3D Printing of Robust and Biocompatible Poly(ethylene glycol) Diacrylate/Nano-Hydroxyapatite Composites via Continuous Liquid Interface Production

Three-dimensional (3D) printing technology with satisfied speed and accuracy has been a powerful force in biomaterial processing. Early studies on 3D printing of biomaterials mainly focus on their biocompatibility and...

A Simplified 2D Numerical Simulation of Photopolymerization Kinetics and Oxygen Diffusion–Reaction for the Continuous Liquid Interface Production (CLIP) System

Additive manufacturing is a versatile technology for producing customized 3D products. In 2015, the Continuous Liquid Interface Production (CLIP) system was developed as a part of projection-type, UV-curable resin 3D printers. The CLIP system utilized the dead zone where oxygen inhibition occurs and prevents the UV-cured product from adhering to the UV illumination window. The CLIP system successfully produced complex shapes in a short time. This study investigated how the relationship between the photopolymerization rate, oxygen inhibition rate, and oxygen diffusion rate affects the shape of the product by means of a numerical simulation of the photopolymerization kinetics with oxygen diffusion and reaction. The results indicate that the vertical production speed and transmittance of UV light are crucial to controlling the conversion and shape precision of products.

Additive Manufacturing of Bovine Serum Albumin-Based Hydrogels and Bioplastics

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).

Additive Manufacturing of Bovine Serum Albumin-Based Hydrogels and Bioplastics

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).