Abstract

Peptide Bioinks for Bioprinting 3D Hydrogel Scaffolds to Build Organotypic Tissue Constructs

Eva Yihua Loo, Research Scientist, Institute of Bioengineering & Nanotechnology (IBN), A*STAR

Three-dimensional (3D) bioprinting is a disruptive technology for creating organotypic constructs for high-throughput screening and regenerative medicine. Despite its promise, the development of bioprinting technologies is constrained by the lack of suitable bioinks to serve as the structural scaffold to maintain the shape of the printed construct, localize the cells, and provide a condusive microenvironment for maintaining cell survival and physiological function. Printable scaffolds with adequate mechanical strength and stiffness are sought after to ensure viability of printed cells and tissues. We report the first peptide bioinks – lysine-containing hexapeptides which self-assemble under physiological conditions into stable, nanofibrous three-dimensional hydrogels with unprecedented stiffness. These peptides demonstrate salt-enhanced gelation. By carefully controlling the peptide and salt concentrations, instantaneous gelation of the ultrashort peptides was attained within physiological conditions, making these formulations ideal for bioprinting. The resulting biocompatible scaffolds support long term 3D cultures such as human stem cells. It also supports the differentiation of primary cells into organotypic (notably gastrointestinal) structures useful for high-throughput screening, diagnosis and tissue engineering.