection, intra-venous administration, and intra-arterial infusion are widely used methods of stem cells delivery but these methods are associated with several complications. As one of the most popular biological delivery systems, amniotic membrane has been widely utilized to support cell proliferation and differentiation therefore facilitating tissue regeneration without endangering the stem cells' viability. It is composed of several extracellular matrix components and growth factors. Due to these characteristics, amniotic membrane can mimic the stem cell's niche and can be an ideal carrier for stem cell transplantation. Here, we provide an overview of the recent progress, challenges, and future perspectives in the use of amniotic membrane as a delivery platform for stem cells., (Copyright © 2021. Published by Elsevier Inc.)

Thanks to its biological properties, the human amniotic membrane (HAM) combined with a bone substitute could be a single-step surgical alternative to the two-step Masquelet induced membrane (IM) technique for regeneration of critical bone defects. However, no study has directly compared these two membranes. We first designed a 3D-printed scaffold using calcium phosphate cement (CPC). We assessed its suitability in vitro to support human bone marrow mesenchymal stromal cells (hBMSCs) attachment and osteodifferentiation. We then performed a rat femoral critical size defect to compare the two-step IM technique with a single-step approach using the HAM. Five conditions were compared. Group 1 was left empty. Group 2 received the CPC scaffold loaded with rh-BMP2 (CPC/BMP2). Group 3 and 4 received the CPC/BMP2 scaffold covered with lyophilized or decellularized/lyophilized HAM. Group 5 underwent a two- step induced membrane procedure with insertion of a polymethylmethacrylate (PMMA) spacer followed by, after 4 weeks, its replacement with the CPC/BMP2 scaffold wrapped in the IM. Micro-CT and histomorphometric analysis were performed after six weeks. Results showed that the CPC scaffold supported the proliferation and osteodifferentiation of hBMSCs in vitro. In vivo, the CPC/BMP2 scaffold very efficiently induced bone formation and led to satisfactory healing of the femoral defect, in a single-step, without autograft or the need for any membrane covering. In this study, there was no difference between the two-step induced membrane procedure and a single step approach. However, the results indicated that none of the tested membranes further enhanced bone healing compared to the CPC/BMP2 group., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Autologous tissue transplantation for urethral repair is often limited and causes donor site complications. Here, a cryopreserved rabbit skin epithelial cell sheet (SEC) combined with an acellular amniotic membrane (AM) was used to repair rabbit urethral defects., Methods: Abdominal skin was collected from 4-week-old New Zealand rabbits, and primary epithelial cells were extracted and cultured to form a cell sheet. Fresh SEC-AMs were constructed and cryopreserved. A cryopreservation system including optimized medium, two-pump perfusion, a programmed freezer and liquid nitrogen storage was established. Cell viability, mechanical strength, electron microscopy, and histological staining were performed in vitro after 1 month. Next, the sheets were transplanted subcutaneously for 2 weeks, and the graft was used to repair the rabbit urethral defect. Urinary function was measured and samples were collected for histological staining after 1 month., Results: We confirmed that cryopreservation damage of SECs was reduced by composition with acellular AMs in terms of high cell activity. The SEC mechanical strength was also enhanced by AMs, which was convenient for the operation. In in vivo experiments, we transplanted sheets into the groin area for two weeks and found that cryopreservation reduced inflammatory cell infiltration and significantly improved vascular density. In the urethral repair experiment, the near-normal passive urine flow rate, smooth mucosa of the gross specimen, intact epithelialization and abundant neovascularization were confirmed in the cryopreserved-SEC-AM group compared with the other groups., Conclusions: Cryopreserved SEC-AMs demonstrated similar outcomes of rabbit urethral defect repair as fresh SEC-AMs, showing good clinical application prospects., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Due to the increasing number of studies performed in the field of regenerative medicine during the last two decades, more analytic studies are still needed to clarify the future prospect of this area of science. The main aim of this research was to review the clinical applications of human Amniotic membrane in the field of regenerative medicine critically. Furthermore, in the light of increasing numbers of available products derived from amniotic membrane, we aimed look in depth to see whether regenerative medicine research strategies have a place in the clinical setting. More specifically, in the present study, we attempted to provide insight on developing the new indication for more research and in the next step, for market leaders companies to expand cost-effectiveness of new derived AM products. 