Optimization of type I collagen for 3D bioprinting

• Main Author: Ong, Wei Li
• Other Authors: Li Hoi Yeung
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Science
• Online Access: http://hdl.handle.net/10356/74249
• Institution: Nanyang Technological University

3D bioprinting has emerged as a promising platform for regenerative medicine. Continuous Liquid Interface Production (CLIP) is a breakthrough 3D printing technology which allows for object fabrication with improved mechanical properties and resolution. However, CLIP technology has not been successfully adopted into 3D bioprinting due to the lack of biomaterials with proper CLIP processing properties. This study aims to optimize the gold standard tissue engineering material, type I collagen for 3D bioprinting with CLIP approach. Type I collagens extracted from bovine, rat, fish and frog were investigated. The collagen hydrogel texture was optimized at neutral and basic pH up to pH 9.0. We showed that fish and frog collagens exhibited the fastest gelation rate while bovine collagen was the slowest, with the longest gelation lag time. Based on this, we formulated a composite collagen with 87.5% bovine collagen and 12.5% fish collagen. Compared to bovine collagen, the specially-formulated collagen presented an improved gelation kinetics while maintaining high protein homology to humans. To achieve CLIP, a photosensitizer, Rose Bengal (RB) was optimized at 0.004% and added to the collagen solution. Lastly, we successfully induced localized gelation of the formulated collagen using laser, showing the feasibility of 3D bioprinting of collagen with CLIP approach.