Síntese de Nanopartículas da Galactomanana da Fava Danta (Dimorphandra gardneriana) Modificada

Abstract

This work aimed the preparation of nanoparticles galactomannan derivatives. The polysaccharide (galactomannan) was from seeds of Dimorphandra gardneriana with yield of 29±3% and mannose/galactose ratio (M:G) of 1.93±0.02. The galactomannan was modified by sulfation raction (FDS), oxidation (FDO) and by acylation with acetic anhydride (FDAc) and proponic (FDPr) and derivates were used in the developmentof nanoparticles by interaction with chitosan by polyelectrolyte complexes, Schiff base formation and by self-assembled. Galactomannan derivatives were characterized by infrared spectroscopy (IR), nuclear magnetic resonance, elemental analysis, gel permeation chromatography and intrinsic viscosity. The degree of substitution for sulfataion reaction were 0.32 and 0.42; the ratio of glycosidic/oxidized units in oxidized derivatives was 10:2; 10:4 and 10:8. The hydrophobic derivatives were confirmed by the appearance of new absorption at 1740 cm-1 in IR, assigned to C=O stretching and water insolubility. Nanoparticles with unimodal profile were obtained on three routes studied. The particles of chitosan and sulfated galactomannan were obtained by complexation polyelectrolytic with diameters ranging from 10±6 to 377±29 nm, polydispersity index from 0.11±0.02 to 0.5±0.1 and zeta potential of –28±2 to 59±4 mV. For chitosan and oxidized galactomannan nanoparticles, obtained by Schiff base, diameters ranging from 8±2 to 20±9 nm, polydispersity index from 0.36±0.04 to 0.57±0.08 and zeta potential of 0.4±0.5 to 14±1 mV were obatined. Hydrophobically modified galactomannan particles were obtained by self-assembled with diameters ranging from 35.3±0.6 to 213±28 nm, polydispersity index from 0.093±0.003 to 0.9±0.1 and zeta potential of –26.3±0.9 to –3±2 mV. The diameter, zeta potential and polydispersity index are influenced by the methodology and derived used, but for all derivatives of galactomannan at least one condition shows nanoparticles compatible for potential use as drug carriers. Factors such as degree of modification, ratio, order of addition and concentration of polysaccharides, pH and addition of drug have influence on size, polydispersity index, zeta potential and solution stability of the particles.