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Partial resection of the urinary bladder in swine and sheep and replacement of the resected segment by biologically inert patches. ACTA VET BRNO 2019. [DOI: 10.2754/avb201887040347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study was performed to examine the adequacy of biological inert patches as a substitute material for the construction of urinary bladder replacement tissue. An animal model experiment was conducted in six sheep and six swine. In all animals partial resection of the urinary bladder was performed; round or oval-shaped, 5–6 cm in diameter. Patches of the same shape, 4–5 cm in diameter were used. Two types of patches, polytetrafluorethylene and small intestinal submucosa were tested in the experiment, sewn with an absorbable 4-0 polydioxanone suture. Following 16 weeks the animals were euthanized followed by autopsy and histologic analysis. All animals showed evidence of bladder regeneration at the replaced segment. The patches were found to be contracted to 12–20 mm in length and 8–10 mm in width, attached to the bladder mucosa with their smaller base and protruding into the bladder lumen. In some animals, no shrunk patches were found, suggesting they had been passed out by urine. Histologically, fibrous tissue completely replacing the substitute tissue was identified with endothelial-lined luminal surface and submucosal and serosal ingrowth of new blood vessels. The replacement tissue showed no evidence of muscle layer ingrowth. Bladder capacity was also measured and no significant decrease was recorded. Our experiment demonstrated the formation of replacement tissue at the site of graft implantation, which allows the resection of a larger portion of bladder without decreasing its capacity and thus constitutes a very good method for surgical treatment of urinary bladder tumours and other defects.
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Wang F, Liu T, Yang L, Zhang G, Liu H, Yi X, Yang X, Lin TY, Qin W, Yuan J. Urethral reconstruction with tissue-engineered human amniotic scaffold in rabbit urethral injury models. Med Sci Monit 2014; 20:2430-8. [PMID: 25424000 PMCID: PMC4257484 DOI: 10.12659/msm.891042] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Mitigating urethral injury remains a great challenge for urologists due to lack of ideal biomaterials for urethroplasty. The application of amniotic membranes (AM) over other synthetic materials make it a better potential source for urethral reconstruction. We separated the basement layer of AM to obtain denuded human amniotic scaffold (dHAS) and then inoculated primary rabbit urethral epithelial cells on the surface of dHAS to define whether this strategy minimize potential rejection and maximize the biocompatibility of human AM. MATERIAL/METHODS After the successful acquisition of dHAS from AM, cell-seeded dHAS were prepared and characterized. Both cell-seeded dHAS and acellular dHAS were subcutaneously implanted. Immune responses were compared by histological evaluation and CD4 cell and CD8 cell infiltrations. Then they were applied as urethroplastic materials in the rabbit models of urethral injury to fully explore the feasibility and efficacy of tissue-engineered dHAS xenografts in urethral substitution application. RESULTS Mild inflammatory infiltration was observed in cell-seeded dHAS grafts, as revealed by fewer accumulations of CD4 cells and CD8 cells (or neutrophils or other immune cells). Urethral defects of rabbits in the urethroplastic group with dHAS implantation (n=6) were completely resolved in one month, while there were one infection and one fistula in the control group with acellular dHAS patches (n=6). Histopathological analysis revealed mild immune response in cell-seeded dHAS group (P<0.05). CONCLUSIONS Tissue-engineered dHAS minimize potential rejection and maximize the biocompatibility of AM, which makes it a potential ideal xenograft for urethral reconstruction.
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Affiliation(s)
- Fuli Wang
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland)
| | - Tao Liu
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China (mainland)
| | - Lijun Yang
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland)
| | - Geng Zhang
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland)
| | - Heliang Liu
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland)
| | - Xiaomin Yi
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland)
| | - Xiaojian Yang
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland)
| | - Tzu-yin Lin
- Department of Internal Medicine, University of California - Davis, Sacramento, USA
| | - Weijun Qin
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland)
| | - Jianlin Yuan
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland)
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Sabetkish N, Kajbafzadeh AM, Sabetkish S, Tavangar SM. Augmentation cystoplasty using decellularized vermiform appendix in rabbit model. J Pediatr Surg 2014; 49:477-83. [PMID: 24650482 DOI: 10.1016/j.jpedsurg.2013.07.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 07/22/2013] [Accepted: 07/25/2013] [Indexed: 11/16/2022]
Abstract
PURPOSE The aim of this study was to produce a decellularized rabbit vermiform appendix (sacculus rotundus) and investigate its feasibility in bladder augmentation or appendicovesicostomy. The superiority of sacculus rotundus over other tissues is its unique mechanical properties as well as its abundant collagen content. MATERIALS AND METHODS The acellular matrix of vermiform appendix underwent different laboratory investigations prior to transplantation. We divided 12 rabbits into 3 groups: group I underwent bladder augmentation cystoplasty by detubularized acellular matrix. Group II underwent implantation of the tapered (tubularized) acellular matrix just beneath the seromuscular part of the bladder without connection to the bladder urothelium. Group III underwent the same procedure as group II plus reimplantation of tapered and tubularized acellular matrix (simulating an appendicovesicostomy). The distal end of the transplanted graft was connected to the bladder mucosal opening and was intubated by a 5Fr double blind ended feeding tube catheter. Biopsies were taken 3, 12, and 36months post-operatively for further histological and immunohistochemical analyses. RESULTS The results of the examinations performed prior to transplantation, revealed a decellularized structure resembling the native tissue with intact extracellular matrix, normal pits and appropriate gaps that will be suitable for further cell seeding. Histopathology examination of the biopsies after transplantations confirmed successful cell seeding with urothelial lining in groups I and III, while the inner lumen in group II showed no urothelial lining. CONCLUSION The results suggest that we can prospect to perform bladder reconstruction by the application of this method without complications of previously reported augmentation cystoplasty. In the current study we used the bladder as a natural bioreactor for autologous recellularization which may pave the road for clinical application in acellular matrix augmentation cystoplasty.
