Nanoparticles Enhanced Hyperthermia - Intracellular Delivery: Fundamentals and Applications - page 585

applies in superficial tumors, while the HIFU (Lynn et al. 1942 ; Zhu et al. 2009 ) is
for the treatment of deep tumors.
Since tumor hyperthermia with many different heating sources, such as IR and
RF irradiation, can be enhanced by the presence of nanoparticles, people believe
that ultrasonic heating method also has the possibility to connect with nanoparticles
with fairish acoustic properties. Now there are many nanoparticles used as UCA
(Calliada et al. 1998 ; Kornmann et al. 2010 ). Some of them are not good agents,
but can bring favorable influence on ultrasonic nano-hyperthermia. Like MNPs, the
ultrasonic nanoparticles also can be used as the enhancer of imaging and hyper-
thermia treatment simultaneously. The studies of Razansky et al. showed that the
maximal temperature elevation obtained during 300 s experiments was 21°C, in a
10 mL volume target containing UCA, insonified by unfocused 3.2 MHz continuous
wave at spatial average intensity of 1.1 W/cm 2 . The results also suggest that higher
frequencies are more efficiently absorbed by commonly used UCA (Razansky et al.
2006a ). Based on theoretical predictions, they designed experiments to measure
the dissipation and heating effects of encapsulated UCA in a well-controlled and
calibrated environment (Razansky et al. 2006b ).
The study of Jozefczak et al. presented acoustic properties of water-based
biocompatible fluids in which magnetite particles (Fe 3 O 4 ) were coated with sodium
oleate and polysaccharide dextran and showed the attenuation coefficient of ultra-
sonic wave (Jozefczak and Skumiel 2007 ).

6 Thermochemical Heating Methods

All of the heating means, RF heating, microwave heating, ultrasonic or laser heating,
have some deficiencies more or less. The common drawbacks are complicated
equipments, high cost and complex surgical operation. In recent years, researchers
have initiated a new method of tumor hyperthermia- the targeted thermochemical
ablation therapy, which breaks inherent heating methods in traditional methods
and do not require complex equipment, so as to achieve a cost-effective treatment
of tumors.
Thermochemical reaction heating method is based on chemical reactions to
release plenty of heat to the target tissues. By delivering appropriate exothermic
materials into the tumor site, tremendous heat will be released from the chemical
reactions among these substances with their tissue environment. Researchers
have suggested two typical thermochemical ablation methods, acid-alkali reac-
tion enabled thermal ablation (Deng and Liu 2007 ) and alkali metal enabled
thermal ablation (Rao and Liu 2008 ; Bauer et al. 2008 ; Rao et al. 2008 ). It was
proved through various experiments that the thermochemical reaction heating
method can ensure releasing high-intensity heat only in the target site, while
ensure the surrounding tissue away from injury by heat mechanical puncture. In
the study of Rao et al. ( 2008 ), some fundamental mechanisms related to the anti-