Acellular Matrix Graft Research Articles

The Use of Vascular Endothelial Growth Factor with Silk Fibroin Scaffolds and Bladder Acellular Matrix Grafts to Support Bladder Reconstruction in Rabbit Model

The Use of Vascular Endothelial Growth Factor with Silk Fibroin Scaffolds and Bladder Acellular Matrix Grafts to Support Bladder Reconstruction in Rabbit Model

279 Bladder acellular matrix grafts seeded with adipose-derived stem cells and incubated intraperitoneally promote the regeneration of bladder smooth muscle in a rat model of bladder augmentation

279 Bladder acellular matrix grafts seeded with adipose-derived stem cells and incubated intraperitoneally promote the regeneration of bladder smooth muscle in a rat model of bladder augmentation

Bladder Acellular Matrix Grafts Seeded with Adipose-Derived Stem Cells and Incubated Intraperitoneally Promote the Regeneration of Bladder Smooth Muscle and Nerve in a Rat Model of Bladder Augmentation.

The objective of this study was to investigate the feasibility of bladder acellular matrix grafts (BAMGs) seeded with adipose-derived stem cells (ASCs) followed by intraperitoneal incubation for bladder reconstruction in a rat model of bladder augmentation, and to explore the underlying mechanism. Autologous CM-DiI-labeled ASC-seeded (experimental group) and unseeded (control group) BAMGs were incubated in the peritoneum of male rats for 2 weeks and then harvested for bladder augmentation. Histological analysis of the incubated BAMGs revealed numerous cells growing in homogeneous collagen bundles in both groups. In the control BAMGs, these cells were mesenchyme derived, while in the ASC-seeded BAMGs, myofibroblasts and mesothelial cells were found inside and on the surface of the scaffold, respectively. Immunofluorescence analysis demonstrated that some of the myofibroblasts were transdifferentiated from the ASCs after 2 weeks of intraperitoneal incubation. The greater bladder capacity was found in the experimental group than the control group both 4 and 14 weeks postoperatively. Histological analysis revealed that the entire urothelium regenerated well both in the experimental group and the control group without significant difference 4 weeks and 14 weeks postoperatively. From the quantitative data of immunohistochemical and immunofluorescence staining, the smooth muscle cells (SMCs) regenerated significantly better in the experimental group than the control group both 4 weeks and 14 weeks postoperatively. Also significantly more nerve cells were found in the experimental group 14 weeks postoperatively. At 4 weeks postoperatively, the immunofluorescence double staining revealed that some SMCs in the BAMG were transdifferentiated from the implanted ASCs, but no CM-DiI labeling of ASCs was detected 14 weeks postoperatively. Taken together, our results demonstrate that ASC-seeded and peritoneally incubated BAMGs promote not only the morphological regeneration of the bladder smooth muscle and nerve, but also the bladder capacity, which indicates their potential for bladder regeneration.

Time-dependent bladder tissue regeneration using bilayer bladder acellular matrix graft-silk fibroin scaffolds in a rat bladder augmentation model

With advances in tissue engineering, various synthetic and natural biomaterials have been widely used in tissue regeneration of the urinary bladder in rat models. However, reconstructive procedures remain insufficient due to the lack of appropriate scaffolding, which should provide a waterproof barrier function and support the needs of various cell types. To address these problems, we have developed a bilayer scaffold comprising a porous network (silk fibroin [SF]) and an underlying natural acellular matrix (bladder acellular matrix graft [BAMG]) and evaluated its feasibility and potential for bladder regeneration in a rat bladder augmentation model. Histological (hematoxylin and eosin and Masson’s trichrome staining) and immunohistochemical analyses demonstrated that the bilayer BAMG-SF scaffold promoted smooth muscle, blood vessel, and nerve regeneration in a time-dependent manner. At 12weeks after implantation, bladders reconstructed with the BAMG-SF matrix displayed superior structural and functional properties without significant local tissue responses or systemic toxicity. These results demonstrated that the bilayer BAMG-SF scaffold may be a promising scaffold with good biocompatibility for bladder regeneration in the rat bladder augmentation model.