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Affiliation(s)
- Nastaran Sabetkish
- Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI)
| | - Abdol-Mohammad Kajbafzadeh
- Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI).
| | - Shabnam Sabetkish
- Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI)
| | - Seyyed Mohammad Tavangar
- Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran (IRI)
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Zhang Y, Atala A. Urothelial cell culture: stratified urothelial sheet and three-dimensional growth of urothelial structure. Methods Mol Biol 2013; 945:383-99. [PMID: 23097119 DOI: 10.1007/978-1-62703-125-7_23] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Urothelial cells line the urinary tract, including the renal pelvis, ureters, bladder, superior urethra, and the central ducts of the prostate. They are highly specialized epithelial cell types possessing unique features, imparting important functional roles in the urinary system. They act as a permeability barrier and protect underlying muscle tissues from the caustic effects of urine while also expanding with bladder filling to adjust urine pressures. The multilayered urothelium is typically structured with differentiated, mature surface cells and less mature basal cells. The basal cell layer contains tissue-specific stem cells able to self-renew for the lifetime of the mammal and also produces a pool of maturing cells for tissue homeostasis. Maintaining regenerative basal cells in a culture facilitates urothelial cell growth in vitro. Additionally, epithelial-mesenchymal communication, epithelial-matrix interactions, and cytokines/growth factors are required to maintain the normal structure and function of mature urothelial cells in vitro and to induce stem cell differentiation into urothelial cells. These cultures are useful to study the biology and physiology of the urinary tract, particularly for the development of cell-based tissue engineering strategies in urology. This chapter describes methods for the isolation of urothelial cells and their maintenance in monolayer culture, and methods for the production of multilayer urothelial cell sheets and three-dimensional cocultures of urothelial and mesenchymal cells.
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Affiliation(s)
- Yuanyuan Zhang
- Department of Urology, Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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Abstract
This chapter reviews the use of urothelial cells as a means to enhance tissue regeneration and wound healing in urinary tract system. It addresses the properties of urothelial cells, including their role as a permeability barrier to protect underlying muscle tissue from the caustic effects of urine and as one of the main cell types, along with smooth muscle cells, that are used in urethral or bladder tissue engineering today. This description includes a general overview of various isolation techniques and culture methods that have been developed to improve urinary tract reconstruction in vivo and aid the characterization of growth factor expression in vitro. The chapter then describes various applications using urothelial cells, including production of multilayer urothelial sheets, tissue engineered bladder mucosa, tissue engineered urethra, and tissue engineered bladder. It also outlines the advantages of sandwich and layered coculture of these cells and the effects of epithelial-stromal cell interactions during tissue regeneration or wound healing processes in the urinary tract.
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Orlando G, Wood KJ, De Coppi P, Baptista PM, Binder KW, Bitar KN, Breuer C, Burnett L, Christ G, Farney A, Figliuzzi M, Holmes JH, Koch K, Macchiarini P, Mirmalek Sani SH, Opara E, Remuzzi A, Rogers J, Saul JM, Seliktar D, Shapira-Schweitzer K, Smith T, Solomon D, Van Dyke M, Yoo JJ, Zhang Y, Atala A, Stratta RJ, Soker S. Regenerative medicine as applied to general surgery. Ann Surg 2012; 255:867-80. [PMID: 22330032 PMCID: PMC3327776 DOI: 10.1097/sla.0b013e318243a4db] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The present review illustrates the state of the art of regenerative medicine (RM) as applied to surgical diseases and demonstrates that this field has the potential to address some of the unmet needs in surgery. RM is a multidisciplinary field whose purpose is to regenerate in vivo or ex vivo human cells, tissues, or organs to restore or establish normal function through exploitation of the potential to regenerate, which is intrinsic to human cells, tissues, and organs. RM uses cells and/or specially designed biomaterials to reach its goals and RM-based therapies are already in use in several clinical trials in most fields of surgery. The main challenges for investigators are threefold: Creation of an appropriate microenvironment ex vivo that is able to sustain cell physiology and function in order to generate the desired cells or body parts; identification and appropriate manipulation of cells that have the potential to generate parenchymal, stromal and vascular components on demand, both in vivo and ex vivo; and production of smart materials that are able to drive cell fate.
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Affiliation(s)
- Giuseppe Orlando
- Wake Forest Institute for Regenerative Medicine, Winston Salem, NC, USA.
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Tissue engineering of bladder using vascular endothelial growth factor gene-modified endothelial progenitor cells. Int J Artif Organs 2012; 34:1137-46. [PMID: 22198599 DOI: 10.5301/ijao.5000069] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE This study assessed the use of vascular endothelial growth factor (VEGF) gene-modified endothelial progenitor cells (EPCs) seeded onto bladder acellular matrix grafts (BAMGs), to enhance the blood supply in tissue-engineered bladders in a porcine model. METHODS Autologous porcine peripheral EPCs were isolated, cultured, expanded, characterized, and modified with the VEGF gene using an adenovirus vector. The expression of VEGF was examined using reverse transcriptase polymerase chain reaction (RT-PCR) and an enzyme-linked immunosorbent assay (ELISA). VEGF gene modified EPCs were seeded onto BAMG and cultured for 3 days before implantation into pigs for bladder tissue engineering. A partial bladder cystectomy was performed in 12 pigs. The experimental group (6 pigs) received VEGF gene-modified EPC-seeded BAMG. The control group (6 pigs) received BAMG without seeded EPCs. The resulting tissue-engineered bladders were subject to a general and histological analysis. Microvessel density (MVD) was assessed using immunohistochemistry. RESULTS The ex vivo transfection efficiency of EPCs was greater than 60%-70% when concentrated adenovirus was used. The genetically modified cells expressed both VEGF and green fluorescent protein (GFP). Scanning electron microscopy (SEM) and Masson's trichrome staining of cross sections of the cultured cells seeded to BAMG showed cell attachment and proliferation on the surface of the BAMG. Histological examination revealed bladder regeneration in a time-dependent fashion. Significant increases in MVD were observed in the experimental group, in comparison with the control group. CONCLUSIONS VEGF-modified EPCs significantly enhanced neovascularization, compared with BAMG alone. These results indicate that EPCs, combined with VEGF gene therapy, may be a suitable approach for increasing blood supply in the tissue engineering of bladders. Thus, a useful strategy to achieve a tissue-engineered bladder is indicated.
