Composições nanoestruturadas de cloreto de cetilpiridínio com β-ciclodextrina: síntese, caracterização físico-química e avaliação da interação com Staphylococcus aureus

Abstract

The high occurrence of multiresistant microorganisms is considered a global health problem, and the presence and dissemination of these organisms has been documented more frequently in recent decades. In order to reduce the number of these pathogens, the use of antiseptics has become an important ally, reducing the risks of contamination. Cetylpyridinium Chloride – CPC is a cationic surfactant that has been used in the United States as a mouthwash for over 70 years and has biocidal activity against a broad spectrum of bacteria. Amongst them, Staphylococcus aureus stands out, that although it is often the usual human microbiota, is an important pathogen that causes a wide variety of clinical infections. In order to try to reduce the inconvenience of bacterial resistance and potentiate the effect of CPC, the complexation of the compound with β-cyclodextrin was proposed in the present work. The initial objective of this work was the synthesis and physicochemical characterization (FTIR, thermal analysis, NMR, ZP, DLS, ITC) of CPC/βCD nanostructured composition, paying special attention to the process of CPC/βCD complexation in face of the possibility self-organization of surfactant in micelle form. Subsequently, the antimicrobial activity of CPC was evaluated, in the absence and presence of βCD, against clinical and standard strains (ATCC) of S. aureus. Finally, the direct interaction of the CPC/βCD complex with S. aureus membranes was investigated in order to understand the mechanism of interaction. The results showed spontaneous formation of the inclusion complex between βCD and CPC, which was preferable to the pure CPC mycelization process, and βCD delays the mycelization process. Regarding its biological activity, it was observed that in the presence of βCD there was a reduction of LD50 and alteration in thermodynamic and colloidal parameters, suggesting that the proposed molecular encapsulation model may be a promising tool.