Urinary Bladder Extracellular Matrix Research Articles

Evaluation of biocompatibility and angiogenic potential of extracellular matrix hydrogel biofunctionalized with the LL-37 peptide.

Biomaterials must allow revascularization for a successful tissue regeneration process. Biomaterials formulated from the extracellular matrix (ECM) have gained popularity in tissue engineering because of their superior biocompatibility, and due to their rheological properties, ECM-hydrogels can be easily applied in damaged areas, allowing cell colonization and integration into the host tissue. Porcine urinary bladder ECM (pUBM) retains functional signaling and structural proteins, being an excellent option in regenerative medicine. Even some small molecules, such as the antimicrobial cathelicidin-derived LL-37 peptide have proven angiogenic properties. The objective of this study was to evaluate the biocompatibility and angiogenic potential of an ECM-hydrogel derived from the porcine urinary bladder (pUBMh) biofunctionalized with the LL-37 peptide (pUBMh/LL37). Macrophages, fibroblasts, and adipose tissue-derived mesenchymal stem cells (AD-MSC) were exposed pUBMh/LL37, and the effect on cell proliferation was evaluated by MTT assay, cytotoxicity by quantification of lactate dehydrogenase release and the Live/Dead Cell Imaging assays. Moreover, macrophage production of IL-6, IL-10, IL-12p70, MCP-1, INF-γ, and TNF-α cytokines was quantified using a bead-based cytometric array. pUBMh/LL37 was implanted directly by dorsal subcutaneous injection in Wistar rats for 24 h to evaluate biocompatibility, and pUBMh/LL37-loaded angioreactors were implanted for 21 days for evaluation of angiogenesis. We found that pUBMh/LL37 did not affect cell proliferation and is cytocompatible to all tested cell lines but induces the production of TNF-α and MCP-1 in macrophages. In vivo, this ECM-hydrogel induces fibroblast-like cell recruitment within the material, without tissue damage or inflammation at 48 h. Interestingly, tissue remodeling with vasculature inside angioreactors was seen at 21 days. Our results showed that pUBMh/LL37 is cytologically compatible, and induces angiogenesis in vivo, showing potential for tissue regeneration therapies.

A Comparative Study of the Resorption and Immune Response for Two Starch-Based Hemostat Powders

IntroductionPowder hemostats are valuable adjuncts to minimize intraoperative and postoperative complications. In addition to promotion of rapid coagulation, resorption, and biocompatibility are desirable attributes. Plant starch-based polysaccharide hemostat powders are effective and widely used hemostatic agents, however their source and/or processing can affect characteristics such as in vivo degradability. For example, Arista is a purified/hydrolyzed starch powder that is rapidly resorbed in vivo; whereas PerClot shows slow resorption and preservation of a crystalline form. Materials and methodsIn the present study, we compared the cellular response to the hemostatic agents PerClot and Arista both in vitro and in vivo, and used potato starch and urinary bladder extracellular matrix (UBM-ECM) as high crystallinity/slowly resorbable and prohealing controls, respectively. ResultsAll test articles and their degradation products were cytocompatible in vitro as measured by cell viability and metabolic activity of bone-marrow macrophages. PerClot induced a stronger proinflammatory, M1-like macrophage response in vitro (P < 0.001) than Arista, likely due to differences in source composition. Histologic examination of the in vivo surgical site showed the almost complete degradation of Arista after 12 h (day 0), whereas both PerClot and potato starch were still present at 28 d with crystals identifiable with polarized light microscopy and periodic acid Schiff (PAS) staining. Macrophage phenotype in vivo showed no differences between PerClot and Arista. Collagen deposition and mononuclear cell accumulation consistent with an early foreign body response were present around PerClot and potato starch crystals, whereas no such cell or connective tissue deposition was noted at the site of Arista or UBM-ECM placement.

