Desktop Robot Based Rapid Prototyping System: An Advanced Extrusion Based Processing of Biopolymers into 3D Tissue Engineering Scaffolds

Abstract

Since ancient times, tissue repair has been the ultimate goal of surgery. Tissue engineering is a technique to regenerate tissues and organs. It involves in vitro seeding and attachment of cells onto a scaffold. These cells then proliferate, migrate and differentiate into the intended specific tissue. The appropriateness of scaffold is essentially crucial to enable the cells to behave in the required manner producing tissues and organs of the desired shape and size. A key issue concerning the tissue engineering scaffold fabrication is the development of processing techniques flexible to building materials to fabricate scaffolds with biocompatibility and mechanical properties as close as local tissues. These techniques must also have the capability of producing adequate porosity in the scaffold to further serve as a framework for cell penetration, new tissue formation, and subsequent remodelling. Therefore, in the design of tissue engineering scaffolds, the characteristics that include pore size, shape, porosity, interconnectivity, and bio-mechanical properties should be optimized to maximize successful inducement of tissue in growth. Conventional scaffold fabrication techniques mostly focus on producing foam like structure from polymeric materials. The limitations of conventional techniques include the lack of structural stability and pore connectivity in the developed scaffolds. With continual advancement of scaffold-based tissue engineering therapies, an increased attention has been paid to the challenges in designing and developing patient-specific 3D scaffolds. Rapid prototyping (RP) technology in combination with synthetic biopolymer could be an up-to-date solution to the challenges in developing appropriate scaffolds in need. RP technology uses layer-manufacturing strategy to build 3D scaffold directly from computer-generated models. It can improve current scaffold design by controlling scaffold parameters such as filament diameter, filament gap and lay-down pattern. These pore scale parameters are correlated to the porosity, pore connectivity and mechanical stability of the scaffolds. This chapter presents the scaffold-based tissue engineering approach, scaffold functions & requirements, materials for scaffolds and scaffold fabrication techniques. In addition, an evaluation study of the scaffolds developed by desktop robot based rapid prototyping (DRBRP) system is reported.