tailieunhanh - Báo cáo hóa học: "Preparation and Characterization of Stimuli-Responsive Magnetic Nanoparticles"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Preparation and Characterization of Stimuli-Responsive Magnetic Nanoparticles | Nanoscale Res Lett 2008 3 289-294 DOI S11671-008-9151-3 NANO EXPRESS Preparation and Characterization of Stimuli-Responsive Magnetic Nanoparticles ShiXing Wang Yang Zhou Wen Guan Bingjun Ding Received 24 May 2008 Accepted 11 July 2008 Published online 7 August 2008 to the authors 2008 Abstract In this work the main attention was focused on the synthesis of stimuli-responsive magnetic nanoparticles SR-MNPs and the influence of glutathione concentration on its cleavage efficiency. Magnetic nanoparticles MNPs were first modified with activated pyridyldithio. Then MNPs modified with activated pyridyldithio MNPs-PDT were conjugated with 2 4-diamino-6-mercaptopyrimidine DMP to form SR-MNPs via stimuli-responsive disulfide linkage. Fourier transform infrared spectra FTIR transmission electron microscopy TEM and X-ray photoelectron spectroscopy XPS were used to characterize MNPs-PDT. The disulfide linkage can be cleaved by reduced glutathione GHS . The concentration of glutathione plays an important role in controlling the cleaved efficiency. The optimum concentration of GHS to release DMP is in the millimolar range. These results had provided an important insight into the design of new MNPs for biomedicine applications such as drug delivery and bio-separation. Keywords Site-specific delivery Surface chemistry Nanoparticles Biomaterials Conjugation Controlled release S. Wang El Y. Zhou W. Guan B. Ding School of Science Xi an Jiaotong University No. 28 Xianning West Road Xi an Shanxi 710049 China e-mail wsxkm@ S. Wang Y. Zhou National Center for Nanoscience and Technology Beijing China Introduction Recently stimuli-responsive magnetic nanoparticles SR-MNPs have attracted considerable attention in the field of nanotechnology as candidates for drug delivery and bioseparation 1-4 . Owing to their ability to switch on and switch off when necessary particularly under the action of local stimuli characteristic of the target zone they have been employed as the .