Increased extracellular matrix stiffness accompanies compromised bladder function in a murine model of radiation cystitis

Radiation cystitis, a long-term bladder defect due to pelvic radiation therapy, results in lower urinary tract symptoms, such as urinary frequency and nocturia, suggestive of compromised bladder compliance. The goal of this study was to identify alterations to the mechanical behavior of the urinary bladder extracellular matrix of a murine model of radiation cystitis, at 3 and 6 months after radiation exposure. The results of this study demonstrated that the extracellular matrix of irradiated bladders was significantly less distensible when compared to age matching controls. These findings coincided with functional bladder changes, including increased number of voids and decreased voided volume. Both mechanical and functional changes were apparent at 3 months post-irradiation and were statistically significant at 6 months, demonstrating the progressive nature of radiation cystitis. Overall, the results of this study indicate that irradiation exposure changes both the mechanical and physiological properties of the bladder. Statement of significanceIn humans, radiation cystitis results in lower urinary tract symptoms, such as urinary frequency and nocturia, suggestive of compromised bladder compliance. This pathology can significantly affect recovery and quality of life for cancer survivors. Gaining knowledge about how alterations to the mechanical behavior of the urinary bladder extracellular matrix can affect urinary function will have a significant impact on this population. The results of this study demonstrated that the extracellular matrix of irradiated bladders was significantly less distensible when compared to age matching controls, in a mouse model of radiation cystitis. These findings were accompanied by functional voiding changes, including increased number of voids and decreased voided volume. The results of this study uncovered that irradiation exposure changes the mechanical and physiological properties of the bladder.

A liquid fraction of extracellular matrix inhibits glioma cell viability in vitro and in vivo.

Suppressive effects of extracellular matrix (ECM) upon various cancers have been reported. Glioblastoma multiforme has poor prognosis and new therapies are desired. This work investigated the effects of a saline-soluble fraction of urinary bladder ECM (ECM-SF) upon glioma cells. Viability at 24 hours in 1, 5, or 10 mg/mL ECM-SF-spiked media was evaluated in primary glioma cells (0319, 1015, 1119), glioma cell lines (A172, T98G, U87MG, C6), and brain cell lines (HCN-2, HMC3). Viability universally decreased at 5 and 10 mg/mL with U87MG, HCN-2, and HCM3 being least sensitive. Apoptosis in 0319 and 1119 cells was confirmed via NucView 488. Bi-weekly intravenous injection of ECM-SF (120 mg/kg) for 10 weeks in Sprague-Dawley rats did not affect weight, temperature, complete blood count, or multi-organ histology (N = 5). Intratumoral injection of ECM-SF (10 uL of 30 mg/mL) at weeks 2–4 post C6 inoculation in Wistar rats increased median survival from 24.5 to 51 days (hazard ratio for death 0.22) and decreased average tumor volume at time of death from 349 mm3 to 90 mm3 over 10 weeks (N = 6). Mass spectrometry identified 2,562 protein species in ECM-SF, parent ECM, and originating tissue. These results demonstrate the suppressive effects of ECM on glioma and warrant further study.

Tissue response, macrophage phenotype, and intrinsic calcification induced by cardiovascular biomaterials: Can clinical regenerative potential be predicted in a rat subcutaneous implant model?

The host immune response to an implanted biomaterial, particularly the phenotype of infiltrating macrophages, is a key determinant of biocompatibility and downstream remodeling outcome. The present study used a subcutaneous rat model to compare the tissue response, including macrophage phenotype, remodeling potential, and calcification propensity of a biologic scaffold composed of glutaraldehyde-fixed bovine pericardium (GF-BP), the standard of care for heart valve replacement, with those of an electrospun polycarbonate-based supramolecular polymer scaffold (ePC-UPy), urinary bladder extracellular matrix (UBM-ECM), and a polypropylene mesh (PP). The ePC-UPy and UBM-ECM materials induced infiltration of mononuclear cells throughout the thickness of the scaffold within 2 days and neovascularization at 14 days. GF-BP and PP elicited a balance of pro-inflammatory (M1-like) and anti-inflammatory (M2-like) macrophages, while UBM-ECM and ePC-UPy supported a dominant M2-like macrophage phenotype at all timepoints. Relative to GF-BP, ePC-UPy was markedly less susceptible to calcification for the 180 day duration of the study. UBM-ECM induced an archetypical constructive remodeling response dominated by M2-like macrophages and the PP caused a typical foreign body reaction dominated by M1-like macrophages. The results of this study highlight the divergent macrophage and host remodeling response to biomaterials with distinct physical and chemical properties and suggest that the rat subcutaneous implantation model can be used to predict in vivo biocompatibility and regenerative potential for clinical application of cardiovascular biomaterials.

