Fabrication and characterization of nano-composite scaffold of PLLA/silane modified hydroxyapatite

In order to improve the interfacial connection of hydroxyapatite (HAP) to poly-L-lactic acid (PLLA), gamma-methacryloxypropyl-trimethoxysilane (gamma-MPS) was used as a coupling agent to modify the surface of nano-HAP (NHAP) particles. The FTIR and XPS results showed gamma-MPS was successfully bonded on the surface of NHAP. Silane modified nano-HAP (MNHAP) and PLLA were fabricated to nano-composite scaffold by a thermally induced phase separation method. The characterization of the composite scaffold showed that the scaffold had a nano-fibrous PLLA network (fiber size 100-800 nm), an interconnective microporous structure (1-8 mu m) and high porosity (>90%). MNHAP was homogeneously distributed in the scaffold, also partly set in the nano-PLLA fibers. As a result, the compressive modulus and the protein adsorption of PLLA/MNHAP (80:20, w/w) composite scaffold increased to 4.2-fold and 2.8-fold compared with those of a pure PLLA scaffold. Incorporating MNHAP into PLLA network also buffered the pH reduction and reduced the weight loss in vitro degradation significantly. (C) 2010 IPEM. Published by Elsevier Ltd. All rights reserved.