University of California San Francisco/University of California Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA.
Biomed Microdevices. 2010 Jun;12(3):363-9. doi: 10.1007/s10544-009-9392-7.
Due to the retina's inability to replace photoreceptors lost during retinal degeneration, significant interest has been placed in methods to implant replacement cells. Polymer scaffolds are increasingly being studied as vehicles for cellular delivery to degenerated retinas. Previously, we fabricated poly(methyl methacrylate) thin film scaffolds that increased survival and integration of implanted retinal progenitor cells (RPCs). Additionally, these scaffolds minimized the trauma and cellular response associated with implantation of foreign bodies into mouse eyes. Here, we demonstrate that biodegradable polycaprolactone (PCL) thin film scaffolds can be fabricated with integrated microtopography. Microfabricated topography in a PCL thin film enhanced the attachment and organization of RPCs compared to unstructured surfaces. Using real-time quantitative polymerase chain reaction we also observed that attachment to microtopography induced cellular differentiation. RPCs grown on PCL thin films exhibited an increase in gene expression for the photoreceptor markers recoverin and rhodopsin, an increase in the glial and Müller cell marker GFAP, and a decrease in SOX2 gene expression (a marker for undifferentiated progenitor cells) compared to cells grown on unmodified tissue culture polystyrene (TCPS).
由于视网膜在退化过程中无法替换失去的光感受器，因此人们对植入替代细胞的方法产生了浓厚的兴趣。聚合物支架作为向退化的视网膜输送细胞的载体，越来越受到研究关注。此前，我们制造了聚甲基丙烯酸甲酯（PMMA）薄膜支架，这些支架增加了植入的视网膜祖细胞（RPCs）的存活率和整合率。此外，这些支架还最大限度地减少了将异物植入小鼠眼睛时引起的创伤和细胞反应。在这里，我们证明可以用集成微形貌来制造可生物降解的聚己内酯（PCL）薄膜支架。与非结构化表面相比，PCL 薄膜中的微加工形貌增强了 RPCs 的附着和组织。通过实时定量聚合酶链反应，我们还观察到，与微形貌的附着诱导了细胞分化。与在未经修饰的组织培养聚苯乙烯（TCPS）上生长的细胞相比，在 PCL 薄膜上生长的 RPCs 表现出光感受器标记物 recoverin 和视蛋白的基因表达增加，神经胶质和 Müller 细胞标记物 GFAP 的基因表达增加，以及未分化祖细胞标记物 SOX2 的基因表达减少。
