Syntheses of some olefin-substituted metal acetylacetonates

Superparamagnetic nanoparticles (SPIONs) could enable cancer theranostics if magnetic resonance imaging (MRI) and magnetic hyperthermia treatment (MHT) were combined. However, the particle size of SPIONs is smaller than the pores of fenestrated capillaries in normal tissues because superparamagnetism is expressed only at a particle size <10 nm. Therefore, SPIONs leak from the capillaries of normal tissues, resulting in low accumulation in tumors. Furthermore, MHT studies have been conducted in an impractical way: direct injection of magnetic materials into tumor and application of hazardous alternating current (AC) magnetic fields. To accomplish effective enhancement of MRI contrast agents in tumors and inhibition of tumor growth by MHT with intravenous injection and a safe AC magnetic field, we clustered SPIONs not only to prevent their leakage from fenestrated capillaries in normal tissues, but also for increasing their relaxivity and the specific absorption rate. We modified the clusters with folic acid (FA) and polyethylene glycol (PEG) to promote their accumulation in tumors. SPION clustering and cluster modification with FA and PEG were achieved simultaneously via the thiol-ene click reaction. Twenty-four hours after intravenous injection of FA- and PEG-modified SPION nanoclusters (FA-PEG-SPION NCs), they accumulated locally in cancer (not necrotic) tissues within the tumor and enhanced the MRI contrast. Furthermore, 24 h after intravenous injection of the NCs, the mice were placed in an AC magnetic field with H = 8 kA/m and f = 230 kHz (Hf = 1.8×109 A/m∙s) for 20 min. The tumors of the mice underwent local heating by application of an AC magnetic field. The temperature of the tumor was higher than the surrounding tissues by ≈6°C at 20 min after treatment. Thirty-five days after treatment, the tumor volume of treated mice was one-tenth that of the control mice. Furthermore, the treated mice were alive after 12 weeks; control mice died up to 8 weeks after treatment.

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“…IAA was prepared by the method described in the literature 33. Hydrazine was purchased from Tokyo Chemical Industry (Tokyo, Japan).…”

Section: Methodsmentioning

confidence: 99%

Superparamagnetic Nanoparticle Clusters for Cancer Theranostics Combining Magnetic Resonance Imaging and Hyperthermia Treatment

Hayashi¹,

Nakamura²,

Sakamoto³

et al. 2013

Theranostics

292

218

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“…Synthesis of (Ni,Zn)Fe 2 O 4 particle/organic hybrid IAA was prepared by the method described in the literature. 17 Commercially available nickel (II) acetylacetonate hydrate (Dotite, Tokyo, Japan) was purified and dehydrated by sublimation at 10 Pa and 100°C. Zinc (II) acetylacetonate hydrate (Tokyo Kasei, Tokyo, Japan) was purified and dehydrated under the same conditions.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of nickel zinc ferrite nanoparticle/organic hybrid from metalorganics

2007

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Ni,Zn)Fe 2 O 4 particle/organic hybrid was synthesized in situ from metalorganics below 100°C. A mixture of nickel (II) acetylacetonate (NA), zinc acetylacetonate (ZA), and iron (III) 3-allylacetylacetonate (IAA) was hydrolyzed and polymerized yielding a spinel oxide particle/organic hybrid. X-ray diffraction analysis revealed that the crystallinity of spinel particles was dependent upon the hydrolysis conditions of NA-ZA-IAA. Nanocrystalline nickel zinc ferrite particles below 5 nm were uniformly dispersed in the organic matrix. The magnetization of hybrid increased with an increasing amount of water for hydrolysis. Nano-sized nickel zinc ferrite particle/organic hybrid showed a magnetization-applied field (BH) curve with no remanence above 40 K. The magnetization versus H/T curves from 40 to 100 K were superimposed on the same curve and satisfied the Langevin equation. The remanent magnetization and coercive field of the hybrid were 7.2 emu/g and 150 Oe, respectively, at 4.2 K. The absorption edge of the hybrid was blue-shifted compared with that of bulk ferrite.

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“…Synthesis of NiFe 2 O 4 particle/organic hybrid IAA was prepared by the method described in the literature. 17 Commercially available nickel (II) acetylacetonate hydrate (Dotite, Tokyo, Japan) was purified and dehydrated by sublimation at 10 Pa and 100°C. Ethanol (Kishida Chemical, Osaka, Japan) was dried over magnesium ethoxide and then distilled before use.…”

Section: Methodsmentioning

confidence: 99%

In situ Synthesis of Nickel Ferrite Nanoparticle/organic Hybrid

Sakamoto

Yogo

2005

J. Mater. Res.

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A NiFe 2 O 4 particle/organic hybrid was synthesized in situ from iron-organic and nickel organic compounds below 100°C. A mixture of nickel (II) acetylacetonate (NA) and iron (III) 3-allylacetylacetonate (IAA) was hydrolyzed and polymerized yielding spinel oxide particle/oligomer hybrid. X-ray diffraction analysis revealed that the crystallinity of spinel particles was dependent upon the hydrolysis conditions of NA-IAA. Nanocrystalline nickel ferrite particles around 10 nm were uniformly dispersed in the organic matrix. The formation of nickel ferrite was confirmed by energy-dispersive x-ray and x-ray photoelectron spectroscopy. The saturation magnetization of hybrid increased with increasing water amount for hydrolysis. Nano-sized nickel ferrite particle/organic hybrid showed a BH curve with no remanence above 75 K. The magnetization versus H/T curves at 300, 200, and 75 K were superimposed on the same curve and satisfied the Langevin equation. The remanent magnetization and coercive field of the hybrid were 7.4 emu/g and 460 Oe, respectively, at 5 K.

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Syntheses of some olefin-substituted metal acetylacetonates

Cited by 24 publications

References 1 publication

Superparamagnetic Nanoparticle Clusters for Cancer Theranostics Combining Magnetic Resonance Imaging and Hyperthermia Treatment

Superparamagnetic Nanoparticle Clusters for Cancer Theranostics Combining Magnetic Resonance Imaging and Hyperthermia Treatment

Synthesis of nickel zinc ferrite nanoparticle/organic hybrid from metalorganics

In situ Synthesis of Nickel Ferrite Nanoparticle/organic Hybrid

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