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Abstract
Despite well-established bone-grafting techniques, large bone defects still represent a challenge for orthopaedic and reconstructive surgeons. Efforts have therefore been made to develop osteoconductive, osteoinductive and osteogenic bone-replacement systems. According to its original definition, tissue engineering is an 'interdisciplinary field that applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function'. It is based on the understanding of tissue formation and regeneration, and aims to grow new functional tissues rather than to build new spare parts. This review focuses on the principles of tissue engineering applied to the creation of bioartificial bone tissue. Important aspects, such as osteogenic cells, matrix materials, inter- and intra-cellular communication, growth factors, gene therapy and current concepts of bone tissue engineering are reviewed. First clinical applications are discussed. An outlook provides insight into the possible future perspectives of bone tissue engineering.
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Mitterberger M, Marksteiner R, Schwaiger W, Klima G, Schwentner C, Müller T, Bartsch G, Radmayr C, Strasser H, Oswald J. Can autologous myoblasts be used as a potential bulking agent? BJU Int 2008; 102:1731-6. [PMID: 18778357 DOI: 10.1111/j.1464-410x.2008.07892.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the behaviour of donor myoblasts at the vesico-ureteric junction (VUJ) and to evaluate their potential as an autologous bulking agent, as myoblast transplantation has been shown to regenerate damaged or degenerated tissue, and it was postulated that they could be used to treat vesico-ureteric reflux. MATERIALS AND METHODS Muscle biopsies were obtained from the lower limb muscles of 10 pigs. The quality of the cells was evaluated by electrophysiological and immunohistochemical tests. The cell membranes of myoblasts were labelled with PKH26, a fluorescent dye. Six weeks after taking of the muscle biopsies all pigs underwent cell transplantation; 30 x 10(6) cells suspended in transplantation medium (in 1-mL syringes) were injected at the VUJ, into the proximal urethra and the rhabdosphincter. At the VUJ volumes of 1 mL were injected, whereas in the urethra and rhabdosphincter small cell depots (0.1 mL) were injected. All the pigs were killed 8 weeks later, and the myoblasts and newly formed myofibres were identified using fluorescence microscopy, with a histological evaluation and investigation of potential local inflammatory reaction. RESULTS Two to three intact layers of autologous myoblasts were found in the outer aspects of the large cell depots in the VUJ. Immunohistochemistry further showed that the myoblasts were only viable at these outermost borders of the large bulking areas, whereas necrosis with red fluorescent cell detritus was visible in the remaining central aspects of the large bulk of cells. By contrast, cells survived and formed myotubes in the wall of the proximal urethra and the rhabdosphincter where the small cell depots had been injected. CONCLUSIONS In small depots, transplanted autologous myoblasts can survive and differentiate into myofibres, while in a large bulk of cells the vast majority of cells become necrotic. The present results show that myoblasts cannot be used for augmentation of large volumes of tissue or as a bulking agent.
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Kajbafzadeh AM, Payabvash S, Salmasi AH, Sadeghi Z, Elmi A, Vejdani K, Tavangar SM, Tajik P, Mahjoub F. Time-Dependent Neovasculogenesis and Regeneration of Different Bladder Wall Components in the Bladder Acellular Matrix Graft in Rats. J Surg Res 2007; 139:189-202. [PMID: 17292410 DOI: 10.1016/j.jss.2006.11.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Revised: 10/30/2006] [Accepted: 11/03/2006] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To determine the time-dependent regeneration of different cellular components in the bladder acellular matrix graft (BAMG) and the involvement of hematopoietic stem cells in BAMG vascular regeneration. METHODS AND MATERIALS Thirty-three male Sprague Dawley rats underwent partial cystectomy and the acellular matrices were grafted to the remaining host bladder. At 4, 7, 14, 30, 60, 90, and 180 d after grafting, animals were sacrificed and their bladders were excised and paraffin-embedded. Tissue sections were stained for determination of CD3, CD20, CD34, CD31, CD68, smooth muscle cell (SMC) alpha-actin, and neurofilament protein as well as elastin fibers and collagen typing. Cystometric evaluation of grafted bladders was also performed 3 mo after procedure. RESULTS In acellular matrices, there was no expression of cellular markers and type-1 collagen fibers were predominant. One month after surgery, all grafted matrices were completely lined with urothelium. Polymorphonuclear cells and lymphocytes densely infiltrated BAMG during the first 2 wk after grafting; however the inflammation resolved by the first post-surgical mo. CD34+ endothelial progenitor cells (EPCs) were found in all grafts 4 d after surgery. The number of CD34+ cells increased continuously and peaked 2 mo after grafting. The increment in number of CD31+ microvessels in grafted matrices followed that of CD34+ cells and reached 144.5% of control values at third post-surgical mo. The mean number of CD34+ and CD31+ cells returned to control ranges by 6 mo after grafting. Expression of SMC alpha-actin was first visualized on day 4 and alpha-actin intensity reached to control values 6 mo after grafting. Neural elements appeared 1 wk after grafting and just 60% of normal intensity was achieved by the sixth post-surgical mo; however complete nerve bundles were found in all grafted matrices after 1 mo. Cystometric studies revealed higher bladder capacity and compliance but lower maximum intravesical pressure in grafted bladders in comparison with controls, 3 mo after surgery. CONCLUSIONS Our results demonstrate the effective cellular regeneration in BAMG and propose a considerable role for the CD34+ EPCs in the neo-vasculogenesis of the grafts.
