The application of nanotechnologies into medicine promises to offer solutions when applied to health challenges such as cancer. In particular the development of new local and focal therapies such as photodynamic therapy will reduce side effects associated with systemic administration of chemotherapy drugs, and will allow preservation or limited resection of organs with small size tumors. Our research projects aim to develop biodegradable anti-cancer materials based on biodegradable porous silicon-based nanostructures to be used for local cancer treatment.

Porous silicon (pSi) nanostructures are fully biodegradable, and nontoxic in vivo. The primary biodegradation product of pSi is orthosilicic acid, which is the bioavailable form of silicon. PSi is easily prepared by electrochemical etching of crystalline silicon. Chemical modification provides a means to adjust the degradation rate of pSi, as well as to load drugs or photosensitizers. Due to their electronic semiconductor-derived properties, pSi nanostructures exhibit intrinsic photoluminescence amenable for imaging. Moreover, they can be excited by near infrared (NIR) two photon excitation light offering possibilities for phototherapies, and for light triggered and targeted treatment, based on tissue-penetrable NIR light response.

The development of photoactive pSi nanostructures functionalized with porphyrins for applications in imaging and photo-activated therapies will be presented.