海藻酸钠/壳聚糖微载体的制备及生物活性评价

Preparation and bioactivities of sodium alginate/chitosan microcarriers

以壳聚糖为基质,通过共混法引入海藻酸钠,采用乳液冷冻干燥法,并结合正戊醇和醋酸铵作致孔剂,制备海藻酸钠/壳聚糖多孔微载体,并在该微载体上培养人肝细胞L-02。通过扫描电子显微镜来观察微载体的微观结构形貌,并通过红外光谱、溶胀性、吸水率、体外降解率、MTT比色法等手段来综合评价海藻酸钠/壳聚糖微载体的性能及生物活性。结果表明,致孔剂不同,则得到的微载体的表观形貌也不同。以正戊醇为致孔剂进行冻干得到的微载体孔径为3～50μm,孔隙率为93%;以正戊醇和醋酸铵2种致孔剂来制孔得到的微载体孔径为15～55μm,孔隙率为94%。且2种方法得到的微载体硬度高,溶胀性良好,吸水率高,空白海藻酸钠/壳聚糖微载体在体外可完全降解。红外光谱显示,海藻酸钠/壳聚糖微载体中,壳聚糖分子链上的氨基和乙酰胺基都与海藻酸钠分子链上的羧酸盐官能团存在很强的静电相互作用。光学显微镜观察L-02人肝细胞在海藻酸钠/壳聚糖微载体上生长良好。

Sodium alginate/chitosan porous microcarriers were prepared by emulsion freeze-drying method through mixing sodium alginate into CS. The microcarriers had been characterized by infrared spectrum a- nalysis. Scanning electron microscope was used to analyze the microscopic structure of the microcarriers and the degradation from them was tested in vitro. Also, the water absorption of the microcarriers was tested. Human liver cell line-02 （L-02） were cultured for testing the bioactivity of the microcarriers. Af- ter the cells adhered on the microcarriers, the cell proliferation and differentiation were analyzed by meth- yl thiazolyl tetrazolium （MTY） assay. The results indicated that by using different pore-foaming agent the sodium alginate/chitosan microcarriers with the different surface structures. The aperture and porosity of the freeze-dried microcarriers using pentanol as pore-foaming agent were 3 - 50 μm and 93%. The micro- carriers using pentanol and NH4Ac as pore-foaming agent were 15 - 55 p,m and 94%. Also, the two kinds of microcarriers had strong hardness and the high water adsorption. The blank microcarriers could biode- grade absolutely in vitro. By infrared spectrum ihteraction between the amino and acetylamino analyses to the microcarriers, there was strong electrostatic of the chitosan molecule and the carboxylic acid salt functional group of the sodium alginate. Human liver ceil line-02 （L-02） grew well on the surface of sodium alginate/chitosan porous microcazTiers.