Comparison of autologous venous grafts and three types of extracellular matrix grafts in Peyronie's disease surgery.

Background/aim: Peyronie's disease (PD) is known as a wound-healing disorder for which surgery remains the gold-standard treatment, but studies comparing graft materials are limited in the literature. The aim of this study was to evaluate the mid- and long-term results of patients who underwent surgery for PD with grafting procedures performed by a single experienced surgeon according to graft materials. Materials and methods: Patients who underwent corporoplasty between 2014 and 2020 with grafting procedures performed by a single experienced surgeon were retrospectively reviewed. A total of 115 patients were divided into 4 groups according to the grafting material used: autologous saphenous venous grafts, Group 1 (n = 36); porcine pericardial extracellular matrix grafts (EMGs; XenoGuard, MBP Medical Biomaterial Products GmbH, Neustadt-Glewe, Germany), Group 2 (n = 40); porcine intestinal submucosal EMGs (BioDesign, Cook Medical, Bloomington, IN, USA), Group 3 (n = 36); and bovine pericardial EMGs (Tutopatch, Tutogen Medical, Inc., Alachua, FL, USA), Group 4 (n = 43). Results: The mean operation time for Group 1 was longer than that of the other groups (p < 0.001). When comparing the groups in pairs, it was observed that the duration of postoperative loss of sensation (LOS) was significantly shorter in Group 3 (12.3 ± 5.3 days) and Group 4 (15.1 ± 3.1 days) (p < 0.05). There was a statistically significant difference between Groups 1 and 4 in penile length loss when the groups were compared in pairs (p = 0.017). There was a statistically significant difference between patients with penile curvatures of 0° to 59° and patients with curvatures of ≥60° in terms of duration of postoperative LOS (14.4 ± 5 vs. 16.4 ± 5.8 days, respectively; p = 0.028) and penile length loss (2.6 ± 5 vs. 5.7 ± 6.8 mm, respectively; p = 0.002). Conclusion: The findings suggest that EMGs should be preferred to autologous venous grafts due to reduced postoperative erectile dysfunction, shorter operation time, and shorter recovery time for LOS.

Treatment of an Exposed Achilles Tendon within a Refractory Mixed Arterial Venous Leg Ulcer with the Novel Use of Pericardium Allograft in Combination with Amniotic Allografting, Synthetic Extracellular Matrix, and Acellular Dermis Allografting: A Case Report.

Xenografts, commonly from porcine or bovine sources, have decades-long documented use in reconstructive surgery, including the repair of Achilles tendons. Despite decellularization processes, the risk of antigenicity with xenografts still poses a threat for graft failure. Allograft tissues reduce the risk of immune response and provide greater likelihood of successful grafting. SteriGraft® Pericardium (BSP) (Bone Bank Allografts, San Antonio, Texas) is a lyophilized allograft obtained from the pericardial sac that has undergone sterilization and processing for use in the surgical repair. The aim of this case study was to highlight the novel use of human pericardium allograft in the repair of an exposed Achilles tendon within a vascular ulceration with the concomitant use of synthetic extracellular matrix, amniotic allografting, dermal allografting, and negative pressure wound therapy to achieve healing of the wound and restoration of limb function.

Effect of Injectable Acellular Adipose Matrix on Soft Tissue Reconstruction in a Murine Model.

