Encapsulation and release of biomolecules from Ca-P/PHBV nanocomposite microspheres and three-dimensional scaffolds fabricated by selective laser sintering

This study focused on the fabrication of calcium phosphate (Ca-P)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanocomposite scaffolds loaded with biomolecules using the selective laser sintering (SLS) technique and their evaluation. Ca-P/PHBV nanocomposite microspheres loaded with bovine serum albumin (BSA) as the model protein were fabricated using the double emulsion solvent evaporation method. The encapsulation efficiency of BSA in PHBV polymer microspheres and Ca-P/PHBV nanocomposite microspheres were 18.06 ± 0.86% and 24.51 ± 0.60%, respectively. The BSA loaded Ca-P/PHBV nanocomposite microspheres were successfully produced into three-dimensional porous scaffolds with good dimensional accuracy using the SLS technique. The nanocomposite microspheres served as protective carriers and maintained the bioactivity of BSA during SLS. The effects of SLS parameters such as laser power and scan spacing on the encapsulation efficiency of BSA in the scaffolds and in vitro BSA release were studied. An initial burst release was observed, which was followed by a slow release of BSA. After 28-day release, The PHBV matrix was slightly degraded after 28-day in vitro release study. It was shown that nanocomposite scaffolds with controlled architecture obtained via SLS could be incorporated with biomolecules, enhancing them with more functions for bone tissue engineering application or making them suitable for localized delivery of therapeutics.