Fabrication of tough poly(ethylene glycol)/collagen double network hydrogels for tissue engineering

In this study, a series of poly(ethylene glycol)/collagen (PEG/Col) double network (DN) hydrogel is fabricated from PEG and Col. Results of the compressive strength test indicate that the strength and toughness of these DN hydrogels are significantly enhanced. The fracture strength of PEG/Col DN hydrogels increases by 9- to 12-fold compared with that of PEG single network (SN) hydrogel, and by 36- to 48-fold compared with that of Col SN hydrogel. Taking advantage of both PEG and Col building blocks, the PEG/Col DN hydrogels possess a strengthened skeleton. Moreover, the water-storage capability and favorable biocompatibility of Col are effectively maintained. Given that the DN hydrogels can provide the appropriate environment for the adhesion, growth, and proliferation of MC3T3-E1 cells, PEG/Col DN hydrogels have potential as a load-bearing tissue repair material. (C) 2017 Wiley Periodicals, Inc.