O efeito de antibióticos na performance antimicrobiana de filmes à base de quitosana visando revestimento de dispositivos médicos

Abstract

Medical devices such as catheters, orthopedic implants and probes, while playing a critical role in patient care, are often associated with the occurrence of bacterial infections, especially when implanted for long periods of time. These devices are classified according to their duration of use: transient for less than 60 minutes, short-term for less than 30 days, and long-term for more than 30 days. An alternative to prevent infection is the use of antimicrobial coatings. Films based on chitosan and cross-linked with tannic acid and iron sulfate showed promising results in terms of antibacterial activity as a function of time, over a month, when the antibiotic gentamicin was impregnated into the film. The intermolecular interaction of the antibiotic with the film matrix and the diffusion rate play a fundamental role in controlling the release kinetics. Therefore, this work aims to evaluate antibiotics with chemical diversity by determining their impact on the physicochemical properties of the films, antimicrobial activity and release kinetics of different antibiotics. The methods used were swelling tests, mass loss, morphological analysis by scanning electron microscopy (SEM) and optical microscopy, physicochemical releases in simulated biological fluids, and static and kinetic antimicrobial tests. Finally, mathematical modeling of the physicochemical release data was performed to determine the mechanism of antibiotic release from the films. The results allowed the antibiotics to be categorized according to their release times, creating a range of options for different applications in medical devices. In conclusion, this work demonstrates that the functional groups and charges of antibiotics can significantly alter the release time, presenting releases of up to six months with antibacterial activity.