Functionalized Chitosan Nanomaterials: A Jammer for Quorum Sensing.

The biggest challenge in the present-day healthcare scenario is the rapid emergence and spread of antimicrobial resistance due to the rampant use of antibiotics in daily therapeutics. Such drug resistance is associated with the enhancement of microbial virulence and the acquisition of the ability to evade the host's immune response under the shelter of a biofilm. Quorum sensing (QS) is the mechanism by which the microbial colonies in a biofilm modulate and intercept communication without direct interaction. Hence, the eradication of biofilms through hindering this communication will lead to the successful management of drug resistance and may be a novel target for antimicrobial chemotherapy. Chitosan shows microbicidal activities by acting electrostatically with its positively charged amino groups, which interact with anionic moieties on microbial species, causing enhanced membrane permeability and eventual cell death. Therefore, nanoparticles (NPs) prepared with chitosan possess a positive surface charge and mucoadhesive properties that can adhere to microbial mucus membranes and release their drug load in a constant release manner. As the success in therapeutics depends on the targeted delivery of drugs, chitosan nanomaterial, which displays low toxicity, can be safely used for eradicating a biofilm through attenuating the quorum sensing (QS). Since the anti-biofilm potential of chitosan and its nano-derivatives are reported for various microorganisms, these can be used as attractive tools for combating chronic infections and for the preparation of functionalized nanomaterials for different medical devices, such as orthodontic appliances. This mini-review focuses on the mechanism of the downregulation of quorum sensing using functionalized chitosan nanomaterials and the future prospects of its applications.