Programmable biodegradable thermoresponsive gels for cell therapy

Polymer systems that undergo phase transitions in response to environmental stimuli have been widely investigated for drug delivery.

A series of programmable gels has been prepared, each with a unique breakable bond in order to facilitate a predetermined rate of gel degradation. These polymers are programmed to release therapeutic materials at defined time intervals and in response to a variety of external stimuli, namely pH changes and presence of reducing agents.

The polymers are PEG-PLA block copolymers that have a cleavable bond either in the block connecting bond or within the block so that when this bond is cleaved, the gel collapses and either dissolves in water or precipitates out of solution.