Polymers which can change their conformation in response to external stimuli are now widely studied for potential applications in biology,engineering and medicine.However,there is also a growing interest in developing materials which can respond to biological stimuli,or which can exploit biological mechanisms to acquire new properties or change existing behaviour.This talk will include some recent work on polymers which respond to stimuli for applications in drug delivery,1,2 sensing3 and microbiology,4,5 and will also consider how prokaryotic and eukaryotic cells can respond in turn.