title: Effects of the sol-gel route on the structural characteristics and antibacterial activity of silica-encapsulated gentamicin.
abstract: The effects of sol-gel processes, i.e., acid-catalyzed gelation, base-catalyzed gelation and base-catalyzed precipitation routes, on the encapsulation of gentamicin were investigated. The resulting xerogels were characterized using a series of complementary instrumental techniques, i.e., the adsorption/desorption of nitrogen, small-angle X-ray scattering, Fourier transform infrared spectroscopy, diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy. The encapsulated gentamicin samples were tested against a series of Gram-positive and Gram-negative bacterial strains. The best antimicrobial activity was observed with the encapsulated gentamicin that was prepared via the precipitation route, even in comparison with the neat antibiotic, especially in the case of the Gram-positive strain Staphylococcus aureus. The gentamicin concentration on the outermost surface and the zeta potential were identified as factors that affected the highest efficiency, as observed in the case of encapsulation via the base-catalyzed process.
authors.affiliation: Universidade Federal do Rio Grande do Sul, Instituto de Química, Av. Bento Gonçalves, 9500, Porto Alegre 91501-970, RS, Brazil.
authors.forename: G G
authors.initials: GG
authors.lastname: Corrêa
authors.affiliation: Universidade Federal do Rio Grande do Sul, Instituto de Química, Av. Bento Gonçalves, 9500, Porto Alegre 91501-970, RS, Brazil.
authors.forename: E C
authors.initials: EC
authors.lastname: Morais
authors.affiliation: Universidade Federal do Rio Grande do Sul, Instituto de Química, Av. Bento Gonçalves, 9500, Porto Alegre 91501-970, RS, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Brambilla
authors.affiliation: Universidade Federal do Rio Grande do Sul, Instituto de Química, Av. Bento Gonçalves, 9500, Porto Alegre 91501-970, RS, Brazil.
authors.forename: A A
authors.initials: AA
authors.lastname: Bernardes
authors.affiliation: Universidade Federal do Rio Grande do Sul, Instituto de Química, Av. Bento Gonçalves, 9500, Porto Alegre 91501-970, RS, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Radtke
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia Catarinense, Campus Concórdia, SC, Brazil.
authors.forename: D
authors.initials: D
authors.lastname: Dezen
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia Catarinense, Campus Concórdia, SC, Brazil.
authors.forename: A V
authors.initials: AV
authors.lastname: Júnior
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia Catarinense, Campus Concórdia, SC, Brazil.
authors.forename: N
authors.initials: N
authors.lastname: Fronza
authors.affiliation: Universidade Federal do Rio Grande do Sul, Instituto de Química, Av. Bento Gonçalves, 9500, Porto Alegre 91501-970, RS, Brazil. Electronic address: jhzds@iq.ufrgs.br.
authors.forename: J H Z Dos
authors.initials: JH
authors.lastname: Santos
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005782:Gels / Q000138:chemical synthesis / Q000737:chemistry; D005839:Gentamicins / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects*; D013329:Structure-Activity Relationship; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D005782:Gels; D005839:Gentamicins; D012822:Silicon Dioxide
keywords: Antibacterial activity; Encapsulation; Gentamicin; Silica; Sol–gel