The Drug Release Properties Of Hydrophobically Modified Alginate And Its Synergistic Flocculation Effect With Chitosan

Sodium alginate, a negatively charged linear polysaccharide, occurs widely in nature. Alginate is a biomaterial widely used in the food industry, biomedical application and other fields given its desirable physiochemical properties, high biocompatibility, non-immune, security and biodegradability. In this paper, the hydrophobic modification of alginate was carried out with alkyl glycidyl ether as a graft material, and amphiphilic alginate derivative was obtained. The micellar behavior of hydrophobically modified alginate(HM-alginate) in aqueous solution was systematic studied by surface tension, dynamic light scattering and Zeta potential. The solubilization ability of HM-alginate on hydrophobic substance and the sustained release properties of HM-alginate in drug delivery were studied. The synergistic flocculation effect of HM-alginate and chitosan was also studied.1. Amphiphilic alginate derivative HM-alginate was successfully obtained in basic aqueous solution, with sodium alginate and dodecyl glycidyl ether(DGE) as materials. The synthesized HM-alginate had obvious surface activity, and it could form micelles in aqueous solution by self-assembly, with hydrophobic alkoxy chain as the core and hydrophilic alginate as the shell. The critical micelle concentration was 0.4 mg/mL. The particle size of 0.4 mg/mL HM-alginate aqueous solution was about 1000 nm, and the Zeta potential was-63±1 mV. The micelles formed by HM-alginate were stable in solution.2. HM-alginate had good solubilization on lipophilic Sudan Ⅳ. The HM-alginate formed micelles with core-shell structures in water solutions, and Sudan Ⅳ preferred to incorporate into the hydrophobic portion of the micelles to increase its solubility in the solution.3. HM-alginate had good solubilization on hydrophobic drugs clofazimine and Amphotericin B. The solubilities of clofazimine and Amphotericin B in the HM-alginate aqueous solution increased 1100 times and 160 times respectively. The solubilities of these two drugs in HM-alginate aqueous solution decreased with the increase of NaCl concentration and pH of the solution.4. HM-alginate exhibited excellent sustained release effect on drug delivery, which increased with concentration.5. The significant flocculation could be observed after the addition of chitosan in the HM-alginate aqueous solution. The flocculation effect of HM-alginate and chitosan could be used to extract the hydrophobic dye Sudan Ⅳ. The removal efficiency of Sudan Ⅳdecreased with the increase of the HM-alginate concentration. With the increase of the chitosan concentration, the removal efficiency of Sudan Ⅳ increased first and then decreased. When pH was 4.0, the optimum concentration was 1.0 mg/mL HM-alginate and 3.0 mg/mL of chitosan solution, and the removal efficiency of Sudan Ⅳ was about 45.1%.6. The flocculation effect of HM-alginate and chitosan was affected by the pH value of the solution. The optimum pH value for flocculating was 3.0-3.8, and the removal efficiency of Sudan Ⅳ was about 75%.7. The flocculation effect of HM-alginate and chitosan could be used to remove hydrophobic dye Sudan Ⅳ selectively from aqueous solutions in the presence of the hydrophilic dye methylene blue. This process was proved to be highly selective and effective, with the removal of ca. 75% of the hydrophobic dye while only 10% of the hydrophilic one was coprecipitated at pH ranged from 3.0 to 3.8.