3D-printed poly(ethylene) glycol diacrylate (PEGDA)-chitosan-nanohydroxyapatite scaffolds: Structural characterization and cellular response

Polymer-based scaffolds with bioactive materials offer great potential in bone tissue engineering. Polyethylene glycol diacrylate (PEGDA) scaffolds fabricated via liquid crystal display 3D printing technique lack inherent osteoconductivity. To improve such properties, chitosan of 10 and 20 wt% and nanohydroxyapatite (nHA) (3-10 wt%) were incorporated into PEGDA scaffolds. nHA, synthesized via wet chemical precipitation, had a particle size of 28 nm and exhibited low crystallinity, as confirmed by X-ray diffraction. PEGDA-chitosan-nHA scaffolds underwent post-curing and 70 % ethanol leaching treatment. The presence of chitosan and nHA in the composite scaffolds was confirmed by their characteristic peaks. TGA analyses further verified nHA content correlating to the intended amount. The scaffolds featured interconnected pores ranging from 2891 to 3382 μm and porosities between 35 and 56 %. The swelling percentage and compressive modulus were reported at ~71-93 % and 0.52-1.18 MPa, respectively. Notably, PEGDA-chitosan-nHA scaffolds showed enhanced in vitro efficacy than pure PEGDA scaffolds, by promoting better MG63 cell adhesion (p < 0.05), higher proliferation and alkaline phosphatase (ALP) activity, particularly in scaffolds with 20 wt% chitosan across all incubation periods in cell proliferation and early osteoblast differentiation studies. These findings suggest that PEGDA-chitosan-nHA scaffolds have promising potential for bone tissue engineering applications.