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Affiliation(s)
- Abdol-Mohammad Kajbafzadeh
- Pediatric Urology Research Center, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
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de Diego Rodríguez E, Roca Edreira A, Villanueva Peña A, Meana Infiesta A, Gómez Llames S, Martín García B, Gómez Ortega JM. [In vitro three-dimensional reconstruction of human bladder mucosa]. Actas Urol Esp 2006; 30:195-205. [PMID: 16700211 DOI: 10.1016/s0210-4806(06)73423-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE The purpose of this study is to apply the in vitro keratinocyte culture techniques and the tissue engineering principles to human urothelium, to reconstruct an in vitro three-dimensional human bladder mucosa, suitable for grafting. MATERIAL AND METHODS Biopsy specimens of human bladder mucosa were obtained from patients undergoing suprapubic prostatectomy, in vitro cultured and finally, an immunohistochemical study was made. RESULTS A three-dimensional in vitro tissue was obtained, composed of a bio-artificial submucosa (fibrin gel and fibroblast) where the uroepithelial cells were seeding. We used a biodegradable polyglycolic acid mesh to facilitate the tissue manipulation and implantation. An immature epithelium was obtained with a weak immunostaining to cytokeratins. The immunohistochemical study could not demonstrate the development of basement membrane. CONCLUSIONS In vitro keratinocyte culture techniques could be applied to other epithelial tissues like the urothelium. We obtained a three-dimensional in vitro tissue suitable for grafting in a relatively short time, which needs the matrix interactions in order to mature.
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Long RA, Nagatomi J, Chancellor MB, Sacks MS. The role of MMP-I up-regulation in the increased compliance in muscle-derived stem cell-seeded small intestinal submucosa. Biomaterials 2006; 27:2398-404. [PMID: 16337680 DOI: 10.1016/j.biomaterials.2005.10.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Accepted: 10/09/2005] [Indexed: 10/25/2022]
Abstract
We have previously observed that muscle-derived stem cells (MDSC) seeded onto porcine small intestinal submucosa (SIS) increase the mechanical compliance of the engineered tissue construct [Lu SH, Sacks MS, Chung SY, Gloeckner DC, Pruchnic R, Huard J, et al. Biaxial mechanical properties of muscle-derived cell seeded small intestinal submucosa for bladder wall reconstitution. Biomaterials 2005;26(4):443-9]. To date, however, the initial remodeling events which occur when MDSC are seeded onto SIS have yet to be elucidated. One potential mechanism responsible for the observed increase in mechanical compliance is the release of matrix metalloproteinase-I (MMP-I). To investigate this finding, MDSC ( approximately 1x10(6)) were cultured on single-layer SIS cell culture inserts (4.7 cm2) for 1-10 days. MDSC MMP-I activity on SIS in the supernatant at 1, 3, 5, 7, and 10 days was determined using a collagenase assay kit. MMP-I activity of the MDSC/SIS was significantly higher (p<0.0025) after one day in culture compared to specimens collected from subsequent time points and the unseeded control. To further study the initial remodeling events, the impact of MMP-I on mechanical compliance was examined. SIS was incubated with 0.16 U/mL collagenase-I for 3, 4.5, 5, and 24h, then biaxial mechanical testing was performed. After 5h of digestion with collagenase-I, mechanical compliance under 1 MPa peak stress was increased by 7% in the circumferential direction, compared to control SIS. These findings suggest that the release of MMP-I in response to initial seeding on SIS and subsequent breakdown of collagen fibers is the mechanism responsible for an increase in mechanical compliance.
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Affiliation(s)
- Rebecca A Long
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15219, USA
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De Diego Rodríguez E, Villanueva Peña A, Roca Edreira A, Martín García B, Meana Infiesta A, Gómez Llames S. [Current status of tissue engineering in urology. Review of the literature]. Actas Urol Esp 2005; 28:636-45. [PMID: 16050197 DOI: 10.1016/s0210-4806(04)73154-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the eighties a new field of the medicine appears wich applies the principles of cellular cultivation to synthetic biodegradable polymers scaffolds with the purpose of creating autologous biological substitutes that could improve, maintain or restore the function of organs or damaged tissues. The Tissue Engineering constitutes a new discipline in full phase of development especially in USA, with multiple potential applications in several medical specialities. Our speciality can't remain indifferent to interest and encouraging future originated by this new science. In this work we have made a wide bibliographical revision in the Medline to know the antecedents, current state and the possible future applications of Tissue Engineering in Urology.
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Bhatia NN, Ho MH. Stem cell therapy for urinary incontinence and pelvic floor disorders: a novel approach. Curr Opin Obstet Gynecol 2005; 16:397-8. [PMID: 15353948 DOI: 10.1097/00001703-200410000-00007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Lu SH, Sacks MS, Chung SY, Gloeckner DC, Pruchnic R, Huard J, de Groat WC, Chancellor MB. Biaxial mechanical properties of muscle-derived cell seeded small intestinal submucosa for bladder wall reconstitution. Biomaterials 2005; 26:443-9. [PMID: 15275818 DOI: 10.1016/j.biomaterials.2004.05.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bladder wall replacement remains a challenging problem for urological surgery due to leakage, infection, stone formation, and extensive time needed for tissue regeneration. To explore the feasibility of producing a more functional biomaterial for bladder reconstitution, we incorporated muscle-derived cells (MDC) into small intestinal submucosa (SIS) scaffolds. MDC were harvested from mice hindleg muscle, transfected with a plasmid encoding for beta-galactosidase, and placed into single-layer SIS cell culture inserts. Twenty-five MDC and/or SIS specimens were incubated at 37 degrees C for either 10 or 20 days. After harvesting, mechanical properties were characterized using biaxial testing, and the areal strain under 1 MPa peak stress used to quantify tissue compliance. Histological results indicated that MDC migrated throughout the SIS after 20 days. The mean (+/-SE) areal strain of the 0 day control group was 0.182 +/- 0.027 (n=5). After 10 days incubation, the mean (+/-SE) areal strain in MDC/SIS was 0.247 +/- 0.014 (n=5) compared to 10 day control SIS 0.200 +/- 0.024 (n=6). After 20 days incubation, the mean areal strain of MDC/SIS was 0.255 +/- 0.019 (n=5) compared to control SIS 0.170 +/- 0.025 (n=5). Both 10 and 20 days seeded groups were significantly different (p=0.027) than that of incubated SIS alone, but were not different from each other. These results suggest that MDC growth was supported by SIS and that initial remodeling of the SIS ECM had occurred within the first 10 days of incubation, but may have slowed once the MDC had grown to confluence within the SIS.