BACKGROUND: The extracellular matrix isolated from adipose tissue, known as acellular adipose matrix (AAM), represents a novel biomaterial. AAM functions as a scaffold that not only supports stem cell proliferation and differentiation but also induces adipogenesis and angiogenesis. This study aims to investigate the volumetric effects and microenvironmental changes associated with injectable AAM in comparison to conventional fat grafting. METHODS: AAM was manufactured from fresh human abdominoplasty fat using a mechanically modified method and then transformed into an injectable form. Lipoaspirate was harvested employing the Coleman technique. A weight and volume study was conducted on athymic nude mice by injecting either injectable AAM or lipoaspirate into the scalp (n=6 per group). After eight weeks, graft retention was assessed through weight measurement and volumetric analysis using micro-computed tomography (micro-CT) scanning. Histological analysis was performed using immunofluorescence staining for perilipin and CD31. RESULTS: Injectable AAM exhibited similar weight and volume effects in murine models. Histological analysis revealed comparable inflammatory cell presence with minimal capsule formation when compared to conventional fat grafts. Adipogenesis occurred in both AAM-injected and conventional fat graft models, with no significant difference in the blood vessel area (%) between the two. CONCLUSIONS: In summary, injectable AAM demonstrates effectiveness comparable to conventional fat grafting concerning volume effects and tissue regeneration in soft tissue reconstruction. This promising allogeneic injectable holds the potential to serve as a safe and effective "Off-the-Shelf" alternative in both aesthetic and reconstructive clinical practices. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Impact of Synthetic Extracellular Matrices in Combination Therapy with Amniotic Allografting in the Treatment of Diabetic Foot Wounds: A Case Series.

Synthetic extracellular matrices are artificial polymers that are elongated and deposited as a matrix of nanofibers which mimic the native extracellular matrix. RenovoDerm® Anthem™ Wound Matrix (Columbus, Ohio) is comprised of polyglycolic acid and poly (L-lactide-co-caprolactone) which degrade by hydrolysis into a-hydroxy and fatty acids, lowering the pH and promoting regenerative cellular activity including angiogenesis. Amniotic allografts contain growth factors, cytokines, amino acids, extracellular matrix proteins, and hyaluronic acid which are recognized as intrinsic to the wound healing process. Synthetic extracellular matrices alone or in combination with amnio allografts do not have large bodies of evidence which demonstrate their effectiveness in the treatment of wounds. Presently, no prior studies have been performed to assess what impact these therapies may have on wound healing when used concurrently. The aim of this investigation was to assess whether a synergistic effect is produced with combination therapy using synthetic extracellular matrix and amniotic allografting. In this article, we present four cases of diabetic foot ulcerations treated with combination therapy. An amniotic fluid allograft, and/or membrane amniotic allograft, was implanted with a synthetic extracellular matrix dressing over top of the graft(s) at weekly intervals. All wounds demonstrated a greater than 80% decrease in wound size within four applications and achieved more than 95% wound closure after six applications.

Entire Mitral Valve Reconstruction Using Porcine Extracellular Matrix: Adding a Ring Annuloplasty.

PURPOSE: This study investigated the implications of inserting a flexible annuloplasty ring after reconstructing the entire mitral valve in a porcine model using a previously investigated tube graft design made of 2-ply small intestinal submucosa extracellular matrix (CorMatrix®). METHODS: An acute model with eight 80-kg pigs, each acting as its own control, was used. The entire mitral valve was reconstructed with a 2-ply small intestinal submucosa extracellular matrix tube graft (CorMatrix®). Subsequently, a Simulus® flexible ring was inserted. The characterization was based on mitral annular geometry and valvular dynamics with sonomicrometry and echocardiography. RESULTS: After adding the ring annuloplasty, the in-plane annular dynamics were more constant throughout the cardiac cycle compared to the reconstruction alone. However, the commissure-commissure distance was statistically significantly decreased [35.0 ± 3.4 mm vs. 27.4 ± 1.9 mm, P < 0.001, diff = - 7.6 mm, 95% CI, - 9.8 to (-5.4) mm] after ring insertion, changing the physiological annular D-shape into a circular shape which created folds at the coaptation zone resulting in a central regurgitant jet on color Doppler. CONCLUSION: We successfully reconstructed the entire mitral valve using 2-ply small intestinal submucosal extracellular matrix (CorMatrix®) combined with a flexible annuloplasty. The annuloplasty reduced the unphysiological systolic widening previously found with this reconstructive technique. However, the Simulus flex ring changed the physiological annular D-shape into a circular shape and hindered a correct unfolding of the leaflets. Thus, we do not recommend a flexible ring in conjunction with this reconstructive technique; further investigations are needed to discover a more suitable remodelling annuloplasty.