20 companies or distributers have offered some commercial products in this field. Survey on more than 90 clinical trials in last five years showed dermatology (and more specific wound healing), orthopedic, and ophthalmology are heavily biased toward multibillion dollar industry. Moreover, urology and dentistry with fewer numbers of clinical data in comparison with the above-mentioned areas, currently are in the path of translation (especially dentistry). In addition, otolaryngology and oncology with the lowest number showed more potential of research thorough understanding the properties that will help guiding the use of AM-derived products in these two areas in future. More than 50% of clinical studies were done or are developing in USA, which have the biggest share in market products. Subsequently, China, Egypt, India, Iran, and Germany with the ongoing clinical trials in different phases may have more approved products in near future., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The diverse application of collagen has created a need to discover renewable and economical sources with prevailing/improved physico-chemical properties. To address this scenario, the present study has extracted collagen from Human Amniotic Membrane (AM) and Umbilical cord, which are treated as medical waste and compared its physico-chemical properties. Collagen was extracted by pepsin solubilization using various salt concentrations (1 M, 2 M and 4 M). Umbilical Cord Collagen (UC) yield was 10% higher than Amniotic Membrane Collagen (AC). UC reported 58% higher sulphated glycosaminoglycan content than AC. Electrophoretic pattern of AC and UC in both disulphide bond reducing and non-reducing conditions showed bands corresponding to collagen type I, III, IV, V and XV. Collagen morphology was examined using SEM and the amino acid content was quantified by HPLC and LC-MS/MS. Triple helicity was confirmed by CD and FTIR spectra. Thermal transition temperature of AC and UC was found equivalent to animal collagen. Self-assembly, fibril morphology and spatial alignment was studied using AFM and DLS. Biocompatibility was analyzed using 3T3 fibroblast cells. In conclusion, UC with higher yield, presented with better physico-chemical, structural and biological properties than AC could serve as an efficient alternative to the existing animal collagen for diverse applications., Competing Interests: Declaration of competing interest Authors declare no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Perinatal tissues are an abundant source of human extracellular matrix proteins, growth factors and stem cells with proved potential use in a wide range of therapeutic applications. Due to their placental origin, these tissues possess unique biological properties, including being angiogenic, anti-inflammatory, anti-fibrotic, anti-microbial and immune privileged. Additionally, as a temporary organ, placenta is usually discarded as a medical waste, thus providing an easily available, cost effective, 'unlimited' and ethical source of raw materials. Although some of these tissues, such as the amniotic membrane and umbilical cord, have been used in clinical practices, most of them continue to be highly under explored. This review aims to outline the most relevant applications of perinatal tissues as a source of biomaterials and stem cells in the exciting fields of tissue engineering and regenerative medicine (TERM), as well as highlight how these solutions can be used to overcome the shortage of adequate scaffolds and cell sources that currently hampers the translation of TERM strategies towards clinical settings. STATEMENT OF SIGNIFICANCE: Stem cells and extracellular matrix derived from perinatal tissues such as placenta and umbilical cord, have drawn great attention for use in a wide variety of applications in the biomedical field. Due to their origin, these tissues possess unique biological properties, including being angiogenic, anti-inflammatory, anti-fibrotic, anti-microbial and immune privileged. Also they are typically considered medical waste, thus providing an easily available, cost effective, 'unlimited' and ethical source of raw materials. This work aims to present and discuss the most relevant applications of perinatal tissues as a source of biomaterials and stem cells in the exciting fields of tissue engineering and regenerative medicine (TERM)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier Ltd.)

