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Advisor(s)
Abstract(s)
As infeções nosocomiais estão a tornar-se cada vez mais recorrentes devido ao aumento de estirpes bacterianas resistentes aos antibióticos. Muitas vezes estas infeções podem também estar associadas a biofilmes microbianos, o que complica o tratamento destas infeções. Além disso, os biofilmes podem formar-se em muitos tipos de superfícies, especialmente nos dispositivos médicos invasivos. Razão pela qual há uma necessidade de desenvolver novos materiais bioativos funcionais e eficazes que possam prevenir a formação destes mesmos biofilmes. Uma alternativa às estratégias antibacterianas convencionais pode ser proporcionada por polímeros de coordenação (CPs) bioativos.
Este documento descreve a preparação, caracterização e avaliação da capacidade antimicrobiana de polímeros bioativos de coordenação (bioCPs) produzidos a partir de precursores de sais metálicos de prata(I), cobre(II) e zinco(II) e dos ligandos orgânicos ácidos 4,4'-sulfonildibenzóico (H2sdba) e 4,4’-oxibis benzóico (H2obba), bem como a sua incorporação em biopolímeros.
Neste trabalho são descritos sete novos bioCPs: [Ag2(sdba)]n (1), {[Cu(sdba)·H2O]·1.5H2O}n (2), {[Zn(sdba)·H2O·NH3]·1/2(NH3)}n (3), [Ag2(obba)]n (4), [Cu2(obba)(NH3)(OH)]n (5a), [Cu(obba)0.5(NH3)]n (5b) e {[Zn(obba)(NH3)2}n (6). Todos os bioCPs foram utilizados como dopantes na preparação de filmes de biopolímeros à base de agarose e fécula de batata. Os filmes produzidos foram testados em bactérias S. aureus (Gram-positiva) e E. coli (Gram-negativa), posteriormente avaliou-se a citotoxicidade destes em células humanas HepG2.
Neste estudo, foi concluído que os filmes compostos por bioCP 1, contendo prata(I), destacam-se como a opção mais promissora para inibir o crescimento bacteriano. Esses filmes demonstraram atividade antibacteriana eficaz contra as bactérias S. aureus e E. coli, sem causar citotoxicidade nas células humanas. Além disso, os filmes à base de bioCP 4 e 6, contendo prata(I) e zinco(II), também apresentaram resultados promissores na inibição bacteriana. Por outro lado, os bioCPs à base de cobre(II) revelaram bioatividade apenas para S. aureus, mas não demonstraram eficácia contra E. coli.
Nosocomial infections are becoming increasingly recurrent due to the increase in antibiotic-resistant bacterial strains. These infections are often associated with microbial biofilms, which complicates the treatment of these infections. Additionally, biofilms can form on many types of surfaces, especially invasive medical devices. Thus, there is a need to develop new and effective bioactive materials that can prevent the formation of biofilms. An alternative to conventional antibacterial strategies is provided by bioactive progressive polymers (CPs). This work describes the ability to prepare, characterize and evaluate antimicrobial bioactive coordination polymers (bioCPs) produced from precursors of metallic salts of silver, copper and zinc and the organic ligands 4,4'-sulfonyldibenzoic acid (H2sdba) and benzoic 4,4'-oxybis (H2obba). It was obtained seven novel bioCPs: [Ag2(sdba)]n (1), {[Cu(sdba)·H2O]·1.5H2O}n (2), {[Zn(sdba)·H2O·NH3]·1/2(NH3)}n (3), [Ag2(obba)]n (4), [Cu2(obba)(NH3)(OH)]n (5a), [Cu(obba)0.5(NH3)]n (5b) and {[Zn(obba)(NH3)2}n (6). All bioCPs were used as dopants for the preparation of agarose and potato starch-based biopolymer films.The films produced were tested on the bacteria S. aureus (Gram-positive) and E. coli (Gram-negative), and their cytotoxicity on human HepG2 cells was subsequently evaluated. In this study, it was concluded that films composed of bioCP 1, containing silver(I), stand out as the most promising option for inhibiting bacterial growth. These films demonstrated effective antibacterial activity against the bacteria S. aureus and E. coli, without causing cytotoxicity in human cells. Furthermore, films based on bioCP 4 and 6, containing silver(I) and zinc(II), also showed promising results in bacterial inhibition. On the other hand, copper(II)-based bioCPs revealed bioactivity only when S. aureus, but did not demonstrate efficacy against E. coli.
Nosocomial infections are becoming increasingly recurrent due to the increase in antibiotic-resistant bacterial strains. These infections are often associated with microbial biofilms, which complicates the treatment of these infections. Additionally, biofilms can form on many types of surfaces, especially invasive medical devices. Thus, there is a need to develop new and effective bioactive materials that can prevent the formation of biofilms. An alternative to conventional antibacterial strategies is provided by bioactive progressive polymers (CPs). This work describes the ability to prepare, characterize and evaluate antimicrobial bioactive coordination polymers (bioCPs) produced from precursors of metallic salts of silver, copper and zinc and the organic ligands 4,4'-sulfonyldibenzoic acid (H2sdba) and benzoic 4,4'-oxybis (H2obba). It was obtained seven novel bioCPs: [Ag2(sdba)]n (1), {[Cu(sdba)·H2O]·1.5H2O}n (2), {[Zn(sdba)·H2O·NH3]·1/2(NH3)}n (3), [Ag2(obba)]n (4), [Cu2(obba)(NH3)(OH)]n (5a), [Cu(obba)0.5(NH3)]n (5b) and {[Zn(obba)(NH3)2}n (6). All bioCPs were used as dopants for the preparation of agarose and potato starch-based biopolymer films.The films produced were tested on the bacteria S. aureus (Gram-positive) and E. coli (Gram-negative), and their cytotoxicity on human HepG2 cells was subsequently evaluated. In this study, it was concluded that films composed of bioCP 1, containing silver(I), stand out as the most promising option for inhibiting bacterial growth. These films demonstrated effective antibacterial activity against the bacteria S. aureus and E. coli, without causing cytotoxicity in human cells. Furthermore, films based on bioCP 4 and 6, containing silver(I) and zinc(II), also showed promising results in bacterial inhibition. On the other hand, copper(II)-based bioCPs revealed bioactivity only when S. aureus, but did not demonstrate efficacy against E. coli.
Description
Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Química e Biológica - Bioprocessos
Keywords
Materiais antimicrobianos Polímeros de coordenação Prata Cobre Zinco Biopolímeros Citotoxicidade Inibição Bacteriana Biofilmes Bioactive materials Biofilms Coordination polymers Silver Copper Zinc Biopolymers Cytotoxicity Bacterial Inhibition
Pedagogical Context
Citation
GUIU, Telma Galvão – Desenvolvimento de materiais híbridos dopados com BioMOFs para aplicações antimicrobianas. Lisboa: Instituto Superior de Engenharia de Lisboa, 2023. Dissertação de Mestrado
Publisher
Instituto Superior de Engenharia de Lisboa