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Exploring Yeast and Bacteria Secondary Metabolites for the Development of Antimicrobial Hydrogel Formulations
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Atualmente as infeções adquiridas em ambiente hospitalar são um problema cada vez mais prevalente, principalmente devido ao desenvolvimento de resistências. Este problema é particularmente relevante no uso de dispositivos médicos invasivos como cateteres vasculares.
Na tese aqui apresentada, foi utilizada a tecnologia de impressão 3D para desenvolver revestimentos antibacterianos constituídos por hidrogéis poliméricos (i.e., quitosano e ácido hialurónico) impregnados com biotensioativos.
Para alcançar este objetivo, foram produzidos e comparados dois biotensioativos (surfactina e soforolípidos). A impressão dos revestimentos de quitosano foi otimizada e estes foram posteriormente caracterizados. De forma a melhorar a reprodutibilidade e impressibilidade dos revestimentos, foi adicionada amido à formulação da bio-ink e foi realizado um desenho experimental para otimizar a concentração de amido utilizada e as configurações de impressão.
Os resultados obtidos demonstraram um melhor rendimento e atividade antibacteriana para os soforolípidos (SLs) comparativamente à surfactina. De modo geral, os revestimentos de quitosano impregnados com SLs apresentaram uma melhor atividade antibacteriana. Adicionalmente, apesar de a atividade antibacteriana contra bactérias planctónicas dos revestimentos baseados em quitosano e quitosano-amido ter sido relativamente parecida, os revestimentos baseados em quitosano apresentaram uma melhor atividade antibiofilme.
Os revestimentos aqui desenvolvidos demonstraram potencial para o seu uso em cateteres vasculares e para estudos futuros com o objetivo de expandir este conceito.
Nowadays, healthcare-associated infections are one of the most common complications faced in a healthcare setting due to an increasing resistance of bacteria towards available antibacterial drugs. This problem is particularly relevant in commonly used invasive medical devices such as vascular catheters. Thus, the demand for antibiofilm alternatives is steadily increasing. In the herein presented thesis, antibacterial coating scaffolds were developed by 3D-printing methodology using polymeric hydrogels (chitosan and hyaluronic acid) impregnated with biosurfactant active agents intended for the coating of vascular catheters and subsequent infection prevention. For this purpose, two biosurfactants (surfactin and sophorolipids) were produced and compared. The printing of chitosan-based scaffolds was optimized, and the resulting coating scaffolds were characterized. To further optimize the printability of the scaffolds, a starch com-ponent was added to the formulation of the bio-ink and a design of experiment was conducted to determine the optimal starch concentration and printing configurations. The results showed a better yield for sophorolipids (SLs) compared with surfactin as well as an overall better antibacterial activity against Gram-positive bacteria. Overall, the SLs impregnated coating scaffolds showed the best antibacterial activity against planktonic bacteria and antibiofilm activity. Furthermore, the developed chitosan-based scaffolds showed a similar antibacterial activity against planktonic bacteria with the chitosan-starch-based scaffolds. However, although the chitosan-starch-based scaffolds showed an improvement in printability and reproducibility, they also showed a slightly lower antibiofilm activity. The developed coatings showed potential for its use in vascular catheters and for further improvement studies on this concept.
Nowadays, healthcare-associated infections are one of the most common complications faced in a healthcare setting due to an increasing resistance of bacteria towards available antibacterial drugs. This problem is particularly relevant in commonly used invasive medical devices such as vascular catheters. Thus, the demand for antibiofilm alternatives is steadily increasing. In the herein presented thesis, antibacterial coating scaffolds were developed by 3D-printing methodology using polymeric hydrogels (chitosan and hyaluronic acid) impregnated with biosurfactant active agents intended for the coating of vascular catheters and subsequent infection prevention. For this purpose, two biosurfactants (surfactin and sophorolipids) were produced and compared. The printing of chitosan-based scaffolds was optimized, and the resulting coating scaffolds were characterized. To further optimize the printability of the scaffolds, a starch com-ponent was added to the formulation of the bio-ink and a design of experiment was conducted to determine the optimal starch concentration and printing configurations. The results showed a better yield for sophorolipids (SLs) compared with surfactin as well as an overall better antibacterial activity against Gram-positive bacteria. Overall, the SLs impregnated coating scaffolds showed the best antibacterial activity against planktonic bacteria and antibiofilm activity. Furthermore, the developed chitosan-based scaffolds showed a similar antibacterial activity against planktonic bacteria with the chitosan-starch-based scaffolds. However, although the chitosan-starch-based scaffolds showed an improvement in printability and reproducibility, they also showed a slightly lower antibiofilm activity. The developed coatings showed potential for its use in vascular catheters and for further improvement studies on this concept.
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Infection Antibacterial Coating Hydrogel 3D-printing biosurfactants