Annihilation of Leishmania by daylight responsive ZnO nanoparticles: a temporal relationship of reactive oxygen species-induced lipid and protein oxidation

Akhtar Nadhman,1–3 Malik Ihsanullah Khan,1,2 Samina Nazir,4 Momin Khan,1,5 Gul Shahnaz,6 Abida Raza,2 Dilawar Farhan Shams,7 Masoom Yasinzai1,3 1Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University, 2Nuclear Medicine Oncology and Radiotherapy Institute, 3Centre for Interdisciplinary Research in Basic Sciences (CIRBS), International Islamic University, 4Nanosciences and Catalysis Division, National Centre for Physics, Quaid-i-Azam University Campus, Islamabad, 5Department of Microbiology, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, 6Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 7Department of Environmental Sciences, Abdul Wali Khan University Mardan, Mardan, Pakistan Abstract: Lipid and protein oxidation are well-known manifestations of free radical activity and oxidative stress. The current study investigated extermination of Leishmania tropica promastigotes induced by lipid and protein oxidation with reactive oxygen species produced by PEGylated metal-based nanoparticles. The synthesized photodynamic therapy-based doped and nondoped zinc oxide nanoparticles were activated in daylight that produced reactive oxygen species in the immediate environment. Lipid and protein oxidation did not occur in dark. The major lipid peroxidation derivatives comprised of conjugated dienes, lipid hydroperoxides, and malondialdehyde whereas water, ethane, methanol, and ethanol were found as the end products. Proteins were oxidized to carbonyls, hydroperoxides, and thiol degrading products. Interestingly, lipid hydroperoxides were produced by more than twofold of the protein hydroperoxides, indicating higher degradation of lipids compared to proteins. The in vitro evidence represented a significant contribution of the involvement of both lipid and protein oxidation in the annihilated antipromastigote effect of nanoparticles. Keywords: lipid peroxidation, protein oxidation, Leishmania tropica, zinc oxide (ZnO), nanoparticles, reactive oxygen species (ROS), photodynamic therapy (PDT), dopin

Visible-light-responsive ZnCuO nanoparticles: benign photodynamic killers of infectious protozoans

Akhtar Nadhman,1,2 Samina Nazir,2 Malik Ihsanullah Khan,1 Attiya Ayub,2,3 Bakhtiar Muhammad,3 Momin Khan,1 Dilawar Farhan Shams,4 Masoom Yasinzai1,5 1Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan; 2Nanosciences and Catalysis Division, National Centre for Physics, Quaid-i-Azam University Campus, Islamabad, Pakistan; 3Department of Chemistry, Hazara University, Dhodial, Pakistan; 4Department of Environmental Sciences, Abdul Wali Khan University Mardan, Mardan, Pakistan; 5Center of Interdisciplinary Research, International Islamic University, Islamabad, Pakistan Abstract: Human beings suffer from several infectious agents such as viruses, bacteria, and protozoans. Recently, there has been a great interest in developing biocompatible nanostructures to deal with infectious agents. This study investigated benign ZnCuO nanostructures that were visible-light-responsive due to the resident copper in the lattice. The nanostructures were synthesized through a size-controlled hot-injection process, which was adaptable to the surface ligation processes. The nanostructures were then characterized through transmission electron microscopy, X-ray diffraction, diffused reflectance spectroscopy, Rutherford backscattering, and photoluminescence analysis to measure crystallite nature, size, luminescence, composition, and band-gap analyses. Antiprotozoal efficiency of the current nanoparticles revealed the photodynamic killing of Leishmania protozoan, thus acting as efficient metal-based photosensitizers. The crystalline nanoparticles showed good biocompatibility when tested for macrophage toxicity and in hemolysis assays. The study opens a wide avenue for using toxic material in resident nontoxic forms as an effective antiprotozoal treatment. Keywords: zinc oxide, nanoparticles, doping, photodynamic therapy, Leishmani