Abstract

Abstract A new approach to control the release of encapsulated materials from liposomes by using thermosensitive block copolymers and magnetic nanoparticles is reported. Hydrophobized Fe 3 O 4 nanoparticles are synthesized via the hydrothermal process, and can be incorporated into liposomal membranes by hydrophobic interactions. Thermosensitive block copolymers of (2‐ethoxy)ethoxyethyl vinyl ether (EOEOVE) and octadecyl vinyl ether (ODVE) are synthesized by living cationic polymerization. The poly(EOEOVE) block acts as a temperature‐sensitive moiety, and the poly(ODVE) block acts as an anchor unit. Hybrid liposomes encapsulating pyranine, a water‐soluble fluorescent dye, are prepared from mixtures of phospholipids, the hydrophobized Fe 3 O 4 nanoparticles, and the copolymer. While the hybrid liposomes released negligible amounts of pyranine under static conditions, the release of pyranine is drastically enhanced by alternating magnetic field irradiation. The magnetically induced release is attributed to the transition of the thermosensitive segment of the copolymer, which is caused by the release of localized heat from the Fe 3 O 4 nanoparticles under magnetic stimuli, rather than the rupture of the capsules. The release rate of the hybrid capsules is controlled by varying the amount of Fe 3 O 4 nanoparticles embedded into the liposomes.

Keywords

CopolymerPyranineMaterials scienceLiving cationic polymerizationNanoparticleVinyl etherLiposomePolymer chemistryCationic polymerizationChemical engineeringMagnetic nanoparticlesPolymerizationMembranePolymerChemistryNanotechnologyComposite material

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Publication Info

Year
2011
Type
article
Volume
7
Issue
12
Pages
1683-1689
Citations
104
Access
Closed

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Cite This

Kiyofumi Katagiri, Yuji Imai, Kunihito Koumoto et al. (2011). Magnetoresponsive On‐Demand Release of Hybrid Liposomes Formed from Fe<sub>3</sub>O<sub>4</sub> Nanoparticles and Thermosensitive Block Copolymers. Small , 7 (12) , 1683-1689. https://doi.org/10.1002/smll.201002180

Identifiers

DOI
10.1002/smll.201002180