Palmar Resurfacing of the Hand With Porcine Urinary Bladder Extracellular Matrix Following Traumatic Injury

Complex wounds of the hand often result in soft tissue defects that are not amenable to primary closure, vacuum-assisted closure, or tissue expansion. Injuries presenting with large defects involving multiple levels of tissue must be addressed by using techniques at higher rungs on the reconstructive ladder, such as split-thickness grafting, pedicled flaps, or free flaps. When repairing palmar tissue, these techniques fall short due to their failure to approximate structure and function of specialized skin. More recently, dermal substitutes containing a decellularized extracellular matrix (ECM) have been used in reconstruction of soft tissue defects, acting as a structural scaffold for the regrowth of native cells. Extracellular matrix products have been shown to improve functional and sensory outcomes in areas requiring highly specialized skin. Urinary bladder matrix (UBM), a porcine ECM scaffold, is unique in that it contains an intact epithelial basement membrane that promotes more organized regrowth through layered structure. This case presents a novel use of this product in resurfacing 80% of a palm after postoperative necrosis following a table saw injury to the right volar palm at the distal crease. The patient had intact sensation and near normal functional outcomes at most recent follow up. The UBM may be a valuable adjunct to achieve soft tissue coverage in large, complex hand wounds, particularly those involving the palmar surfaces.

Porcine Urinary Bladder Extracellular Matrix for Treatment of Periocular Skin Defects.

To describe the experience of 4 oculoplastic surgeons with porcine bladder matrix for periocular anterior lamella and donor site skin defects either as stand-alone treatment or in conjunction with other reconstructive procedures. The authors hypothesized that defect size and location influence the requirement for additional matrix treatments or ancillary procedures. Following the Institutional Review Board approval, the authors conducted a retrospective review of 17 patients treated with porcine bladder matrix at 2 oculoplastic practices between 2016 and 2018. Powdered matrix was applied to the skin defect and overlaid with a matrix sheet. Subsequent rounds of matrix treatment or other reconstructive procedures were performed as necessary. Defect size and location were correlated to the number of ancillary matrix treatments or surgical procedures via univariate analysis. Twenty-five sites (21 primary and 4 donor) in 17 individuals (8-95 years, M = 58.8 years, 10 males) were treated with porcine bladder matrix. All wounds healed successfully. Additional matrix treatments were administered at 5 sites. Ancillary procedures were performed for 7 sites. Upper lid involvement and larger defect size tended to require additional ancillary procedures (p = 0.006), while lower eyelid and other periocular defects required fewer procedures (p < 0.001). Porcine bladder matrices are useful adjuncts to healing periocular anterior lamella defects in various settings. Such repairs are useful in nonsurgical candidates, but must take into account varying levels of complexity based on lesion location. Smaller defects are more conducive to application of matrices as stand-alone treatment, while larger or upper eyelid defects often require additional procedures.

Utility of decellularised urinary bladder extracellular matrix in full mucosalisation of a post-oncological maxillectomy defect.

This report highlights the utility of MatriStem Surgical Matrix Thick UBM™ (rebranded as Gentrix® ACell, Inc), a decellularised urinary bladder extracellular matrix in the reconstruction of a post-oncological maxillectomy defect. In utilising this biological construct to serve as a biological dressing, our patient underwent complete mucosalisation of his surgical site without the development of an oroantral fistula and with adequate maxillary vestibule to allow for definitive oral rehabilitation with a removable partial denture.

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.