Intraperitoneal incubation of bladder acellular matrix grafts improves bladder smooth muscle regeneration via neovascularization

The objective of this study was to investigate whether intraperitoneal incubation improves the regenerative capacity of bladder acellular matrix grafts (BAMGs) in a rat model of bladder augmentation. After 2 weeks of incubation in the peritoneum of male rats, BAMG flaps with vascular pedicles were harvested for autologous bladder augmentation. As the control, BAMGs were directly used for bladder augmentation without intraperitoneal incubation. Histological analyses of the incubated BAMGs demonstrated extensive cell growth and vasculature in homogeneous collagen bundles. The cells were positive for vimentin and negative for α-smooth muscle actin and pan-cytokeratin AE1/AE3. Cystography revealed smoother contours of the augmented bladders in the incubated group at 4 and 12 weeks postoperatively. However, the bladder capacity was not significantly different between the two groups. In both groups, the entire urothelium regenerated well without obvious differences. At both time points, compared with the control group, increased numbers of smooth muscle cells (SMCs) and blood vessels were found in the incubated group. At 12 weeks, the SMCs in the incubated group were more similar to those in the native smooth muscle fiber bundles of the bladder. Taken together, our results demonstrated that BAMGs preincubated in the peritoneum promote the regeneration of bladder smooth muscle via neovascularization in a rat bladder augmentation model.

Bladder Acellular Matrix Graft Reinforced Silk Fibroin Composite Scaffolds Loaded VEGF with Aligned Electrospun Fibers in Multiple Layers.

Bombyx mori silk is of great interest to people for its outstanding mechanical and biological properties. However, the traditional electrospun regenerated silk fibroin (RSF) scaffolds from aqueous solution were weak and had limited applications. This study was to fabricate reinforced scaffolds with well-aligned RSF fibers electrospun on a layer of native extracellular matrix, bladder acellular matrix graft (BAMG). The silk fibroin fibers were well-aligned as a grill in multiple layers. Both the BAMG and the grill structure significantly improved the tensile properties and suture retention of the composite scaffolds, which can be sutured well with tissue during implantation. In vitro assay indicates that the scaffolds had a good biocompatibility. Porcine iliac endothelial cells (PIECs) attached and proliferated well on the vascular endothelial growth factor (VEGF) loaded scaffolds compared with those without VEGF. Moreover, the grill-like structure guides PIECs well along the aligned fiber.

Results of Acellular Dermis Matrix graft used for Tympanoplasty in Guinea pig model.

To describe the underlay tympanoplasty technique using an acellular dermal graft(AlloDerm) for tympanic membrane (TM) reconstruction in a guinea pig model and to demonstrate the feasibility of the technique using AlloDerm tissue harvested from the prepuce as a source of tissue for future grafting in human TM reconstruction. The prepuce was divided during circumcision and the acellular dermis was prepared using a number of standard processes. Two groups of guinea pigs were prepared. In the case group (20 guinea pigs and 40 ears) removal of TM was performed with tympanoplasty using AlloDerm, and in the control group (eight guinea pigs and 16 ears), removal of TM was performed without tympanoplasty. In each group, the TM was completely removed in one ear and partially removed on the other side, and the integrity of the TMs was re-evaluated after 8 weeks. In the case group, the healing rates in the completely and partially removed TMs were 83.3% and 94.4%, respectively. The difference in healing rate (0% and 66.7%, respectively) was statistically significant (P<0.05). The use of AlloDerm is safe and effective in the repair of TM perforations in a guinea pig model. Acceptable results of AlloDerm tympanoplasty in a guinea pig model may pave the way for the effective use of this material in human TM reconstructions.

