Biomimetic and photo crosslinked hyaluronic acid/pluronic F127 hydrogels with enhanced mechanical and elastic properties to be applied in tissue engineering

Abstract

Biosynthetic hydrogels have proved to be a credible solution in developing cost effective scaffolds with superlative mechanical properties for biomedical applications. Elastic hydrogels have emerged with advanced application possibilities for cartilage tissue regeneration and cell implantation. However, a hydrogel scaffold that mimics the properties of biological tissues in terms of elasticity, provision of favorable environment for cell growth and biocompatibility are rarely reported. In this research, we developed photocrosslinked hyaluronic acid/pluronic F127 (HA/PF) porous hydrogels with exceptional mechanical and water sorption properties. In order to retain the micellar phase of PF in the hydrogels, we restrained their concentrations to 8 wt% in the hydrogel matrices. Further optimization such as duration of photocrosslinking resulted in hydrogel scaffolds with remarkable mechanical properties. Topical and cross-sectional scanning electron microscopy images depicted the dense interconnected porous networks within the hydrogel matrices. Rheology studies confirmed the importance of PF concentrations in obtaining the hydrogels with enhanced toughness and mechanical properties. The results from the microscopic rheology studies were further testified by applying macroscopic mechanical distortions over the hydrogels. Hydrogels with higher PF concentrations restrained the degradations and displayed enhanced mechanical properties. By retaining the micellar structures in the HA/PF hydrogel scaffolds, the polypropylene blocks in PF were able to reversibly fold and unfold to favor the energy dissipation during the mechanical deformation and aid in improving the mechanical properties of the hydrogels. The overall properties of the HA-PF hydrogels show optimum feasibility for hard tissue engineering application.