ABSTRACT
BACKGROUND:Superparamagnetic iron oxide nanoparticles (Fe3O4 NPs) have been widely used in MRI. It is vital to prepare the superparamagnetic MRI contrast agent with high stability, biocompatibility and tumor targeting in order to prevent the aggregation of Fe 3 O 4 NPs and realize the high-precision diagnose of tumor. OBJECTIVE:To prepare the amphiphilic superparamagnetic composite particles with tumor targeting mediated by folate receptor. METHODS:The stable amphiphilic superparamagnetic composite particles with tumor targeting function were prepared by coating the Fe3O4 NPs with a Pluronic F127-folic acid conjugate, which was synthesized via an esterification reaction between the carboxyl group of the tumor targeting molecule, folic acid and the hydroxyl group of an amphiphilic triblock copolymer, Pluronic F127. The resultant Pluronic F127-folic acid-Fe3O4 composite particles were characterized by transmission electron microscopy, Fourier transform infrared-spectra, UV-vis absorption spectra, thermal gravimetric analysis, vibrating sample magnetometer and T2-weighted imaging. WST assay was used to characterize their cytotoxicity preliminarily. RESULTS AND CONCLUSION:The Pluronic F127-folic acid conjugates were prepared via esterification reaction. Then Fe 3 O 4 NPs were wrapped with Pluronic F127-folic acid to result in the superparamagnetic composite particles with wel dispersion and biocompatibility. The size of most superparamagnetic composite particles was less than 200 nm and the size of Fe 3 O 4 core was 10-20 nm from the observation of transmission electron microscopy. The results from the Fourier transform infrared-spectra and UV-vis absorption spectroscop confirmed that folic acid molecules were modified on the surface of the superparamagnetic composite particles successful y. The mass ratio of Pluronic F127-folic acid conjugate was determined by thermal gravimetric analysis as 27.2 wt%in the resultant Pluronic F127-folic acid-Fe 3 O 4 composite particles. The saturated magnetic intensity of the superparamagnetic composite particles was 47.35 emu/g by vibrating sample magnetometer and the relaxation rate was 0.025×106 mol/s from MRI. The WST assay showed the negligible cellcytotoxicity of Pluronic F127-folic acid-Fe3O4. The superparamagnetic composite particles have potential application as the MRI contrast agents with tumor targeting, and the Pluronic F127-folic acid-Fe 3 O 4 composite particles is expected to be used as a MRI contrast agent for tumor targeting.
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This study aimed at immobilizing the antibodies on the surfaces of the solid host membranes in order to improve the property of the biomaterial. The von Willebrand factor (vWf) antibodies were immobilized on the surface of Bombyx mori silk fibroin and PLA (Poly Lactic Acid) membrane by NH3 plasma treatment followed by covalent cross-linking reaction. The immobilization efficiency was evaluated by two methods including the antibody surplus and enzyme-linked immunosorbent assay (ELISA). The in vitro antithrombogenicity representing the activity of immobilized vWf antibody was determined by the method of Activated Partial Thromboplastin Time (APTT), Prothrombin Time (PT) and Thrombin Time (TT) test. The results demonstrate that the vWf antibodies are immobilized on silk fibroin and PLA membranes in an efficient way with the efficiency of antibody surplus up to 23.88% and ELISA reaction is positive. APTT and TT exceeded the upper limits distinctly, but the value of PT did not change noticeably. The in vitro antithrombogenicity represented the is activity-retaining form of antibodies. These results extend the application of antibody immobilization technique and provide a new idea about the design of biomaterials relating to the coagulation factors.
Subject(s)
Antibodies , Chemistry , Lactic Acid , Chemistry , Polyesters , Polymers , Chemistry , von Willebrand Factor , Allergy and ImmunologyABSTRACT
ObjectTo study the application of ultrasonic circulation technique for the extraction of triterpenoids from Ganoderma lucidum (Leyss.ex Fr.) Karst. Methods On the basis of conventional method, the processing steps of ultrasonic circulation treatment were added. Results The comparative experiments showed that less amounts of various solvents and shorter extraction time were needed for ultrasonic circulation extraction, with the product ratio of about 40 percent higher than that of conventional method. Furthermore, a good consistency of the target product analyzed by HPLC was found between two different extraction methods. Conclusion The ultrasonic circulation technique has a potential application to the extraction of triterpenoids from G. lucidum.
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Using an anti-nucleolar protein B23 monoclonal antiboby, we examined the changes of protein B23 content in NIH3T3 fibroblasts during serum-induced proliferation and the difference in protein B23 content between mitotic and interphase NIH3T3 fibroblasts by immunofluorescence and im-munoblot methods. When NIH3T3 cells grew confluent, the serum containing medium was removed and replaced by serum-free medium,and the cells were cultured for another 24h. Then cells were refed with serum and further cultured. The results showed that protein B23 content was low in serum-starved NIH3T3 cells,and it markedly increased after serum addition. Furthermore,the increase occurred early at 6h after serum treatment. It was also showed that protein B23 content in mitotic cells blocked by the microtubule inhibitor colcemid was much higher than that in interphase ones. Our results suggested that nucleolar protein B23 might play some roles in the early stage of serum- induced proliferation and during transition from G2 to mitosis in cell cycle.