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Posted: May 18, 2006
Smart magnetic hydrogels for drug release
(Nanowerk Spotlight) Smart magnetic hydrogels were investigated by researchers in Taiwan for the development of a new magnetically induced drug delivery system. By applying magnetic fields, they were able to switch the the drug release profile of the hydrogels between ‘‘on’’ and ‘‘off’’ mode.
The research was carried out by Professor San-Yuan Chen and his group at the Department of Materials Science and Engineering at National Chiao Tung University in Taiwan.
So far, there has been little advance in the field of ferrogel specifically for drug delivery applications although magnetic materials have been widely used in the field of biotechnology in bio-separation, artificial muscles and drug carriers. The Taiwanese researchers' recent work demonstrates a good example for ferrogel applications, and going further, a controlled drug delivery and release mechanism that can be externally manipulated.
Their work primarily explores the physical mechanism of the mechanical movement of the ferrogel (magnetic hydrogel) upon the introduction of magnetic particles of different size and different inorganic/organic concentrations.
The sensitivity of the resulting ferrogel upon a given magnetic field can be enhanced by manipulating from nanoscale to microscale. Furthermore, this magnetic-sensitive ferrogel is even superior to traditional stimuli response polymer, such as pH or thermal sensitive polymer, because magnetic stimulation is an action-at-distance force (non-contact force) that is easier to adapt to biomedical devices.
Mechanism of magnetic-sensitive behaviors (Source: San-Yuan Chen, National Chiao Tung University)
Chen explains to Nanowerk the specific problem that his team's work has overcome: "In conventional drug delivery systems the drug is continuously released from the drug carrier, once it is administrated into patient's body, even when there is no need any more. This could raise potential toxicity issues."
"However, for the ferrogel prepared in our current work," Chen says "the release of the drug can be held or ceased altogether when the patient's body does not require any further dose; and the drug can be released again if and when needed via an externally-triggered magnetic field. As a result, an efficient and effective drug therapy can be administered at the right time with the right dosage."
Chen sees biologically triggered, magnetically-induced drug delivery systems as an important contribution to future biotech developments. "This work is one of the fundamental achievements in our research team" he says.