Department of Materials Engineering, Bangalore 560012, India.
Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India.
Nanoscale. 2016 Mar 28;8(12):6820-36. doi: 10.1039/c5nr06906h.
Toward preparing strong multi-biofunctional materials, poly(ethylenimine) (PEI) conjugated graphene oxide (GO_PEI) was synthesized using poly(acrylic acid) (PAA) as a spacer and incorporated in poly(ε-caprolactone) (PCL) at different fractions. GO_PEI significantly promoted the proliferation and formation of focal adhesions in human mesenchymal stem cells (hMSCs) on PCL. GO_PEI was highly potent in inducing stem cell osteogenesis leading to near doubling of alkaline phosphatase expression and mineralization over neat PCL with 5% filler content and was ≈50% better than GO. Remarkably, 5% GO_PEI was as potent as soluble osteoinductive factors. Increased adsorption of osteogenic factors due to the amine and oxygen containing functional groups on GO_PEI augment stem cell differentiation. GO_PEI was also highly efficient in imparting bactericidal activity with 85% reduction in counts of E. coli colonies compared to neat PCL at 5% filler content and was more than twice as efficient as GO. This may be attributed to the synergistic effect of the sharp edges of the particles along with the presence of the different chemical moieties. Thus, GO_PEI based polymer composites can be utilized to prepare bioactive resorbable biomaterials as an alternative to using labile biomolecules for fabricating orthopedic devices for fracture fixation and tissue engineering.
为了制备强多功能材料，使用聚丙烯酸 (PAA) 作为间隔物合成了接枝氧化石墨烯的聚乙烯亚胺 (GO_PEI)，并将其以不同比例掺入聚己内酯 (PCL) 中。GO_PEI 显著促进了人骨髓间充质干细胞 (hMSCs) 在 PCL 上的增殖和焦点黏附的形成。GO_PEI 能够强烈诱导干细胞成骨，使碱性磷酸酶的表达和矿化程度接近纯 PCL 的两倍，填充含量为 5%，比 GO 高约 50%。值得注意的是，5%GO_PEI 的功效与可溶性成骨诱导因子相当。GO_PEI 上的氨基和含氧官能团增加了对成骨因子的吸附，从而增强了干细胞的分化。GO_PEI 还具有高效的杀菌活性，与纯 PCL 相比，在 5%的填充含量下，大肠杆菌菌落数量减少了 85%，比 GO 高两倍多。这可能归因于颗粒的锐利边缘以及不同化学基团的协同作用。因此，基于 GO_PEI 的聚合物复合材料可用于制备生物活性可吸收生物材料，作为使用不稳定生物分子制造用于骨折固定和组织工程的骨科设备的替代方法。
