title: PEGylated silver doped zinc oxide nanoparticles as novel photosensitizers for photodynamic therapy against Leishmania.
abstract: We describe daylight responsive silver (Ag) doped semiconductor nanoparticles of zinc oxide (DSNs) for photodynamic therapy (PDT) against Leishmania. The developed materials were characterized by X-ray diffraction analysis (XRD), Rutherford backscattering (RBS), diffused reflectance spectroscopy (DRS), and band-gap analysis. The Ag doped semiconductor nanoparticles of zinc oxide were PEGylated to enhance their biocompatibility. The DSNs demonstrated effective daylight response in the PDT of Leishmania protozoans, through the generation of reactive oxygen species (ROS) with a quantum yield of 0.13 by nondoped zinc oxide nanoparticles (NDSN) whereas 0.28 by DSNs. None of the nanoparticles have shown any antileishmanial activity in dark, confirming that only ROS produced in the daylight were involved in the killing of leishmanial cells. Furthermore, the synthesized nanoparticles were found biocompatible. Using reactive oxygen species scavengers, cell death was attributable mainly to 77-83% singlet oxygen and 18-27% hydroxyl radical. The nanoparticles caused permeability of the cell membrane, leading to the death of parasites. Further, the uptake of nanoparticles by Leishmania cells was confirmed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). We believe that these DSNs are widely applicable for the PDT of leishmaniasis, cancers, and other infections due to daylight response.
authors.affiliation: Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan; Nanosciences and Catalysis Division, National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad, Pakistan.
authors.forename: Akhtar
authors.initials: A
authors.lastname: Nadhman
authors.affiliation: Nanosciences and Catalysis Division, National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad, Pakistan. Electronic address: seegasami01@yahoo.com.
authors.forename: Samina
authors.initials: S
authors.lastname: Nazir
authors.affiliation: Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Malik Ihsanullah
authors.initials: MI
authors.lastname: Khan
authors.affiliation: Nanosciences and Catalysis Division, National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad, Pakistan; Department of Chemistry, Hazara University, KPK, Pakistan.
authors.forename: Syeda
authors.initials: S
authors.lastname: Arooj
authors.affiliation: Department of Chemistry, Hazara University, KPK, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Bakhtiar
authors.affiliation: Department of Pharmacy, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Gul
authors.initials: G
authors.lastname: Shahnaz
authors.affiliation: Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Masoom
authors.initials: M
authors.lastname: Yasinzai
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D001156:Artemia; D002463:Cell Membrane Permeability; D002470:Cell Survival; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical; D006801:Humans; D020128:Inhibitory Concentration 50; D007895:Leishmania tropica / Q000187:drug effects / Q000378:metabolism; D007896:Leishmaniasis / Q000188:drug therapy*; D008264:Macrophages / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D012834:Silver / Q000737:chemistry*; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D000981:Antiprotozoal Agents; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D012834:Silver; D011092:Polyethylene Glycols; D015034:Zinc Oxide
keywords: Daylight; Doping; ICP-AES; Leishmaniasis; Nanoparticles; Photodynamic therapy (PDT); Reactive oxygen species (ROS); Zinc oxide (ZnO)