Synthesis of mechanically stiff and bioactive hybrid hydrogels for bone tissue engineering applications

A 3D microenvironment is essential for the cell adhesion and proliferation necessary to achieve the desired regeneration of damaged tissues or organs. To this end, hydrogels may provide an appropriate 3D microenvironment; however, their applicability may be limited owing to low mechanical stability. We have effectively synthesized cellulose nanocrystals-reinforced polyacrylamide/sodium alginate/silica glass hybrid hydrogels with good compressive stiffness, and have provided insight into the possible chemistry of the materials in the respective hydrogel networks. The obtained hybrid hydrogels showed high porosity and an interconnected pore structure after freeze drying. The incorporation of cellulose nanocrystals (ranging from 2.5 wt% to 10.0 wt%) improved the mechanical performance, in vitro degradation stability, thermal stability, and yielded good in vitro MC3T3-E1 cell adhesion and proliferation onto the hybrid hydrogels without affecting their apatite-forming ability (bioactivity) in the simulated body fluid. The obtained hybrid hydrogels were found to exhibit strong potential for further in vivo characterization for bone tissue engineering applications. (C) 2017 Elsevier B.V. All rights reserved.