title: ZnS nanocrystal cytotoxicity is influenced by capping agent chemical structure and duration of time in suspension.
abstract: As a result of their characteristic physical and optical properties, including their size, intense fluorescence, broad excitation, narrow emission and resistance to photobleaching, semiconductor nanocrystals are potentially useful for a variety of biological applications including molecular imaging, live-cell labeling, photodynamic therapy and targeted drug delivery. In this study, zinc sulfide (ZnS) semiconductor nanocrystals were synthesized in the 3 to 4 nm size range with selected capping agents intended to protect the nanocrystal core and increase its biological compatibility. We show that the biocompatibility of ZnS nanocrystals with primary murine splenocytes is influenced by the chemical structure of the outer capping agent on the nanocrystal. Additionally, the cytotoxicity of ZnS nanocrystals increases markedly as a function of time spent in suspension in phosphate-buffered saline (PBS). These data suggest that the potential therapeutic and/or biological use of ZnS nanocrystals is inherently dependent upon the proper choice of capping agent, as well as the conditions of nanocrystal preparation and storage.
authors.affiliation: Department of Biology, Lebanon Valley College, Annville, PA 17003, USA.
authors.forename: Justin N
authors.initials: JN
authors.lastname: Weilnau
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Black
authors.forename: Veronica J
authors.initials: VJ
authors.lastname: Chehata
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schmidt
authors.forename: Kimberly L
authors.initials: KL
authors.lastname: Holt
authors.forename: Lindsay M
authors.initials: LM
authors.lastname: Carl
authors.forename: Collin J
authors.initials: CJ
authors.lastname: Straka
authors.forename: Anderson L
authors.initials: AL
authors.lastname: Marsh
authors.forename: Walter A
authors.initials: WA
authors.lastname: Patton
authors.forename: Courtney M
authors.initials: CM
authors.lastname: Lappas
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D005260:Female; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D057872:Pulp Capping and Pulpectomy Agents / Q000737:chemistry; D013154:Spleen / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013440:Sulfides / Q000737:chemistry / Q000633:toxicity*; D013535:Suspensions; D013997:Time Factors; D017967:Zinc Compounds / Q000737:chemistry / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D057872:Pulp Capping and Pulpectomy Agents; D013440:Sulfides; D013535:Suspensions; D017967:Zinc Compounds; C031238:zinc sulfide