title: Structural, textural and morphological characteristics of tannins from Acacia mearnsii encapsulated using sol-gel methods: Applications as antimicrobial agents.
abstract: Tannins from Acacia mearnsii were encapsulated using four different sol-gel methods acid (SGAR), basic (SGBR), silicate (SGSR) and non-hydrolytic (SGNHR) routes. The hybrid materials were analyzed using a set of techniques to characterize their structure, texture and morphology. The antimicrobial performance of the encapsulated materials was evaluated against different microorganisms (Staphylococcus aureus, Escherichia coli, Aspergillus niger and Candida sp.). The data showed that the encapsulation route significantly affects the characteristics of the resulting hybrid materials. Better functional performances were obtained using the silicate route, which produced mesoporous materials with a small surface area (0.96m2g-1) and small particle size (<1nm). These characteristics promoted the gradual release of tannins in an aqueous medium and improved their interactions with microorganisms. Furthermore, the process demonstrated the preservation of tannins after synthesis and increased antimicrobial activity (via a controlled tannin release), as demonstrated by the moderate activity against filamentous fungi and yeast.
authors.affiliation: Instituto de Química, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, Brazil.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Dos Santos
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia Catarinense, Campus Concórdia, SC, Brazil.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Vargas
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia Catarinense, Campus Concórdia, SC, Brazil.
authors.forename: Ney
authors.initials: N
authors.lastname: Fronza
authors.affiliation: Instituto de Química, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, Brazil. Electronic address: jhzds@iq.ufrgs.br.
authors.forename: João Henrique Zimnoch
authors.initials: JHZ
authors.lastname: Dos Santos
mesh_terms: D000045:Acacia / Q000737:chemistry*; D000327:Adsorption; D000890:Anti-Infective Agents / Q000737:chemistry*; D001234:Aspergillus niger; D002175:Candida / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D006868:Hydrolysis; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D009584:Nitrogen / Q000737:chemistry; D010316:Particle Size; D044367:Phase Transition; D016062:Porosity; D012542:Scattering, Radiation; D017640:Silicates / Q000737:chemistry; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects; D013499:Surface Properties; D013634:Tannins / Q000737:chemistry*; D014965:X-Rays
chemical_list: D000890:Anti-Infective Agents; D017640:Silicates; D013634:Tannins; D009584:Nitrogen
keywords: Acacia mearnsii; Antimicrobial; Silica; Sol-gel; Tannins