Fabrication of silk-based composite scaffold for bone-ligament-bone graft using aqueous polymeric dispersion technique

Abstract

Tissue engineering is a promising technology for treating tissue defects or replacing nonfunctional tissues/organs. It relies upon a temporary scaffold that is basically an artificial structure which provides the support for 3D tissue formation or organogenesis. Ideally, scaffolds should be able to accommodate human cells, orchestrate their growth and differentiation leading to tissue regeneration and ultimately make it feasible for implantation. Major sports injuries involve the damage of cartilages, ligaments, tendons and the enthesis. Since ligament injury is most common and ligament-alone grafts are not so successful to replace the injured ligaments, the researchers are experimenting with the construction of a composite scaffold which can guide the stem cells to differentiate into fibrocartilage that bridges of Bone-Ligament interface i.e. enthesis. In the current project, a composite silk-based scaffold was fabricated by incorporating multiple compartments for B-L-B graft. The core scaffold was prepared by knitting the silk fibers (from Bombyx mori) to provide required mechanical strength. The individual compartments over the knitted scaffold were coated with specific biocompatible components (i.e. hydroxyapatite for bone, Polyethylene oxide and & Polyethylene glycol for ligament and cartilage) blended with gelatin using Aqueous Polymer Dispersion (APD) Technique. The morphology of fabricated scaffolds was studied under optical microscope and SEM (Scanning Electron Microscope) while the mechanical properties were analysed through the Texture Analyzer. The particle sizes were found to be between 10-1000 nm. It was concluded that silk based multi-compartmental scaffolds fabricated from APD technique are suitable for enthesis tissue engineering due to their porosity and matching mechanical properties. However, the scaffolds need to be confirmed for their bioactivity by culturing live cells on respective compartments