Strong and osteoconductive poly(lactic acid) biocomposites by high-shear liquid dispersion of hydroxyapatite nanowhiskers

Abstract

Abstract Controlled incorporation of bioactive hydroxyapatite (HA) into poly(lactic acid) (PLA) signifies a promising approach to design and development of biomedical-adaptive materials. Here we unravel a microwave-assisted biomineralization approach to synthesis of HA nanowhiskers (HANWs), which were characterized by well-controlled diameter (∼30 nm) and length (80 − 120 nm), combined with a desirable calcium − phosphorus ratio (Ca/P) of 1.67. A high-shear liquid dispersion (HSLD) method that provided a combination of high pressure (up to 50 kPa) and high shear rate approaching 10000 s −1 was established to fabricate homogeneous PLA/HANWs composites. In particular, upon incorporation of 30 wt % HANWs the tensile strength and elastic modulus of PLA-HA30 (76.7 MPa and 3.3 GPa) were elevated by 48% and 84% compared to those of pure PLA, respectively, as accompanied by a nearly 2-fold increase in the cell viability. This work paves a facile yet effective roadway to strong and osteoconductive PLA composites appealing for bone tissue repairing. Graphical Abstract Synopsis: Biomineralization concepts are abstracted to synthesize well-defined and bioactive HANWs, which could be uniformly dispersed in PLA biofilms by high-shear liquid exfoliation.