Composite thin film and electrospun biomaterials for urologic tissue reconstruction

Abstract

A replacement material for autologous grafts for urinary tract reconstruction would dramatically reduce the complications of surgery for these procedures. However, acellular materials have not proven to work sufficiently well, and cell-seeded materials are technically challenging and time consuming to generate. An important function of the urinary tract is to prevent urine leakage into the surrounding tissue--a function usually performed by the urothelium. We hypothesize that by providing an impermeable barrier in the acellular graft material, urine leakage would be minimized, as the urothelium forms in vivo. However, since urothelial cells require access to nutrients from the supporting vasculature, the impermeable barrier must degrade over time. Here we present the development of a novel biomaterial composed of the common degradable polymers, poly(ε-caprolactone) and poly(L-lactic acid) and generated by electrospinning directly onto spin-coated thin films. The composite scaffolds with thin films on the luminal surface were compared to their electrospun counterparts and commercially available small intestinal submucosa by surface analysis using scanning electron microscopy and by analysis of permeability to small molecules. In addition, the materials were examined for their ability to support urothelial cell adhesion, proliferation, and multilayered urothelium formation. We provide evidence that these unique composite scaffolds provide significant benefit over commonly used acellular materials in vitro and suggest that they be further examined in vivo.

Engineering Functional Epithelium for Regenerative Medicine and In Vitro Organ Models: A Review

“…It was observed that the epithelial cells proliferate less on highly fibrillar structures, especially when the fibers are closer to microscale. 32 Qualitative analyses confirmed that the attachment of epithelial cells to synthetic surfaces can be challenging. 33 Thus, for culturing epithelial cells on surfaces that do not contain BM components such as poly (L-lactic acid) 34 or chitosan/gelatin hydrogels, 35 it is critical to mimic the physical characteristics of BM to promote cell attachment and migration.…”

Tissue Engineering in Low Urinary Tract Reconstruction

“…Various materials have been examined for their ability to support cellular adhension, proliferation and formation of a multilayerd urothelium. The results provide the evidence that electrospinning scaffolds show significant benefitsa over commonly used acellular materials in vitro, and suggest that they should be further examined in vivo (20).…”

“…The initial study demonstrated that using SIS combined with cell culture could be a valuable model for the study of tissue engineering in bladder reconstruction. To address the problem of graft contraction, Brown et al showed that opposite-side co-culture of smooth muscle cells and epithelial cells produced a less pronounced matrix contraction than same-side co-culture (20) (Fig 13). The other problem to be addressed in tissue engineering bladder in vitro is cellular infiltration.…”

Urethra Reconstruction with Tissue-Engineering Technology

“…Одним из наиболее распространенных и тщательно изученных матриксов из децеллюляризированной ткани является СТК: показано, что в отличие от децеллюляризированных тканей мочевого пузыря или губчатого тела он менее всего пригоден для тканевой инженерии уретры [52]. Более того, одно из проведенных исследований выявило, что СТК менее эффективен для создания тканеинженерной конструкции уретры, чем синтетические матриксы на основе PLLA и PLC [53]. Предполагается, что эти результаты обусловлены тем фактом, что СТК имеет низкую пористость материала, которая, между тем, может быть увеличена с помощью 5% раствора надуксусной кислоты.…”