Surface-Modified Hydroxyapatite Nanoparticle-Reinforced Polylactides for Three-Dimensional Printed Bone Tissue Engineering Scaffolds.

Bone defects represent a clinical challenge that severely impacts the quality of life of affected patients. To match the shape of a bone defect area exactly, additive manufacturing has emerged as a promising technology to produce customized bone regeneration scaffolds for bone defect treatment. In this study, new three-dimensional (3D)-printed poly(L-lactic acid) (PLLA)/hydroxyapatite (HA) composite scaffolds were developed. HA nanoparticles were first modified by a straightforward, economical method. Briefly, HA nanoparticles were modified with dopamine and hexamethylenediamine, and PLLA chains were grafted onto the HA nanoparticles by aminolysis reaction. Then, the PLLA-modified HA nanoparticles were blended with PLLA to form a thermoplastic composite for 3D printing. Due to the high compatibility between the PLLA matrix and PLLA-modified HA nanoparticles, the 3D-printed PLLA/HA scaffolds possess robust mechanical properties and good biocompatibility. This study provides a flexible strategy to fabricate scaffolds for the customized treatment of bone defects.