Objective: To explore the method of 99 Tc m direct labeling of angiostatin (AS) and investigate the stability and bioactivity of the 99 Tc m labeled AS in vitro . Methods: AS was extracted, validated, and then labeled...Objective: To explore the method of 99 Tc m direct labeling of angiostatin (AS) and investigate the stability and bioactivity of the 99 Tc m labeled AS in vitro . Methods: AS was extracted, validated, and then labeled with 99 Tc m after having been reduced by 2 ME or SnCl 2. The best labeling condition was screened by cross design. The labeling efficiency was measured by TLC and column chromatography. The stability of 99 Tc m AS was observed and compared when BSA, saline and different molar ratios of Cys∶AS were separately added. The bioactivity of 99 Tc m AS was observed in human umbilical vein endothelial cell (CEV304). Results: The labeling efficiency can reach (97±1 5)% for the 2 ME reducing approach. Its best experimental condition was as follows: AS 100 μg,PB(0 5 mol/L, pH 7 3)1 ml, 2 ME 100 μg, MDP (dissolved in 1 ml saline) 10 μl, and 99 Tc mO 4 - 185 MBq. The labeling efficiency using SnCl 2 reducing method can reach (90±3 0)%. The best experimental procedure was as follows: AS 100 μg,boric acid buffer(0 1 mol/L, pH 9 0)1 ml, 2%SnCl 2 (dissolved in 1 mol/L hydrochloric acid) 20 μl, was added into MDP, which was diluted with 1 ml deoxygenized water, and then 20 μl, 99 Tc mO 4 - 185 MBq was added. The product of 99 Tc m labeled AS was stable in vitro and had the same bioactivity as AS. Conclusion: 99 Tc m direct labeling of AS is simple and efficient. And the bioactivity of 99 Tc m AS has no significant change compared with AS.展开更多
文摘Objective: To explore the method of 99 Tc m direct labeling of angiostatin (AS) and investigate the stability and bioactivity of the 99 Tc m labeled AS in vitro . Methods: AS was extracted, validated, and then labeled with 99 Tc m after having been reduced by 2 ME or SnCl 2. The best labeling condition was screened by cross design. The labeling efficiency was measured by TLC and column chromatography. The stability of 99 Tc m AS was observed and compared when BSA, saline and different molar ratios of Cys∶AS were separately added. The bioactivity of 99 Tc m AS was observed in human umbilical vein endothelial cell (CEV304). Results: The labeling efficiency can reach (97±1 5)% for the 2 ME reducing approach. Its best experimental condition was as follows: AS 100 μg,PB(0 5 mol/L, pH 7 3)1 ml, 2 ME 100 μg, MDP (dissolved in 1 ml saline) 10 μl, and 99 Tc mO 4 - 185 MBq. The labeling efficiency using SnCl 2 reducing method can reach (90±3 0)%. The best experimental procedure was as follows: AS 100 μg,boric acid buffer(0 1 mol/L, pH 9 0)1 ml, 2%SnCl 2 (dissolved in 1 mol/L hydrochloric acid) 20 μl, was added into MDP, which was diluted with 1 ml deoxygenized water, and then 20 μl, 99 Tc mO 4 - 185 MBq was added. The product of 99 Tc m labeled AS was stable in vitro and had the same bioactivity as AS. Conclusion: 99 Tc m direct labeling of AS is simple and efficient. And the bioactivity of 99 Tc m AS has no significant change compared with AS.
