Síntese e caracterização de géis de galactomanana de fava danta (Dimorphandra gardneriana) para aplicação biológica

Abstract

Seeds of Dimorphandra gardineriana Tul. (“fava danta”) were used to obtain galactomannan and the effectiveness of the process was determined based on polysaccharide yield. The “fava danta” galactomannan was purified by Fehling method in order to reduce protein content. This treatment results in 36% of protein reduction and a decrease in the gum solution viscosity due to the molar mass reduction. “Fava danta” galactomannan without purification (GFDNP) and purified one (GFDP) were crosslinked with glutaraldehyde to produced fluid hydrogels. The crosslinking reaction was followed using rheological measurement. The increase of polysaccharide solution viscosity with increasing reaction time is gradual and can be interrupted at the moment that a fluid hydrogel is obtained through dialysis against water. Fluid hydrogel from “fava danta” galactomannan without purification (GelGFDNP) and purified (GelGFNDP) were obtained after 15 and 17 days respectively. For GelGFDNP an increase of viscosity of nine times was observed while for the GelGFDNP sample, the increase was of one hundred thirty times. At the end of crosslinking reaction, in the health knees frequency, the G´was greater than G” and the G´/G” ratio was higher than 3, showing that a true and strong gel was obtained. Fava-danta galactomannan gels and Hilano G-F 20, commercial gel used in the osteoarthritis treatment, shows a characteristic of pseudoplastic fluid. This behavior is the same observed in sinovial fluid present in healthy knees. The viscosity values of “fava danta” galactomannan gels (GelGFDNP and GelGFDP) are in the same order of values found for Hilano G-F 20. The rheological characteristic of “fava danta” galactomannan gels indicate that these gels have potential as a viscosuplement agent