Composite Biosynthetic Graft for Repair of Long-Segment Tracheal Stenosis: A Pilot In Vivo and In Vitro Feasibility Study.

Pediatric patients who undergo surgery for long-segment congenital tracheal stenosis (LSCTS) have suboptimal outcomes and postsurgical complications. To address this, we propose a biosynthetic graft comprising (1) a porcine small intestinal submucosa extracellular matrix (SIS-ECM) patch for tracheal repair, and (2) a resorbable polymeric exostent for biomechanical support. The SIS-ECM patch was evaluated in vivo in an ovine trachea model over an 8 month period. Concurrently, the biosynthetic graft was evaluated in a benchtop lamb trachea model for biomechanical stability. In vivo results show that SIS-ECM performs better than bovine pericardium (control) by preventing granulation tissue/restenosis, restoring tracheal architecture, blood vessels, matrix components, pseudostratified columnar and stratified epithelium, ciliary structures, mucin production, and goblet cells. In vitro tests show that the biosynthetic graft can provide the desired axial and flexural stability, and biomechanical function approaching that of native trachea. These results encourage future studies to evaluate safety and efficacy, including biomechanics and collapse risk, biodegradation, and in vivo response enabling a stable long-term tracheal repair option for pediatric patients with LSCTS and other tracheal defects.

Bone Marrow Aspirate Matrix: A Convenient Ally in Regenerative Medicine.

The rise in musculoskeletal disorders has prompted medical experts to devise novel effective alternatives to treat complicated orthopedic conditions. The ever-expanding field of regenerative medicine has allowed researchers to appreciate the therapeutic value of bone marrow-derived biological products, such as the bone marrow aspirate (BMA) clot, a potent orthobiologic which has often been dismissed and regarded as a technical complication. Numerous in vitro and in vivo studies have contributed to the expansion of medical knowledge, revealing optimistic results concerning the application of autologous bone marrow towards various impactful disorders. The bone marrow accommodates a diverse family of cell populations and a rich secretome; therefore, autologous BMA-derived products such as the "BMA Matrix", may represent a safe and viable approach, able to reduce the costs and some drawbacks linked to the expansion of bone marrow. BMA provides -it eliminates many hurdles associated with its preparation, especially in regards to regulatory compliance. The BMA Matrix represents a suitable alternative, indicated for the enhancement of tissue repair mechanisms by modulating inflammation and acting as a natural biological scaffold as well as a reservoir of cytokines and growth factors that support cell activity. Although promising, more clinical studies are warranted in order to further clarify the efficacy of this strategy.

Clinically Significant Outcomes Following the Treatment of Focal Cartilage Defects of the Knee With Microfracture Augmentation Using Cartilage Allograft Extracellular Matrix: A Multicenter Prospective Study.

PURPOSE: To determine the short-term outcomes following microfracture augmented with cartilage allograft extracellular matrix for the treatment of symptomatic focal cartilage defects of the adult knee. METHODS: Forty-eight patients enrolled by 8 surgeons from 8 separate institutions were included in this study. Patients underwent microfracture augmented by cartilage allograft extracellular matrix (BioCartilage; Arthrex, Naples, FL) and were followed at designated time points (3, 6, 12, and 24 months) to assess patient-reported outcomes (PROs), clinically significant outcomes (CSOs), and failure and complication rates. Magnetic resonance imaging (MRI) was offered at 2 years postoperatively regardless of symptomatology, and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 score was documented. RESULTS: PRO compliance was 81.3% at 6 months, 72.9% at 12 months, and 47.9% at 2 years. All joint-specific and function-related PROs significantly improved compared to baseline at 3, 6, 12, 18, and 24 months of follow-up (P < .01), apart from Marx activity scale, which demonstrated a significant decline in postoperative scores at 2 years (P = .034). The percentage of patients achieving CSOs (as defined for microfracture) at 2 years was 90% for minimal clinically important difference and 85% for patient acceptable symptomatic state. Patient factors including age, sex, body mass index, symptoms duration, smoking, presence of a meniscal tear, lesion size, and location were not associated with CSO achievement at 2 years. One patient (2.1%) failed treatment 9.5 months postoperatively due to graft delamination and required a reoperation consisting of arthroscopic debridement. One complication (2.1%) consisting of complaints of clicking, grinding, and crepitus 15 months following the index procedure was reported. Two-year postoperative MRI demonstrated a mean 40.5 ± 22.9 MOCART 2.0 score. CONCLUSIONS: In this preliminary study, we found cartilage allograft extracellular matrix to be associated with improvement in functional outcomes, high rates of CSO achievement, and low failure and complication rates at 2-year follow-up. LEVEL OF EVIDENCE: Level III, prospective multicenter cohort study.

