Photodynamic therapy on skin melanoma and epidermoid carcinoma cells using conjugated 5-aminolevulinic acid with microbial synthesised silver nanoparticles

The present research work describes the use of photodynamic therapy (PDT) of drug 5-aminolevulinic acid (5-ALA) conjugated with microbial synthesised silver nanoparticles on skin melanoma (B16F10) and epidermoid carcinoma (A431) cell lines. Silver nanoparticles were synthesised using the bacterial strain Bacillus licheniformis. The morphology of the nanoparticles was studied using scanning electron microscopy (SEM) and elemental analysis of nanoparticles was carried out using energy dispersive X-ray spectroscopy (EDX). Fourier-transform infrared spectroscopy (FTIR) analysis was performed to assess the functional groups of the nanoparticles. Crystalline nature of nanoparticles was assessed using powder X-ray diffraction (XRD).The cytotoxicity of pure nanoparticles and conjugated nanoparticles with 5-ALA using polyethylene glycol (PEG) was assessed on B16F10 and A431 cell lines and also compared with standard 5-ALA. Production of ROS molecules was measured using a 2,7-dichlorofluorescein-diacetate (DCFH-DA) probe. The results showed that the 5-ALA-silver nanoparticles conjugate had higher cytotoxicity on both the cell lines than the pure ALA and silver nanoparticles. Antimicrobial activity of silver nanoparticles was also carried out on food borne pathogens and nanoparticles showed comparable antimicrobial activity with standard antibiotics.