Application of composite skin grafts consisting of allogeneic acellular dermal matrix and autologous scalp to the repair of defects after excision of giant pigmented nevi in children

Objective To evaluate the efficacy of composite skin grafts consisting of allogeneic acellular dermal matrix and autologous scalp in the repair of defects after excision of giant pigmented nevi in children.Methods Eighteen children with giant pigmented nevi were included in this study.All the patients received excision of giant pigmented nevi.The defects were repaired using composite skin grafts consisting of allogeneic acellular dermal matrix and autologous razor-thin scalp grafts in 10 children from June 2009 to October 2012 (test group),and using autologous thin or intermediate-thickness skin grafts in 8 children from March 2006 to May 2009 (control group).Donor site healing time,skin graft survival rate,and the degree of scar proliferation were compared between the two groups.Results Significant differences were observed at donor sites between the test group and control group in healing time ((5.31 ± 1.45) vs.(11.63 ± 1.69) days,P ＜ 0.05) and scar score (1.62 ± 0.38 vs.6.38 ± 0.58,P ＜ 0.05).At recipient sites,the survival rate of skin grafts was similar between the test group and control group ((94.44 ± 2.56)％ vs.(95.13 ± 3.13)％,P ＞ 0.05),while scar score was significantly different (5.38 ±0.62 vs.8.40 ± 0.41,P ＜ 0.05).Conclusion Composite skin grafts consisting of allogeneic acellular dermal matrix and autologous scalp appear to be a good option for the repair of defects after excision of giant pigmented nevi in children,with minor donor-site injuries and satisfying cosmetic and functional outcomes at recipient sites. Key words: Nevus; Child; Skin transplantation; Dermis

Comparison of oral mucosa vs.homologous dermal acellular matrix graft for complex anterior urethral stricture

Objective To evaluate the clinical efficacy of oral mucosal graft in the treatment of complex anterior urethral stricture and to compare this technique with homologous dermal acellular matrix graft (AMG).Methods From January 2006 to August 2012,the clinical data and therapeutic methods of 51 patients with complex anterior urethral stricture were retrospectively reviewed,including 26 cases of oral mucosal graft urethroplasty and 25 cases of acellular matrix graft urethroplasty.The operative time,intraoperative blood loss,complication ratio and success rate were compared between two groups.Results All the operations were implemented smoothly.In oral mucosal graft group and acellar matrix graft group,the operative time was (138.3 ± 12.4) min and (119.1 ± 11.7) min (P ＜ 0.05),intraoperative blood loss was (45.2 ± 8.4) ml and (39.3 ± 6.7) ml (P ＞ 0.05),postoperative peak flow rate (PFR) was (20.1 ± 1.7) ml/s and (19.8 ±2.1) ml/s (P＞0.05),urinary fistula rate was 3.8％ (1/26) and 4.0％ (1/25) (P ＞ 0.05),incidence of urethral stricture was 7.7％ (2/26) and 32.0％ (8/25) (P ＜ 0.05),and success rate was 88.5 ％ (23/26) and 64.0％ (16/25) (P ＜ 0.05),respectively.Conclusion Oral mucosal urethroplasty for complex anterior urethral stricture has the advantage of more satisfactory effectiveness and lower reccurrence rate than acellular matrix graft urethroplasty. Key words: Urethral stricture; Mouth mucosa; Acellular matrix graft

1079 Intraperitoneal prefabricated bladder acellular matrix grafts to improve bladder smooth muscle regeneration and neovascularization in a rat model

1079 Intraperitoneal prefabricated bladder acellular matrix grafts to improve bladder smooth muscle regeneration and neovascularization in a rat model

179 Human umbilical mesenchymal stem cells-seeded bladder acellular matrix grafts for reconstruction of bladder defects in a canine model

179 Human umbilical mesenchymal stem cells-seeded bladder acellular matrix grafts for reconstruction of bladder defects in a canine model

