Development of elastic biomaterials as high performance candidates for tissue engineering applications

Abstract

Tropoelastin is an extracellular matrix protein, which polymerises to form elastin in the body. Due to its distinctive structural, mechanical and biological properties, tropoelastin provides a versatile building block for manufacturing biomaterials applicable to tissue engineering. Silk fibroin is a fibrous protein that has been widely used in biomedical applications because of its strength and durability. Hybrid protein polymers comprised of recombinant human tropoelastin and silk fibroin have favourable characteristics as implantable scaffolds in terms of mechanical and biological properties. In this thesis, a new class of elastic biomaterials based on tropoelastin and silk protein mixtures was developed. Tropoelastin and silk proteins were mixed and stabilised using a novel methodology and the fabrication, characterisation and potential applications of two different materials, a biocompatible film and a highly twisted yarn were explored. The fabricated tropoelastin-silk films were considered for potential corneal replacement applications. They performed similarly to the natural cornea in terms of optical clarity, refractive index, glucose permeability and mechanical properties. They showed a remarkable combination of physical properties encompassing flexibility, elasticity and suturability. Furthermore, the films supported both corneal epithelial and endothelial cell growth and function indicating that this new biomaterial may be suitable for corneal tissue regeneration. The fabricated tropoelastin-silk yarns were continuous, uniform, well twisted and strong. The yarns were easy to handle and could be used to fabricate woven meshes. The meshes supported cell growth and proliferation in vitro and were well-tolerated on in vivo implantation. The compatibility of the tropoelastin-silk yarns with textile technology processing methodologies makes them applicable for the manufacturing of a range of 3D materials suitable for tissue engineering applications