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Local vs. global heat generation to explain the success -or failure- of
magnetic hyperthermia
C. Munoz-Menendez, D. Serantes, S. Ruta, O. Hovorka, K. Livesey, O. Chubykalo-Fesenko, R. Chantrell and D. Baldomir
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A. Riedinger, et. al., Nano Lett., 2013, 13, 2399–2406 J. T. Dias, et. al., Angew. Chem., Int. Ed., 2013, 52, 11526–11529
ACS Nano 2011
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A. Riedinger, et. al., Nano Lett., 2013, 13, 2399–2406 J. T. Dias, et. al., Angew. Chem., Int. Ed., 2013, 52, 11526–11529
ACS Nano 2011
NEED TO STUDY LOCAL HEATING BESIDES THE GLOBAL ONE
Global vs. local heating
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‘The role of size polydispersity in magnetic fluid hyperthermia: average vs. local infra/over-heating effects’, C. Munoz-Menendez, et. al., Phys. Chem. Chem. Phys., 2015, 17, 27812–27820
Temperature effect kMC for T>0K
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‘Distinguishing between heating power and hyperthermic cell-treatment efficacy in magnetic fluid hyperthermia’, C. Munoz-Menendez, et. al., 2016, Soft Matter, 12, 8815-8818
Interaction effect
Inverted loops Negative area
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Physical sense: 𝐻𝑑𝑖𝑝𝑜𝑙𝑎𝑟 modifies 𝐻𝑙𝑜𝑐𝑎𝑙: 𝜇 𝑠𝑚𝑎𝑙𝑙 flips if 𝐻𝑙𝑜𝑐𝑎𝑙 > 𝐻𝐶
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o Negative area?
Alternative way to quantify dissipated heat by each particle?
D1 = 20 nm D2 = 10 nm
𝐻𝑎𝑝𝑝𝑧 D
𝑀𝑆𝑉1𝑧 𝑀𝑆𝑉2𝑧
Simple case (T=0K):
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Premiss: global area IS dissipated heat
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𝟏) − 𝐻𝐾1 − 𝑀𝑆2𝑉2
𝑟3
2) − 𝐻𝐾2 + 𝑀𝑆1𝑉1
𝑟3
3) 𝐻𝐾2 − 𝑀𝑆1𝑉1
𝑟3
4) 𝐻𝐾1 + 𝑀𝑆2𝑉2
𝑟3
1 2 3 4
𝑀𝑆1𝑉1 - 𝑀𝑆2𝑉2
𝑀𝑆1𝑉1 + 𝑀𝑆2
𝑉2
−𝑀𝑆1𝑉1 - 𝑀𝑆2𝑉2
−𝑀𝑆1𝑉1 + 𝑀𝑆2𝑉2
𝑎𝑟𝑒𝑎 = 4 𝐻𝐾1𝑀𝑆1𝑉1 + 4 𝐻𝐾2𝑀𝑆2𝑉2
No interaction strength dependance!
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Global area is recovered from these jumps :
‘Irreversible’ jumps
state changes
Energy evolution, non-interacting
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NP A feels the jump of NP B
‘Reversible’ jumps, stored E
no change of state
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Energy evolution, interacting
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Time asymmetry
Area – energy jumps comparison
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Area – energy jumps comparison
!!
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0 MSAT 0 MSAT Area – energy jumps comparison
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Conclusions
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• Experiments show the need to study local heating
• Size polydispersity is important for MFH because of local effects
o Heating and hyperthermia performance are not equivalent concepts!
o Local inverted hysteresis loops appear for strong interaction conditions
• For 2 particles: Can energy jumps of individual NPs be used to reproduce the global area?
o For major loops yes
o Further work necessary for minor loops in the tilted easy-axis case