Epithelial-Differentiated Adipose-Derived Stem Cells Seeded Bladder Acellular Matrix Grafts for Urethral Reconstruction: An Animal Model

The limited amount of available epithelial tissue is considered a main cause of the high rate of urethral reconstruction failures. The aim of this study was to investigate whether epithelial-differentiated rabbit adipose-derived stem cells (Epith-rASCs) could play a role of epithelium in vivo functionally and be a potential substitute of urothelium. Substitution urethroplasty was performed to repair an anterior urethral defect in male New Zealand rabbits using Epith-rASCs seeded bladder acellular matrix grafts (BAMGs) after 5-bromo-2'-deoxyuridine (BrdU) labeling, based on the in vitro epithelial induction system we previously described. Urethroplasty with cell-free BAMGs and with undifferentiated rASCs (Und-rASCs) seeded BAMGs were performed as controls. After surgery, a notable amelioration of graft contracture and recovery of urethral continuity were observed in the Epith-rASCs/BAMG group by retrograde urethrograms and macroscopic inspection. Immunofluorescence revealed that the BrdU-labeled Epith-rASCs/Und-rASCs colocalized with cytokeratin 13 or myosin. Consistent with the results of western blotting, at early postimplantation stage, the continuous epithelial layer with local multilayered structure was observed in the Epith-rASCs/BAMG group, whereas no significant growth and local monolayer growth profile of epithelial cells were observed in the BAMG and Und-rASCs/BAMG group, respectively. The results showed that Epith-rASCs could serve as a potential substitute of urothelium for urethral tissue engineering and be available to prevent lumen contracture and subsequent complications including recurrent stricture.

Correction: Human Umbilical Mesenchymal Stem Cells-Seeded Bladder Acellular Matrix Grafts for Reconstruction of Bladder Defects in a Canine Model

Correction: Human Umbilical Mesenchymal Stem Cells-Seeded Bladder Acellular Matrix Grafts for Reconstruction of Bladder Defects in a Canine Model

Human Umbilical Mesenchymal Stem Cells-Seeded Bladder Acellular Matrix Grafts for Reconstruction of Bladder Defects in a Canine Model

BackgroundThe goal of this study was to explore the feasibility of utilizing human umbilical mesenchymal stem cells (HUMSCs)-seeded Bladder acellular matrix graft (BAMG) for bladder reconstruction in a canine model.Methodology/Principal FindingsHUMSCs were isolated from newborn umbilical cords and identified by flow cytometry. Partial cystectomy was performed in the experimental and control group. Bladder defects were repaired with HUMSCs-BAMG in the experimental group and repaired with unseeded-BAMG in control group. The implanted grafts were harvested after surgery. H&E and immunohistochemistry staining were performed to evaluate the regeneration of the bladder defect. Primary cultured HUMSCs displayed typical fibroblast morphology with spindle-shaped. Flow cytometry indicated that these cells were positive for CD105 (97.3%) and CD44 (99%), but negative for CD34 (2.8%), CD31 (2.1%), and CD45 (1.7%). Immunohistochemistry staining showed that a multilayered urothelium and well-developed smooth muscle were observed at 12 weeks in experiment group. In contrast, multilayered urothelial tissues were also observed at 12 weeks in group B, but well-developed smooth muscle bundles were observed.Conclusions/SignificanceOur preliminary results demonstrate that UMSC-seeded BAMGs are superior to unseeded BAMGs to promote the regeneration of bladder defects. Our findings indicated that HUMSCs may be a potential cell source for bladder tissue engineering.

