Effects of surface functionalization of PLGA membranes for guided bone regeneration on proliferation and behavior of osteoblasts

Covalent immobilization of bioactive compounds onto modified poly lactic-co-glycolic acid (PLGA) surfaces is being rapidly developed in tissue engineering, but the compounds and the grafting procedure require optimization. Here, PLGA membranes were grafted with various ratios of collagen/chitosan (COL/CHI) composites after modification by polydopamine and then analyzed using attenuated total reflectance Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and a contact angle meter. Mechanical properties of the membranes were examined by tensile testing. Proliferation of osteoblastic cell line MC3T3-E1 cultured on the membranes was examined by MTT (3-(4, 5-dimethylthiozole-2-yl)-2, 5-diphenyltetrazolium bromide) and flow cytometric analysis. Effects on cell behavior, including cytotaxis, adhesion, and migration, were further investigated by continuous time-lapse imaging for 8 h. The COL/CHI composites were successfully immobilized onto PLGA surfaces. PLGA mainly contributed the mechanical properties, while COL/CHI played a major role in bioactivity. COL facilitated cell adhesion and spread, but the addition of CHI decreased both. A critical ratio of COL/CHI (2:1) above which the addition of CHI only slightly impacted cell proliferation was found. The results should be useful for combining versatile materials from different origins to construct guided bone regeneration membranes and to further optimize the ratio of COL/CHI composites. (C) 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A:4453, 2013.