Glycemic variability is an important risk factor for metabolic diseases such as diabetes, obesity and cardiovascular diseases, which are closely related to life and diet style. Random eating or eating irregular meals and poor patient compliance with lifestyle changes often happens and makes more difficult to control glycemic variability in life through hypoglycemic drugs around meals. The inhibition of the activity of digestion enzymes in the gut represents an effective strategy for prevention and treatment of glycemic variability. In this study, immune response was employed to induce antibodies (immunoglobulin of egg yolk, IgY) against α-amylase through the subcutaneous injection of α-amylase as the antigen in laying hens. IgY-coupled magnetic nanocomposite hydrogel as α-amylase inhibitor was further developed for long-time against glycemic variability. IgY was covalently coupled to PEG-coated Fe₃O₄ nanoparticles (PEG/Fe₃O₄@IgY nanoparticles) and then fabricated by embedding of PEG/Fe₃O₄@IgY nanoparticles in chitosan-alginate (CS/AS) hydrogels. Under the external magnetic field, lgY-coupled magnetic nanocomposites as α-amylase inhibitors were magnetically anchored in the small intestine for long-time against glycemic variability, resulting in a long-time (>36 h) and effective postprandial hyperglycemia management. This study opens a new door to the health care of the metabolic diseases such as diabetes, obesity and cardiovascular disease.

血糖变异性是糖尿病、肥胖和心血管疾病等代谢性疾病的重要危险因素，与生活方式和饮食方式密切相关。乱吃或不规律进餐以及患者对生活方式改变的依从性差经常发生，这使得通过餐前降糖药物控制生活中的血糖变异性变得更加困难。抑制肠道中消化酶的活性代表了预防和治疗血糖变异性的有效策略。在本研究中，通过将α-淀粉酶作为抗原皮下注射蛋鸡，利用免疫反应诱导针对α-淀粉酶的抗体（蛋黄免疫球蛋白，IgY）。进一步开发了 IgY 偶联磁性纳米复合水凝胶作为 α-淀粉酶抑制剂，以长期对抗血糖波动。IgY 与 PEG 包被的 Fe 共价偶联₃ O ₄纳米颗粒（PEG/Fe ₃ O ₄ @IgY 纳米颗粒），然后通过将 PEG/Fe ₃ O ₄ @IgY 纳米颗粒嵌入壳聚糖-海藻酸盐 (CS/AS) 水凝胶中制成。在外部磁场下，作为 α-淀粉酶抑制剂的 lgY 偶联磁性纳米复合材料在小肠中长时间磁锚定以对抗血糖变异，从而实现长时间（> 36 小时）和有效的餐后高血糖管理。该研究为糖尿病、肥胖症和心血管疾病等代谢性疾病的保健打开了一扇新的大门。