A Combinatorial Approach to the Design of Boronate Ester Hydrogels Reveals the Remarkable Binding Properties of a Bicyclic Diol

We demonstrated that this is due to norbodiol’s exceptional association constants (<i>K</i>_a) with PBAs, which can reach values of up to 6600 M^–1. Compared to a list of other diols, we further showed that the remarkable properties of norbodiol could be explained by its rigid bicyclic structure and the specific three-dimensional orientation of its two hydroxyl groups. These findings provide initial insights toward a deeper understanding of the optimal diol structure for BE formation and stability.

Norbodiol-based BE crosslinking produced hydrogels whose relaxation properties were 20- to 200-fold greater than those of previous systems. We further optimized two hydrogel formulations with single or dual BE crosslinking for use in various biomedical applications, highlighting the potential of our discovery.