Co-delivery, triggerable release and bioimaging of magnetic nanocapsules by one-step double-emulsion process
| Autor: | Liao, Bang-Jie, 廖邦傑 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 In this study, one-step double-emulsion magnetic hollow nanocapsule (HNCs) was successfully designed. Without other emulsifier or surfactant, we used only one amphiphilic polymer, Poly vinyl alcohol (PVA), incorporated with hydrophobic magnetite nanoparticles. PVA can act as a surfactant, and is able to stabilize W/O and O/W interfaces in the meantime when the molecular weight (MW) is in certain range that we have verified in HLB (hydrophilic-lipophilic balance) test. Since hydrophobicity of polymer increases with MW, it also affects the morphology of nanocapsules. We display the hollow/spherical change in this report. Size of HNCs was below 200 nm and is appropriate for entering human body. HNCs is low cytotoxic because PVA and magnetite nanoparticles are biocompatible. HNCs possesses outstanding advantages that it can act as MRI contrast agent and can be used in hyperthermia since the present of superparamagnetic magnetite nanoparticles. Drug release can be controlled by applying AC magnetic field. Hydrophilic and hydrophobic molecules can be encapsulated at the same time because of the water-in-oil-in-water structure of HNCs. We use two common anticancer drugs, Paclitaxel (PTX) and Doxorubicin (DOXO) to discuss the kinetic of drug release. And choose two cancer cells, HeLa cell and MCF-7 cell to demonstrate in vivo experimental. Through drug release profiles we analyzed the releasing mechanisms dominated by different structures. Both drugs behaved low nature release revealed the drugs were well encapsulated in HNCs. Drugs released in a burst-like way when exposed to AC magnetic field. In cell culture, we coupled a targeting ligand to surface of HNCs. Hence HNCs could target cancer cells to enhance the activity of anticancer drugs by high intracellular drug level. Magneto-induced hyperthermia and chemotherapy showed high cancer cell inhibit efficacy. Dual-drug delivery behaved high anticancer activity, and the site effect caused by two drugs might be diminished in the help of HNCs. In summary, HNCs has great potentials in biomedical applications including co-delivery, controlled release, targeted therapy and bioimaging. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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