Improved mathematical model of APA microcapsules

It is essential to investigate the diffusion characteristics of alginate-po lylysine-alginate (APA) microcapsule system for its broad applications. An advanced mathematical model for protein diffusion in APA microcapsules is e stablished, which presents the resistance coefficient of microcapsule membr ane and distribution coefficient in microcapsule matrix. These two paramete rs as the important basis of optimizing preparation and directing applicati on of microcapsule are determined by the measurement of the protein concent ration in the extracapsular solution. With assistance of mathematical model , membrane diffusion characteristics affected by reaction time in membrane forming are analyzed: (1) microcapsule shows greater resistance constant an d distribution constant to the diffusion of protein with greater molecular weight, (2) prologation reaction time results in increase in resistance con stant and distribute constant of microcapsule.