Preparation and properties of g-TTCP/PBS nanocomposites and its in vitro biocompatibility assay

In an effort to decrease the aggregation of tetracalcium phosphate (TTCP, Ca4(PO4)2O) in composites and develop better bone substitute materials, a series of poly(l-lactic acid) (PLLA)-grafted TTCP (g-TTCP) particles were prepared by a ring-opening polymerization with l-lactide (the monomer for synthesizing PLLA) in the presence of catalyst stannous octoate [Sn(Oct)2]. The g-TTCP/poly(1,4-butylene succinate) (PBS) composites with the different g-TTCP contents were prepared via melting processing. The bonding between the PLLA and the TTCP particles was analyzed by FTIR, TG, 1H NMR and XPS. The results confirmed that the PLLA was grafted on the surface of the TTCP particles. Time-dependent phase monitoring indicated that the g-TTCP had enhanced dispersion in the PBS solution. Water contact angle measurement and cell culture were also used to investigate the properties of the g-TTCP/PBS composites. The g-TTCP in composites provided more favorable environments for rat osteoblast to attach and grow on the surface of the g-TTCP/PBS composites. Cell proliferated well in the extracted solution of the g-TTCP/PBS composites with different g-TTCP content, and there was no necrotic or suspended cells appeared.