Plasma and protein surface functionalization for three-dimensional polycaprolactone tissue scaffolds

In regenerate tissue in an in vitro environment, scientists usually need to create a biomimic cellular microenvironment to provide structural, chemical, physical and biological cues to the cells. Introduction of those cues to a cellular environment can be done by applying proper surface functionalization techniques. Plasma induced surface modification is one of the effective techniques that can enhance cellular functions for cell attachment, proliferation, and differentiation through changing the surface physicochemical properties.;The objective of this thesis is to develop scientific and engineering knowledge in surface functionalization of polymer scaffolds through plasma and plasma/fibronectin functionalization to understand how cellular functions respond to multiple cues from their microenvironment. In this study, a plasma and protein surface functionalization technique was investigated and applied to introduce biophysical and biochemical cues to three-dimensional (3D) polycaprolactone (PCL) tissue scaffolds. The major research tasks include: (1) development of experimental techniques for plasma and protein surface functionalization; (2) development of a multi-module computational engineering model to predict the degree of surface functionalization; (3) surface functionalization of 3D PCL tissue scaffolds by combined plasma/fibronectin surface treatment; and (4) development of a novel dual functional freeform microplasma generated maskless surface patterning process to create spatially patterned topological and chemical features on biopolymer surface that are useful for tissue engineering applications.;The results in surface analysis of oxygen-based plasma modification and fibronectin coating revealed that both techniques introduced oxygen containing functional groups (hydroxyl, carboxyl, carbonyl) on PCL tissue scaffold surfaces, and altered the surface topographies, the surface energy and the surface hydrophilicity. The changes in surface properties further resulted in an improved cell adhesion strength, proliferation and differentiation. In addition, the developed multi-module engineering model can be applied to predict the changes of the surface physicochemical properties without conducting costly and time consumed experimental measurements. The preliminary data show that the developed dual functional freeform microplasma technique is capable of generating surface patterning and printing biomolecules in one single step to create micro-scale surface functionalized patterns without using any masks, master stamps or chemical treatments.