Monitoring the cytotoxic effect of novel nanoconjugates during and after in-vivo photodynamic therapy

Looking for new and innovative remediation for cancer is a significant problem worldwide. Nanotherapeutics are considered new ways to overcome several limitations of conventional drug delivery systems, such as non-specific targeting and lack of water solubility. Although Nanoconjugates can be expanded as therapeutics and diagnostic tools, the parenteral administration of nanoconjugates may also be considered an important cause of toxicity. However, most in vivo toxicity focuses primarily on oral, pulmonary, and dermal exposure to ultrafine particles. In the present work, the toxicity of novel Phythalocyanine-Gold nanoconjugates (Pc-Au NCs) on the adult BALB/c mice before, during, and after the photodynamic therapy (PDT) has been assessed. In this context, the cytotoxicity has been evaluated on five mice groups, the control group G1 and four treated groups (G2, G3, G4, and G5). G2 was treated with laser light at a wavelength of 650 nm from a diode laser. G3 was intravenously treated with a dose of 10 µg/kg/day of Pc-Au NCs. Finally, the G4 (PDT group) was irradiated with laser light after treatment with Pc-Au NCs. The G5 was the PDT group after two weeks from the treatment. Forty-eight hours after the injection, the mice were sacrificed, and the organs were collected for morphological and histological studies. The results manifested that PC-Au NCs are safe and non-toxic in dark conditions. Furthermore, when the photosensitizer is used in PDT, it showed very low toxicity that disappeared after two weeks from the treatment through the recovery of the cells. This result will open the door for using this new nanoconjugate in many in vivo phototherapeutic applications.