Preparation and in Vitro Degradation of Novel Bioactive Polylactide/wollastonite Scaffolds

Composite scaffolds for applications in bone engineering from poly(D,L-lactide) (PDLLA) incorporated with different proportional bioactive wollastonite powders were prepared through a salt-leaching method, using NH4HCO3 as porogen. The pore structures and morphology of the scaffolds were determined by scanning electron microscopy (SEM). The bioactivity of composite materials was evaluated by examining its ability to initiate the formation of hydroxyapatite (Ca-10(PO4)(6)(OH)(2))(HAP) on its surface when immersed in simulated body fluids (SBF). The in vitro degradation behaviors of these scaffolds were systematically monitored at varying time periods of 1, 2, 4, 6, 8, 11, 14, 17, 20, 24, and 28 weeks postimmersion in SBF at 37 degrees C. FT-IR, XPS, XRD, and SEM measurements revealed that hydroxyapatite commenced to form on the surface of the scaffolds after 7 days of immersion in SBF. The measurements of weight loss, pH, and molecular weight of the samples indicated that PDLLA/wollastonite composite scaffolds degraded slower than the pure PDLLA scaffolds do. Addition of wollastonite enhanced the mechanical property of the composite scaffolds. The in vitro osteoblast culture experiment confirmed the biocompatibility of the scaffold for the growth of osteoblasts. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 3396-3406,2009