Preparation Of Polyarginine/Calcium Alginate Microcapsule And Its Properties Investigation

Polyarinine is biocompatible and biodegradable. Moreover, its degraded products have both the nutritional function and pharmacological efficacy. So, if we use polyarginine as membrane material in microcapsule manufacturing, maybe we can obtain an intervening therapeutic and biodegradable drug carrier. Based on the consideration above, we studied the feasibility of polyarinine using in microcapsule manufacturing and studied the properties of polyarginine/calcium alginate microcapsule.First, we prepared microcapsules using high-voltage electrostatic droplet generator because the polyelectrolytical complex reaction between polyarginine and alginate group. We studied the influence of several physical and chemical factors on microcapsule manufacturing, then ensured the basic operating parameters (6#pinhead, pump speed 4ml/h-20ml/h, distance between pinhead and solvent surface 15mm, pulse width 2ms, frequency 80Hz, voltage 275V, concentration of CaCl2 0.1M, concentration of sodium alginate 0.8%-1.5%(w/v)), and obtained microcapsules which had narrow particle distribution (controlled range was from 200 u m to 500 u m), good spherical degree and smooth surface.Second, we changed the experimental conditions, and studied the influence of sodium alginate concentration, membrane-forming time, molecular weight of polyarginine and polyarginine concentration on membrane strength and membrane permeating property. The results showed that the membrane thickness was only about 10 u m, the swollen degree was obvious, but there was no microcapsule broken, the membrane strength was good. And, all prepared microcapsules showed high drug loading efficiency and excellent permeating property(entrapment efficiency was above 96%, the highest value was 98.5%).Third, we utilized the cell culture technology in vitro, and studied the polyarginine/calcium alginate microcapsule's biocompatibility through cell toxic tests. We found that cells could live regularly inside and ouside the microcapsules. Itshowed that the material itself had no toxicity to cell growth. Furthermore, the membrane surface was smooth, there was no adhesion phenomenon, the sphericity kept well. All those showed that the biocompatibility of polyarginine/calcium alginate microcapsule was good.Finally, we studied the drug release dynamics using hemoglobin and 5-flouracil as the representatives of polypeptides and low molecular drugs respectively in the mock in vitro physiological conditions. The results showed that the microcapsules prepared had good slow release efficiency to polypeptide drugs (release ratio 58% at 8h), but not obvious to low molecular drugs.