Biomimetic Micropatterning of Electrospun Scaffolds for Tissue Engineering

The nanostructure of the extracellular matrix (ECM) can direct cell attachment, alignment, and organization. Similarly, ECM microstructures such as tubes and branched networks organize cells into larger functional units. To mimic this complex cellular microenvironment in tissue engineered scaffolds, we need new fabrication methods capable of constructing structures on both the nano- and micro-scale. Furthermore, these methods should be compatible with a variety of biomaterials to allow tailoring of mechanical and degradation properties. Electrospinning is a useful technique for creating fibrous scaffolds, but there have been few reports introducing microstructures. \ud This dissertation describes the development of a new versatile fabrication approach that combines electrospinning with a fused deposition modeling (FDM) 3D printer to create microstructures that mimic tissues. We hypothesized that these structures would improve cell migration and positioning within electrospun scaffolds. We tested this hypothesis by patterning scaffolds for peripheral nerves and microvascular networks. We first demonstrate the feasibility of templated electrospinning for generating linear channels in fibrous nerve guides that mimic the endoneurial/fascicular tubes of nerve and promote faster Schwann cell infiltration. This micropatterning technique was combined with FDM production of branched templates to create microvascular networks within fibrous scaffolds. Finally, material properties were improved by developing a technique to fabricates scaffolds with electrospun poly(glycerol sebacate)(PGS)