title: In vitro cytotoxicity and phototoxicity of surface-modified gold nanoparticles associated with neutral red as a potential drug delivery system in phototherapy.
abstract: The surface of gold nanoparticles (AuNP) was modified, improving their interaction with neutral red (NR), by using sodium thioglycolate (TGA) as a covering agent. The resulting NR-AuNPTGA system was evaluated as a potential drug delivery system for photodynamic therapy (PDT). The associations of NR with the gold nanoparticles were evaluated using UV-vis spectrometry and measurement of their zeta potential and size distribution. The toxicity and phototoxicity of NR, AuNPTGA and NR-AuNPTGA were evaluated in NIH-3T3 fibroblast and 4T1 tumor cell lines. The compounds NR and NR-AuNPTGA induced toxicity in 4T1 tumor cells and NIH-3T3 fibroblasts under visible light irradiation. Modification of the surface of AuNP with TGA prevented nanoparticle aggregation and allowed greater association with NR molecules than for naked AuNP. The photosensitizer (PS) characteristics were not affected by its association with the modified surface of the gold nanoparticles, leading to a reduction of cell viability in both cell lines assayed. This NR-AuNPTGA system is a promising drug delivery system for photodynamic cancer therapy.
authors.affiliation: School of Health Sciences, University of Brasilia, Brasilia, Brazil; Laboratory of Photochemistry and Nanobiotechnology, Faculty of Ceilandia, University of Brasilia, Brasilia, Brazil.
authors.forename: Tanira V
authors.initials: TV
authors.lastname: Verissimo
authors.affiliation: School of Health Sciences, University of Brasilia, Brasilia, Brazil.
authors.forename: Naiara T
authors.initials: NT
authors.lastname: Santos
authors.affiliation: Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil.
authors.forename: Jaqueline R
authors.initials: JR
authors.lastname: Silva
authors.affiliation: Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil.
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Azevedo
authors.affiliation: School of Health Sciences, University of Brasilia, Brasilia, Brazil; Laboratory of Photochemistry and Nanobiotechnology, Faculty of Ceilandia, University of Brasilia, Brasilia, Brazil. Electronic address: ajgomes@unb.br.
authors.forename: Anderson J
authors.initials: AJ
authors.lastname: Gomes
authors.affiliation: School of Health Sciences, University of Brasilia, Brasilia, Brazil; Laboratory of Photochemistry and Nanobiotechnology, Faculty of Ceilandia, University of Brasilia, Brasilia, Brazil. Electronic address: clunardi@unb.br.
authors.forename: Claure N
authors.initials: CN
authors.lastname: Lunardi
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004337:Drug Carriers / Q000737:chemistry*; D000067493:Dynamic Light Scattering; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D051379:Mice; D041681:NIH 3T3 Cells; D009369:Neoplasms / Q000188:drug therapy; D009499:Neutral Red / Q000008:administration & dosage / Q000737:chemistry* / Q000633:toxicity; D010316:Particle Size; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity; D013499:Surface Properties; D013864:Thioglycolates / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D017319:Photosensitizing Agents; D013864:Thioglycolates; D009499:Neutral Red; D006046:Gold; C017487:2-mercaptoacetate
keywords: 4T1 cell; Gold nanoparticle; NIH-3T3 cell; Neutral red; Photodynamic therapy; Photosensitizer