The Effect of Tissue-Mimicking Phantom Compressibility on Magnetic Hyperthermia

Abstract

During hyperthermia, magnetite nanoparticles placed in an AC magnetic field become a source of heat. It has been shown that in fluid suspensions, magnetic particles move freely and generate heat easily. However, in tissues of different mechanical properties, nanoparticle movement is limited and leads to a small temperature rise in tissue. Therefore, it is crucial to conduct magnetic hyperthermia experiments in similar conditions to the human body. The effect of tissue-mimicking phantom compressibility on the effectiveness of magnetic hyperthermia was investigated on agar phantoms. Single and cluster nanoparticles were synthesized and used as magnetic materials. The prepared magnetic materials were characterized by transmission electron microscopy (TEM), and zeta potential measurements. Results show that tissue-mimicking phantom compressibility decreases with the concentration of agar. Moreover, the lower the compressibility, the lower the thermal effect of magnetic hyperthermia. Specific absorption rate (SAR) values also proved our assumption that tissue-mimicking phantom compressibility affects magnetic losses in the alternating magnetic field (AMF).

Comparison of Iron Oxide Nanoparticles in Photothermia and Magnetic Hyperthermia: Effects of Clustering and Silica Encapsulation on Nanoparticles’ Heating Yield

“…environment) of nanoparticles and nanoparticles hierarchical organization may have an impact on different therapeutic [17] and diagnostic modalities [35]. The mechanical properties of the surrounding environment [36] or the clustering SPIONs may thus affect the nanoparticles' heating yields [17]. In magnetic hyperthermia, external mechanical constraints [36], as well as nanoparticle confinement or aggregation, decreases the thermal yield because mechanically Similar to photothermia, a series of magnetic hyperthermia measurements were performed when the suspensions of nanomaterials were exposed to an alternating magnetic field (frequency 470 kHz, field 18 mT).…”

“…The mechanical properties of the surrounding environment [36] or the clustering SPIONs may thus affect the nanoparticles' heating yields [17]. In magnetic hyperthermia, external mechanical constraints [36], as well as nanoparticle confinement or aggregation, decreases the thermal yield because mechanically Similar to photothermia, a series of magnetic hyperthermia measurements were performed when the suspensions of nanomaterials were exposed to an alternating magnetic field (frequency 470 kHz, field 18 mT). Here, temperature elevation curves were recorded at a higher concentration of iron, specifically [Fe] = 130 mM ( Figure 3D), and attained temperatures of 42.38 • C for SPIONs, 41.71 • C for SPIONs-SIL, and 27.91 • C for MNCs.…”

“…The local surrounding (e.g., environment) of nanoparticles and nanoparticles hierarchical organization may have an impact on different therapeutic [17] and diagnostic modalities [35]. The mechanical properties of the surrounding environment [36] or the clustering SPIONs may thus affect the nanoparticles' heating yields [17]. In magnetic hyperthermia, external mechanical constraints [36], as well as nanoparticle confinement or aggregation, decreases the thermal yield because mechanically constrained or aggregated nanoparticles have less freedom to rotate (which inhibits Brownian relaxation) or because the inter-nanoparticle distance decreases, increasing nanoparticle interactions (which hampers Néel relaxation).…”

Localized and triggered release of oxaliplatin for the treatment of colorectal liver metastasis

“…Compact induction heating system (EASYHEAT Ambrell Corporation, Scottsville, NY) was used to generate AMF as described elsewhere 28 in the present study. After liposome infusion, each of the anesthetized rat was inserted into magnetic induction coil in such a way that the abdomen region reside in the coil.…”

Magnetically Modified Electrospun Nanofibers for Hyperthermia Treatment

“…On the contrary to the standard hyperthermia treatment with free magnetic particles, where usually two distinct heating mechanisms are considered (namely Brownian motion and Néel relaxation), the iron oxide particles in magnetically modified fibers are strongly anchored onto the polymer phase [14][15][16]. That's why the Brownian motion is probably very limited, while the Néel relaxation and hysteresis losses (for relatively large nanoparticles) are the main mechanisms of magnetic energy dissipation.…”