Verteporfin Loaded Graphitic Carbon Nitride Nanosheets for Combined Photo-Chemotherapy

Verteporphin loaded g-C3N4 represents a multifunctional therapeutic platform for synchronous cancer imaging and treatment through the synergistic effect of phototherapy and chemotherapy. A biocompatible nanocarrier using g-C3N4 nanosheets for high loading and anticancer activity of photosensitizer drug verteporfin (VP) is designed. The drug encapsulation efficiency (%) of optimized mannose functionalized g-C3N4 formulation was observed to be 68.5 % for 5 mg of nanocarrier. It was found that 63.3 % and 81 % of the total bound drug was released from the nanocarrier at pH 5.4 and pH 1.2 respectively after 48 h. Under neutral conditions (pH 7.4), 45.2 % of the drug was released from the nanocarrier in the first 48 h. The % cytotoxicity of the free drug, the drug loaded nanocarrier against human breast cancer cell line (MCF-7) was found to be 91.47 % and 91.23 % respectively at the dose of 40 mu g/mL and 5 mg/mL after 48 h. IC50 values also manifest the significantly lower cytotoxicity of drug loaded nanocarriers (IC50=0.195 mg/mL) as compared to free-drug (IC50=0.156 mu g/mL). For mannosylated graphitic carbon nitride (g-C3N4), verteporfin and man-g-C3N4@VP the values of mean +/- std. deviation were found to be 4.14 +/- 2.46; 55.39 +/- 2.76; 63.27 +/- 1.74 respectively. Terephthalic acid assay confirmed formation of hydroxyl radicals in the solution treated with nanocarrier. This study suggests that g-C3N4 is a promising use in drug carrier, cancer diagnosis and therapy. The combined effects of the high efficacy of ROS generation under UV light irradiation, low toxicity, and bio-compatibility highlight the potential of verteporphin loaded g-C3N4 for PDT.