title: Collagen-based silver nanoparticles for biological applications: synthesis and characterization.
abstract: BACKGROUND
  Type I collagen is an abundant natural polymer with several applications in medicine as matrix to regenerate tissues. Silver nanoparticles is an important nanotechnology material with many utilities in some areas such as medicine, biology and chemistry. The present study focused on the synthesis of silver nanoparticles (AgNPs) stabilized with type I collagen (AgNPcol) to build a nanomaterial with biological utility. Three formulations of AgNPcol were physicochemical characterized, antibacterial activity in vitro and cell viability assays were analyzed. AgNPcol was characterized by means of the following: ultraviolet-visible spectroscopy, dynamic light scattering analysis, Fourier transform infrared spectroscopy, atomic absorption analysis, transmission electron microscopy and of X-ray diffraction analysis.
  
  
  RESULTS
  All AgNPcol showed spherical and positive zeta potential. The AgNPcol at a molar ratio of 1:6 showed better characteristics, smaller hydrodynamic diameter (64.34 ± 16.05) and polydispersity index (0.40 ± 0.05), and higher absorbance and silver reduction efficiency (0.645 mM), when compared with the particles prepared in other mixing ratios. Furthermore, these particles showed antimicrobial activity against both Staphylococcus aureus and Escherichia coli and no toxicity to the cells at the examined concentrations.
  
  
  CONCLUSIONS
  The resulted particles exhibited favorable characteristics, including the spherical shape, diameter between 64.34 nm and 81.76 nm, positive zeta potential, antibacterial activity, and non-toxicity to the tested cells (OSCC).
authors.affiliation: Research Center in Biodiversity and Biotechnology (Biotec), Campus Parnaíba, Federal University of Piauí, Av São Sebastian 2819, 64202-020, Parnaíba, Piauí, Brazil. vscfisio@ufpi.edu.br.|Physiotherapy Department, Campus Parnaíba, Federal University of Piauí, Av. São Sebastião 2819, 64202-020, Parnaíba, Piauí, Brazil. vscfisio@ufpi.edu.br.
authors.forename: Vinicius S
authors.initials: VS
authors.lastname: Cardoso
authors.affiliation: Research Center in Biodiversity and Biotechnology (Biotec), Campus Parnaíba, Federal University of Piauí, Av São Sebastian 2819, 64202-020, Parnaíba, Piauí, Brazil. pquelemes@gmail.com.
authors.forename: Patrick V
authors.initials: PV
authors.lastname: Quelemes
authors.affiliation: Research Center in Biodiversity and Biotechnology (Biotec), Campus Parnaíba, Federal University of Piauí, Av São Sebastian 2819, 64202-020, Parnaíba, Piauí, Brazil. adriany1210@gmail.com.
authors.forename: Adriany
authors.initials: A
authors.lastname: Amorin
authors.affiliation: Departamento de Química, Laboratório de Fotobiologia e Fotomedicina, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, Ribeirão Preto, SP, Brazil. fernandolucasprimo@gmail.com.
authors.forename: Fernando Lucas
authors.initials: FL
authors.lastname: Primo
authors.affiliation: Departamento de Química, Laboratório de Fotobiologia e Fotomedicina, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, Ribeirão Preto, SP, Brazil. gragobbo@yahoo.com.br.
authors.forename: Graciely Gomides
authors.initials: GG
authors.lastname: Gobo
authors.affiliation: Departamento de Química, Laboratório de Fotobiologia e Fotomedicina, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, Ribeirão Preto, SP, Brazil. atedesco@usp.br.
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Tedesco
authors.affiliation: Institute of Physics of São Carlos (IFSC), University of São Paulo (USP), 13566-590, São Carlos, SP, Brazil. mafud@usp.br.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Mafud
authors.affiliation: Institute of Physics of São Carlos (IFSC), University of São Paulo (USP), 13566-590, São Carlos, SP, Brazil. yvonne@if.sc.usp.br.
authors.forename: Yvonne P
authors.initials: YP
authors.lastname: Mascarenhas
authors.affiliation: Laboratory of Microscopy, Institute of Biology, University of Brasília, 70910900, Brasília, DF, Brazil. joseraimundocorrea@gmail.com.
authors.forename: José Raimundo
authors.initials: JR
authors.lastname: Corrêa
authors.affiliation: Area of Morphology, Faculty of Medicine, University of Brasília, Brasília, 70910900, DF, Brazil. selmask@gmail.com.
authors.forename: Selma A S
authors.initials: SA
authors.lastname: Kuckelhaus
authors.affiliation: Interdisciplinary Laboratory for Advanced Materials (LIMAV), Federal University of Piauí, 64049-550, Teresina, PI, Brazil. carla.eiras.ufpi@gmail.com.
authors.forename: Carla
authors.initials: C
authors.lastname: Eiras
authors.affiliation: Research Center in Biodiversity and Biotechnology (Biotec), Campus Parnaíba, Federal University of Piauí, Av São Sebastian 2819, 64202-020, Parnaíba, Piauí, Brazil. jrsaleite@gmail.com.
authors.forename: José Roberto S A
authors.initials: JR
authors.lastname: Leite
authors.affiliation: Research Center in Biodiversity and Biotechnology (Biotec), Campus Parnaíba, Federal University of Piauí, Av São Sebastian 2819, 64202-020, Parnaíba, Piauí, Brazil. durcileneas@yahoo.com.br.
authors.forename: Durcilene
authors.initials: D
authors.lastname: Silva
authors.affiliation: Department of Chemistry, Campus Teresina, Federal University of Piauí, 64049-550, Teresina, Piauí, Brazil. jribeiro@ufpi.edu.br.
authors.forename: José Ribeiro
authors.initials: JR
authors.lastname: dos Santos Júnior
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D060326:Chemistry Techniques, Synthetic; D024042:Collagen Type I / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D004353:Drug Evaluation, Preclinical / Q000379:methods; D000067493:Dynamic Light Scattering; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D053768:Metal Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D012834:Silver / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D024042:Collagen Type I; D012834:Silver