pH-Responsive amphiphilic homopolymers derived from green solvent CyreneTM

Stimuli-responsive polymers possess the ability to sense external stimuli and translate it into an observable response based on physiochemical changes. However, the development of stimuli-responsive polymers has hitherto been limited to amphiphilic block copolymers, which usually require sequential controlled chain-growth polymerization steps, or amphiphilic homopolymers derived from petroleum sources. Here, we report the preparation of an amphiphilic homopolyacetal derived from green solvent dihydrolevoglucosenone, commercialized under the trade name of Cyrene™. First, an allylic-bearing diol was synthesized using Cyrene^TM as a starting reagent. Second, a bio-based homopolyacetal was obtained through the polyaddition of the aforementioned diol with 1,4-butanediol divinyl ether (DVE). To introduce amphiphilicity into the homopolymer, a thiol-ene click post-polymerization modification using 2-mercaptoethanol was employed. Thereafter, the self-assembly of the amphiphilic homopolymer in an aqueous solution resulted in the formation of nanostructures capable of loading active cargo molecules and releasing them under relevant biological acidic conditions. Combining a straightforward preparation with ability to self-assemble, this new pH-responsive homopolymer paves the way for the development of bio-based amphiphilic homopolymers for specific applications such as drug delivery.