Abstract and Introduction
Abstract
Magnetic nanoparticles are attractive targets owing to their unique characteristics that are not shared by bulk materials. Magnetic particles, ranging from nanometer-sized to 1 µm in size, are being used in an increasing number of medical applications. The important properties of magnetic particles for medical applications are nontoxicity, biocompatiblilty, injectability and high-level accumulation in the target tissue or organ. Magnetic nanoparticles modified with organic molecules have been widely used for biotechnological and biomedical applications as their properties can be magnetically controlled by applying an external magnetic field. They offer high potential for numerous biomedical applications, such as cell separation, automated DNA extraction, gene targeting, drug delivery, MRI and hyperthermia. When coated with, for example, an antibody, they can be applied in highly sensitive immunoassays or small substance recoveries. Furthermore, a novel application of magnetic nanoparticles and magnetic forces for tissue engineering, termed 'magnetic force-based tissue engineering' has been proposed. Particular attention had been paid to the preparation methods that allow the synthesis of particles of nearly uniform size and shape.
Introduction
Delivery of drugs is an important component of the treatment of diseases both from a commercial and a scientific point of view, as the method by which a drug is delivered can have a significant effect on its efficacy. Scientifically, it is extremely challenging, as the goal is to find a drug-delivery system with the capability for site-specificity as well as controlled release. In the past few years, considerable interest has been devoted towards the design of new drug-delivery systems with the aim to target the drug to a specific site, such that the drug is released at a controlled rate and at the desired time. Drug targeting has emerged as one of the modern technologies for drug delivery.[1] Targeting specific sites in the body simplifies drug administration procedures, reduces the quantity of drug required to reach therapeutic levels, decreases the drug concentration at on-target sites (possibly reducing side effects) and, essentially, increases the concentration of the drug at target sites.[2–5] There are many different approaches to targeted drug delivery, which are classified into three categories: chemical approaches that incorporate chemical delivery systems and allow targeting of active biological molecules to specific target sites or organs based on predictable enzymatic activation; biological approaches, which involve delivery of the drug using a carrier system, for example antibodies or lecithin; and physical approaches, which require formulation of the drug using a particulate delivery device, (e.g., magnet) that by virtue of its physical localization will allow differential release of the drug.
Nanomedicine. 2009;4(7):799-812. © 2009
Cite this: Magnetically Modulated Nanosystems: A Unique Drug-delivery Platform - Medscape - Oct 01, 2009.
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