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Affiliation(s)
- Shing-Hwa Lu
- Department of Urology, University of Pittsburgh, Pittsburgh, PA 15219, USA
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de Diego Rodríguez E, Villanueva Peña A, Roca Edreira A, Martín García B, Meana Infiesta A, Gómez Llames S, Gómez Román J. [Experimental study about viability of autologous free graft in vitro cultivated urinary epithelium]. Actas Urol Esp 2005; 28:714-31. [PMID: 15666514 DOI: 10.1016/s0210-4806(04)73173-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The purpose of this study is to apply the in vitro keratinocyte culture techniques and the tissue engineering principles to urothelium, to obtain a three-dimensional autologous tissue suitable for grafting. We also showed the viability of free graft cultured urothelium in an experimental model. MATERIAL AND METHODS An animal experimental model was designed to apply the techniques of cellular culture and tissue engineering. Biopsy specimens of bladder mucosa were obtained, in vitro cultured and posteriorly implanted in each animal. We established three groups based on different follow-up periods (7, 14 and 30 days), and made a final histomorphological study to demonstrate the viability of the graft at the end of its respective follow-up period. RESULTS A three-dimensional in vitro tissue was obtained, composed of a bio-artificial submucosa (fibrin gel and fibroblast) where the uroepithelial cells were seeding; a biodegradable polyglycolic acid mesh was used to facilitate the tissue manipulation and implantation. In the morphological study all the implants appeared viable, but the grafts with longer implantations periods were better conformed, showing a tisular structure with multiple cellular layers. CONCLUSIONS In vitro keratinocyte culture techniques could be applied to other epithelial tissues as the urothelium. We obtained a three-dimensional in vitro tissue suitable for grafting in a relatively short time. The histological study demonstrated that free autologous urothelial graft is totally viable, opening future clinics applications.
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Cho JH, Kim SH, Park KD, Jung MC, Yang WI, Han SW, Noh JY, Lee JW. Chondrogenic differentiation of human mesenchymal stem cells using a thermosensitive poly(N-isopropylacrylamide) and water-soluble chitosan copolymer. Biomaterials 2004; 25:5743-51. [PMID: 15147820 DOI: 10.1016/j.biomaterials.2004.01.051] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2003] [Accepted: 01/16/2004] [Indexed: 10/26/2022]
Abstract
Poly(N-isopropylacrylamide) (PNIPAAm) is known to be thermally responsive material and has a lower critical solution temperature (LCST, 32 degrees C) at which a macromolecular transition from a hydrophilic to a hydrophobic structure occurs. Chitosan is a useful natural polymeric biomaterial due to its biocompatibility and biodegradable properties. It has good characteristics for cell attachment, proliferation and viability. The aim of this study was to assess the ability to differentiate from mesenchymal stem cells (MSCs) to chondrocytes and mass formation using a newly developed injectable material, a thermosensitive (water-soluble chitosan-g-PNIPAAm) gel, and evaluate cartilage formation in vivo after injecting a cell-thermosensitive gel complex. The MSCs were cultured in the chitosan-PNIPAAm in vitro. Fluorescence-activated cell sort analysis, viability test, collagen type I, II, X formation and the aggrecan levels were examined. These cultured cells can be easily recovered from a copolymer gel by simply lowering the temperature. An animal study was performed to assess cartilage formation in the submucosal layer of the bladder of rabbits. The cartilage formation could be detected. This can be used to treat vesicoureteral reflux or reflux esophagitis by the effective mass effect. This is a simple method (sol-gel technique in LCST), and good cartilage formation occurs in the bladder tissue.
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Affiliation(s)
- Jae Ho Cho
- Department of Orthopaedic Surgery, Ajou University College of Medicine, San 5, Wonchun-Dong, Paldal-Gu, Suwon 442-749, South Korea
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Bisson I, Kosinski M, Ruault S, Gupta B, Hilborn J, Wurm F, Frey P. Acrylic acid grafting and collagen immobilization on poly(ethylene terephthalate) surfaces for adherence and growth of human bladder smooth muscle cells. Biomaterials 2002; 23:3149-58. [PMID: 12102186 DOI: 10.1016/s0142-9612(02)00061-3] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In tissue engineering, degradable or non-degradable polymer matrices can act as cell-carrier-scaffolds. Cell adhesion and growth on these scaffolds can be promoted by immobilizing extracellular matrix proteins. Therefore, in this study, polymer poly(ethylene terephthalate) (PET) films were surface modified by graft polymerization of acrylic acid, to subsequently allow collagen (types I and III) immobilization and human smooth muscle cell expansion. The surfaces of PET were activated by plasma, followed by acrylic acid graft polymerization, resulting in covalently bound brushes, containing an average of either 0.22+/-0.1 or 5.93+/-0.87 microg/cm2 of poly(acrylic acid) (PAA). Subsequent electrostatic adsorption of collagen gave a surface concentration of 4.96 and 17.2 microg/cm2, respectively, as determined using radiolabelled 125I collagen. Both PET films grafted with 0.22 microg/cm2 of PAA with or without adsorbed collagen were apt for smooth muscle cell adhesion and proliferation. However, films grafted with 5.93 microg/cm2 were not. PAA-grafted PET films, onto which serum proteins of the culture medium adsorbed spontaneously, proved to be better matrices than films on which collagen has been immobilized. It, therefore, can be speculated that other serum proteins are more important than collagen for the human smooth muscle cell adhesion and growth on surface-modified polymer matrices.
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Affiliation(s)
- Isabelle Bisson
- Centre Hospitalier Universitaire Vaudois, Department of Pediatric Surgery, Lausanne, Switzerland.
