Photocrosslinkable carboxylated polyvinyl alcohol nanocomposite hydrogels with enhanced compressive strength and cell adhesion

Polyvinyl alcohol (PVA) hydrogel is a kind of biomaterial with broad application prospects in the biomedical fields, but its poor mechanical properties and weak cell adhesion hinder its development. Herein, carboxylated PVA with acrylate groups (PVAGMACOOH) is synthesized, and consequently carboxylated PVA nanocomposite hydrogels are fabricated by UV-irradiating the mixture of PVAGMACOOH solution and nano-scale hydroxyapatite (HAP). The nanocomposite hydrogel can gel within several seconds under the UV light irradiation. Notably, it exhibits excellent compressive strength without fracture in the strain of more than 90%, while its tensile strength is 14.6 times of the pure PVA hydrogel without HAP, indicating energy dissipation mechanism by macromolecular chain creep and good load transferring from macromolecules to nanoparticles. Furthermore, the introduction of HAP significantly enhances cytocompatibility and cell adhesion of the hydrogel. The hydrogel would be a potential candidate for various biomedical applications.