负极性驻极体对胰岛素介电特性及降糖效果的影响

目的 研究负极性驻极体外静电场对胰岛素介电特性和结构的影响，观察经电场作用的胰岛素的降糖效果。方法 采用栅压电晕充电系统将聚丙烯膜制备成－500、－1 000、－1 500 V的负极性驻极体，分别作用于胰岛素，使用补偿法测量实验各驻极体在48 h内的等效表面电位，通过介电常数d₃₃测量胰岛素的极化规律与外静电场的关系，采用核磁共振和凝胶电泳检测外静电场对胰岛素分子结构的影响。将经不同表面电位负极性驻极体作用12 h的胰岛素溶液注入糖尿病大鼠体内，观察驻极体作用后胰岛素的降糖效果。结果 不同表面电位负极性驻极体作用胰岛素溶液48 h时，0～4 h内胰岛素溶液两侧的电位差均随时间延长呈指数规律上升，4 h后逐渐趋于恒定。－500、－1 000和－1 500 V驻极体作用胰岛素贴剂12 h时d₃₃值相比无驻极体静电场作用分别提高了14.7倍、26.7倍和45.0倍，12 h后趋于稳定。经外电场作用后胰岛素的空间结构没有发生明显变化，而大部分基团的氢键含量减少；胰岛素结构中单聚体的比例提高，主要以单聚体和二聚体的形式存在。－500 V和－1 000 V驻极体作用胰岛素治疗组处理8 h时大鼠的血糖含量与无驻极体作用胰岛素组相比分别下降了50.9%和22.1%（P<0.05），具有良好的降糖效果。结论 负极性驻极体可进一步改善胰岛素的降糖效果。

Effect of negative polarity electret on dielectric properties and hypoglycemic effects of insulin

Objective To study the effect of negative polarity electret on the dielectric properties and structure of insulin, and to observe the influence of electrostatic field on the hypoglycemic effect of insulin. Methods Negative polarity electrets of -500, -1 000 and -1 500 V were prepared using polypropylene film by a gate voltage corona charging system, and were used to treat insulin, respectively. The equivalent surface potential of each electret within 48 h was measured by compensation method. The relationship between the polarization of insulin and the electrostatic field was measured by the dielectric constant d₃₃. The influence of the electrostatic field on the molecular structure of insulin was examined by nuclear magnetic resonance and gel electrophoresis. Insulin exposed to -500, -1 000 and -1 500 V negative polarity electret for 12 h was injected into the diabetic rats, and then the hypoglycemic effect of insulin were observed. Results The potential differences between the two sides of insulin solution effected by negative polarity electrets with different surface potentials were exponentially increased within 0-4 h and gradually became constant at 4-48 h. Compared with the insulin patch treated by non-electret electrostatic field, the d₃₃ values of insulin patch effected by -500, -1 000 and -1 500 V electret for 12 h were increased by 14.7 times, 26.7 times and 45.0 times, respectively, and all tended to be stable after 12 h. The spatial structure of insulin exposed to electrostatic field did not change, but the hydrogen bond content of most perssad was decreased; the proportion of monomers of the insulin was increased, and the main structures of the insulin were monomers and dimers. Compared with the electret-free insulin treatment group, the blood glucose content of diabetic rats treated with the -500 V and -1 000 V negative polarity electrets insulin for 8 h were decreased by 50.9% and 22.1%, respectively (P<0.05). Conclusion Negative polarity electret can further improve the hypoglycemic effect of insulin.