中空海藻酸钙微胶囊的强度和扩散性

制备了一种新型的中空海藻酸钙微胶囊,考察了海藻酸钠质量浓度对微胶囊机械强度等的影响以及牛血清白蛋白(V)在微胶囊内的截留能力,利用非稳态传递模型计算了小分子底物在微胶囊中的混合扩散系数和在微胶囊膜中的扩散系数.研究结果表明,随着海藻酸钠质量浓度的提高,微胶囊的直径和膜厚度减小,机械强度增大.各种小分子底物在微胶囊中的混合扩散系数比它们在纯水中的扩散系数约小6%,在微胶囊膜中的扩散系数比在纯水中的约小30%.牛血清白蛋白(V)不能扩散进入微胶囊.不同质量浓度(8～12 g/L)的海藻酸钠溶液对微胶囊的扩散系数影响不大.

Compression intensity and diffusivity of intra-hollow Ca-alginate gel microcapsule

Intra-hollow Ca-alginate gel microcapsules were prepared and the compression intensity, diameter and membrane thickness of the microcapsule were studied. Diffusivities from the solution into the microcapsules of substrates, such as glucose, lactose, lactic acid, glutamic acid, tyrosine, lysine, phenylalanine and bovine serum albumin Fraction V (BSA(V)) were also investigated. Higher sodium alginate concentration resulted in higher compression intensity and lower diameter and membrane thickness of microcapsules. Except BSA(V), all small molecular substrates tested could diffuse easily through the microcapsule by the pores on the microcapsule membrane. According to the established mathematical model, the values of the combined diffusion coefficients from the solution into the microcapsule are about 6% lower than the diffusion coefficients in pure water while the diffusion coefficients through the microcapsule membrane are 30% lower. No diffusion of BSA(V) into the microcapsules was observed. In all cases diffusion coefficients are independent of sodium alginate concentration ranging from 8 to 12 g/L.