A decellularized human corneal scaffold for anterior corneal surface reconstruction.

Allogenic transplants of the cornea are prone to rejection, especially in repetitive transplantation and in scarred or highly vascularized recipient sites. Patients with these ailments would particularly benefit from the possibility to use non-immunogenic decellularized tissue scaffolds for transplantation, which may be repopulated by host cells in situ or in vitro. So, the aim of this study was to develop a fast and efficient decellularization method for creating a human corneal extracellular matrix scaffold suitable for repopulation with human cells from the corneal limbus. To decellularize human donor corneas, sodium deoxycholate, deoxyribonuclease I, and dextran were assessed to remove cells and nuclei and to control tissue swelling, respectively. We evaluated the decellularization effects on the ultrastructure, optical, mechanical, and biological properties of the human cornea. Scaffold recellularization was studied using primary human limbal epithelial cells, stromal cells, and melanocytes in vitro and a lamellar transplantation approach ex vivo. Our data strongly suggest that this approach allowed the effective removal of cellular and nuclear material in a very short period of time while preserving extracellular matrix proteins, glycosaminoglycans, tissue structure, and optical transmission properties. In vitro recellularization demonstrated good biocompatibility of the decellularized human cornea and ex vivo transplantation revealed complete epithelialization and stromal repopulation from the host tissue. Thus, the generated decellularized human corneal scaffold could be a promising biological material for anterior corneal reconstruction in the treatment of corneal defects.

Engraftment of bioengineered three-dimensional scaffold from human amniotic membrane-derived extracellular matrix accelerates ischemic diabetic wound healing.

Human amniotic membrane (HAM) is traditionally used for the treatment of non-healing wounds. However, high density of HAM-matrix (HAM-M) diminishes cellular contribution for successful tissue regeneration. Herein we investigated whether a bioengineered micro-porous three-dimensional (3D) HAM-scaffold (HAM-S) could promote healing in ischemic wounds in diabetic type 1 rat. HAM-S was prepared from freshly decellularized HAM. Then, 30 days after inducing diabetes, an ischemic circular excision was generated on rats' skin. The diabetic animals were randomly divided into untreated (Diabetic group), engrafted with HAM-M (D-HAM-M group) and HAM-S (D-HAM-S group). Also, non-diabeticuntreated rats (Healthy group) were considered as control. Stereological, molecular, and tensiometrical assessments were performed on post-surgical days 7, 14, and 21. We found that the volumes of new epidermis and dermis, the numerical density of epidermal basal cells and fibroblasts, the length density of blood vessels, the numbers of proliferating cells and collagen deposition as well as biomechanical properties of healed wound were significantly higher in D-HAM-S group in most cases compared those of the diabetic group, or even in some cases compared to D-HAM-M group. Furthermore, in D-HAM-S group, the transcripts for genes contributing to regeneration (Tgf-ß, bFgf and Vegf) upregulated more than those of D-HAM-M group, when compared to diabetic ones. Overall, the HAM-S had more impact on delayed wound healing process compared to traditional use of intact HAM. It is therefore suggested that the bioengineered three dimensional micro-porous HAM-S is more suitable for cells adhesion, penetration, and migration for contributing to wounded tissue regeneration.

Extracellular Matrix Enterocutaneous Fistula Plugs Show Promise for Low-Flow Colocutaneous and Enterocutaneous Fistulae.

