title: Cytotoxicity and cellular uptake of ZnS:Mn nanocrystals biofunctionalized with chitosan and aminoacids.
abstract: Highly luminescent, manganese doped, zinc sulphide (ZnS:Mn) nanocrystals biofunctionalized with chitosan and various aminoacids such as L-citrulline, L-lysine, L-arginine, L-serine, L-histidine and glycine were synthesized by chemical capping co-precipitation method at room temperature, which is a simple and cost effective technique. The synthesized nanocrystals were structurally characterized by TEM, XRD, EDXS and FT-IR spectroscopy techniques. They possess high colloidal stability with strong orange red photoluminescence emission at 598 nm. The intensity of orange red emission has been observed to be maximum in L-citrulline capped ZnS:Mn nanocrystals in which the emission at 420 nm is effectively quenched by surface passivation due to capping. Taking into consideration the prospects of these highly luminescent, bio-compatible ZnS:Mn nanocrystals in bio-imaging applications, cytotoxicity studies were conducted to identify the capping combination which would accomplish minimum toxic effects. ZnS:Mn nanocrystals biofunctionalized with chitosan, L-citrulline, glycine, L-artginine, L-serine and L-histidine showed least toxicity up to 10 nM concentrations in mouse fibroblast L929 cells, which further confirms their cytocompatibility. Also the ZnS:Mn nanocrystals biofunctionalized with l-arginine showed maximum uptake in in vitro studies carried out in human embryonic kidney cells, HEK-293T, which shows the significant role of this particular amino acid in fetoplacental nutrition. The present study highlights the suitability of aminoacid conjugated ZnS:Mn nanocrystals, as promising candidates for biomedical applications.
authors.affiliation: Department of Physics, St. Teresa's College, Kochi 682 011, Kerala, India. Electronic address: sajimollazar@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Sajimol Augustine
authors.affiliation: Council of Scientific and Industrial Research, National Institute of Oceanography, Regional Centre, Cochin 682 018, India.
authors.forename: Abdulaziz
authors.initials: A
authors.lastname: Anas
authors.affiliation: Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India.
authors.forename: Ani V
authors.initials: AV
authors.lastname: Das
authors.affiliation: Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India.
authors.forename: S
authors.initials: S
authors.lastname: Sreekanth
authors.affiliation: Department of Physics, Cochin University of Science and Technology, Kochi 682 022, Kerala, India. Electronic address: jayalekshmi@cusat.ac.in.
authors.forename: S
authors.initials: S
authors.lastname: Jayalekshmi
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry*; D004705:Endocytosis / Q000187:drug effects*; D057809:HEK293 Cells; D006801:Humans; D049449:Luminescence; D008345:Manganese / Q000633:toxicity*; D051379:Mice; D053758:Nanoparticles / Q000633:toxicity* / Q000648:ultrastructure; D017550:Spectroscopy, Fourier Transform Infrared; D013440:Sulfides / Q000633:toxicity*; D014961:X-Ray Diffraction; D017967:Zinc Compounds / Q000633:toxicity*
chemical_list: D000596:Amino Acids; D013440:Sulfides; D017967:Zinc Compounds; D008345:Manganese; D048271:Chitosan; C031238:zinc sulfide
keywords: Aminoacids; Biofunctionalized; Cellular uptake; Chitosan; Cytotoxicity; Nanocrystals