Chitosan Nanoparticles as a Potential Drug Delivery System for Photodynamic Therapy of Cancer

Objective: Chitosan nanoparticles (CS-NP) can imbibe water insoluble anticancer agents into its hydrophobic multicores. In the present study, chitosan nanoparticles, a nanoscale drug carrier system is investigated for its potential as a drug delivery system for porphyrin based photodynamic therapy. Methods: Zinc meso tetra phenyl porphyrin (ZnmTPP) encapsulated CS-NP was prepared by ionic gelation method. The synthesized nanoparticles were characterized using dynamic light scattering studies, zeta potential analysis and AFM analysis. Results: Freshly prepared chitosan nanoparticles had an average hydrodynamic diameter of 175 nm and are nearly spherical in shape as per light scattering measurements and atomic force imaging respectively. As nanoscale drug carriers, (ZnmTPP) encapsulated chitosan nanoparticles exhibited high encapsulation efficiency and controlled release pattern. The encapsulated photosensitizer exhibited efficient singlet oxygen generation upon photo irradiation, retaining the photosensitization capacity of encapsulated hydrophobic ZnmTPP. The in vitro phototoxicities of free and nano-encapsulated ZnmTPP, studied using MTT assay in DLA cell lines demonstrate a concentration dependent response of photosensitizer in free and CS-nano formulations.