Non-covalently functionalized SWNTs as potential delivery agents for novel BODIPY*based PDT sensitizers & the design and synthesis of dendritic light harvesters

Abstract

Photodynamic therapy (PDT) is a non-invasive method used for the treatment of a number of diseases including certain cancers and some cardiovascular diseases. Photodynamic action depends on absorbance of photosensitizer (PS) in near IR region of the spectrum and subsequent generation of cytotoxic singlet oxygen in the vicinity of the PS. Carbon nanotubes are widely used for biomedical applications due to their inertness, biocompatibility, cellular internalization, facile and multi-modification. We have synthesized and characterized novel water soluble boradiazaindacene (BODIPY)-based PS, noncovalently attached on to the single wall carbon nanotube (SWNT). We have observed that near infrared absorbing photosensitizer preserve its singlet oxygen generation capability upon adsorption on SWNT. We have demonstrated that SWNTs can be used as the delivery vehicle of PS for the use in PDT. In the second part of this research, multichromatic cascade-type light harvesting BODIPY dendrimers were synthesized and highly efficient energy transfer was observed. Successful channeling of energy in a predefined region of the dendrimer was revealed.