Light-responsive hybrid sponges for on demand chemical release

Stimuli-responsive biomaterials have attracted much attention for their prospective application in several fields including biomedicine, biotechnology and biosensing. On the basis of our previous work [1], we have succeeded in fabricating an implantable device for on demand chemical release in the form of a light-activated nanocomposite sponge [2]. The sponge consists of a porous chitosan scaffold containing a dispersion of gold nanorods (GNRs), which acts as an absorber of an incoming laser light, and of thermosensitive PCL-PEG-PCL micelles, which serve as a reservoir for the drug molecules to be released. The photothermal response of the GNRs contained inside the sponge triggers a contraction in proximal micelles, thus promoting the expulsion of the drug that in turn is released to the external environment. The peculiar features of the nanocomposite sponges impart a number of interesting characteristics to this drug release system, including the possibility of spatially confining the therapeutic treatment as well as of a precise control over the amount of released drug as a function of duration and power of the excitation light. [1] Matteini P et al. ?Chitosan films doped with gold nanorods as laser-activatable hybrid bioadhesives?. Adv Mater 22 4313 (2010) [2] Matteini P et al. ?Light-responsive nanocomposite sponges for on demand chemical release with high spatial and dosage control? J Mater Chem B DOI: 10.1039/C2TB00310D (2013)