Local hyperthermia for esophageal cancer in a rabbit tumor model: Magnetic stent hyperthermia versus magnetic fluid hyperthermia

A Functional Stent Encapsulating Radionuclide in Temperature-Memory Spiral Tubes for Malignant Stenosis of Esophageal Cancer

Stent implantation is a commonly used palliative treatment for alleviating stenosis in advanced esophageal cancer. However, tissue proliferation induced by stent implantation and continuous tumor growth can easily lead to restenosis. Therefore, functional stents are required to relieve stenosis while inhibiting tissue proliferation and tumor growth, thereby extending the patency. Currently, no ideal functional stents are available. Here, iodine-125 (125 I) nuclides are encapsulated into a nickel-titanium alloy (NiTi) tube to develop a novel temperature-memory spiral radionuclide stent (TSRS). It has the characteristics of temperature-memory, no cold regions at the end of the stent, and a uniform spatial dose distribution. Cell-viability experiments reveal that the TSRS can reduce the proliferation of fibroblasts and tumor cells. TSRS implantation is feasible and safe, has no significant systemic radiotoxicity, and can inhibit in-stent and edge stenosis caused by stent-induced tissue proliferation in healthy rabbits. Moreover, TSRS can improve malignant stenosis and luminal patency resulting from continuous tumor growth in a VX2 esophageal cancer model. As a functional stent, the TSRS combines the excellent properties of NiTi with brachytherapy of the 125 I nuclide and will make significant contributions to the treatment of malignant esophageal stenosis.

Nanomedicine and Hyperthermia for the Treatment of Gastrointestinal Cancer: A Systematic Review

The incidence of gastrointestinal cancers has increased in recent years. Current treatments present numerous challenges, including drug resistance, non-specificity, and severe side effects, needing the exploration of new therapeutic strategies. One promising avenue is the use of magnetic nanoparticles, which have gained considerable interest due to their ability to generate heat in tumor regions upon the application of an external alternating magnetic field, a process known as hyperthermia. This review conducted a systematic search of in vitro and in vivo studies published in the last decade that employ hyperthermia therapy mediated by magnetic nanoparticles for treating gastrointestinal cancers. After applying various inclusion and exclusion criteria (studies in the last 10 years where hyperthermia using alternative magnetic field is applied), a total of 40 articles were analyzed. The results revealed that iron oxide is the preferred material for magnetism generation in the nanoparticles, and colorectal cancer is the most studied gastrointestinal cancer. Interestingly, novel therapies employing nanoparticles loaded with chemotherapeutic drugs in combination with magnetic hyperthermia demonstrated an excellent antitumor effect. In conclusion, hyperthermia treatments mediated by magnetic nanoparticles appear to be an effective approach for the treatment of gastrointestinal cancers, offering advantages over traditional therapies.

Targeted removal of leukemia cells from the circulating system by whole-body magnetic hyperthermia in mice

Until now, magnetic hyperthermia was used to remove solid tumors by targeting magnetic nanoparticles (MNPs) to tumor sites. In this study, leukemia cells in the bloodstream were directly removed by whole-body hyperthermia, using leukemia cell-specific MNPs. An epithelial cellular adhesion molecule (EpCAM) antibody was immobilized on the surface of MNPs (EpCAM-MNPs) to introduce the specificity of MNPs to leukemia cells. The viability of THP1 cells (human monocytic leukemia cells) was decreased to 40.8% of that in control samples by hyperthermia using EpCAM-MNPs. In AKR mice, an animal model of lymphoblastic leukemia, the number of leukemia cells was measured following the intravenous injection of EpCAM-MNPs and subsequent whole-body hyperthermia treatment. The result showed that the leukemia cell number was also decreased to 43.8% of that without the treatment of hyperthermia, determined by Leishman staining of leukemia cells. To support the results, simulation analysis of heat transfer from MNPs to leukemia cells was performed using COMSOL Multiphysics simulation software. The surface temperature of leukemia cells adhered to EpCAM-MNPs was predicted to be increased to 82 °C, whereas the temperature of free cells without adhered MNPs was predicted to be 38 °C. Taken together, leukemia cells were selectively removed by magnetic hyperthermia from the bloodstream, because EpCAM-modified magnetic particles were specifically attached to leukemia cell surfaces. This approach has the potential to remove metastatic cancer cells, and pathogenic bacteria and viruses floating in the bloodstream.

