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Industrial Applications
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
A micro-accelerator of particles generates a highly energetic ion beam penetrating and modifying the surface of materials to enhance their properties without any coating. The penetration depth might reach up to 10 microns and the treatment effects are still measurable until 1mm. Depending on the nature of the implanted ions and the process parameters, you may obtain nano hammering effect, doping effect, surface amorphization, re-alloying, nano-structuring effect and even chemical modification if reactive gases are used. The part temperature never exceeds 80 °C: a cold metallurgy. The technology might be combined with other low-pressure technologies like PVD and PECVD processes to obtain even more breakthrough properties and performances: surface preparation for hard coatings, cobalt depletion, enhanced adhesion, etc.
Recent Progress in Cancer Thermal Therapy Using Gold Nanoparticles *
Published in Valerio Voliani, Nanomaterials and Neoplasms, 2021
Nardine S. Abadeer, Catherine J. Murphy
Currently, only one gold nanoparticle photothermal treatment system has progressed to clinical trials. Nanospectra Biosciences, Inc., founded in 2002, is a company focused on commercializing photothermal therapeutics for destruction of solid tumors. AuroLase Therapy consists of AuroShell particles which are 150 nm gold nanoshells (λmax = 780–820 nm) and functionalized with a 5000 molecular weight PEG-thiol. The nanoshells are injected intravenously, and PEGylation allows them to circulate in the blood long enough to accumulate in tumors via the EPR effect. Then, a fiber optic NIR laser (808 nm) is inserted through the skin into or near the tumor, and subsequent irradiation(s) may result in cancer cell death and tumor regression [150]. A fiber optic laser is used because NIR light can only penetrate up to 10 cm in tissue so tumors in deep areas of the body cannot be treated with lasers at/above the skin [151]. The use of a fiber optic laser inserted into the body is a useful solution to the problem of limited penetration depth. This was demonstrated by Schwartz et al., who used an optical fiber to carry photothermal treatment in a venereal tumor in a canine brain model [152].
Ultrasound and Microwave Hyperthermia in the Treatment of Superficial Human Cancerous Tumors
Published in Leopold J. Anghileri, Jacques Robert, Hyperthermia in Cancer Treatment, 2019
C. Marchal, P. Bey, S. Hoffstetter, J. Robert
In soft tissues, the most frequent propagation type is the compression mode with vibrational movement along the axis of propagation. But in bone, transverse propagation may also occur. Ultrasound absorption processes in tissues are largely caused by macromolecule content, and to a lesser extent, by cellular structure.241-245 Up to 3 MHz, tissue water content does not significantly contribute to the absorption processes. Penetration depth is found to be inversely proportional to frequency.246-254
Stimuli-sensitive nano-drug delivery with programmable size changes to enhance accumulation of therapeutic agents in tumors
Published in Drug Delivery, 2023
Mohammad Souri, Mohammad Kiani Shahvandi, Mohsen Chiani, Farshad Moradi Kashkooli, Ali Farhangi, Mohammad Reza Mehrabi, Arman Rahmim, Van M. Savage, M. Soltani
First, 150 nm primary nanoparticles are considered, which carry secondary nanoparticles in sizes of 1, 5, 12, and 20 nm. This means that the scale of the drug delivery system decreases from 7.5 to 150 times within the microvascular network. This will increase tumor accumulation and then increase the penetration depth. The primary nanoparticles are not small enough to be quickly excreted by the kidneys, nor are they large enough to be trapped by the spleen and liver. Meanwhile, they are large enough to carry a significant load. Furthermore, the size of the primary nanoparticles is larger than 0.6 of the tumor vessel pore size (200 nm), so they do not pass through the pores due to hydrodynamic and electrostatic interactions (Chauhan et al., 2012; Stylianopoulos et al., 2018). Primary nanoparticles in the microvascular network of the tumor release their cargo rapidly in response to temperature, so their concentration decreases sharply during the period of hyperthermia in the microvascular network. However, these changes do not affect the concentrations in the circulation because the volume of tumor plasma is very small compared to the total volume Figure 6(a)).
Validation and practical use of Plan2Heat hyperthermia treatment planning for capacitive heating
Published in International Journal of Hyperthermia, 2022
Figure 8 shows simulated normalized SAR distributions, as well as measured and simulated profiles for a homogenous 2/3 fat-muscle phantom set-up with two 15 cm diameter electrodes for the Celsius TCS device. Profiles were normalized to 100% at 1 cm depth. Both measured and predicted penetration depth are about 4 cm. The measurements show a decay toward a minimum SAR value of ∼30%, which is accurately reproduced by the simulation. Since the bottom electrode is effectively slightly larger than 15 cm due to the coupling effect of the electrode to the treatment table, the resulting profile is slightly asymmetrical. The SAR value near the bottom electrode (at 15 cm depth) is about 70%. Measured and simulated profiles show an excellent agreement, with a correspondence within 5%.
The role of women scientists in the development of ultrashort pulsed laser technology-based biomedical research in Armenia
Published in International Journal of Radiation Biology, 2022
Gohar Tsakanova, Elina Arakelova, Lusine Matevosyan, Mariam Petrosyan, Seda Gasparyan, Kristine Harutyunyan, Nelly Babayan
The development of near-infrared femtosecond-pulsed lasers allowed to use these types of lasers as a primary source for multiphoton microscopy, which has a number of advantages over the conventional microscopy including confocal microscopy. With the latter, the researchers face a number of challenges. One of them is the penetration depth, the limitation of which occurs due to the light-scattering properties observed in biological tissues. The development of multiphoton excitation techniques allowed to avoid these issues as the light source in near-infrared wavelength range used in these techniques gives the opportunity to conduct deep tissue imaging experiments. This advantages make multiphoton microscopy a powerful tool in many research fields, such as neuroscience, vascular biology, cancer biology. Complementing conventional optical microscopy, it provides an opportunity to conduct in vivo three-dimensional imaging of deep tissue in different mediums, including highly scattering mediums (Brown et al. 2001; Kerr and Denk 2008; Ando et al. 2009; Choi et al. 2011; Yoon and Choi 2017).