Green-Synthesized Silver Nanoparticle–Assisted Radiofrequency Ablation for Improved Thermal Treatment Distribution

Abstract

Thermal ablation therapy is known as an advantageous alternative to surgery allowing the treatment of multiple tumors located in hard-to-reach locations or treating patients with medical conditions that are not compatible with surgery. Appropriate heat propagation and precise control over the heat propagation is considered a weak point of thermal ablation therapy. In this work, silver nanoparticles (AgNPs) are used to improve the heat propagation properties during the thermal ablation procedure. Green-synthesized silver nanoparticles offer several attractive features, such as excellent thermal conductivity, biocompatibility, and antimicrobial activity. A distributed multiplexed fiber optic sensing system is used to monitor precisely the temperature change during nanoparticle-assisted radiofrequency ablation. An array of six MgO-based nanoparticles doped optical fibers spliced to single-mode fibers allowed us to obtain the two-dimensional thermal maps in a real time employing optical backscattering reflectometry at 2 mm resolution and 120 sensing points. The silver nanoparticles at 5, 10, and 20 mg/mL were employed to investigate their heating effects at several positions on the tissue regarding the active electrode. In addition, the pristine tissue and tissue treated with agarose solution were also tested for reference purposes. The results demonstrated that silver nanoparticles could increase the temperature during thermal therapies by propagating the heat. The highest temperature increase was obtained for 5 mg/mL silver nanoparticles introduced to the area close to the electrode with a 102% increase of the ablated area compared to the pristine tissue.

Rational Design of Biomaterials to Potentiate Cancer Thermal Therapy

“…53 Currently, diverse metallic biomaterials, including Au-, Ag-, and Fe-based nanoparticles, have been reported to enhance the conversion of RF current to heat to achieve better RFA treatment outcomes. 46,48,54 Among them, gold nanoparticles have been reported to be able to increase RFA heating via the Joule heating principle, although this is still under debate. In a recent work by Tudor Mocan et al, it was uncovered that swine livers with percutaneous injection of PEG-coated gold nanoparticles through the electrode channel during RFA treatment showed a large coagulation zone volume as determined by using contrastenhanced ultrasound (CEUS).…”

Green synthesis of silver nanoparticles: methods, biological applications, delivery and toxicity

“…They are currently synthesized in many forms to catalyse reactions, protein separation, polymer preparation, sensor technology, optoelectronic recording media and heat propagating in thermal ablation therapy [31][32][33][34][35] . Nowadays, various disease imaging systems like magnetic resonance imaging, positron emission tomography, surface-enhanced Raman spectroscopy (SERS) and optical imaging are in use based on the magnetic property of NPs 36 . Wei et al in 2015 opined that weak interaction with AgNPs causes oscillation of conduction band electrons of AgNPs, and thereby, photon energy changes into thermal energy so that the SERS effect can be tamed to develop photothermal and thermolytic laser therapies 37 .…”

Optical Fiber Distributed Sensing Network for Thermal Mapping in Radiofrequency Ablation Neighboring a Blood Vessel

“…RFA provides a treatment that combines the miniaturization of the applicator and its tip electrodes with the localization of the bio-heating process in the surrounding tissue [ 11 ], as well as allowing the ablation of large volumes. Recent studies, in addition, have shown how the use of gold [ 12 ] and silver [ 13 ] nanoparticles might significantly expand the treated area. For example, Ashikbayeva et al reported a 102% increase in the ablated surface area when using green-synthesized Ag nanoparticles in an agarose gel, and a 72% increase when using agarose only.…”

“…For example, Ashikbayeva et al reported a 102% increase in the ablated surface area when using green-synthesized Ag nanoparticles in an agarose gel, and a 72% increase when using agarose only. Agarose gel is widely used in biomedicine material; it has biocompatible, antimicrobial characteristics, and demonstrates good heating performance in terms of temperature, heat distribution and the short time it takes to reach cytotoxic temperature ranges [ 13 ]. Overall, RFA allows a rapid (30–120 s) treatment, capable of reaching cytotoxic (>42 °C) and instantaneous cell mortality (>60 °C) temperature values [ 14 ] within a few seconds from the start.…”

“…Despite the different working principles, both TCs and FBGs require the accurate positioning of the sensing devices in the tissue in order to provide the exact measurement of the heat-sink effect [ 17 ]. In order to overcome this limitation, distributed sensing networks have been utilized [ 13 , 27 ]: in this case, rather than using an optical fiber as the sensing element, the temperature detection is encoded in the back reflection due to the Rayleigh scattering that occurs in all optical fibers, including single-mode telecom fibers [ 28 ].…”