We are inspired by the responsive and adaptable properties which define biological macromolecules: proteins, polysaccharides, DNA. These assemblies are capable of taking external signals (stimuli) and translating them into a useful outcome - such as binding to ions to open porins, stretching and contracting in response to electrical signals or releasing glucose in response to enzymes.
Reproducing these functions with synthetic polymers is highly desirable for biotechnological applications, owing to the fact that synthetic polymers have: huge monomer scope; tunable properties; scalability (i.e. multi-ton manufacture); reduced immunogenicty and potential low toxicity. The vast majority of work in this field has focussed on thermo-responsive polymers which change their form in relation to a rise (or fall) in temperature. This transition is interesting, but has mostly been used for simple precipitation - heating a polymer with an LCST leads to it being insoluble. We are interesting in making this transition far more useful in two ways
In real biological/medical settings, application of a precise temperature gradient is extremely challenging. As an example, light can cause heating at the surface, but has poor penetration through deep tissue. We are engineering these responsive polymers to enable transitions without a temperature change: isothermally. This allows all the useful properties to be triggered by alternate stimuli, including biochemicals. We have particually studied the use of glutathione as a trigger as it is present at 1000 x higher concentrations inside cells, compared to outside.
Modulating biodistribution and LogP
Key References from the Group
Advanced Functional Materials, 2013, DOI: 10.1002/adfm.201202227. "Molecular sieving on the surface of a protein provides protection without loss of activity"
Chemical Communications, 2013, DOI: 10.1039/C2CC34236G “Isothermal” LCST Transitions Triggered by Bioreduction of Single Polymer End-Groups", link. Feature article in Chem. Commun. Emerging Investigator Issue
Biomacromolecules, 2012, 13, 3200 - 3208 "Biodegradable, poly(disulfide)s derived from RAFT polymerization. Monomer scope, glutathione degradation and tunable thermal responses" link Top 10 most accessed article in Sept/Oct
Macromolecular Rapid Communications, 2012, 33, 779 - 784 , "Exploiting Thermoresponsive Polymers to Modulate Lipophilicty: Interactions with Model Membranes" link Invited article for special issue "Polymer Science the Next Generation" and featured in Materials Views Magazine.