2957 Non-Mesh Sacrospinous Ligament Suspension for the Correction of Massive Vaginal Vault Prolapse and Ascites in A Patient With Stage IV Metastatic Colon Cancer

Video Objective The objective of this video is to demonstrate a non-mesh sacrospinous ligament (SSL) suspension for massive vaginal vault prolapse with ascites in a patient with stage IV metastatic colon cancer. Polyether-ether-ketone (PEEK) anchors and porcine bladder extracellular matrix for fixation and bio-scaffolding are utilized. The patient desired to undergo definitive surgical treatment of her symptomatic prolapse for the purposes of “personal dignity”. The patient also desired to maintain sexual options. Fixation utilizing PEEK anchors provides a vaginal repair that requires less dissection than traditional approaches to the SSL since anchoring is performed via palpation rather than tissue visualization. This is of great importance in patients with massive vault prolapse because of the obliteration of the operative field. The extracellular matrix provides bio-scaffolding which promotes constructive remodeling of the tissue rather than encapsulation of synthetic mesh. Risks and benefits were discussed at length including the direct spread of disease if the peritoneal cavity were entered. Synthetic polypropelene mesh continues to show diminishing acceptance with patients and continues to be a source of mass tort litigation. Internationally several jurisdictions have restricted the accessibility or banned the use of transvaginal mesh. Setting St. Agnes Hospital, Baltimore, Maryland Interventions The patient underwent transvaginal SSL suspension, anterior and posterior colporrhaphy, vaginal enterocele repair and perineoplasty utilizing PEEK anchors and porcine urinary bladder extracellular matrix. There were no intra-operative or post-operative complications. The follow up has been 8 months. The patient is currently sexually active. Conclusion Sacrospinous ligament suspension for the correction of massive vaginal vault prolapse utilizing PEEK anchors and porcine urinary bladder extracellular matrix is a reasonable alternative to transvaginal synthetic mesh repairs. Advantages to this vaginal approach include: 1) Avoidance of laparoscopic risks in a patient with massive ascites, 2) Avoidance of chronic pain, erosion and extrusion associated with synthetic mesh.

Impact of polypropylene prolapse mesh on vaginal smooth muscle in rhesus macaque

The use of polypropylene prolapse mesh to treat pelvic organ prolapse has been limited by mesh-related complications. Gynemesh PS mesh, implanted via sacrocolpopexy in rhesus macaques, had a negative impact on the vagina with thinning of vaginal muscularis and decreased vaginal smooth muscle contractility. The negative effect was attenuated when a bioscaffold derived from urinary bladder extracellular matrix was used as a composite with Gynemesh PS. The objective of the study was to further elucidate the impact of Gynemesh PS polypropylene mesh and MatriStem extracellular matrix bioscaffolds on the vaginal smooth muscle in terms of micromorphology of vaginal smooth muscle (muscle bundles and individual myocytes), innervation, and nerve-mediated contractile function following their implantations in a rhesus macaque model via sacrocolpopexy. Thirty-two middle-aged rhesus macaques were randomized to undergo either a sham surgery (sham, n= 8), or the implantation of Gynemesh PS alone (n= 8) vs composite mesh comprised of Gynemesh PS plus 2-ply MatriStem (n= 8) vs 6-ply MatriStem alone (n= 8) via sacrocolpopexy. The graft-vagina complexes were harvested 3 months later. Histomorphometrics of smooth muscle bundles and myocytes were performed by immunofluorescent labeling of alpha smooth muscle actin, caveolin-3 (membrane protein), and cell nuclei followed by confocal imaging. The cross-sectional diameters of smooth muscle bundles and individual myocytes were quantified using images randomly taken in at least 5 areas of each section of sample. Contractile proteins alpha smooth muscle actin and smoothelin were quantified by Western immunoblotting. Nerve density was measured by immunohistochemical labeling of a pan-neuron marker, PGP9.5. Nerve-mediated smooth muscle contractility was quantified using electrical field stimulation. One-way analysis of variance and appropriate post hoc tests were used for statistical comparisons. Compared with sham, the implantation of Gynemesh PS alone resulted in a disorganized smooth muscle morphology with the number of small muscle bundles (cross-sectional diameter less than 20 μm) increased 67% (P= .004) and the myocyte diameter decreased 22% (P < .001). Levels of contractile proteins were all decreased vs sham with alpha smooth muscle actin decreased by 68% (P= .009), low-molecular-weight smoothelin by 51% (P= .014), and high-molecular-weight smoothelin by 40% (P= .015). Nerve density was decreased by 48% (P= .03 vs sham) paralleled by a 63% decrease of nerve-mediated contractility (P= .02). Following the implantation of composite mesh, the results of measurements were similar to sham (all P > .05), with a 39% increase in the myocyte diameter (P < .001) and a 2-fold increase in the level of alpha smooth muscle actin relative to Gynemesh (P= .045). Following the implantation of MatriStem alone, the number of small muscle bundles were increased 54% vs sham (P= .002), while the other parameters were not significantly different from sham (all P > .05). The implantation of Gynemesh PS had a negative impact on the structural and functional integrity of vaginal smooth muscle evidenced by atrophic macro- and microscopic muscle morphology, decreased innervation, and impaired contractile property, consistent with a maladaptive remodeling response. The extracellular matrix bioscaffold (MatriStem), when used with Gynemesh PS as a composite (2 ply), attenuated the negative impact of Gynemesh PS; when used alone (6 ply), it induced adaptive remodeling as evidenced by an increased fraction of small smooth muscle bundles with normal contractility.

