Three-dimensional scaffolds for enhanced tissue regeneration

• Main Author: Tam, Chong Meng
• Other Authors: Chew Sing Yian
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Chemical engineering::Biotechnology
• Online Access: http://hdl.handle.net/10356/16464
• Institution: Nanyang Technological University

An emerging area of interest in tissue engineering is to fabricate biomimetic constructs that closely resembles the extracellular matrix architecture, so as to allow cells to undergo minimum remodeling as tissue regenerates in vivo. The fibrous and porous structure of electrospun scaffolds makes them ideal candidates for tissue engineering applications. By having control over the porosity and architecture of scaffolds potentially allows control over the cell migration rate into the scaffold, as well as the cellular functional and gene expression changes. However, the degree of control of these parameters is still at infancy stage. Researchers have produced scaffolds using electrospinning which resultantly end up in two-dimensional membrane structures, often lacking the porosity and depth essential for cell proliferation during tissue regeneration. The purpose of this study was to develop electrospinning techniques that overcome the problems of conventional polymer scaffold by producing a three-dimensional scaffold of predictable morphologies that have the strength and size of nanofibers, and structural similarity with extracellular matrix so that it allows enhanced tissue regeneration. Coaxial electrospinning technique was proposed to prepare biodegradable core-shell fibrous scaffolds with poly-ε-caprolactone (PCL) comprising the core structure and gelatin forming the coating of the fibers. It was hypothesized that by controlling the degree of crosslinking of the outer gelatin layer with glutaraldehyde before hydrating the scaffolds with water, a resultant three-dimensional hydrogel will be formed due to the water uptake of the outer gelatin layer in water and fusing of this gelatin sheath layer that extend throughout the entire scaffold. Mechanical strength of the hydrogel would be maintained by the presence of embedded hydrophobic PCL fibers in the core region. In the preparation of the proposed core-sheath nanofibers, factors such as polymer concentrations, solution flow rates and crosslinking time were shown to affect the dimensions of the bicomponent fibers. These findings would be useful to successful scaffold design with the coaxial electrospinning technique. The promising three-dimensional hydrogel architecture developed in this study showed good mechanical properties, well defined dimensions and reproducibility, therefore the hydrogel scaffolds will have very high potential in tissue engineering.