Multimaterial coextrusion (bio)printing of composite polymer biomaterial ink and hydrogel bioink for tissue fabrication

Bone tissue engineering strategies face considerable challenges owing to the complexity of the bone. This study introduces an unconventional method based on multimaterial 3D coextrusion-(bio)printing to address some of these challenges. The strategy enables simultaneous (bio)printing of a poly(lactic-co-glycolic acid)-based polymer ink laden with hydroxyapatite and a gelatin methacryloyl (GelMA)-based hydrogel bioink containing mesenchymal stem cells (MSCs). The resulting composite scaffolds exhibited a trabecular bone-like porosity and favorable compressive properties, surpassing those of GelMA alone. The (bio)printed MSCs demonstrated favorable viability, proliferation, morphology, and differentiation. This converged approach in multimaterial (bio)printing has the potential to transform the field of bone tissue engineering, offering a more efficient and effective way to regenerate skeletal tissues.