Goma de cajueiro ftalada para aplicações como Biomaterial no desenvolvimento de nanopartículas: metálicas e poliméricas

Abstract

Cashew gum (CG) is a heteropolysaccharide obtained from the exudate of Anacardium occidentalis L., which is cultivated in biotechnological areas, mainly in the pharmaceutical industry. This is due to the fact that it presents a versatile structure for applications in nanobiomedical devices. The chemical modifications in the structure of the polysaccharides, involve the introduction of functional groups, which make it possible to obtain new biomaterials with new properties. This work aims to promote the modification in cashew gum using phthalic anhydride (PA), a reaction that does not use solvent and aims to obtain new biomaterials with hydrophobic character for the development of nanoparticles. The reaction was performed to obtain four derivatives (PCG1, PCG2, PGC3 and PCG4), varying the ratio of CG/PA (1: 2 to 1: 5) in the ratio (w/w) and the reaction time of 20 and 40 minutes for each ratio. The PA was melted at 130°C, then the CG was added and the time was measured. At the end of the reaction the derivatives were precipitated in ultra pure water and washed until removal of by-products and lyophilized. The obtained derivatives were characterized by Infrared Spectroscopy, elemental analysis, potentiometric titration and thermogravimetric analysis. The PCG4 derivative was used as a reducing and stabilizing agent to obtain silver nanoparticles (AgNPs), synthesized by two routes via green synthesis and using the chemical sodium borohydride reductant. AgNPs were characterized by UV-VIS, nanoparticle tracking analysis, zeta potential, inductively coupled plasma atomic emission spectrometry and atomic force microscopy. The antimicrobial activity of AgNPs was determined by the minimum inhibitory concentration (MIC) test against the bacteria Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922 and against the fungi Trichophyton interdigitale (73826), Fonsecaea pedrosoi ATCC 46428 and Sporothrix schenckii ATCC 201679. The PCG1 derivative was used for the production of polymeric nanoparticles (NPs) loaded with the drug naproxen (NSAIDs) using the dialysis technique. The NPs without and with the drug were characterized by dynamic light scattering to obtain hydrodynamic size, polydispersity index and zeta potential. The colloidal stability of the system was evaluated for a period of 5 months and the system was stable, with no significant changes in size, potential zeta and polydispersity index. The efficiency of incorporation, encapsulation and in vitro release of the nanoparticles was also evaluated, indicating that the system is promising to be used in the delivery of drugs.