Kalpana Hari, Premkumar Kumpati*

Cancer Genetics and Nanomedicine Laboratory, Department of Biomedical Science, School of Basic Medical Sciences, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, India

Basically i am a biologist (Biochemistry) doing my doctoral degree (going to submit) in the field of nanomedicine under the guidance of Dr.K.Premkunar, Assistant professor, Cancer Genetics and Nanomedicine Laboratory, Dept. of Biomedical Science, Bharathidasan university, Tiruchirappalli, India. I am currently working on the development of nanomaterials to enhance the out come of Photodynamic and photothermal therapy. My research interest is always on the diagnosis and therapy against cancer using nanomaterials to improve our society healthy.

Plasmonic metal nanoparticles can be used in photomedicine owing to their unique photophysical properties like surface plasmon resonance, high optical extinction, and extensive thermal stability, which makes the metal nanoparticles more suitable for the application of cancer phototherapy. Here, we exploited the appropriateness of chitosan reduced Gold nanoparticles (AuNPs) as a photothermal converter, photodynamic carrier and contrast agent to exhibit bioimaging, photothermal (PTT) and photodynamic therapy (PDT) concurrently to destroy the malignant cells. Also, synthesized AuNPs tested for cellular uptake and phototoxicity potential in breast cancer cells. AuNPs were successfully conjugated by non-covalent interaction with a hydrophilic photosensitizer, acridine orange (AO) through Glutathione (GSH) to achieve an improved PDT and PTT therapy. Results of the study demonstrated that AO tethered AuNPs (AO@GSH-AuNPs) conjugate exhibited high loading efficiency, excellent photothermal stability with enhanced cellular uptake. The anticancer activity of AO@GSH-AuNPs in combination with blue light irradiation (492 nm) was studied in in vitro using human MCF-7 breast cancer cells. Furthermore, the enhanced antitumor effect of AO@GSH-AuNPs with irradiation may be due to both the cytotoxic photodynamic effect of AO coupled nanoconjugate and photothermal ablation intervened by AuNPs. From the results we conclude that AO@GSH-AuNPs in the combined PDT and PTT based approach, could be employed as a multifunctional single nanocarrier for enhanced anticancer therapy.