Silk protein as a biomaterial for tissue engineering application: theoretical and experimental study

Abstract

Biocompatible and biodegradable polymeric biomaterials are used to develop biological matrix or scaffolds not only for Tissue Engineering but also for various biomedical applications including, wound dressings, membrane filters and drug delivery. Natural materials are of considerable interest due to their structural properties and superior biocompatibility. In the world of natural fibers, silk has long been recognized as the wonder fiber for its unique combination of high strength and rupture elongation. Of particular interests are the silk fibers from silkworm Bombyx mori and spider Nephila clavipes. This research deals with fabrication of tissue scaffolds from silk protein. In particular, we fabricated and characterized silk nanofibers for bone Tissue Engineering application. Two types of silk protein viz., natural cocoon fibers from silkworm Bombyx mori and transgenic spider silk from Nephila clavipes were evaluated for the feasibility of generating nanofibers using electrospinning procedure. The mechanical properties of silk nanofibers were tailored using various post-spinning methods. Nanocomposite nanofibers made up of silk and carbon nanotube (CNT) were fabricated with the intension of improving mechanical and electrical properties of the scaffolds. The biocompatibility of silk nanofiber scaffolds was compared with the nanofibrous scaffolds made up of Type I collagen and poly lactic-co-glycolic acid (PLAGA). The structural changes in silk protein in silkworm’s glands during natural spinning process and the electrospinning process were studied using molecular dynamics simulation. Cell-scaffolds interaction study was carried out on various scaffolds using primary fetal bovine osteoblasts.%%%%Ph.D., Biomedical Engineering – Drexel University, 2006