Development and imaging of zinc oxide nanorods as a photosensitizer for the diagnosis and treatment of cancer using lasers11Web: www.nilop.edu.pk/faculty.html

Abstract

A diversity of strategies is utilized for the diagnosis and treatment of cancer with limitations and side effects. Light-activated phototherapy with a suitable photosensitizer can provide a cancer cure at high specificity and tumor selectivity. The recent exposure of nanotechnology and nanoparticles in the field of medical science could assist cancer patients with light control in the presence of a suitable chemical. The cell death and tumor marker are directly related to the nanoparticles’ physiochemical composition, size, shape, self-fluorescence and activation upon suitable light excitation.In our experimental study, we demonstrated zinc oxide nanorods (ZnO NRs) as a photosensitizer and biomarker for cervical carcinoma cell line photodynamic therapy (PDT). The zinc oxide (ZnO) nanoparticles, nanoflowers and nanorods among other expensive nanoparticles have great potential in cancer therapy without toxicity and side effects. ZnO NRs have strong surface plasma resonance light absorption compared to nanoparticles and are a source of near-infrared light for deep tissue penetration. The ZnO NRs are synthesized with a hydrothermal method and characterized for their structural, physical, chemical, mechanical and optical properties. The x-ray diffraction pattern of the ZnO nanorods indicates sharp and strong diffraction peaks due to the crystalline structure with the diameter in the range of 80–120 nm and the mean diameter of 100 nm calculated through the Scherrer equation and confirmed by scanning electron microscopy using the ImageJ technique and Fourier transform infrared spectroscopy. The fluorescence and light activation of ZnO nanorods in cancer cells were determined through laser scanning confocal microscopy (LSCM) and fluorescence spectroscopy with excitation of 488 and 514 nm wavelength Ar + and He–Ne lasers. The surface profile at a fluorescence of 500–635 nm and 635–750 nm, a differential contrast image and combined LSCM image indicate fluorescence conformation, surface morphology and a diameter of 100–150 nm. The fluorescence of the ZnO NRs conjugated with the well-known PDT photosensitizer aminolevulinic acid was monitored for effective necrosis of the cancerous cells. The results indicate that ZnO NRs are active candidates for tumor narcosis under suitable light activation and are a biomarker in the diagnosis of malignant diseases.