PURPOSE: To evaluate extracellular matrix enterocutaneous fistula plugs (ECMFPs) in treatment of enteric fistulae at a single institution. MATERIALS AND METHODS: The study included 18 patients who had an ECMFP placed between 2012 and 2018 with treatment follow-up through July 2020. Median patient age was 52.5 years (interquartile range, 11.5 y). There were 28 ECMFP procedures performed on 19 separate fistulae. Fistulae locations were gastrocutaneous (n = 4), enterocutaneous (n = 9), and colocutaneous (n = 6). Descriptive statistics were used to define closure rates, recurrence rates, and complications. RESULTS: Fistula closure was achieved in 1 of 4 gastrocutaneous (25%), 4 of 9 enterocutaneous (44%), and 3 of 6 colocutaneous (50%) locations. The median time from procedure to fistula tract closure was 29 days interquartile range 25 days. The median time from ECMFP placement to fistula recurrence was 28 days (interquartile range 27 days). Of the fistulae that eventually closed, 6 of 8 closed after the first attempt (75%), and 2 closed after the second attempt (25%). Of the procedures that resulted in complete closure, 7 of 8 were categorized as low flow, and 1 of 8 was categorized as high flow. Complications were seen in 4 patients (23%), with major complications in 3 patients (17%). CONCLUSIONS: Low-flow fistulae originating from the small bowel are most likely to have complete closure. High-flow and/or gastrocutaneous fistulae are less likely to benefit from this intervention. In patients who are not surgical candidates or who have failed surgical management, ECMFPs may provide a solution.

In vitro evaluation of surface biological properties of decellularized aorta for cardiovascular use.

The aim of this study was to determine an in vitro evaluation method that could directly predict in vivo performance of decellularized tissue for cardiovascular use. We hypothesized that key factors for in vitro evaluation would be found by in vitro assessment of decellularized aortas that previously showed good performance in vivo, such as high patency. We chose porcine aortas, decellularized using three different decellularization methods: sodium dodecyl-sulfate (SDS), freeze-thawing, and high-hydrostatic pressurization (HHP). Immunohistological staining, a blood clotting test, scanning electron microscopy (SEM) analysis, and recellularization of endothelial cells were used for the in vitro evaluation. There was a significant difference in the remaining extracellular matrix (ECM) components, ECM structure, and the luminal surface structure between the three decellularized aortas, respectively, resulting in differences in the recellularization of endothelial cells. On the other hand, there was no difference observed in the blood clotting test. These results suggested that the blood clotting test could be a key evaluation method for the prediction of in vivo performance. In addition, evaluation of the luminal surface structure and the recellularization experiment should be packaged as an in vitro evaluation because the long-term patency was probably affected. The evaluation approach in this study may be useful to establish regulations and a quality management system for a cardiovascular prosthesis.

Bioreactivity of decellularized animal, plant, and fungal scaffolds: perspectives for medical applications.

Numerous biomedical applications imply supportive materials to improve protective, antibacterial, and regenerative abilities upon surgical interventions, oncotherapy, regenerative medicine, and others. With the increasing variability of the possible sources, the materials of natural origin are among the safest and most accessible biomedical tools. Animal, plant, and fungal tissues can further undergo decellularization to improve their biocompatibility. Decellularized scaffolds lack the most reactive cellular material, nuclear and cytoplasmic components, that predominantly trigger immune responses. At the same time, the outstanding initial three-dimensional microarchitecture, biomechanical properties, and general composition of the scaffolds are preserved. These unique features make the scaffolds perfect ready-to-use platforms for various biomedical applications, implying cell growth and functionalization. Decellularized materials can be repopulated with various cells upon request, including epithelial, endothelial, muscle and neuronal cells, and applied for structural and functional biorepair within diverse biological sites, including the skin and musculoskeletal, cardiovascular, and central nervous systems. However, the molecular and cellular mechanisms behind scaffold and host tissue interactions remain not fully understood, which significantly restricts their integration into clinical practice. In this review, we address the essential aspects of decellularization, scaffold preparation techniques, and its biochemical composition and properties, which determine the biocompatibility and immunogenicity of the materials. With the integrated evaluation of the scaffold profile in living systems, decellularized animal, plant, and fungal scaffolds have the potential to become essential instruments for safe and controllable biomedical applications.

