In-vitro Study of Cartilage Differentiation for Enthesis Tissue Engineering

Abstract

Ligaments are a dense connective tissue responsible for joint movements and stability. Anterior Cruciate Ligament (ACL) is one of the four major ligaments of the knee. Being subjected to high physiological loads, ACL is commonly injured,Surgical management with ligament grafts is often required, but these treatments are associated with complications of reduced strength, joint stiffness, repair-rupture. Interface Tissue engineering (ITE) may effectively address these complications where an artificial ligament incorporating the interfacial fibrocartilage can be engineered to provide similar mechanical and functional characteristics as the native tissue. Therefore a multi-compartmental scaffold that can induce the growth and differentiation of fibrocartilage at the interface of engineered bone and ligament tissues would mimic the native structure of bone-ligament –bone block with deposition of appropriate extracellular matrix (ECM) in respective compartments and possession of adequate mechanical properties to support the healing tissue. The current project has focused on the fabrication of a silk-based knitted scaffold which comprises of three compartments, one each for the bone, ligament and enthesis tissues. an array of methods were adopted for surface modification of the compartmentalized knitted silk scaffold by using bio-polymers such as silk solution, chitosan, gelatin and hydroxyapatite on the appropriate compartments. The ligament and bone compartments were reserved for mature cell line culture like MG63 and Saos-2. The various methods used for coatings of polymers over the knitted-silk were alternate soaking, plain coating and freeze-drying. The knitted scaffold was characterized for its water absorption biodegradability,tensile strength, and bio compatibility. Such a complex graft with incorporation of enthesis in laboratory can provide natural insertional strength at the interface and can change the current scenario of replacing injured ligaments.