| Albumin nanosphere is one kind of the ideal medicine carriers and sustained release targeting capsules which has netlike gap structure. Albumin nanosphere is modified by albumin and mPEG which can avoid the capture of phagocyte and increase the ways of carrying medicine. SC-mPEG was prepared by N-hydroxysuccinimide and mPEG activated with bis-(trichloromethyl) carbonate. mPEG-HSA was prepared by SC-mPEG and HSA, then make it into nanosphere using chemical cross-linking-desolvation process. The pharmacological action of the nanosphere carrying with recombinant human growth hormone is studied.The synthesis conditions of mPEG and mPEG-HSA incluing reaction time,Ph,reaction temperature, mole ratio and concentration are optimized in order to reach high activity and yield. The nanosphere is prepared by chemical cross-linking-desolvation technique. The influence elements including reaction time and dosage are evaluated to receive the best properties of the morphology,size distribution,drug loading and trapping eficiency.The optimal preparation elements are confirmes and the morphology and size distribution are in the controled system.The products are analyzed and characterized by Spectrophotometer,FTIR,HPLC, TEM, SDS-PAGE, LPA(laser particle analyzer).The activated mPEG analyzed by FTIR has the characteristic peak of NHS,so it shows the product is SC-mPEG.The activation rate of mPEG is 75%. mPEG-HSA analyzed by HPLC and SDS-PAGE indicates that HSA connects some different numbers of mPEG,and then the activation grade of HSA measured by Spectrophotometer reaches 45%.It is indicated that the nanospheres possess a smooth and round appearance and the diameters are mainly between 600nm and 700nm. Recombinant human growth hormone is carried by the prepared nanospheres and the result shows that the nanospheres has sustained releasing characteristics.It provides a good carrier for sustained-release dosage form and lays a foundation for studying targeting capsules in the future.
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