Light-responsive nanocomposite sponges for on demand chemical release with high spatial and dosage control

We present a biocompatible device for on demand chemical release in the form of a light-activated sponge-like nanocomposite scaffold, which ensures excellent control over the principal parameters ofchemical release and dosage in order to sustain effective therapeutic action. The sponge consists of a porous biopolymer scaffold containing a dispersion of gold nanorods, which acts as an absorber of theincoming laser light, and of thermosensitive micelles, which serve as a reservoir for the drug molecules to be released. The photothermal response of the nanoparticles contained inside the sponge triggers acontraction in proximal micelles, thus promoting the expulsion of the drug that in turn is released from the sponge to the external environment. The peculiar physiochemical and structural properties of thenanocomposite sponges impart a number of interesting features to the proposed drug release system, including the possibility of spatially confining the therapeutic treatment as well as precise control of theamount of released drug as a function of duration and power of the excitation light.