Printable glycosaminoglycan graded gelatin methacryloyl acetyl hydrogels

Hydrogels are considered as appropriate scaffold materials for cell encapsulation. This is due to their high water binding capacity similar to the native extracellular matrix. However, the equilibrium degree of swelling of simple hydrogels is related to the cross-linking degree of the hydrogels and thereby not freely adjustable. We decoupled the correlation of equilibrium degree of swelling and cross-linking density by chemical modification of the biopolymer gelatin and sophisticated hydrogel formulations. These formulations contained different amounts of chemical modified glycosaminoglycans, genuine components of native extracellular matrix of cartilage. We created glycosaminoglycan-graded hydrogels by layer-wise dispensing three hydrogel precursor solutions on top of each other. We investigated the viability of the encapsulated chondrocytes 28 days after printing and evaluated the production of newly synthesized extracellular matrix.