A novel shape memory poly(ɛ-caprolactone)/hydroxyapatite nanoparticle networks for potential biomedical applications

Abstract

A series of smart shape memory poly(ɛ-caprolactones) (PCL)/hydroxyapatite (HA) networks with different PCL arm lengths are designed and fabricated by the thiol-ene click reaction of thiol-modified HA particles with functional acrylate-terminated PCL. Compared with traditional physical blending of nanoparticles into polymer, this paper constructs a well-defined network architecture on the basis of the molecular level. Thermal and crystalline results indicate that the shape memory transition temperature (Ttrans) of the composites is correlated to the initial PCL diol molecular weight, the melting and crystallization temperature of the networks gradually increase with increasing PCL diol molecular weight. Meanwhile, the HA-PCL networks all exhibit good shape memory capability under thermal stimulus with good shape fixing ratio and recovery ratio irrespective of the molecular weight of PCL diol. An advantage of these network is that the intrinsic biocompatibility of HA nanoparticles as a netpoint for biodegradable PCL renders it a good prospects in the bone biomedical applications.