Femtosecond Laser Maskless Optical Projection Lithography of Cartilage PCM Inspired 3D Protein Matrix to Chondrocyte Phenotype.

Hydrogels containing chondrocytes have exhibited excellent potential in regenerating hyaline cartilage. However, chondrocytes are vulnerable to dedifferentiation during in vitro culture, leading to fibrosis and mechanical degradation of newly formed cartilage. It is proposed to modulate cartilage formation via the developed chondrocyte pericellular matrix (PCM) -like scaffolds for the first time, in which the S, M, and L-sized scaffolds are fabricated by femtosecond laser maskless optical projection lithography (FL-MOPL) of bovine serum albumin-glyceryl methacrylate hydrogel. Chondrocytes on the M PCM-like scaffold can maintain round morphology and synthesize extracellular matrix (ECM) to induce regeneration of hyaline cartilage microtissues by geometrical restriction. A series of M PCM-like scaffolds is fabricated with different stiffness and those with a high Young's modulus are more effective in maintaining the chondrocyte phenotype. The proposed PCM-like scaffolds are effective in modulating cartilage formation influenced by pore size, depth, and stiffness, which will pave the way for a better understanding of the geometric cues of mechanotransduction interactions in regulating cell fate and open up new avenues for tissue engineering.