Controlled Vascular Cellular Growth By Microstructured Patterned Surfaces On Implantable Biodegradable Polymer Scaffold.

The technological advances in the field of MEMS and biodegradable polymers with elastomeric properties have opened new areas of application for engineering of soft tissues such as blood vessel, heart valves, cartilage, tendon, and bladder, which exhibit elastic properties. In this thesis work, Microfabrication technology has successfully been applied to biodegradable polymer films to encourage cell growth in designated area. This work is presented with the final goal of fabricating implantable polymer scaffolds to produce small diameter blood vessels in a controlled manner spatially by using the concept of wettability and contact guidance.There are several methods to control cell growth including patterned chemical cues on the surface. Although successful in patterned cell growth, chemical cues are not suitable for implantation. While the concept of "contact guidance" uses physical cues to guide cell growth most of the research has been done on either conventional microelectronic materials such as silicon and metals or non-implantable polymers such as PDMS.Thus, we have introduced microscale roughness to the CUPE biodegradable polymer film surface by making microdome structures and have achieved a very high contact angle on polymer surface, where cell adhesion is preferentially much lower than on smooth scaffold surfaces.We have also successfully transferred microchannel structure patterns over the CUPE polymer, and NIH 3T3 cell growth patterns were observed for a 5 day study. The results of the patterned cell study were compared with the cells cultured on polymer films without micropattern. The results indicated that cells exhibited aligned and elongated morphology in microchannels. The cells on film without micropatterns were randomly oriented.This in-vitro study of microfabricated films proves the concept of selective and guided cell growth without using any chemical modification on implantable scaffold.