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20
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Bisson I, Hilborn J, Wurm F, Meyrat B, Frey P. Human urothelial cells grown on collagen adsorbed to surface-modified polymers. Urology 2002; 60:176-80. [PMID: 12100958 DOI: 10.1016/s0090-4295(02)01642-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES Tissue engineering methods can be applied to regenerate diseased, or congenitally missing, urinary tract tissues. Urinary tract tissue cell cultures must be established in vitro and adequate matrices, acting as cell carriers, must be developed. Although degradable and nondegradable polymer matrices offer adequate mechanical stability, they are not optimal for cell adherence and growth. To overcome this problem, extracellular matrix proteins, permitting cell adhesion and regulation of cell proliferation and differentiation, can be adsorbed to the surface-modified polymer. METHODS In this study, nondegradable polymer films, poly(ethylene terephthalate), were used as an experimental model. Films were modified by graft polymerization of acrylic acid to subsequently allow collagen type I and III immobilization. The following adhesion, proliferation of human urothelial cells, and induction of their stratification were analyzed. RESULTS Collagen adsorption on 0.2 microg/cm2 poly(acrylic acid)-grafted polymer films rendered the matrix apt for human urothelial cell adhesion and proliferation. Furthermore, stratification of urothelial cells was demonstrated on these surface-modified matrices. CONCLUSIONS These results have shown that surface-modified polymer matrices can be used to act as cell carriers for cultured human urothelial cells. Such a cell-matrix construct could be applied in reparative surgery of the urinary tract.
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Affiliation(s)
- Isabelle Bisson
- Laboratory for Experimental Pediatric Urology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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21
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Sofer M, Rowe E, Forder DM, Denstedt JD. Ureteral segmental replacement using multilayer porcine small-intestinal submucosa. J Endourol 2002; 16:27-31. [PMID: 11890446 DOI: 10.1089/089277902753483682] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To assess the outcome of segmental ureteral replacement using a new multilayer porcine small-intestinal submucosa (SIS), Surgisis ES (Cook Inc., Stouffville, ON, Canada) designed to provide enhanced strength. MATERIALS AND METHODS The ureters of five female farm pigs were accessed through a median laparotomy incision. A segment of 2-cm midureter was resected bilaterally. The left ureteral segments were replaced by 10F tubularized SIS segments using 5-0 PDS interrupted sutures. The right ureters were primarily end-to-end anastomosed, serving as controls. Internal pigtail stents were left bilaterally for 6 weeks. One animal at 3 weeks, one animal at 6 weeks, and three animals at 12 weeks were sacrificed. The patency of the ureters was assessed by retrograde pyelography at 6 and 12 weeks, while inflammation and regeneration were assessed grossly and histologically. RESULTS At 3 and 6 weeks, both experimental and control ureters were patent without extravasation on retrograde studies. Adhesions and signs of ureteral inflammation were found only on the SIS side. The graft was partially and completely epithelialized at 3 and 6 weeks, respectively. However, at 12 weeks, all the ureters on the experimental side were completely occluded, while on the control side, all were patent. Although histologically, urothelium and muscular cells had proliferated over the graft, they were embedded in an intense fibrotic and inflammatory process. At 12 weeks, all animals had developed hydroureteronephrosis above the grafts. CONCLUSIONS Technically, Surgisis ES was easily modeled, providing conditions for a water-tight anastomosis. None of the animals developed urinary fistula. Regeneration of urothelium and muscle were induced and supported by the graft. However, functional replacement was not successful. A suitable material for this purpose has yet to be discovered.
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Affiliation(s)
- Mario Sofer
- Division of Urology, The University of Western Ontario, London, Canada
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22
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Abstract
OBJECTIVES To determine the anatomical steps leading to bladder agenesis in rats prenatally exposed as fetuses on gestational days (GD) 6-9 to adriamycin. MATERIALS AND METHODS Timed-pregnant Sprague-Dawley rats were injected intraperitoneally with adriamycin at 2 mg/kg (n = 28) on GD 6-9 (vaginal plug = day 0). The control group (n = 21) received saline. Fetuses were harvested on GD 10, 11, 12, 13, 14, 15 and 16. Serial paraffin sections were prepared from a minimum of 10 experimental and five control fetuses at each gestational age, and stained with either trichrome or haematoxylin and eosin, and examined by light microscopy. RESULTS In the control group the urorectal septum first became visible and the mesonephric ducts apparently abutting the anterior cloaca on GD 12. The presumptive urinary bladder was clearly defined on GD 14. On GD 15, the common excretory ducts became incorporated into the newly formed urogenital sinus and the ureters opened into the bladder. In the treated animals, beginning on GD 11, the undivided cloaca was noticeably smaller and by GD 13-14, the vesical extension of the urogenital sinus was conspicuously absent. Instead, opposite ureters joined to drain directly into the proximal blind-ending urethra or the persistent distal urogenital sinus. CONCLUSIONS Prenatal exposure of rat fetuses to adriamycin resulted in primary agenesis rather than secondary resorption of the bladder. The ontogeny showed that the mechanism underpinning bladder development is unique and is under the influence of factors that can be targeted by adriamycin. Further work will elucidate the unique nature of bladder organogenesis and should have important applications in future research into artificial bladders.
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Affiliation(s)
- M I Liu
- F. Douglas Stephens Surgical Research Laboratory, Murdoch Children's Hospital Research Institute, Melbourne, Australia
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23
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Minuth WW, Schumacher K, Strehl R, Kloth S. Physiological and cell biological aspects of perfusion culture technique employed to generate differentiated tissues for long term biomaterial testing and tissue engineering. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2001; 11:495-522. [PMID: 10896044 DOI: 10.1163/156856200743832] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Optimal results in biomaterial testing and tissue engineering under in vitro conditions can only be expected when the tissue generated resembles the original tissue as closely as possible. However, most of the presently used stagnant cell culture models do not produce the necessary degree of cellular differentiation, since important morphological, physiological, and biochemical characteristics disappear, while atypical features arise. To reach a high degree of cellular differentiation and to optimize the cellular environment, an advanced culture technology allowing the regulation of differentiation on different cellular levels was developed. By the use of tissue carriers, a variety of biomaterials or individually selected scaffolds could be tested for optimal tissue development. The tissue carriers are to be placed in perfusion culture containers, which are constantly supplied with fresh medium to avoid an accumulation of harmful metabolic products. The perfusion of medium creates a constant microenvironment with serum-containing or serum-free media. By this technique, tissues could be used for biomaterial or scaffold testing either in a proliferative or in a postmitotic phase, as is observed during natural development. The present paper summarizes technical developments, physiological parameters, cell biological reactions, and theoretical considerations for an optimal tissue development in the field of perfusion culture.
