Tissue engineering is a promising therapeutic approach to treat large tissue defects, addressing the challenges of limited tissue sources or potential host rejection in traditional treatment methods such as autograft and allograft. To obtain engineered tissues with ideal physiological conditions, two components are crucial for the tissue regeneration process: scaffold materials and biomimetic stimuli. Each of these components and their interactions have a significant impact on the functionality of engineered tissues.
In this dissertation, from a materials science and engineering aspect, advances in the development of functional scaffold materials and novel stimulation devices were performed. Relevant mechanisms of the interactions between the developed materials, or devices, with biological responses were also systematically studied.
In the first part of this dissertation, a high-throughput, low-cost, industrial-scale fabrication method was developed to produce a series of multi-functional polymer composites as scaffold materials for tissue engineering applications. With the inclusion of newly synthesized multi-functional additives, the produced polymer composites exhibited excellent osteogenic inducibility to human adipose-derived stem cells and satisfactory antibacterial efficiency against both E. coli and S. aureus. Relative to previously reported methods of direct loading silver nanoparticles into polymeric materials, the developed composites exhibited significantly reduced silver associated cytotoxicity. Also, a novel synergistic antibacterial effect at the material interface was found on the fabricated polymer composite, where the material exhibited significantly lower affinity to bacterial adhesion.
In the second part of this dissertation, a novel electrical field stimulation device was developed. The micro-fabricated stimulation device consists of micro-sized interdigitated electrodes, which provide a stable and consistent electric field above the surface. This configuration ensures the generation of a physiologically relevant electric field, even with application of ultra-low electric voltages, eliminating potential adverse electrochemical effects. Polymers were also coated onto the surface of the electrodes to further improve the biocompatibility of the stimulation device.
In summary, this dissertation successfully demonstrated the potential of applying industrial polymer processing technologies as a promising alternative approach to produce specially functionalized scaffolds for tissue engineering and regenerative medicine applications. The developed electrical field stimulation device provides manipulation and activation methods for stem cells that can be used without immunogenic bio-agents or complicated equipment.