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

The diaphragm is a physical barrier separating the thoracic and abdominal cavities. Its physiological function is fundamental to pulmonary ventilation. Congenital diaphragmatic hernia (CDH) is a malformation that leaves a hole in the diaphragm during fetal development. Synthetic nondegradable membranes are currently used for the repair of diaphragm holes. However, these membranes do not help cells to adhere and proliferate. There is a need for biodegradable membranes composed of muscular and fibroblast cells to replicate a simplified diaphragmatic tissue. We thus 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 bioink based on methacrylated collagen and hyaluronic acid, containing porous poly(D,L-lactic-co-glycolic acid) solid microscaffolds to protect myoblast and fibroblast cells against mechanical stress during extrusion printing. We found that metabolic activity of C2C12 myoblast increased by 215% in the presence of a polylysine-coated microscaffolds, compared to those cultured without microscaffolds. Microscaffolds loaded with C2C12 and NIH 3T3 cells increased viability (30% and 15%) and cell activity (527% and 567%) either after co-culture (5.6% increased viability and 588% cell activity) bioprinting on albumin membrane, compared to cells in bioink without microscaffolds. Cell-loaded microscaffolds embedded in bioink enhance C2C12 to NIH3T3 cross-migration on albumin membrane. This work is a preliminary proof of concept of cellularization of myoblasts and fibroblasts by extrusion bioprinting on a new biodegradable albumin membrane designed for diaphragmatic hernia patches.