Korean scientists have developed solvent-responsive polymer nanocapsules. Kimoon Kim and co-workers from Pohang University of Science and Technology and Korea University, Seoul, found that these nanocapsules swelled or deswelled in response to a change in the solvent mixture. The swelling led to an increase in the permeability of the capsule, resulting in the controlled release of an encapsulated fluorescent dye.
Hollow capsules, particularly stimuli-responsive capsules, are of considerable interest because of their potential applications in various areas including drug delivery. Kim explains that ‘although there are a number of examples of stimuli-responsive polyelectrolyte capsules, vesicles, and self-assembled synthetic capsules, stimuli-responsive cross-linked polymer capsules with controlled permeability are still rare.’
However, Kim says that designing and making these capsules for practical applications is still a challenge. ‘For such stimuli-responsive nanocapsules to be clinically useful in drug delivery or diagnostic applications, they should be non-toxic, non-immunogenic and cleared from the body after a certain period of time,’ he explains.
‘One of our ultimate goals is to develop a universal drug carrier useful in targeted drug delivery using such stimuli-responsive polymer nanocapsules with a versatile surface modification capability,’ says Kim. ‘This work is a first major step toward this goal.’
Original publication: Eunju Kim et al., Chem. Commun., 2009.