744 - Mid-Urethral Sling: Utilizing Porcine Urinary Bladder Extra-Cellular Matrix (ECM) and Poly-Ether-Ether-Ketone (PEEK) Anchors

Objective: The objective of this video is to demonstrate the surgical technique for the insertion of a biologic mid-urethral sling (MUS) for the treatment of stress urinary incontinence (SUI) utilizing polyetheretherketone (PEEK) anchors and porcine urinary bladder extra-cellular matrix (ECM).

2036 Extracellular matrix as a novel approach to glioma therapy

2036 Extracellular matrix as a novel approach to glioma therapy

Роль структурных изменений внеклеточного матрикса мочевого пузыря в возникновении побочных эффектов лучевой терапии разной степени тяжести

To investigate the role of structural changes of the urinary bladder extracellular matrix in the occurrence of different grades of adverse events after radiation therapy. The connective tissue matrix was studied using 126 images obtained from the histological sections of the bladder biopsy specimens of 12 patients classified according to the clinical presentation and the grades of late bladder toxicity according to RTOG/EORTC Late Radiation Morbidity Scoring Scheme. Control images of the normal bladder (n=23) were collected from the autopsy samples. We used nonlinear microscopy imaging method capturing the second harmonic generation (SHG) signal and two-photon excitation auto-fluorescence (TPEA). The findings of nonlinear microscopy of urinary bladder histological sections showed that the structural changes in the connective tissue differed depending on the grade of adverse events: grade II adverse events were associated with the preservation of the structure of collagen fibers and their compression, grade III adverse events caused pronounced disorganization of collagen fibers, blurring without a definite fiber direction. At the same time, in a normal bladder, the structure of collagen fibers was visualized; they had a spiral shape and in some areas were collected in bundles. Collagen fibers and bundles were loosely arranged and accompanied by elastic fibers. The findings suggest that the grade of urinary bladder radiation injury correlates with the data detected by nonlinear microscopy. The mosaic structure of radiation-induced alterations of the bladder tissue, even in the areas most affected by radiation (posterior bladder wall, bladder trigone, and bladder neck) indicates that patients with radiation-induced high-grade toxicity need comprehensive care designed to preserve the bladder functional reserves and capacity. The prevention of radiation-related adverse events before radiation therapy should be based on urologic care aimed to detect and treat chronic inflammatory diseases of the bladder and preserve its functional reserves. Another way to improve outcomes is to optimize the management of adverse events. The examination of bladder tissue specimens taken from different parts of the bladder carried out using nonlinear microscopy in the SHG and TPEA modes revealed that the degree of structural changes in the connective tissue matrix in the post-radiation period varies and correlates with the grades of the radiation bladder toxicity. The results of this study can be used to substantiate measures to prevent the onset of high-grade toxicity after radiation therapy of pelvic malignancies.

