DLP fabricating of precision GelMA/HAp porous composite scaffold for bone tissue engineering application

Abstract

The hydrogel composited hydroxyapatite (HAp) scaffold shown biomimetic extracellular matrix and osteogenic activity, which is a promising bone regeneration biomaterial. 3D printing has been widely used in fabrication of customized and complex bone regeneration scaffold. However, it is still a challenge to prepare high-precision HAp reinforced composites by digital light processing (DLP) printing that can effectively promote bone regeneration. In this study, shear-thinning gelatin methacrylamide (GelMA)/hydroxyapatite (HAp) composite inks were prepared to fabricate high-precision scaffolds by DLP printing for bone repair. Firstly, GelMA hydrogels with adjustable mechanical, rheological and printing properties were synthesized to screen hydrogel concentration and degree of substitution. Then carefully selected biocompatible dispersants to reduce the agglomeration of hydroxyapatite. The actual printing resolution of the GelMA/HAp porous composite scaffolds with excellent mechanical strength through DLP 3D printing was up to about 100 μm. In vitro, the 3D printed composite scaffold significantly promoted the adhesion and proliferation of osteoblasts, as well as promoted osteogenic differentiation. In vivo, the GelMA/HAp porous composite scaffolds showed excellent ability in accelerating the formation of new bone in rabbit skull defects. The GelMA/HAp porous composite scaffolds fabricated by the composite inks with good printability, mechanical properties and osteogenic activity have fascinating potential in bone repair application.