Desenvolvimento de um Hidrogel à base de Laponita com liberação controlada de oxigênio para aplicações em feridas cutâneas infectadas

Abstract

Skin wounds are a worldwide problem with significant morbidity and mortality, particularly when infection occurs. The most common pathogens are Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. In tissue repair, control of bacterial colonization is essential. Biomaterials are used in this process, among them, hydrogels with nanoparticles. This work aims at the production of hydrogel based on laponite with controlled release of oxygen for application in infected skin wounds. Many clays are added to polymers to improve their properties, among them, Laponite of formula Na + 0.7 [(Si8Mg5.5Li0.3) O20 (OH) 4]. Substances have been associated with hydrogels to be released into wounds, including oxides in aqueous media. This is an experimental, descriptive and quantitative study verifying in vitro the bactericidal activity of laponite hydrogel with calcium peroxide (CPO) releasing oxygen. E. Coli and S. Aureus were grown. They were formulated in 9% laponite hydrogels with 5% CPO, 10% and 20% laponite. The bactericidal activity of the hydrogels was verified by the size of the inhibitory halo, in millimeters. The relationship between the size of the inhibitory halos and the concentrations was verified through Pearson's Correlation with a significance level of 5%. During the first 5h, the CPO hydrogels in laponite showed increased oxygen release. Considering the release of oxygen present in the hydrogel, dispersing through the medium and inhibiting microbial growth, it was possible to observe the formation of inhibition halos in all tested concentrations. The results showed that the three formulations of 9% laponite containing calcium peroxide were able to inhibit microbial growth by 100%, with halos greater than 9 mm against both bacterial strains. Against S. aureus, it was found that the correlation between the size of the inhibitory halos and the activity of the hydrogels at different concentrations showed a statistically significant difference (p <0.05). Against E. coli there is a strong correlation between the size of the inhibitory halos and the highest concentrations of hydrogel, particularly at 10%, which showed a statistically significant difference. Laponite acted as an efficient barrier to oxygen and showed antomicrobial activities and the hydrogel produced was a potential candidate for the treatment of infections and healing of skin wounds.