Fetal extracellular matrix nerve wraps locally improve peripheral nerve remodeling after complete transection and direct repair in rat

In peripheral nerve (PN) injuries requiring surgical repair, as in PN transection, cellular and ECM remodeling at PN epineurial repair sites is hypothesized to reduce PN functional outcomes by slowing, misdirecting, or preventing axons from regrowing appropriately across the repair site. Herein this study reports on deriving and analyzing fetal porcine urinary bladder extracellular matrix (fUB-ECM) by vacuum assisted decellularization, fabricating fUBM-ECM nerve wraps, and testing fUB-ECM nerve wrap biocompatibility and bioactivity in a trigeminal, infraorbital nerve (ION) branch transection and direct end-to-end repair model in rat. FUB-ECM nerve wraps significantly improved epi- and endoneurial organization and increased both neovascularization and growth associated protein-43 (GAP-43) expression at PN repair sites, 28-days post surgery. However, the number of neurofilament positive axons, remyelination, and whisker-evoked response properties of ION axons were unaltered, indicating improved tissue remodeling per se does not predict axon regrowth, remyelination, and the return of mechanoreceptor cortical signaling. This study shows fUB-ECM nerve wraps are biocompatible, bioactive, and good experimental and potentially clinical devices for treating epineurial repairs. Moreover, this study highlights the value provided by precise, analytic models, like the ION repair model, in understanding how PN tissue remodeling relates to axonal regrowth, remyelination, and axonal response properties.

Porcine Urinary Bladder Extracellular Matrix for the Salvage of Fibula Free Flap Skin Paddle: Technical Note and Description of a Case.

This report establishes a novel application of a commercially available porcine urinary bladder extracellular matrix, MatriStem (ACell, Inc., Columbia, MD), in the salvage of partial loss of the skin paddle of a fibula osteoseptocutaneous free flap that was utilized for mandibular reconstruction.

Mechanical reinforcement of urinary bladder matrix by electrospun polycaprolactone nanofibers

For a successful bladder tissue repair and reconstruction, fabrication of scaffolds with proper biochemical and biomechanical characteristics is necessary. Decellularized bladder tissue has been proposed in previous studies as a gold standard material for scaffold fabrication. However, the weak mechanical properties for such load-bearing tissue has remained a challenge. Incorporation of both biological and synthetic materials has been known as an effective strategy for improving mechanical and biological properties of the scaffolds. In present work, a simple process is developed to fabricate hybrid hydrogel scaffolds with a biomimetic architecture from the natural urinary bladder extracellular matrix (ECM) and synthetic polycaprolactone (PCL) nanofibers, in order to obtain a scaffold with optimized mechanical and biological properties for bladder tissue engineering. To this gaol, the ECM gel was derived from rat bladder and the electrospun PCL nanofibers was embedded within the gel, followed by incubating the composite to shape the hybrid hydrogel. These reinforced scaffolds showed more structural integrity and mechanical stability. The introduced concept of nanofiber-reinforced ECM can be applied as a promising platform in engineering of bladder or other load-bearing soft tissues.

Urinary bladder extracellular matrix hydrogels and matrix-bound vesicles differentially regulate central nervous system neuron viability and axon growth and branching

Central nervous system neurons often degenerate after trauma due to the inflammatory innate immune response to injury, which can lead to neuronal cell death, scarring, and permanently lost neurologic function. Extracellular matrix bioscaffolds, derived by decellularizing healthy tissues, have been widely used in both preclinical and clinical studies to promote positive tissue remodeling, including neurogenesis, in numerous tissues, with extracellular matrix from homologous tissues often inducing more positive responses. Extracellular matrix hydrogels are liquid at room temperature and enable minimally invasive extracellular matrix injections into central nervous system tissues, before gelation at 37℃. However, few studies have analyzed how extracellular matrix hydrogels influence primary central nervous system neuron survival and growth, and whether central nervous system and non-central nervous system extracellular matrix specificity is critical to neuronal responses. Urinary bladder extracellular matrix hydrogels increase both primary hippocampal neuron survival and neurite growth to similar or even greater extents, suggesting extracellular matrix from non-homologous tissue sources, such as urinary bladder matrix-extracellular matrix, may be a more economical and safer alternative to developing central nervous system extracellular matrices for central nervous system applications. Additionally, we show matrix-bound vesicles derived from urinary bladder extracellular matrix are endocytosed by hippocampal neurons and positively regulate primary hippocampal neuron neurite growth. Matrix-bound vesicles carry protein and RNA cargos, including noncoding RNAs and miRNAs that map to the human genome and are known to regulate cellular processes. Thus, urinary bladder matrix-bound vesicles provide natural and transfectable cargoes which offer new experimental tools and therapeutic applications to study and treat central nervous system neuron injury.

