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Magnetic-, Acoustic-, and Optical-Triple-Responsive Microbubbles for Magnetic Hyperthermia and Pothotothermal Combination Cancer Therapy
Published on: May 22, 2020
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Bacterially synthesized ferrite nanoparticles for magnetic hyperthermia applications
Eva Céspedes1, James M Byrne, Neil Farrow
1Institute for Science and Technology in Medicine (ISTM), Keele University, Stoke-on-Trent ST4 7QB, UK. e.cespedes@keele.ac.uk.
Nanoscale
|September 19, 2014
Summary
Biogenic magnetic nanoparticles offer enhanced cancer therapy. Zinc-doped particles from Geobacter sulfurreducens provide effective heating for cancer treatment, even when immobilized, and improve MRI contrast.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Cancer Therapy
Background:
- Magnetic hyperthermia utilizes magnetic nanoparticles (MNPs) to generate heat for cancer cell destruction via alternating current (AC) stimulation.
- Naturally produced MNPs from magnetotactic bacteria exhibit high heating efficiency but require extreme magnetic field parameters for effective use.
- Existing MNPs often face limitations due to magnetic blocking, restricting heating to mobile particles outside clinical magnetic field constraints.
Purpose of the Study:
- To investigate extracellularly produced MNPs from Geobacter sulfurreducens with cobalt (Co) or zinc (Zn) doping.
- To tune magnetic anisotropy, saturation magnetization, and particle size for efficient heating within clinical magnetic field limits.
- To determine heating mechanisms and assess potential for combined diagnostics and cancer therapy.
Main Methods:
- Extracellular production of MNPs by Geobacter sulfurreducens with Co or Zn doping.
- Frequency-dependent specific absorption rate (SAR) measurements to quantify heating efficiency.
- AC susceptometry simulations using a realistic model of polydisperse nanoparticle clusters in suspension.
Main Results:
- Both Co and Zn doped MNPs exhibit magnetization relaxation and heating effects in water under low AC frequency and field.
- Zn-doped particles uniquely maintain relaxation and hysteresis losses even when immobilized, crucial for biological applications.
- Specific absorption rates (SARs) obtained are discussed in the context of clinical applicability and enhanced MRI contrast.
Conclusions:
- Extracellularly produced biogenic MNPs, particularly Zn-doped variants, offer tunable magnetic properties for hyperthermia.
- Zn-doped Geobacter sulfurreducens MNPs provide effective heating within clinical constraints and retain functionality when immobilized.
- These biogenic nanoparticles show promise for combined cancer diagnostics and therapy due to their heating capabilities and MRI contrast enhancement.
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