Magnetic aerosol drug targeting in lung cancer therapy using permanent magnet

Primary bronchial cancer accounts for almost 20% of all cancer death worldwide. One of the emerging techniques with tremendous power for lung cancer therapy is magnetic aerosol drug targeting (MADT). The use of a permanent magnet for effective drug delivery in a desired location throughout the lung requires extensive optimization, but it has not been addressed yet. In the present study, the possibility of using a permanent magnet for trapping the particles on a lung tumor is evaluated numerically in the Weibel's model from G0 to G3. The effect of different parameters is considered on the efficiency of particle deposition in a tumor located on a distant position of the lung bronchi and bronchioles. Also, the effective position of the magnetic source, tumor size, and location are the objectives for particle deposition. The results show that a limited particle deposition occurs on the lung branches in passive targeting. However, the incorporation of a permanent magnet next to the tumor enhanced the particle deposition fraction on G2 to up to 49% for the particles of 7 µm diameter. Optimizing the magnet size could also improve the particle deposition fraction by 68%. It was also shown that the utilization of MADT is essential for effective drug delivery to the tumors located on the lower wall of airway branches given the dominance of the air velocity and resultant drag force in this region. The results demonstrated the high competence and necessity of MADT as a noninvasive drug delivery method for lung cancer therapy.

ROS-induced HepG2 cell death from hyperthermia using magnetic hydroxyapatite nanoparticles

HepG2 cell death with magnetic hyperthermia (MHT) using hydroxyapatite nanoparticles (mHAPs) and alternating magnetic fields (AMF) was investigated in vitro. The mHAPs were synthesized as thermo-seeds by co-precipitation with the addition of Fe²⁺. The grain size of the HAPs and iron oxide magnetic were 39.1 and 19.5 nm and were calculated by the Scherrer formula. The HepG2 cells were cultured with mHAPs and exposed to an AMF for 30 min yielding maximum temperatures of 43 ± 0.5 °C. After heating, the cell viability was reduced by 50% relative to controls, lactate dehydrogenase (LDH) concentrations measured in media were three-fold greater than those measured in all control groups. Readouts of toxicity by live/dead staining were consistent with cell viability and LDH assay results. Measured reactive oxygen species (ROS) in cells exposed to MHT were two-fold greater than in control groups. Results of cDNA microarray and Western blotting revealed tantalizing evidence of ATM and GADD45 downregulation with possible MKK3/MKK6 and ATF-2 of p38 MAPK inhibition upon exposure to mHAPs and AMF combinations. These results suggest that the combination of mHAPs and AMF can increase intracellular concentrations of ROS to cause DNA damage, which leads to cell death that complement heat stress related biological effects.

Functionalized Non-vascular Nitinol Stent via Electropolymerized Polydopamine Thin Film Coating Loaded with Bortezomib Adjunct to Hyperthermia Therapy

Gastrointestinal malignancies have been a tremendous problem in the medical field and cover a wide variety of parts of the system, (i.e. esophagus, duodenum, intestines, and rectum). Usually, these malignancies are treated with palliation with the use of non-vascular nitinol stents. However, stenting is not a perfect solution for these problems. While it can enhance the quality of life of the patient, in time the device will encounter problems such as re-occlusion due to the rapid growth of the tumor. In this study, we propose a functionalization technique using electropolymerization of polydopamine directly onto the nitinol stent struts for the combined application of hyperthermia and chemotherapy. The coating was characterized using FESEM, XPS, and FT-IR. Drug release studies show that facile release of the anticancer drug BTZ from the surface of the polydopamine-coated stent could be achieved by the dissociation between catechol groups of polydopamine and the boronic acid functionality of BTZ in a pH-dependent manner. The anti-cancer property was also evaluated, and cytotoxicity on ESO26 and SNU-5 cancer cell lines were observed. Our results suggest that the introduced approach can be considered as a potential method for therapeutic stent application.