Use of Scaffolding Tissue Biografts To Bolster Vesicourethral Anastomosis During Salvage Robot-assisted Prostatectomy Reduces Leak Rates and Catheter Times

BackgroundOne of the key factors contributing to morbidity associated with salvage radical prostatectomy is a significant vesicourethral anastomosis (VUA) disruption or postoperative tissue dehiscence in the region of the distal bladder neck that causes a large prolonged urinary leak, perineal pain, and delayed catheter removal. ObjectiveTo describe our surgical technique using a urinary bladder extracellular matrix (UB-ECM) scaffold incorporated into the base of the VUA and the distal bladder neck during salvage robot-assisted radical prostatectomy (sRARP) and to assess outcomes and safety. Design, setting, and participantsFrom March to July 2015, 15 patients underwent sRARP performed after primary therapy failure by a single surgeon. Two other groups were identified via analysis of propensity score matching. Group 2 (n=45) underwent sRARP with standard suturing without use of the graft. Group 3 (control group; n=45) underwent primary RARP with no graft placement. These two groups were compared group 1 (n=15), in which patients underwent sRARP and received the scaffold in a 1:3:3 match. Surgical proceduresRARP with use of a UB-ECM scaffold in the posterior aspect of the VUA and distal bladder neck. Outcome measurements and statistical analysisClinical data were prospectively collected in a customized database and retrospectively analyzed. Analysis of variance and Student's t-test were used to test the equality of means for continuous variables, while the χ2 test was used to test categorical variables. Results and limitationsThere were no anastomotic leaks in the control group, with an average catheter time of 6.3 d (5–7 d). However, a clinically significant VUA/bladder neck disruption was observed in 16 patients (35.5%) in group 2, with a median catheterization time of 17.4 d (9–47 d), while in group 1 only one patient (6.66%) had a significant anastomotic leak on cystography (p=0.045), with median catheterization time of 11.2 d (10–52 d) for this group (p<0.05). ConclusionsIncorporation of a UB-ECM scaffold into the base of the VUA and distal bladder neck should be considered as an option to decrease morbidity associated with sRARP since it decreased the rate of VUA disruption, enhanced healing, and reduced catheterization time. This technique could be a valuable tool for all surgeons performing sRARP. Patient summaryWe investigated the use of a scaffolding tissue graft when connecting the urethra to the bladder during salvage robot-assisted laparoscopic prostatectomy. This technique was found to be effective and safe.

In vitro evaluation of acellular porcine urinary bladder extracellular matrix – A potential scaffold in tissue engineered skin

Abstract Current tissue engineered skin substitutes employ a cellular scaffold, typically a collagen biopolymer to support the transfer of cells to the wound bed. These scaffolds however, exhibit poor approximation of epidermal–dermal histogenesis and delayed vascularisation upon implantation in vivo. In this study we evaluate a novel decellularised extracellular matrix (ECM) scaffold derived from the porcine urinary bladder wall; termed urinary bladder matrix (UBM). ECM scaffolds possess intrinsic angiogenic properties in the form of functional proteins and potent angiogenic growth factors. They have repeatedly demonstrated rapid angiogenesis and constructive remodelling in clinical trials. UBM is notable for containing an epithelial basement membrane, which offers improved approximation of epidermal–dermal histogenesis. In this study human dermal fibroblasts were seeded on UBM constructs in vitro. UBM ultrastructure was assessed using scanning electron microscopy and histology sections. Cell/scaffold interactions were examined, including cellular adhesion, proliferation, migration and protein synthesis using quantitative indicators. Cell morphology was determined using scanning electron microscopy. The study demonstrated that UBM supported the viability of human dermal fibroblasts. Cells displayed uninhibited proliferation and collagen synthesis was supported. Histological analysis showed the cells had organised spatially via the basement membrane. Cells grown on the basement membrane surface formed a monolayer while those grown on the opposite abluminal surface penetrated the scaffold. A high degree of cellular attachment was observed on the luminal and abluminal surfaces, 93.068 ± 2.3% and 92.045 ± 4.3%, respectively with no significant difference between the two surfaces ( P = 0.121, n = 3). This study demonstrates that UBM fulfils the fundamental properties for scaffold design and is a promising novel scaffold for future skin tissue engineering efforts.