Objective: To evaluate the efficacy and safety of amniotic membrane (AM) for the healing of split-thickness skin graft donor sites (STSGDS)., Method: Electronic search of PubMed, Cochrane library and EMBASE for randomized controlled trials (RCTs) or non-randomized clinical trials (NRCTs) of AM therapy in STSGDS. Review Manager5.3 was utilized to analyze and present the data., Results: Seven studies with 219 patients were included. Compared with other treatments, the mean difference (MD) in healing time was -3.87 days (95% CI -4.39, -3.35; P < 0.00001); Relative risk for the healing rate was 1.61 (95% CI 0.0.47-5.47; P = 0.44); There was no statistical difference in the sensation of pain (P > 0.05); The relative risk for infection rate was 0.66 (95% CI 0.29, 2.18; I 2  = 0%; P = 0.65)., Conclusion: This systematic review and meta-analysis indicate that it is effective and safe to use AM for treating STSGDS., (Copyright © 2019 Elsevier Ltd and ISBI. All rights reserved.)

Human amniotic membrane (hAM) is considered as an attractive biological scaffold for tissue engineering. For this application, hAM has been mainly processed using cryopreservation, lyophilization and/or decellularization. However, no study has formally compared the influence of these treatments on hAM properties. The aim of this study was to develop a new decellularization-preservation process of hAM, and to compare it with other conventional treatments (fresh, cryopreserved and lyophilized). The hAM was decellularized (D-hAM) using an enzymatic method followed by a detergent decellularization method, and was then lyophilized and gamma-sterilized. Decellularization was assessed using DNA staining and quantification. D-hAM was compared to fresh (F-hAM), cryopreserved (C-hAM) and lyophilized/gamma-sterilized (L-hAM) hAM. Their cytotoxicity on human bone marrow mesenchymal stem cells (hBMSCs) and their biocompatibility in a rat subcutaneous model were also evaluated. The protocol was effective as judged by the absence of nuclei staining and the residual DNA lower than 50 ng/mg. Histological staining showed a disruption of the D-hAM architecture, and its thickness was 84% lower than fresh hAM (p < 0.001). Despite this, the labeling of type IV and type V collagen, elastin and laminin were preserved on D-hAM. Maximal force before rupture of D-hAM was 92% higher than C-hAM and L-hAM (p < 0.01), and D-hAM was 37% more stretchable than F-hAM (p < 0.05). None of the four hAM were cytotoxic, and D-hAM was the most suitable scaffold for hBMSCs proliferation. Finally, D-hAM was well integrated in vivo. In conclusion, this new hAM decellularization process appears promising for tissue engineering applications., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Human amniotic membrane (AM) offers unique advantages as a matrix to support the transplantation of limbal stem cells (LSCs) due to its inherent pro-regenerative and anti-inflammatory properties. However, the widespread use of AM in clinical treatments of ocular surface disorders is limited by its weak mechanical strength and fast degradation, and high cost associated with preserving freshly isolated AM. Here we constructed a composite membrane consisting of an electrospun bioabsorbable poly(ε-caprolactone) (PCL) nanofiber mesh to significantly improve the ultimate tensile strength, toughness, and suture retention strength by 4-10-fold in comparison with decellularized AM sheet. The composite membrane showed extended stability and conferred longer-lasting coverage on wounded cornea surface compared with dAM. The composite membrane maintained the pro-regenerative and immunomodulatory properties of dAM, promoted LSC survival, retention, and organization, improved re-epithelialization of the defect area, and reduced inflammation and neovascularization. This study demonstrates the translational potential of our composite membrane for stem cell-based treatment of ocular surface damage. STATEMENT OF SIGNIFICANCE: Human decellularized amniotic membrane (dAM) has been widely shown as a biodegradable and bioactive matrix for regenerative tissue repair. However, the weak mechanical property has limited its widespread use in the clinic. Here we constructed a composite membrane using a layer of electrospun poly(ε-caprolactone) (PCL) nanofiber mesh to reinforce the dAM sheet through covalent interfacial bonding, while retaining the unique bioactivity of dAM. In a rabbit model of limbal stem cell (LSC) deficiency induced by alkaline burn, we demonstrated the superior property of this PCL-dAM composite membrane for repairing damaged cornea through promoting LSC transplantation, improving re-epithelialization, and reducing inflammation and neovascularization. This new composite