The role of polymer nanosurface roughness and submicron pores in improving bladder urothelial cell density and inhibiting calcium oxalate stone formation
The role of polymer nanosurface roughness and submicron pores in improving bladder urothelial cell density and inhibiting calcium oxalate stone formation
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DOI：
10.1088/0957-4484/20/8/085104
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发表时间：
2009-02-25
期刊：
影响因子：
3.5
通讯作者：
Webster, Thomas J.
中科院分区：
文献类型：
--
作者：
Chun, Young Wook;Khang, Dongwoo;Webster, Thomas J.
合成聚合物已被提出用于替代切除的膀胱癌组织。然而，在此类应用中使用的常规(或纳米光滑)聚合物(如聚醚氨基甲酸酯(PU)和聚乳酸-乙醇酸(PLGA))由于膀胱组织再生不良、细胞相容性差和钙结石形成过多而经常在临床上失效。为了成功地重建膀胱组织，应该对聚合物表面进行修饰以解决这些常见的问题。沿着这些思路，在聚合物表面上实施纳米级表面特征，模拟膀胱组织的自然粗糙度，可以促进适当的细胞生长，加速膀胱组织再生，并抑制膀胱钙结石的形成。为了验证这一假设，在本研究中，研究了不可生物降解聚合物(PU)和可生物降解聚合物(PLGA)在化学物质(分别为HNO3和NaOH)中刻蚀后的细胞相容性。化学腐蚀后的PU具有亚微米级的气孔和大量的纳米表面特征，而PLGA气孔较少，表面粗糙度较高。这项研究的结果有力地支持了这样的断言，在PU和PLGA上产生的纳米级表面粗糙度促进了尿路上皮细胞(位于膀胱内部的细胞)的密度，其中纳米管PLGA上观察到的尿路上皮细胞密度最大。此外，与各自的常规聚合物相比，结果提供了纳米PU和PLGA抑制草酸钙结石形成的证据，其中亚微米孔纳米PU对草酸钙结石形成的抑制作用最大。因此，本研究的结果表明，纳米地形线索对于为膀胱组织工程应用设计更好的材料具有重要意义。
Synthetic polymers have been proposed for replacing resected cancerous bladder tissue. However, conventional (or nanosmooth) polymers used in such applications (such as poly(ether) urethane (PU) and poly-lactic-co-glycolic acid (PLGA)) often fail clinically due to poor bladder tissue regeneration, low cytocompatibility properties, and excessive calcium stone formation. For the successful reconstruction of bladder tissue, polymer surfaces should be modified to combat these common problems. Along these lines, implementing nanoscale surface features that mimic the natural roughness of bladder tissue on polymer surfaces can promote appropriate cell growth, accelerate bladder tissue regeneration and inhibit bladder calcium stone formation. To test this hypothesis, in this study, the cytocompatibility properties of both a non-biodegradable polymer (PU) and a biodegradable polymer (PLGA) were investigated after etching in chemicals (HNO3 and NaOH, respectively) to create nanoscale surface features. After chemical etching, PU possessed submicron sized pores and numerous nanometer surface features while PLGA possessed few pores and large amounts of nanometer surface roughness. Results from this study strongly supported the assertion that nanometer scale surface roughness produced on PU and PLGA promoted the density of urothelial cells (cells that line the interior of the bladder), with the greatest urothelial cell densities observed on nanorough PLGA. In addition, compared to respective conventional polymers, the results provided evidence that nanorough PU and PLGA inhibited calcium oxalate stone formation; submicron pored nanorough PU inhibited calcium oxalate stone formation the most. Thus, results from the present study suggest the importance of nanometer topographical cues for designing better materials for bladder tissue engineering applications.