Towards the Fabrication of Bioresorbable Constructs with Customized Properties using Additive Manufacturing

Abstract

Additive Manufacturing (AM) has been employed to fabricate medical constructs for over two decades. This dissertation investigates the effects of AM process parameters on raster level geometric features and structural properties of bioresorbable constructs. The development of an open architecture custom multi-process 3D printer employed for fabricating bioscaffolds and test structures is discussed. Bioresorbable polymers including a newly synthesized radiopaque polymer, poly (glycerol sebacate fumarate) gadodiamide (Rylar) and medical grade poly-L-lactic acid (PLLA) were investigated. In the first part, the effects of process parameters on raster geometry were investigated to aid in the fabrication of structures with improved geometric features using Fused Filament Fabrication (FFF). In the second part, the effects of FFF laydown patterns on PLLA scaffold degradation in PBS were studied. In the third part, a UV in situ photopolymerization module was developed, integrated with the in-house 3D printer, and used to investigate the effects of process parameters on the structural and thermal properties of Rylar constructs using a dynamic mechanical analyzer. Design of Experiments was employed to analyze the effects of process parameters on the properties. Predictive models were developed and verified using randomly selected process parameter levels. The developed AM procedures could be employed to fabricate customized bioconstructs with desired functionality for specific soft and hard tissue applications such as tracheal airways and bones, respectively.