A tough and biocompatible double-network hydrogel for 3D bioprinting
In this work, I developed a 3D printable collagen-based double-network (DN) hydrogel, which demonstrated excellent mechanical properties and low cytotoxicity. Collagen fibrils and poly(AAM-co-DMAPS) formed the double network structure and increased the toughness, as well as elastic modulus, to as high as 2,380% and 2,070%, respectively, compared with a pure collagen hydrogel. The fracture energy of DN hydrogels is 1,100% that of the pristine synthetic hydrogel. Through introduction of collagen, the cell viability of DN hydrogels reached 88%, which is 900% higher compared to pristine polymer hydrogel in viability. A human nose model with good resolution was fabricated using the optimized DN resin by DLP 3D bioprinting, which demonstrates the good potential in tissue engineering for articular cartilage.