Use of graphen and carbon nanotubes as adjuvants in vaccine based in outer membrane vesicles from Neisseria meningitidis

Abstract

Gram-negative bacteria have the characteristic of originating vesicles from the outer layer of their cell membranes, the outer membrane vesicles (OMV). The processes by which they are produced are not yet fully elucidated, but their functions are related to mechanisms of DNA transfer for transformation purposes, inactivation of antibiotics and toxins from the extracellular environment, competitive advantage within a population, and as a mode of model the structure of the membrane, regulating its composition against external stresses. In addition, it is known that all the surface of these vesicles exist proteins that can serve as antigens and molecular markers, as is the case of Neisseria meningitidis, whose OMVs are already being used for vaccination against meningitis. Within this context, a search for optimization of vaccine formulations was started from OMVs. It is known that a vaccine consists of three components: the antigen, which will trigger the specific immune response against that organism; the carrier, an inert molecule that increases the rate at which the antigen presenting cells encompass the vaccine; and finally the adjuvants, which are helper molecules which alone induce a robust immunogenic response. Because of this, nanomaterials have been object of study due to their physicochemical properties, mechanisms of interaction with biological systems and as potential candidates in vaccine formulations. Among them, carbon nanotubes and graphene have gained prominence, and consequently health research has associated them with vaccines to find out what effects they would have. Because they are inert, resistant materials that promote coupling and stability of biological molecules, their application as carriers has been observed. However, some studies were done in the adjuvant part and their results indicated that their association with other molecules or even with the vaccine itself stimulates the triggered immune response, becoming potential adjuvants. The aim of the present project is to analyze the adjuvant properties of carbon nanotubes and graphene in association with OMVs of N. meningitidis and to compare their response with adjuvants currently used in the market.