Continued sustained release of VEGF by PLGA nanospheres modified BAMG stent for the anterior urethral reconstruction of rabbit

ObjectiveTo study the biocompatibility and neovascularization of the PLGA nanospheres wrapped with vascular endothelial growth factor (VEGF), which can improve bladder acellular matrix graft (BAMG) with local continuous release of VEGF. MethodsA total of 18 rabbit model (length of stenosis: 3cm) with anterior urethral stricture were used as experimental animals and divided into three groups. Group A as the control group: Simple BAMG scaffold materials for urethral reconstruction. Group B as the blank group: PLGA microspheres modified BAMG for urethral reconstruction. Group C: PLGA conjugated with VEGF and modified BAMG for the urethral reconstruction. All rabbits underwent urethral angiography after 7 days, 15 days, 1 month and 3 months after the operation, and one rabbit in each group was sacrificed to be prepared for the organization histologic examination, HE staining, masson staining, CD31, 34 and a-SAM immunohistochemical detection in the repaired sites. ResultsIn group A, significant urethral restenosis occurred in two rabbits after 15 days of the operation, HE and masson staining showed a lot of collagen arranged in the repaired sites, and there were a large number of inflammatory cell infiltration, and there were also CD31, 34 in the repaired sites. a-SAM microvascular tag count showed a small amount of microvascular; Group B showed anastomotic restenosis, HE and masoon staining showed inflammatory cell infiltration and collagen deposition; Group C: urethrography showed lumen patency. There were a small amount of inflammatory cell infiltration after 7 and 15 days after the operation, and there were also CD31, 34 in the repaired sites. The a-SAM microvascular tag count showed many microvascular. And the difference was significant. ConclusionsAnterior urethral reconstruction with sustained-release of VEGF by PLGA nanospheres modified BAMG stents can reduce postoperative restenosis. It can also reduce collagen deposition and scar formation, promote angiogenesis of the repair tissue; therefore it in valuable in the tissue-engineered urethral reconstruction.

Preliminary experimental study of urethral reconstruction with tissue engineering and RNA interference techniques.

This study investigated the feasibility of replacing urinary epithelial cells with oral keratinocytes and transforming growth factor-β1 (TGF-β1) small interfering RNA (siRNA)-transfected fibroblasts seeded on bladder acellular matrix graft (BAMG) in order to reconstruct tissue-engineered urethra. Constructed siRNAs, which expressed plasmids targeting TGF-β1, were transfected into rabbit fibroblasts. The effective siRNA was screened out by RT-PCR and was transfected into rabbit fibroblasts again. Synthesis of type I collagen in culture medium was measured by enzyme-linked immuno sorbent assay (ELISA). Autologous oral keratinocytes and TGF-β1 siRNA-transfected fibroblasts were seeded onto BAMGs to obtain a tissue-engineered mucosa. The tissue-engineered mucosa was assessed morphologically and with the help of scanning electron microscopy. The TGF-β1 siRNA decreased the expression of fibroblasts synthesis type I collagen. Oral keratinocytes and TGF-β1 siRNA-transfected fibroblasts were seeded onto sterilized BAMG to obtain a tissue-engineered mucosa for urethral reconstruction. The compound graft was assessed using scanning electron microscope. Oral keratinocytes and TGF-β1 siRNA-transfected fibroblasts had a good compatibility with BAMG. The downregulation of fibroblasts synthesis type I collagen expression by constructed siRNA interfering TGF-β1 provided a potential basis for genetic therapy of urethral scar. Oral keratinocytes and TGF-β1 siRNA-transfected fibroblasts had good compatibility with BAMG and the compound graft could be a new choice for urethral reconstruction.

253 EPITHELIAL-DIFFERENTIATED ADIPOSE-DERIVED STEM CELLS SEEDED BLADDER ACELLULAR MATRIX GRAFTS FOR URETHRAL RECONSTRUCTION: AN ANIMAL MODEL