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Affiliation(s)
- W W Minuth
- Department of Anatomy, University of Regensburg, Germany.
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24
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Reddy PP, Barrieras DJ, Wilson G, Bägli DJ, McLorie GA, Khoury AE, Merguerian PA. Regeneration of functional bladder substitutes using large segment acellular matrix allografts in a porcine model. J Urol 2000; 164:936-41. [PMID: 10958712 DOI: 10.1097/00005392-200009020-00005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE We previously reported on the short-term (4 weeks) morphometric analysis of a large bladder acellular matrix allograft used as a bladder bioprosthesis (average size 24 cm.2). We demonstrated cellular repopulation through the entire thickness of the graft. We now present the long-term (12 weeks) morphometric results of graft regenerated porcine bladders using segments measuring an average of 40 cm.2. MATERIALS AND METHODS Bladders harvested from pigs were subjected to detergent and enzymatic extractions to render them acellular. Partial cystectomy was performed in 21 pigs and the defect was repaired with a bladder acellular matrix allograft (average size 40.52 cm.2). Of the animals 8 were sacrificed at 1, 2 and 4 weeks and 13 were sacrificed at 8 and 12 weeks. To evaluate cellular repopulation and matrix reorganization the native bladder and graft were analyzed using standard histological and immunofluorescent techniques. To evaluate for calcium deposits in the grafts a radiological evaluation of the graft was performed after explantation. RESULTS All animals survived the surgical procedure and there were no significant urinary leaks. No stones were noted in any of the bladders. At 1 week there was a diffuse infiltration with acute inflammatory cells. At 2 weeks the luminal surface of the graft was lined with a single layer of urothelium, and there was stromal infiltration with unorganized smooth muscle cells and angiogenesis. At 4 weeks the urothelium was multilayered with organizing groups of smooth muscle cells and angiogenesis. At 8 and 12 weeks there was repopulation throughout the bladder acellular matrix allograft implant with all native cellular components participating. CONCLUSIONS We present evidence that large patch bladder acellular matrix allograft implantation is technically feasible and may prove to be a viable surgical alternative to bladder augmentation with intestinal segments. Its advantages may include the potential for complete and functional regeneration of a bladder substitute.
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Affiliation(s)
- P P Reddy
- Division of Urology, Department of Surgery, The Hospital for Sick Children, University of Toronto, Ontario, Canada
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REDDY PRAMODP, BARRIERAS DIEGOJ, WILSON GREGORY, BÄGLI DARIUSJ, McLORIE GORDONA, KHOURY ANTOINEE, MERGUERIAN PAULA. REGENERATION OF FUNCTIONAL BLADDER SUBSTITUTES USING LARGE SEGMENT ACELLULAR MATRIX ALLOGRAFTS IN A PORCINE MODEL. J Urol 2000. [DOI: 10.1016/s0022-5347(05)67221-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- PRAMOD P. REDDY
- From the Division of Urology, Department of Surgery, and Department of Cellular and Molecular Pathology, The Hospital for Sick Children, University of Toronto, Ontario, Canada
| | - DIEGO J. BARRIERAS
- From the Division of Urology, Department of Surgery, and Department of Cellular and Molecular Pathology, The Hospital for Sick Children, University of Toronto, Ontario, Canada
| | - GREGORY WILSON
- From the Division of Urology, Department of Surgery, and Department of Cellular and Molecular Pathology, The Hospital for Sick Children, University of Toronto, Ontario, Canada
| | - DARIUS J. BÄGLI
- From the Division of Urology, Department of Surgery, and Department of Cellular and Molecular Pathology, The Hospital for Sick Children, University of Toronto, Ontario, Canada
| | - GORDON A. McLORIE
- From the Division of Urology, Department of Surgery, and Department of Cellular and Molecular Pathology, The Hospital for Sick Children, University of Toronto, Ontario, Canada
| | - ANTOINE E. KHOURY
- From the Division of Urology, Department of Surgery, and Department of Cellular and Molecular Pathology, The Hospital for Sick Children, University of Toronto, Ontario, Canada
| | - PAUL A. MERGUERIAN
- From the Division of Urology, Department of Surgery, and Department of Cellular and Molecular Pathology, The Hospital for Sick Children, University of Toronto, Ontario, Canada
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Chancellor MB, Yokoyama T, Tirney S, Mattes CE, Ozawa H, Yoshimura N, de Groat WC, Huard J. Preliminary results of myoblast injection into the urethra and bladder wall: a possible method for the treatment of stress urinary incontinence and impaired detrusor contractility. Neurourol Urodyn 2000; 19:279-87. [PMID: 10797585 DOI: 10.1002/(sici)1520-6777(2000)19:3<279::aid-nau9>3.0.co;2-m] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The purpose of this study is to explore the feasibility of myoblasts, the precursors of muscle fibers, injected periurethrally as a potential treatment of stress urinary incontinence. We also studied myoblast injection into the bladder wall to potentially improve detrusor contractility. A myoblast cell line was transduced with adenovirus carrying the expression of the beta-galactosidase reporter gene while in culture. The cells were incubated with fluorescent latex microspheres (FLMs) to follow the outcome of the injected cells. The tissue was harvested 3-4 days after injection; sectioned, fixed, assayed for beta-galactosidase expression, and counterstained with H+E. Photographs of the slides were taken under light and fluorescence microscopy. We have noted a large number of cells expressing beta-galactosidase and containing FLMs in the urethral and bladder walls under fluorescent microscopy (8 animals). Many regenerative myofibers expressing beta-galactosidase were also seen in the urethral and bladder walls. The fusion of injected myoblasts to form myotubes was seen in both the urethral and bladder walls. The introduction of myoblasts into the urethral and bladder wall is feasible and results in formation of myotubes and myofibers in the smooth muscle layers of the lower urinary tract. We hypothesize that myoblast injections can be used as a non-allergenic agent to enhance urethral closure and bladder function.
