Nanocompósitos de lactato de quitosana e NPsAg com atividade antimicrobiana

Abstract

The chemically modified of chitosan lactate are among the chitosan derivatives that have much superior non-cytotoxic properties when compared to other chitosan derivatives. Chitosan lactate, has a solubility close to physiological pH (pH=7.0) which significantly improves its applications in controlled drug release systems. Chitosan lactate has been proposed for various biomedical applications as wound dressings and dental membranes. In the present work, the synthesis of chitosan lactate from methyl and ethyl lactate with chitosan was performed, the modification was proven by the techniques of infrared spectroscopy with Fourier transform (FTIR), thermogravimetric analysis (TGA), calorimetric differential scanning (DSC), proton nuclear magnetic resonance (1H NMR). The characterization techniques of DSC and 1H NMR showed that in the chemical modification of chitosan in addition to chitosan lactate grafts of poly(lactic acid) oligomers were obtained in the chitosan chain (QUI-g-PLA). Electrospinning of chemically modified chitosan QUI-g-PLA containing the complex of chondroitin sulfate (SC) and silver nanoparticles (NPsAg) was performed and then the controlled release of silver nanoparticles and chondroitin sulfate was studied, since the nanoparticles silver have antimicrobial activity and chondroitin sulfate has cell proliferation properties. The study of antimicrobial activity was carried out, which showed inhibition for both Gram positive and Gram negative bacteria and a cytotoxicity study was also carried out, showing that the produced nanofibers do not have a negative effect on cell viability, actually showing an increase in cell proliferation. So far, the author of this doctoral proposal has not observed any work that mentions the use of QUI-g-PLA/SC:NPsAg nanofibers as dressings, on this aspect it seems to be important to develop dressings for the treatment of wounds in its various modalities: burns, contact wounds, among others, which have antimicrobial properties combined with increased healing of cell tissue.