Multi-Mechanophore Polymers for Mechanically Triggered Small Molecule Release with Ultrahigh Payload Capacity

Polymers that release small molecules in response to mechanical force are promising for a variety of applications including drug delivery, catalysis, and sensing. While a number of mechanophores have been developed for the release of covalently bound payloads, existing strategies are either limited in cargo scope, or in the case of more general mechanophore designs, are restricted to the release of one or two cargo molecules per polymer chain. Herein, we introduce a non-scissile mechanophore based on a masked 2-furylcarbinol derivative that enables the preparation of multi-mechanophore polymers with ultrahigh payload capacity. We demonstrate that polymers prepared via ring-opening metathesis polymerization are capable of releasing hundreds of small molecule payloads per polymer chain upon ultrasound-induced mechanochemical activation. This non-scissile masked 2-furylcarbinol mechanophore overcomes a major challenge in cargo loading capacity associated with previous 2-furylcarbinol mechanophore designs, enabling applications that benefit from much higher concentrations of delivered cargo.