Silk Based Three Dimensional Bioprinting for Meniscus Tissue Engineering

Abstract

Meniscus is a fibrocartilaginous avascular tissue present in the knee joint between the femoral condyles and tibial plateau. The heterogenous cellular composition of fibrogenic, chondrogenic and fibrochondrogenic phenotypes and extracellular composition of collagen, glycosaminoglycans and adhesion glycoproteins dictates the physiological function of this loadbearing tissue. Meniscus is prone to tears and injuries due to various trauma, accidents, and physiological conditions. These tears are conventionally treated with resection, suturing and implants. Most of them have their respective drawbacks related to patient-specificity for size and shape, material properties, cellular make-up and mechanical resilience being the major factors. This thesis identifies the requisite design considerations for treatment of full and partial thickness meniscus tears of both larger and smaller dimensions. 3D printing, injectable hydrogel and ultrasound-based strategies have been explored to potentially treat meniscus defects. Silk fibroin from mulberry (B. mori) and non-mulberry (A. assama) sources have been blended with various other bioactive polymers to formulate shear-thinning and thermo-reversible hydrogel inks for 3D printing and injection.