Applications of decellularized materials in tissue engineering: advantages, drawbacks and current improvements, and future perspectives.

Decellularized materials (DMs) are attracting more and more attention because of their native structures, comparatively high bioactivity, low immunogenicity and good biodegradability, which are difficult to be imitated by synthetic materials. Recently, DMs have been demonstrated to possess great potential to overcome the disadvantages of autografts and have become a kind of promising material for tissue engineering. In this systematic review, we aimed to not only provide a quick access for understanding DMs, but also bring new ideas to utilize them more appropriately in tissue engineering. Firstly, the preparation of DMs was introduced. Then, the updated applications of DMs derived from different tissues and organs in tissue engineering were comprehensively summarized. In particular, their advantages, drawbacks and current improvements were emphasized. Moreover, we analyzed and proposed future perspectives.

Mitral Valve Replacement in Pediatrics Using an Extracellular Matrix Cylinder Valve: A Case Series.

Mitral valve replacement (MVR) in children under 2 years is associated with significant morbidity and mortality. Decellularized porcine intestinal submucosa is a commercially available formulation of an extracellular matrix (ECM) with an indication for cardiac tissue repair. The present study reports our experience using ECM cylinder valves in patients for MVR. A retrospective review of patients under 2 years who underwent ECM custom-made cylinder mitral valve (ECM-MV) replacement was performed. Clinical, demographic, operative and post-operative follow-up data, including serial echocardiographic data are presented. Eight patients (age 5.6 ± 1.6 months; weight: 6.0 ± 1.1 kg) were identified who underwent ECM-MVR. There was one in-hospital death and no major neurological events. Six patients underwent replacement of their cylinder valve with either a Melody valve inside the ECM-MVR (n = 3), a mechanical valve (n = 2), or a decellularized bovine pericardial cylinder valve (n = 1). The mean time to replacement surgery was 8.4 ± 2.6 months after ECM-MV. The indications for replacement of ECM-MV included mitral stenosis/regurgitation (n = 4) or dehiscence (n = 2). One remaining patient is 24 months from ECM-MV, with trivial regurgitation and no stenosis. Mitral valve creation using ECM is an option for MVR in pediatrics, avoiding anticoagulation, and provides a suitable construct for later placement of a Melody valve, extending surgical and non-surgical options. However, the durability of the native ECM-MV in the mitral position is concerning considering the high re-intervention rate in a relatively short time period. Further studies are needed to determine the longer-term outcomes of this valve in this complex patient population.

In vivo testing of an injectable matrix gel for the treatment of shoulder cuff muscle fatty degeneration.

INTRODUCTION: Extracellular matrix (ECM) gels have shown efficacy for the treatment of damaged tissues, most notably cardiac muscle. We hypothesized that the ECM gel prepared from skeletal muscle could be used as a treatment strategy for fatty shoulder cuff muscle degeneration. METHODS: We conducted experiments to (1) evaluate host biocompatibility to ECM gel injection using a rat model and (2) examine the effect of ECM gel injection on muscle recovery after delayed repair of a released supraspinatus (SSP) tendon using a rabbit model. RESULTS: The host biocompatibility to the ECM gel was characterized by a transient rise (first 2 weeks only) in several genes associated with macrophage infiltration, matrix deposition, and inflammatory cytokine production. By 8 weeks all genes had returned to baseline levels and no evidence of fibrosis or chronic inflammation was observed from histology. When gel injection was combined with SSP tendon repair, we observed a significant reduction (7%) in SSP muscle atrophy (24 + 3% reduction from uninjured) when compared with treatment with tendon repair only (31 + 7% reduction). Although fatty degeneration was elevated in both treatment groups, fat content trended lower (2%) in response to combined tendon repair and intramuscular ECM injection (4.1 + 2.1%) when compared with tendon repair only (6.1 + 2.9%). Transcriptome analysis revealed adipogenesis and osteoarthritis pathway activation in the repair only group. These key pathways were abrogated in response to treatment using combined repair plus gel. DISCUSSION: The findings suggest that ECM injection had a modest but positive effect on muscle mass, fatty degeneration, and key cellular signaling pathways.