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Affiliation(s)
- M B Chancellor
- Division of Urologic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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Xie H, Shaffer BS, Wadia Y, Gregory KW. Use of reconstructed small intestine submucosa for urinary tract replacement. ASAIO J 2000; 46:268-72. [PMID: 10826734 DOI: 10.1097/00002480-200005000-00005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
We used reconstructed SIS (ReSIS), a photocrosslinked biomaterial, to create grafts in various shapes and sizes. Sheets of ReSIS were placed in 14 swine to repair bladder defects, and ReSIS tubes were placed in six swine to replace a segment of excised ureter. Histologic analysis of the bladder repair revealed transitional urothelial cells lining the ReSIS by 1 week. After 2 weeks, fibroblasts and mononuclear cells had infiltrated the ReSIS, neovascularization had occurred, and the urothelial lining was more complex, containing multiple cell layers. After 4 weeks, a definite submucosa was present and the ReSIS was starting to degrade. An initial muscular regeneration was demonstrated at 12 weeks. No foreign body reaction, calcification, or sedimentation was noted in any animal. The ureteral implants showed identical histologic changes, without obstruction or leakage of the replaced segment. The ReSIS allowed rapid urothelial regeneration, ingrowth of new blood vessels, and the orderly deposition and organization of new collagen. Our study demonstrates that the photocrosslinking technique used to create larger sheets and tubes of this biomaterial (ReSIS) does not detract from the positive attributes of the SIS and should improve its usefulness in accomplishing larger bladder augmentations and ureter replacements.
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Affiliation(s)
- H Xie
- Oregon Medical Center, Portland, USA
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28
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Pariente JL, Bordenave L, Bareille R, Baquey C, Le Guillou M. Cultured differentiated human urothelial cells in the biomaterials field. Biomaterials 2000; 21:835-9. [PMID: 10721752 DOI: 10.1016/s0142-9612(99)00253-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To review the use of normal cultured differentiated human urothelial cells in the biomaterials field, we checked the literature for human urothelial cells in culture (HUC) both for their use in biocompatibility assessment and as bioartificial devices. The in vitro culture of differentiated human urothelium is now a simple and reliable procedure. These techniques provide new tools for biocompatibility assessment of urinary biomaterials, because for the rational design of a testing procedure, it is preferable that the particular cell culture models selected should be closely related to the end-use application. The emerging use of HUC culture should lead to the development of bioartificial tissue for urinary tract reconstruction. Tissue engineering techniques require urothelial cells and cell delivery matrices. The cytocompatibility of novel artificial delivery matrices should be assessed in vitro before implantation using cultured HUC to find the best material available.
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Affiliation(s)
- J L Pariente
- Department of Urology, Le Tripode, Pellegrin University Hospital, France
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29
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Probst M, Piechota HJ, Dahiya R, Tanagho EA. Homologous bladder augmentation in dog with the bladder acellular matrix graft. BJU Int 2000; 85:362-71. [PMID: 10671897 DOI: 10.1046/j.1464-410x.2000.00442.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the functional potential and antigenicity of the homologous bladder acellular matrix graft (BAMG) in a dog model. MATERIALS AND METHODS Seven mongrel dogs underwent partial cystectomy (20-50%) and grafting with an equal-sized BAMG; two control animals underwent partial cystectomy (40%) only. The dogs were killed after 30 (one), 120 (one) and 210 days (five dogs). Blood samples were obtained before and at 1, 2, 4, 7, 14, 30, 90 and 210 days after surgery. The dogs underwent cystography, intravenous pyelography and ultrasonography before and after surgery, and on the day they were killed, with cystoscopy carried out just before death. The grafted tissue was assessed using routine and immunohistochemical techniques. RESULTS All the dogs survived surgery; a complete blood cell count, chemical panel and white blood cell count showed no significant difference between the experimental and control animals. Cystography, cystoscopy and ultrasonography revealed no pathological changes in the upper urinary tract. After 7 months, the mean bladder capacity in the augmented dogs was significantly higher (P = 0.035) than in the controls (264 vs 172 mL). Histological evaluation showed an invasion of all bladder wall components during the first month; at 7 months, the morphological examination showed essentially complete regeneration. CONCLUSION In this dog model, the potential of the BAMG as a bladder augmentation graft was confirmed, having minimal antigenicity with maximal acceptance. The reconstructed bladder matched the morphological and functional properties of the normal bladder.
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Affiliation(s)
- M Probst
- Department of Urology, University of California School of Medicine, San Francisco, California 94143 0738, USA
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31
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Kershen RT, Atala A. New advances in injectable therapies for the treatment of incontinence and vesicoureteral reflux. Urol Clin North Am 1999; 26:81-94, viii. [PMID: 10086052 DOI: 10.1016/s0094-0143(99)80008-1] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Clinical experience over the last two decades has demonstrated that the endoscopic correction of primary vesicoureteral reflux and urinary incontinence caused by intrinsic sphincteric dysfunction is both possible and effective. The ideal material for use in these regards has yet to be developed. As a result, there has been a continuing research effort directed towards the development of new injectable substances. Nonautologous substances, such as Teflon, collagen, and Deflux, and autologous substances such as fat, chondrocytes and muscle, have been used either clinically or are under investigation. Although the ideal substance has yet to be determined, many of the substances currently under development appear promising. The use of a particular substance may best be determined by the clinical circumstance involving each individual patient.
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Affiliation(s)
- R T Kershen
- Department of Urology, Children's Hospital, Boston, Massachusetts, USA
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Affiliation(s)
- B R Unsworth
- Department of Biology, Marquette University, Milwaukee, Wisconsin 53233, USA
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