Development of a Biomimetic Scaffold for Ligament Tissue Engineering

Abstract

The focus of this thesis was to design a scaffold for in vitro culture that would mimic the structure of the native ligament in order to influence primary ligament cells towards the production of ligament-specific tissue. A major part of this project was material selection and subsequent testing to determine if the chosen materials were suitable for the scaffold design. A 20:80 (CL:DLLA) poly(ε-caprolactone-co-D,L-lactide) copolymer (PCLDLLA) was synthesized and electrospun with sub-cellular fibre diameters. The fibres were manufactured into aligned arrays to mimic the collagen fibrils of the ligament. To enhance cell and protein adhesion properties, the PCLDLLA polymer surface was modified using a base catalyzed etching technique. A photocrosslinked methacrylated glycol chitosan (M-GC) hydrogel was used to deliver encapsulated ligament cells to the biomimetic scaffold and mimic the hydrated proteoglycan matrix portion of the ligament. The scaffolds were cultured in vitro for a 4 week period and characterized using immunohistochemistry to identify and localize ligament specific proteins produced within the scaffolds. Cell culture results indicated that the M-GC hydrogel was an effective method of delivering viable cells evenly throughout the biomimetic scaffold. Compared to the unmodified PCLDLLA surfaces, the base-etched electrospun PCLDLLA fibre surfaces increased cell adhesion and acted as new tissue growth guides in the biomimetic scaffold. The biomimetic scaffolds produced and accumulated ligament specific proteins: collagens type I and III. The biomimetic scaffold design was determined to be a viable alternative to the current designs of ligament tissue engineering scaffolds.