Pancreatic extracellular matrix and platelet-rich plasma constructing injectable hydrogel for pancreas tissue engineering.

The development of pancreatic extracellular matrices enriched with insulin-secreting ß-cells is a promising tissue engineering approach to treat type 1 diabetes. However, its long-term therapeutic efficacy is restricted by the defensive mechanism of host immune response and the lack of developed vascularization as appropriate after transplantation. Platelet-rich plasma (PRP), as an autologous platelet concentrate, contains a large number of active factors that are essential for the cell viability, vascularization, and immune regulation. In this study, we have incorporated pancreatic extracellular matrix (PEM) with PRP to develop a three-dimensional (3D) injectable PEM-PRP hydrogel to coculture and transplant rat insulinoma cells (INS-1) and human umbilical vein endothelial cells (HUVECs). Results from this study demonstrated that PEM-PRP hydrogel mimicked the biochemical compositions of native extracellular matrices, and possessed the enhanced elastic modulus and resistance to enzymatic degradation that enabled biomaterials to maintain its volume and slowly degrade. Additionally, PEM-PRP hydrogel could release growth factors in a sustained manner. In vitro, PEM-PRP hydrogel significantly promoted the viability, insulin-secreting function, and insulin gene expression of gel encapsulated INS-1 cells. Moreover, HUVECs encapsulated in PEM-PRP hydrogel were found to constitute many lumen-like structures and exhibited high expression of proangiogenic genes. In vivo transplantation of PEM-PRP hydrogel encapsulated with INS-1 cells and HUVECs improved the viability of INS-1 cells, promoted vascularization, inhibited the host inflammatory response, and reversed hyperglycemia of diabetic rats. Our study suggests that the PEM-PRP hydrogel offers excellent biocompatibility and proangiogenic property, and may serve as an effective biomaterial platform to maintain the long-term survival and function of insulin-secreting ß cells.

Outcomes of Dog Bite Avulsion Injury Reconstruction With Urinary Bladder Matrix.

Dog bite avulsion injuries of the head and neck are difficult to manage in pediatric patients. This study assesses the outcomes of using porcine urinary bladder extracellular matrix (UBM) for reconstruction of these complete avulsion injuries. Five male pediatric patients underwent reconstruction using UBM. Two (40%) patients underwent reconstruction of the nose; the other 3 patients underwent reconstruction of the forehead, forehead/glabella, and auricle. The average size of the avulsion defect was 7.0 ± 2.4 cm2. No patient developed wound dehiscence, graft loss, or wound infection. Four (80%) patients received pulsed dye laser treatment to improve wound cosmesis. Use of UBM is a safe and effective reconstructive option after dog bite avulsion injuries of the head and neck. Given the advantages of convenient availability and avoidance of donor site morbidity, UBM can be considered for reconstruction of posttraumatic avulsion injuries or Mohs defects.

Fabrication of Corneal Extracellular Matrix-Derived Hydrogels.

Hydrogels derived from corneal extracellular matrix (ECM) represent a promising biomaterial for corneal repair and regeneration. To fabricate these hydrogels, first corneas need to be decellularized using repeated freeze-thaw cycles and nucleases to remove all nuclear and cellular components. The remaining corneal ECM is lyophilized to remove all water and milled into a fine powder. The ECM powder is weighed and dissolved in pepsin solution at a concentration of 20 mg/mL. Hydrogels are formed by neutralizing the pH of the solution and maintaining it at 37 °C until fibrillogenesis has occurred. Corneal stromal cells may be suspended throughout the hydrogel solution prior to gelation to generate a corneal stromal substitute.