Evaluation of nano-magnetic fluid on malignant glioma cells

The temperature variation rule of nano-magnetic fluid in the specific magnetic field and the effect on the treatment of malignant glioma were examined. The temperature variation of nano-magnetic fluid in the specific magnetic field was investigated by heating in vitro, and cell morphology was observed through optical microscopy and electron microscopy. MTT detection also was used to detect the effect of Fe₃O₄ nanometer magnetic fluid hyperthermia (MFH) on the proliferation of human U251 glioma cell line. The Fe₃O₄ nano MFH experiment was used to detect the inhibition rate of the tumor volume in nude mice with tumors. The results of the experiment showed that the heating ability of magnetic fluid was positively correlated with its concentration at the same intensity of the magnetic field. The results also indicated the prominent inhibitory effect of nanometer MFH on the proliferation of glioma cells, which was a dose-dependent relationship with nanometer magnetic fluid concentration. The hyperthermia experiment of nude mice with tumors displayed a significant inhibiting effect of Fe₃O₄ nanometer magnetic fluid in glioma volume. These results explain that iron (II, III) oxide (Fe₃O₄) nanometer MFH can inhibit the proliferation of U251 glioma cells, and has an obvious inhibitory effect on glioma volume, which plays a certain role in the treatment of brain glioma.

Laboratory animal models for esophageal cancer

The incidence of esophageal cancer is rapidly increasing especially in developing countries. The major risk factors include unhealthy lifestyle practices such as alcohol consumption, smoking, and chewing tobacco to name a few. Diagnosis at an advanced stage and poor prognosis make esophageal cancer one of the most lethal diseases. These factors have urged further research in understanding the pathophysiology of the disease. Animal models not only aid in understanding the molecular pathogenesis of esophageal cancer but also help in developing therapeutic interventions for the disease. This review throws light on the various recent laboratory animal models for esophageal cancer.

Regional thermochemotherapy versus hepatic arterial infusion chemotherapy for palliative treatment of advanced hilar cholangiocarcinoma: a retrospective controlled study

OBJECTIVES

To retrospectively assess the efficacy of regional thermochemotherapy (TCT) compared with hepatic arterial infusion chemotherapy (HAIC)-alone for palliative treatment of advanced hilar cholangiocarcinoma (HC) and to determine the prognostic factors associated with survival.

METHODS

Forty-three consecutive patients with advanced HC underwent regional TCT (TCT group) and HAIC (HAIC group). We analyzed baseline characteristics, overall survival (OS), progression-free survival (PFS), stent patency time (SPT), adverse events (AEs), and prognostic factors for OS between the two groups.

RESULTS

OS of patients treated with regional TCT was significantly longer compared to that of patients treated with HAIC (median OS: 20.3 vs. 13.2 months, P = 0.004), and SPT and PFS were significantly increased in the TCT group compared with the HAIC group (median SPT: 26.5 vs. 10.5 months, P < 0.001; median PFS: 16.5 vs. 10.2 months, P = 0.001). TCT and metal stent insertion were two independent prognostic factors associated with survival. The treatment-related AEs were tolerable and similar in the two groups, except for hilar pain (34.6 %) and skin rashes (24.6 %) in the TCT group.

CONCLUSIONS

Our results show that regional TCT is safe and more effective than HAIC-alone and may be a promising option for palliative treatment of advanced HC. Metal stenting before TCT appears to improve patients' OS.

KEY POINTS

• Regional TCT is a novel combination for palliative treatment of advanced HC • Our data showed significantly promising outcomes in the TCT group • HC patients with metal stenting appeared to derive greater benefit from TCT.

Percutaneous ultrasound guided implantation of VX2 for creation of a rabbit hepatic tumor model

Creation of a VX2 tumor model has traditionally required a laparotomy and surgical implantation of tumor fragments. Open surgical procedures are invasive and require long procedure times and recovery that can result in post-operative morbidity and mortality. The purpose of this study is to report the results of a percutaneous ultrasound guided method for creation of a VX2 model in rabbit livers. A total of 27 New Zealand white rabbits underwent a percutaneous ultrasound guided approach, where a VX2 tumor fragment was implanted in the liver. Magnetic resonance imaging was used to assess for tumor growth and necropsy was performed to determine rates of tract seeding and metastatic disease. Ultrasound guided tumor implantation was successful in all 27 rabbits. One rabbit died 2 days following the implantation procedure. Two rabbits had no tumors seen on follow-up imaging. Therefore, tumor development was seen in 24/26 (92%) rabbits. During the follow-up period, tract seeding was seen in 8% of rabbits and 38% had extra-hepatic metastatic disease. Therefore, percutaneous ultrasound guided tumor implantation safely provides reliable tumor growth for establishing hepatic VX2 tumors in a rabbit model with decreased rates of tract seeding, compared to previously reported methods.