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磁性氧化铁纳米颗粒及其在MRI中的应用


Contents
前言
第一章 阿瑞匹坦体外分析方法的建立和理化性质研究 第二章 阿瑞匹坦纳米混悬剂的制备及药剂学性质研究 第三章 阿瑞匹坦纳米混悬剂的制备及药剂学性质研究 第四章 阿瑞匹坦固体分散体和纳米混悬剂体内药动学研究

第五章 阿瑞匹坦固体分散体和纳米混悬剂离体肠吸收研究
第六章 阿瑞匹坦固体分散体和纳米混悬剂Caco-2细胞跨膜转运研究

前言

第一章阿瑞匹坦体外分析方法的建立及理化性质研究

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Introduction Structure of MRI functioned magnetic nanoparticles

Introduction Preparation of MRI functioned magnetic nanoparticles

Preparation of the core of the particle

Protection /Stabilization of particles

Functionalization

Protection/Stabilization of Magnetic Particles

Surface Passivation by Mild Oxidation

Surfactant and Polymer Coating
Form a core-shell structure that isolate the core with the environment Precious-Metal Coating Silica Coating Carbon Coating Matrix-Dispersed Magnetic Nanoparticles

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating

● Surfactants or polymers can be chemically anchored or physically
adsorbed on magnetic nanoparticles to form a single or double layer which creates repulsive(mainly as steric repulsion) forces to balance the magnetic and the van der Waals attractive forces acting on the nanoparticles.

● Polymers containing functional groups, such as carboxylic acids,
phosphates, and sulfates, can bind to the surface of magnetite.

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating(chemical combination)
Example: FeCo/graphitic-shell nanocrystals as advanced magnetic-resonance-imaging and near-infrared agents

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating(chemical combination)

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating(chemical combination)

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating(physical combination)
Example: Magnetite-loaded polymeric micelles as ultrasensitive magnetic-resonance probes

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating(physical combination)

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating(physical combination)
Example: Maghemite Nanoparticles Protectively Coated with Poly(ethylene imine) and Poly(ethylene oxide)-block-poly(glutamic acid)

Protection/Stabilization of Magnetic Particles

Surfactant and Polymer Coating(physical combination)

Magnetic resonance signal intensity of liver parenchyma of rats in T2-weighted sequences.
A:before injection B:after injection maghemite nanoparticles (0.6 mg of Fe/kg) C:before injection D:after injection Resovist (0.6 mg of Fe/kg)

Protection/Stabilization of Magnetic Particles

Silica Coating



This coating stabilizes the magnetite nanoparticles in two different ways. One is by shielding the magnetic dipole interaction with the silica shell. On the other hand, the silica nanoparticles are negatively charged. Therefore, the silica coating enhances the coulomb repulsion of the magnetic nanoparticles. Silica coatings have several advantages arising from their stability under aqueous conditions (at least if the pH value is sufficiently low), easy surface modification, and easy control of interparticle interactions, both in solution and within structures, through variation of the shell thickness.



Protection/Stabilization of Magnetic Particles

Silica Coating

Protection/Stabilization of Magnetic Particles

Carbon Coating

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Carbon-based materials have many advantages over polymer or silica, such as much higher chemical and thermal stability as well as biocompatibility. Though carbon-coated magnetic nanoparticles have many advantageous properties, such particles are often obtained as agglomerated clusters, owing to the lack of effective synthetic methods, and a low degree of understanding of the formation mechanism. The synthesis of dispersible, carbon-coated nanoparticles in isolated form is currently one of the challenges in this field.

Protection/Stabilization of Magnetic Particles

Matrix-Dispersed Magnetic Nanoparticles

Protection/Stabilization of Magnetic Particles

Matrix-Dispersed Magnetic Nanoparticles

SPIO-loaded Carbon nanotubes

Structural and Physicochemical Characterization

Characterization

Size, Polydispersity, Shape, Surface Characterization

Magnetic Properties Characterization

Structural and Physicochemical Characterization

Size, Polydispersity, Shape, and Surface Characterization
Transmission electron microscope (TEM) High-Resolution Transmission electron microscope(HRTEM)

Structural and Physicochemical Characterization

Size, Polydispersity, Shape, and Surface Characterization

Scanning electron microscope(SEM)

X-Ray diffraction(XRD)
Dynamic light scattering(DLS)

Structural and Physicochemical Characterization

Magnetic Properties Characterization

superparamagnetism Saturation magnetization Coercive field strength Remained magnetic field strength

Structural and Physicochemical Characterization

Magnetic Properties Characterization

T2 relaxivity

Structural and Physicochemical Characterization

Other Properties Characterization

Magnetic content Stability

Acid and alkali resistance

Functionalization and Applications of Magnetic Nanoparticles

Functionalization and Applications of Magnetic Nanoparticles

Functionalization and Applications of Magnetic Nanoparticles

Example: A novel strategy for surface modification of superparamagnetic iron oxide nanoparticles for lung cancer imaging

Functionalization and Applications of Magnetic Nanoparticles

Functionalization and Applications of Magnetic Nanoparticles

Functionalization and Applications of Magnetic Nanoparticles

Functionalization and Applications of Magnetic Nanoparticles

Conclusions and Perspectives
Conclusions
For in vitro and in vivo stabilization, the surfaces of magnetic iron oxide nanoparticles are usually coated with various hydrophilic/amphiphilic polymers. Whereas, for targeted magnetic delivery, the particle surface is derivatized with various proteins, peptides or monoclonal antibodies as ligands to target the cellexpressed surface receptors.
The magnetic nanoparticles have the potential to combine both detection and treatment into a singer process. The drug-coated particles may be used to detect early the inflammation, atherosclerosis, cancer or diabetes through MRI, as well as to deliver cytotoxic drug, for example, directly to tumor cells, thereby minimizing destructive side effect.

Conclusions and Perspectives
Perspectives

Conclusions and Perspectives

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