Bio-sourced and biodegradable polymers for additive manufacturing could
enable the rapid fabrication of parts for a broad spectrum of applications
ranging from healthcare to aerospace. However, a limited number of these
materials are suitable for vat photopolymerization processes. Herein, we report a two-step additive
manufacturing process to fabricate robust protein-based constructs using a
commercially available laser-based SLA printer. Methacrylated bovine serum
albumin (MA-BSA) was synthesized and formulated into aqueous resins that were used
to print complex 3D objects with a resolution comparable to a commercially
available resin. The MA-BSA resins were characterized by rheometry to determine
the viscosity and the cure rate, as both of these parameters can ultimately be
used to predict the printability of the resin. In the first step of patterning
these materials, the MA-BSA resin was 3D printed, and in the second step, the
printed construct was thermally cured to denature the globular protein and
increase the intermolecular noncovalent interactions. Thus, the final 3D
printed part was comprised of both chemical and physical cross-links. Compression
studies of hydrated and dehydrated constructs demonstrated a broad range of
compressive strengths and Young’s moduli that could be further modulated by
adjusting the type and amount of co-monomer. The printed hydrogel constructs
demonstrated good cell viability (> 95%) after a 21-day culture period. These
MA-BSA resins are expected to be compatible with other vat photopolymerization
techniques including digital light projection (DLP) and continuous liquid
interface production (CLIP).