Nitric oxide releasing polymeric nanoparticles for antibacterial applications

Abstract

Nitric oxide (NO) has important biomedical impacts, since it controls several physiological processes, such as the dilation of blood vessels, the inhibition of platelet adhesion and aggregation, the promotion and acceleration of wound healing, and at high concentrations, NO has cytotoxic effects against pathogens, such as bacteria. Nowadays, NO is considered a potent microbiocide agent against several pathogens, including bacteria. At high concentrations, NO covalently bond to DNA, proteins and lipids of invading bacteria, inhibiting bacterial growth. As NO is a free radical, in the biological medium there are several species able to inactive NO. Low molecular weight thiols (RSH) are nitrosated leading to the formation of S-nitrosothiols (RSNOs), which act as NO donors. Due to the biomedical roles of NO, there is a great interest in the developing vehicles that act as NO carriers and donors. A promising approach that has been using is the combination of biocompatible nanoparticles with NO donors (such as RSNOs). In this work, biodegradable and biocompatible polymeric nanoparticles comprised by alginate/chitosan will be prepared for the encapsulation of NO donors (RSNOs) for biomedical applications. Alginate and chitosan are natural polymers that have been using in drug delivery. In this context, this project aims to prepare NO-releasing alginate/chitosan nanoparticles, characterize the nanoparticles, and investigate the kinetic release profiles of NO from the nanoparticles. In addition, the antibacterial activity of these nanoparticles will be evaluated against Staphylococcus aureus resistant to antibiotics. These bacteria are the major cause of bovine mastitis, a disease that affects the milk production. This project aims to obtain a promising system to carry and to deliver NO with a great potential to combat resistance bacteria in the treatment and prevention of bovine mastitis.