免疫球蛋白Y的微胶囊化:响应面法优化及其模拟胃肠道控释

Microencapsulation of immunoglobulin Y: optimization with response surface morphology and controlled release during simulated gastrointestinal digestion

目的:制备、优化、表征和体外评价包埋免疫球蛋白Y(Ig Y)的壳寡糖-海藻酸盐微胶囊,以实现Ig Y的胃肠道控释,提高Ig Y胃肠道消化过程中的活性保持率。创新点:以壳寡糖为涂层,采用两步法制备包埋Ig Y的微胶囊;采用响应面法全面优化了微胶囊的配方工艺;对Ig Y的体外控释进行了系统的评价。方法:通过两步离子凝胶法制备包埋Ig Y的微胶囊,采用响应面法优化微胶囊配方工艺,通过包埋率、负载率、平均粒径、微观形貌、色度和球形度等指标表征微胶囊,采用模拟胃肠道消化体系体外评价Ig Y的释放动力学和免疫活性保持率。结论:采用响应面法优化的微胶囊配方工艺为海藻酸钠浓度1.56%(15.6 g/L)、壳寡糖浓度0.61%(6.1 g/L)和Ig Y/海藻酸钠比率62.44%(质量比),由此制备的微胶囊包埋率达65.19%,负载率达33.75%,平均粒径为588.75μm。壳寡糖涂层通过填充效应和静电相互作用使微胶囊表面更加光滑和连续,从而显著降低了模拟胃肠道消化过程中Ig Y的释放速率。微胶囊中Ig Y的模拟胃部控释和模拟肠道控释分别符合零级动力学方程和一级动力学方程(R2>0.99)。微胶囊在模拟胃肠道消化4h后的Ig Y免疫活性保持率达84.37%,远高于未进行微胶囊化保护的Ig Y(5.33%)。

Immunoglobulin Y(Ig Y)is an effective orally administered antibody used to protect against various intestinal pathogens,but which cannot tolerate the acidic gastric environment.In this study,Ig Y was microencapsulated by alginate(ALG)and coated with chitooligosaccharide(COS).A response surface methodology was used to optimize the formulation,and a simulated gastrointestinal(GI)digestion(SGID)system to evaluate the controlled release of microencapsulated Ig Y.The microcapsule formulation was optimized as an ALG concentration of 1.56%(15.6 g/L),COS level of 0.61%(6.1 g/L),and Ig Y/ALG ratio of 62.44%(mass ratio).The microcapsules prepared following this formulation had an encapsulation efficiency of 65.19%,a loading capacity of 33.75%,and an average particle size of 588.75μm.Under this optimum formulation,the coating of COS provided a less porous and more continuous microstructure by filling the cracks on the surface,and thus the GI release rate of encapsulated Ig Y was significantly reduced.The release of encapsulated Ig Y during simulated gastric and intestinal digestion well fitted the zero-order and first-order kinetics functions,respectively.The microcapsule also allowed the Ig Y to retain 84.37%immune-activity after 4 h simulated GI digestion,significantly higher than that for unprotected Ig Y(5.33%).This approach could provide an efficient way to preserve Ig Y and improve its performance in the GI tract.