You have accessJournal of UrologyStem Cell Research1 Apr 2013253 EPITHELIAL-DIFFERENTIATED ADIPOSE-DERIVED STEM CELLS SEEDED BLADDER ACELLULAR MATRIX GRAFTS FOR URETHRAL RECONSTRUCTION: AN ANIMAL MODEL Hong-Bin Li, Yue-Min Xu, Qiang Fu, Chao Li, Qin Zhang, Min-Kai Xie, and Ying Wang Hong-Bin LiHong-Bin Li Shanghai, China, People's Republic of More articles by this author , Yue-Min XuYue-Min Xu Shanghai, China, People's Republic of More articles by this author , Qiang FuQiang Fu Shanghai, China, People's Republic of More articles by this author , Chao LiChao Li Shanghai, China, People's Republic of More articles by this author , Qin ZhangQin Zhang Shanghai, China, People's Republic of More articles by this author , Min-Kai XieMin-Kai Xie Shanghai, China, People's Republic of More articles by this author , and Ying WangYing Wang Shanghai, China, People's Republic of More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.1635AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The limited amount of available epithelial tissue is considered a main cause of the high rate of urethral reconstruction failures. The aim of this study was to investigate whether epithelial-differentiated rabbit adipose-derived stem cells (Epith-rASCs) could play a role of epithelium in vivo functionally and be a potential substitute of urothelium. METHODS Substitution urethroplasty was performed to repair an anterior urethral defect in male New Zealand rabbits using Epith-rASCs seeded bladder acellular matrix grafts (BAMGs) after 5-bromo-2`-deoxyuridine (BrdU) labeling of the implanted cells, based on the in vitro epithelial induction system we previously described. Urethroplasty with unseeded BAMGs, and with undifferentiated rASCs (Und-rASCs) seeded BAMGs were performed as controls. After operation, retrograde urethrograms and macroscopic inspection were performed for the assessment of urethral caliber and continuity. Immunofluorescent staining and western blot analysis were performed to evaluate the development of BrdU labeled Epith-rASCs and epithelial markers expression. RESULTS A notable amelioration of graft contracture and recovery of urethral continuity were observed in the Epith-rASCs/BAMG group, in contrast to the two controls. Immunofluorescence revealed that the labeled Epith-rASCs/Und-rASCs colocalized with cytokeratin 13 and myosin. Consistent with the results of the western blot analysis, at 1 and 2 months postimplantation, multi-layered epithelial cells were observed in the Epith-rASCs/BAMG group, whereas no significant growth and local monolayer growth profile of epithelial cells were observed in BAMG group and Und-rASCs/BAMG group, respectively. CONCLUSIONS The results showed that Epith-rASCs could produce functional effects of urothelium as seeding cells for urethral tissue engineering, and be available to prevent lumen contracture and subsequent complications including recurrent stricture. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e104 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hong-Bin Li Shanghai, China, People's Republic of More articles by this author Yue-Min Xu Shanghai, China, People's Republic of More articles by this author Qiang Fu Shanghai, China, People's Republic of More articles by this author Chao Li Shanghai, China, People's Republic of More articles by this author Qin Zhang Shanghai, China, People's Republic of More articles by this author Min-Kai Xie Shanghai, China, People's Republic of More articles by this author Ying Wang Shanghai, China, People's Republic of More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Lichtenstein repair of indirect inguinal hernias with acellular tissue matrix grafts in adolescent patients: a prospective, randomized, controlled trial

To evaluate the outcomes of Lichtenstein hernioplasty using acellular tissue matrix (ACTM) grafts in adolescent patients. One hundred patients, 13-18years old, with primary unilateral indirect inguinal hernias, were randomly assigned to receive Lichtenstein hernioplasty using ACTM or traditional high ligation of the hernia sac (control group).The outcome measures were the length of the operation, postoperative visual analogue scale (VAS) pain score, length of hospitalization, postoperative complications and recurrence rate. The length of hospitalization and VAS score were not different between the groups, and the minimum follow-up was 30months. No postoperative wound infections, chronic postoperative pain or local foreign body sensation occurred in either group. Six patients (14.3%) in the experimental group and five (11.6%) in the control group developed scrotal hydroceles (P>0.05); all resolved with conservative management. There were no recurrences in the experimental group, while there were three (6%) in the control group (P>0.05) and all occurred in patients with Gilbert type 3 hernias. Lichtenstein hernioplasty using ACTM grafts has comparable safety and efficacy to traditional high ligation of the indirect hernia sac in adolescent patients. ACTM can reduce the incidence of recurrence in adolescents with Gilbert type 3 hernias.

