Bioprinting of BSA membranes with C2C12 and NIH 3T3 pre-cellularized PLGA microscaffold: a step toward diaphragmatic...

The diaphragm is a physical barrier that separates the thoracic and abdominal cavities. It plays a fundamental role in pulmonary ventilation. Congenital diaphragmatic hernia is a malformation that leads to a hole in the diaphragm during fetal development. Currently, synthetic, nondegradable membranes are used to repair diaphragm holes. However, these membranes do not promote cell adhesion and proliferation. There is a need for biodegradable membranes composed of muscle and fibroblast cells that can replicate simplified diaphragmatic tissue. Thus, we developed a biocompatible and biodegradable salt-compacted albumin membrane. C2C12 myoblasts were bioprinted as central spokes surrounded by a ring of NIH 3T3 fibroblasts onto albumin membranes. We used a bioink consisting of methacrylated collagen and hyaluronic acid that contained porous poly(D,L-lactic-co-glycolic acid) solid microscaffolds. This bioink protected myoblast and fibroblast cells against mechanical stress during extrusion printing. We found that the metabolic activity of C2C12 myoblasts increased by 215% in the presence of polylysine-coated microscaffolds compared to myoblasts cultured without microscaffolds. Microscaffolds loaded with C2C12 and NIH 3T3 cells increased cell viability by 30% and 15%, respectively, and cell activity by 527% and 567%, respectively, after co-culture (5.6% increased viability and 588% cell activity) and bioprinting on an albumin membrane compared to cells in bioink without microscaffolds. Cell-loaded microscaffolds embedded in bioink promoted cross-migration of C2C12 to NIH3T3 on an albumin membrane. This study provides a preliminary proof of concept of cellularizing myoblasts and fibroblasts using extrusion bioprinting on a new biodegradable albumin membrane designed for diaphragmatic hernia patches.