Precision Gels from Collagen-Inspired Triblock Copolymers

Gelatin hydrogels find broad medical application. The current materials, however, are from animal sources, and their molecular structure and thermal properties cannot be controlled. This study describes recombinant gelatin-like polymers with a general design that inherently offers independent tuning of the cross-link density, melting temperature, and biocompatibility of the gel. The polymers contain small blocks with thermoreversible trimerization capacity and defined melting temperature, separated by hydrophilic nontrimerizing blocks defining the distance between the knot-forming domains. As an example, we report the secreted production in yeast at several g/L of two nonhydroxylated ∼42 kDa triblock copolymers with terminal trimerizing blocks. Because only the end blocks formed cross-links, the molecular architecture of the gels is much more defined than that of traditional gelatins. The novel hydrogels had a ∼37 °C melting temperature, and the dynamic elasticity was independent of the thermal history. The concept allows to produce custom-made precision gels for biomedical applications.