Desenvolvimento de dispositivo baseado em nanofibras poliméricas incorporando extrato seco de Schinopsis brasiliensis Engler para uso odontológico sobre espécies de Candida causadoras de infecções orais

Abstract

OBJECTIVE: To develop and characterize polymeric nanofibers of PLA / PEG incorporated with dry leaf extract of Schinopsis brasiliensis Engl. for the treatment of prosthetic stomatitis. METHODOLOGY: The Minimum Inhibitory Concentration (MIC) and Minimum Fungicide Concentration (MFC) determinations o extract of the nebulized extract of S. brasiliensis against the strains of Candida albicans ATCC 90028, C. tropicalis ATCC 750, C. krusei ATCC 341 and C glabrata ATCC 2001 and on three strains of C. albicans and two strains of C. tropicalis from clinical isolates, compared with nystatin. For the production of polymeric nanofibers, solutions of PLA/PEG (70/30%) in chloroform were prepared and the concentration of 10% of the extract was added in the concentrations of 10X to MIC/2, MIC, MICx2 and MICx4. Solution blowing spinning (SBS) method was used. The nanofibers were characterized by scanning electron microscopy (SEM), thermal behavior (TG) and infrared absorption spectroscopy (FTIR). The action of nanofibers on growth kinetics by counting colony-forming units (CFU) was evaluated on multi-species inoculum of C. albicans ATCC 60193, C. tropicallis CBS 94 and C. krusei CBS 73. For biocompatibility assays the Vero cell line (ATCC CCL-81) was adopted. The data of the kinetic curves were analyzed by ANOVA One Way, followed by Tukey's multiple post-hoc comparison for each time to evaluate the comparison between nanofibers, nystatin and growth control. For cell viability tests, the medians of values of the groups tested were adopted. Comparisons were performed using the Kruskal Wallis test, followed by Dunn’s post hoc (α=0.05). RESULTS: The MIC88.8% of S. brasiliensis was 62.5 µg/mL. The MFC/MIC ratio revealed fungicidal activity of the extract for all strains. The morphology of the nanofibers was as expected by the SBS technique in all tested compositions. The analysis of the nanofibers diameter revealed that the addition of S. brasiliensis extract produced less thick fibers (p<0.05) when compared to PLA/PEG fibers. The PLA/PEG/Bra fibers showed loss of mass in two stages. The spectra that prove the functional groups of the S. brasiliensis extract are related to the groups present in gallic acid in wave-length of 2926, 1713 and 1265 cm-1 . The PLA/PEG/Bra 2500 nanofiber was able to reduce fungal growth after 4 hours of exposure, similar to that observed when compared to nystatin in the MIC concentration. All nanofibers, under the conditions tested, were cytocompatible with use in mammals. CONCLUSION: PLA/PEG polymeric nanofibers, produced by SBS, incorporating S. brasiliensis extract in different concentrations, proved to be biocompatible for use in humans, being able to inhibit the growth of Candida spp. This study points to the potential application of nanofibers incorporated with plant extracts to control prosthetic stomatitis.