Urethral Reconstruction With Tissue Engineering and RNA Interference Techniques in Rabbits

To investigate the feasibility of replacing urinary epithelial cells with oral keratinocytes and transforming growth factor β (TGF-β)1 siRNA transfected fibroblasts seeded on bladder acellular matrix graft (BAMG) to reconstruct urethra. Autologous oral keratinocytes and TGF-β1 siRNA transfected fibroblasts were seeded onto BAMGs to obtain a tissue-engineered mucosa. The tissue-engineered mucosa was assessed using morphology and scanning electron microscopy. In 27 male rabbits, a ventral urethral mucosal defect was created. Urethroplasty was performed with autogenic oral keratinocyte and TGF-β1 siRNA transfected fibroblast-seeded BAMGs (9 rabbits, group 1), with autogenic oral keratinocyte-seeded BAMGs (9 rabbits, group 2) or with BAMGs with no cell seeding (9 rabbits, group 3). Retrograde urethrography and histological analyses were performed to evaluate the results of urethroplasty. In vitro, oral keratinocytes and TGF-β1 siRNA transfected fibroblasts had good biocompatibility with BAMGs. In vivo, the urethra kept a wide caliber in groups 1 and 2. Strictures were observed in group 3. Histologically, the retrieved urethra in group 3 showed fibrosis and inflammation during 6 months. Stratified epithelial layer regenerated in group 2, whereas there was no evidence of formation of capillary in the epithelial lower layer during the study period. Stratified epithelial layer and formation of capillary in the epithelial lower layer were evident after 6 months in group 1. Our study suggested that oral keratinocytes and TGF-β1 siRNA transfected fibroblasts could be used as a source of seed cells for urethral tissue engineering.

Simultaneous implantation of bilateral ureters into bladder acellular matrix graft after partial cystectomy in a porcine model

What's known on the subject? and What does the study add? The process of bladder regeneration with a bladder acellular matrix graft (BAMG) is thought to be accelerated by administration of vascular endothelial growth factor into the host bladder. In the present study, we showed that simultaneous implantation of bilateral ureters into a BAMG after a partial cystectomy is reasonable and provides an increased opportunity to the bio-scaffold for communication with host tissues from which a blood supply and stem cells will be generated. • To evaluate if the implantation of bilateral ureters into a bladder acellular matrix graft (BAMG) at the time of its implantation would enhance bladder regeneration in a partial substitution BAMG. • Partial cystectomies were performed under general anaesthesia in 12 pigs, followed by augmentation with a BAMG. • Six (ureteric implantation group) also received simultaneous implantation of bilateral ureters into the BAMG, while the remaining six (control group) did not have ureteric implantation. • In both groups, bladder regeneration was evaluated using endoscopic and histopathological methods at 1, 2, 4, and 8 weeks after implantation. • At 1 week after BAMG implantation, there were significant inflammatory changes on the host bladder in both groups, while no significant endoscopic changes were seen on the BAMG luminal surfaces. • At 2 weeks, inflammatory changes were diminished and epithelialisation on the BMAG was identified, especially near the host bladder in both groups. • Similarly, epithelialisation on the BAMG near the implanted ureters was seen in the ureteric implantation group. • At 4 and 8 weeks, epithelialisation remained in progress in both groups, although it was more active and expansive in the ureteric implantation group. • In our porcine model, endoscopic and histopathological examinations showed that simultaneous implantation of bilateral ureters into a BAMG enhanced epithelialisation of the AMG. • This new approach using host ureters and bladder as a potential source of bladder regeneration may provide for rapid and complete regeneration of a bladder substitute.