NBT光照法测定聚(2-乙基-2-噁唑啉)化超氧化物歧化酶模拟物脂质体的活性

Determination of the Activity of PEOZ Liposomal SOD Mimic Using NBT-Illumination Method

目的建立聚(2-乙基-2-噁唑啉)[poly(2-ethyl-2-oxazoline),PEOZ]修饰超氧化物歧化酶(superoxide dismutase,SOD)模拟物脂质体的活性测定方法。方法以薄膜分散法制备聚(2-乙基-2-噁唑啉)化超氧化物歧化酶模拟物脂质体,利用氮蓝四唑(NBT)光照法对超氧化物歧化酶模拟物及聚(2-乙基-2-噁唑啉)化超氧化物歧化酶模拟物脂质体的活性进行测定。结果超氧化物歧化酶模拟物的抑制率曲线方程为IR%=33.421lnρ+49.715(r2=0.999 2),IC50为1.008 6×10-3μmol.L-1;聚(2-乙基-2-噁唑啉)化超氧化物歧化酶模拟物脂质体的抑制率曲线方程IR%=33.521lnρ+49.671(r2=0.999 1),IC50为1.009 9×10-3μmol.L-1。结论氮蓝四唑光照法操作简单、稳定可靠、经济实用,可用于超氧化物歧化酶模拟物聚(2-乙基-2-噁唑啉)脂质体的活性测定;经脂质体包裹后超氧化物歧化酶模拟物的活性未发生变化。

OBJECTIVE To establish the method for determinating the activity of [ poly（2-ethyl-2-oxazoline）, PEOZ 1-modified liposomes encapsulated superoxide dismutase （SOD） mimic （PEOZ-L-SOD）. METHODS PEOZ-L-SOD was prepared by fihn dis- persion method, and the activities of the SOD mimic and PEOZ-L-SOD were determined by NBT-Illumination method. RESULTS The fitted equation of the inhibition rate curve of the SOD mimic was IR% = 33.4211np ＋ 49. 715 （r2 = 0. 999 2）and the IC50 was 1. 008 6 ×10^-3μmol·L^-1 ;the fitted equation of the inhibition rate curve of PEOZ-L-SOD was IR% = 33. 5211np ＋49. 671 （r2 = 0. 999 1 ） and the IC50 was 1. 009 9 ×10^-3μmol·L^-1. CONCLUSION The NBT-Illumination method is simple, reliable, econom- ic and practical, and can be used as an efficient method to determine the activity of SOD mimic liposomes. The experiment proves that the activity of SOD mimic did not change after it was encapsulated in the liposomes.