| Nanoscience and nanotechnology as an integrated cross-discipline over the past few decades has developed very quickly. Nanotechnology is now widely used in many areas of biomedical, materials science, chemistry, electronics and information engineering, and has become the most important research topic. Nanomaterials have many unique properties such as excellent quantum size effect, small size effect, surface effect and tunnel effect, and has a wide range of applications. Researchers hope to understand the microstructure of nanomaterials through self-assembly, hybridization, molecular engineering and other to control nanomaterials shape, structure, composition, and others, in order to achieve better performance of nano-materials and applications. How finely adjusted by controlling various parameters, uniform size and shape of the homogeneous preparation of nanomaterials to enhance their special properties, it is still a challenge for nanoscience and nanotechnology. For these reasons, the main research contents are as follows:(1) The Ag nanoclusters were biosynthesized intracellular by cancerous cells incubated with silver ions, while this does not occur in non-cancerous cells even after longer incubation times. The present observations demonstrate that such specific biosynthetic ability to generate Ag nanoclusters from silver salts offers a promising strategy for highly sensitive and rapid in vivo self-imaging of cancer cells in a culture of living tumors ideal for biomedical applications requiring specific and sensitive diagnosis and imaging of tumors.(2) Different sized porous SPION nanospheres (Zni/3Feg/3O4) were synthesized by a new rational method of elevated-temperature hydrolysis of chelateiron alkoxide complexes in solutions of corresponding alcohol, diethyleneglycol (DEG) and diethanolamine (DEA). The size of the SPION could be controlled by changing the ratio of the reaction medium. It is observed that the highly water dispersible porous SPION with narrow size distribution can be tuned from 6.5 to 200 nm, each of which is composed of many single magnetite crystallites approximately 6.0 nm in size. The nanospheres show superparamagnetic properties at room temperature. The SPION-induced cytotoxic effects on HepG2 cells demonstrate that different SPION porous spheres had no cytotoxicity after 48 h of incubation. The SPION porous spheres exhibited relatively fast cell uptake. DOX released from the SPION porous spheres had a sustained release pattern, and the DOX-loaded spheres exhibited greater cytotoxicity than free DOX, indicating its potential clinic application as ideal candidates for target drug delivery to realize efficient cancer diagnosis & therapy.(3) The novel multifunctional nanomaterial of Zn1/3Feg/3O4@Ag was synthesized, which could be used in multi-modality imaging about NIRF, MRI and CT imaging. Such multifunctional nanomaterial are made of porous superparamagnetic Zn1/3Fe8/3O4 nanospheres cores covered by a thin layer of Ag clusters shell. While the Ag clusters shell provide efficient near-infrared fluorescence (NIRF) imaging, porous superparamagnetic Zn1/3Feg/3O4 nanospheres cores allow external magnetic manipulation and use for magnetic resonance imaging (MRI) and computed tomography (CT) imaging.(4) The Ag@PNIPAM nanocomposites were synthesized through fast reduction of silver ions in a solution of silver nitrate and GSH. The GSH used here is a natural compound and acts as a very good chelating and reducing agent; and the as-prepared Ag@PNIPAM nanocomposites demonstrate much more effective antimicrobial activity for bacteria like S. aureus than that of Ag NCs alone. This raises the possibility to utilize the relevant Ag@PNIPAM nanocomposites as the promising new antibacterial agents or antimicrobial packaging materials for efficient wound dressings. |
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