Photopolymerization Parameters Influence Mechanical, Microstructural, and Cell Loading Properties of Rapidly Fabricated Cell Scaffolds
Brittany N. Allen, Rion J. Wendland, Jacob D. Thompson, Budd A. Tucker, Kristan S. Worthington
Abstract
Engineered scaffolds are commonly used to assist in cellular transplantations, providing crucial support and specific architecture for a variety of tissue engineering applications. Photopolymerization as a fabrication technique for cell scaffolds enables precise spatial and temporal control of properties and structure. One simple technique to achieve a two-dimensional structure is the use of a patterned photomask, which results in regionally selective photo-cross-linking. However, the relationships between photopolymerization parameters like light intensity and exposure time and outcomes like structural fidelity and mechanical properties are not well-established. In this work, we used photopolymerization to generate degradable polycaprolactone triacrylate (PCLTA) scaffolds with a defined microstructure. We examined the impact of light intensity and exposure time on scaffold properties such as shear modulus and micropore structure. To assess feasibility in a specific application and determine the relationship between parameter-driven properties and cell loading, we cultured retinal progenitor cells on the PCLTA scaffolds. We found that light intensity and polymerization time directly impact the scaffold stiffness and micropore structure, which in turn influenced the cell loading capacity of the scaffold. Because material stiffness and topography are known to impact cell viability and fate, understanding the effect of scaffold fabrication parameters on mechanical and structural properties is critical to optimizing cell scaffolds for specific applications.