membrane offers great translational potential in supporting stem cell-based treatment of ocular surface damage., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Background: Human amniotic membranes (HAMs), as a biological membrane with healing, osteogenic, and cell therapy potential, has been in the spotlight to enhance the outcomes of treating bone defects. Present study aims to clinically assess the potential of HAM loaded with buccal fat pad-derived stem cells (BFSCs) as an osteogenic coverage for onlay bone grafts to maxillomandibular bone defects., Materials and Methods: Nine patients with jaw bone defects were enrolled in the present study. The patients were allocated to two study groups: Iliac crest bone graft with HAM coverage (n = 5), and Iliac bone grafts covered with HAM loaded with BFSCs (n = 4). Five months following the grafting and prior to implant placement, cone beam computed tomography was performed for radiomorphometric analysis., Results: The mean increase in bone width was found to be significantly greater in the HAM + BFSCs group (4.42 ± 1.03 mm versus 3.07 ± 0.73 mm, p < 0.05). Further, the changes in vertical dimension were greater in the HAM + BFSCs group (4.66 ± 1.06 mm versus 4.14 ± 1.03 mm, p > 0.05)., Conclusion: Combined use of HAM with mesenchymal stem cells may enhance bone regeneration specifically in the horizontal dimension. Moreover, this methodology reduces the amount of harvested autogenous bone and diminish secondary bone resorption., (Copyright © 2019 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Human amniotic membrane (AM) has intrinsic anti-inflammatory, anti-fibrotic and antimicrobial properties. Tissue preservation methods have helped to overcome the short shelf life of fresh AM allowing "on demand" use of AM grafts. Cryopreserved AM that retains all native tissue components, including viable cells, has clinical benefits in treating chronic wounds. However, cryopreservation requires ultra-low temperature storage, limiting the use of cryopreserved products. To overcome this limitation, a new lyopreservation method has been developed for ambient storage of living tissues. The goal of this study was to investigate the viability and functionality of AM cells following lyopreservation. Fresh AM and devitalized lyopreserved AM (DLAM) served as positive and negative controls, respectively. Using live/dead staining, we confirmed the presence of living cells in viable lyopreserved AM (VLAM) and showed that these cells persisted up to 21 days in culture medium. The functionality of cells in VLAM was assessed by their differentiation potential and anti-fibrotic activity in vitro. With osteogenic induction, cells in VLAM deposited calcium within the membrane, a marker of osteogenic cells, in a time-dependent manner. The migration of human lung fibrotic fibroblasts in a scratch wound assay was reduced significantly in the presence of VLAM-derived conditioned medium. Quantitative PCR analyses indicated that VLAM reduced the expression of pro-fibrotic factors such as type I collagen and increased the expression of anti-fibrotic factors such as hepatocyte growth factor and anti-fibrotic microRNA in fibrotic fibroblasts. Taken together, these results demonstrate that endogenous cells in VLAM remain viable and functional post-lyophilization. STATEMENT OF SIGNIFICANCE: This study, for the first time, provides direct evidence showing that tissue viability and functional cells can be preserved by lyophilization. Similar to fresh amniotic membrane (AM), viable lyopreserved AM (VLAM) retains viable cells for extended periods of time. More importantly, these cells are functional and maintain their osteogenic differentiation potential and anti-fibrotic activity. Our results confirmed that the novel lyophilization method preserves tissue viability., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

In orthopedic sports medicine, amniotic-derived products have demonstrated promising preclinical and early clinical results for the treatment of tendon/ligament injuries, cartilage defects, and osteoarthritis. The amniotic membrane is a metabolically active tissue that has demonstrated anti-inflammatory, antimicrobial, antifibrotic, and epithelialization-promoting features that make it uniquely suited for several clinical applications. Although the existing clinical literature is limited, there are several ongoing clinical trials aiming to elucidate the specific applications and benefits of these products. This article reviews the current amniotic-derived treatment options and the existing literature on outcomes, complications, and safety profile of these products for use in sports medicine., (Copyright © 2018 Elsevier Inc. All rights reserved.)