A Precised Surface Modification of Hydroxyapatite with Poly(methylmethacrylate) for Tissue Engineering & Regenerative Medicine

Abstract

The poly(methylmethacrylate) (PMMA) grafted biocompatible hydroxyapatite nanocrystals (HAPs) hybrid nanocomposites (PMMA-g-HAPs) were synthesized by employing surface thiol-lactam initiated radical polymerization (TLIRP) through grafting from strategy. At first, the surface of HAPs was functionalized by 3-mercaptopropyl-trimethoxysilane in one-step process to prepare thiol immobilized HAPs (HAPs-SH). Subsequently, a controlled radical polymerization of MMA by using two component initiating system comprising of HAPs-SH and butyrolactam (BL) successfully afforded PMMA-g-HAPs nanocomposites. The resulting structure and morphological feature of nanocomposites was systematically characterized by FT-IR and XRD analyses. GPC studies of cleaved polymers from nanocomposites of different time revealed that the grafting polymerization from the surface of HAP was well controlled in nature. Moreover, the thermal property of the PMMA was found to be improved by incorporation of inorganic HAP nanoparticles in the polymer matrix as revealed by TGA and DSC studies. The colloidal stability of the synthesized nanocomposites was observed to be exceptionally good in organic solvents as suggested by the time dependent monitoring using UV-visible spectroscopy and captured digital photographs. The synthesized nanocomposites show a great promise for the safe application in tissue engineering and regenerative medicine.