Gomillion Cheryl T, Lakhman Rubinder Kaur, Kasi Rajeswari M, Weiss R A, Kuhn Liisa T, Goldberg A Jon
Department of Reconstructive Sciences, Center for Biomaterials, University of Connecticut Health Center, Farmington, Connecticut, 06030.
J Biomed Mater Res A. 2015 Feb;103(2):500-10. doi: 10.1002/jbm.a.35190. Epub 2014 Apr 28.
End-capping by covalently binding functional groups to the ends of polymer chains offers potential advantages for tissue engineering scaffolds, but the ability of such polymers to influence cell behavior has not been studied. As a demonstration, polylactide (PLA) was end-capped with lithium carboxylate ionic groups (hPLA13kLi) and evaluated. Thin films of the hPLA13kLi and PLA homopolymer were prepared with and without surface texturing. Murine osteoblast progenitor cells from collagen 1α1 transgenic reporter mice were used to assess cell attachment, proliferation, differentiation, and mineralization. Measurement of green fluorescent protein expressed by these cells and xylenol orange staining for mineral allowed quantitative analysis. The hPLA13kLi was biologically active, increasing initial cell attachment and enhancing differentiation, while reducing proliferation and strongly suppressing mineralization, relative to PLA. These effects of bound lithium ions (Li(+) ) had not been previously reported, and were generally consistent with the literature on soluble additions of lithium. The surface texturing generated here did not influence cell behavior. These results demonstrate that end-capping could be a useful approach in scaffold design, where a wide range of biologically active groups could be employed, while likely retaining the desirable characteristics associated with the unaltered homopolymer backbone.
通过将官能团共价结合到聚合物链的末端进行封端，为组织工程支架提供了潜在的优势，但此类聚合物影响细胞行为的能力尚未得到研究。作为一个实例，聚丙交酯（PLA）用羧酸锂离子基团进行封端（hPLA13kLi）并进行评估。制备了有和没有表面纹理的hPLA13kLi和PLA均聚物薄膜。使用来自1α1型胶原转基因报告小鼠的小鼠成骨细胞祖细胞来评估细胞附着、增殖、分化和矿化。通过测量这些细胞表达的绿色荧光蛋白以及用二甲苯酚橙染色检测矿化情况来进行定量分析。相对于PLA，hPLA13kLi具有生物活性，可增加初始细胞附着并增强分化，同时减少增殖并强烈抑制矿化。结合的锂离子（Li(+)）的这些作用此前尚未见报道，并且总体上与关于锂的可溶性添加的文献一致。此处产生的表面纹理不影响细胞行为。这些结果表明，封端可能是支架设计中的一种有用方法，在这种方法中可以使用多种生物活性基团，同时可能保留与未改变的均聚物主链相关的理想特性。
