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Simple Summary: Pancreatic cancer is one of the most deadly forms of cancer. Current treatment options often fail because too little of the chemotherapy gets into the cancer. Hyperthermia, or heat treatment, has shown some promise in treating pancreatic cancer and may make it more likely for the chemotherapy to enter into the cancer. This study aims to design liposomes that can increase the amount of chemotherapy reaching pancreatic cancer by targeting the liposomes with hyperthermia. Treatment of pancreatic ductal adenocarcinoma with gemcitabine is limited by an increased desmoplasia, poor vascularization, and short plasma half-life. Heat-sensitive liposomes modified by polyethylene glycol (PEG; PEGylated liposomes) can increase plasma stability, reduce clearance, and decrease side effects. Nevertheless, translation of heat-sensitive liposomes to the clinic has been hindered by the low loading efficiency of gemcitabine and by the difficulty of inducing hyperthermia in vivo. This study was designed to investigate the effect of phospholipid content on the stability of liposomes at 37 °C and their release under hyperthermia conditions; this was accomplished by employing a two-stage heating approach. First the liposomes were heated at a fast rate, then they were transferred to a holding bath. Thermosensitive liposomes formulated with DPPC: DSPC: PEG2k (80:15:5, mole%) exhibited minimal release of carboxyfluorescein at 37 °C over 30 min, indicating stability under physiological conditions. However, upon exposure to hyperthermic conditions (43 °C and 45 °C), these liposomes demonstrated a rapid and significant release of their encapsulated content. The encapsulation efficiency for gemcitabine was calculated at 16.9%. Additionally, fluorescent analysis during the removal of unencapsulated gemcitabine revealed an increase in pH. In vitro tests with BxPC3 and KPC cell models showed that these thermosensitive liposomes induced a heat-dependent cytotoxic effect comparable to free gemcitabine at temperatures above 41 °C. This study highlights the effectiveness of the heating mechanism and cell models in understanding the current challenges in developing gemcitabine-loaded heat-sensitive liposomes. [ABSTRACT FROM AUTHOR]

Abstract Background Lung cancer remains the leading cause of cancer-related mortality despite continuous efforts to find effective treatments. Data from the American Cancer Society indicate that while the overall incidence of lung cancer is declining, it continues to rise in women. Stem cell-based therapy has been an emerging strategy to treat various diseases. The purpose of this paper is to determine the efficacy of an intrinsic anti-cancer effect of rat umbilical cord matrix stem cells (UCMSCs) on lung cancer. Methods A mouse syngeneic lung carcinoma model was used to test the basic ability of UCMSCs to control the growth of lung cancer. Lung tumors were experimentally induced by tail vein administration of Lewis lung carcinoma (LLC) cells derived from the lung of C57BL/6 mouse. Rat UCMSCs were then administered intratracheally five days later or intravenously on days 5 and 7. The tumor burdens were determined by measuring lung weight three weeks after the treatment. Results Co-culture of rat UCMSCs with LLC significantly attenuated the proliferation of LLC cells as monitored by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), a tetrazole cell proliferation assay, thymidine uptake, and direct cell counts. In vitro colony assays with rat UCMSCs as feeder layers markedly reduced LLC colony size and number. Co-culture of rat UCMSCs with LLCs causes G0/G1 arrest of cancer cells. This is evident in the decrease of cyclin A and CDK2 expression. The in vivo studies showed that rat UCMSC treatment significantly decreased tumor weight and the total tumor mass. Histological study revealed that intratracheally or systemically administered rat UCMSCs homed to tumor areas and survived for at least 3 weeks without any evidence of differentiation or adverse effects. Conclusions These results indicate that rat UCMSCs alone remarkably attenuate the growth of lung carcinoma cells in vitro and in a mouse syngeneic lung carcinoma graft model and could be used for targeted cytotherapy for lung cancer.

Abstract Background There is renewed interest in magnetic hyperthermia as a treatment modality for cancer, especially when it is combined with other more traditional therapeutic approaches, such as the co-delivery of anticancer drugs or photodynamic therapy. Methods The influence of bimagnetic nanoparticles (MNPs) combined with short external alternating magnetic field (AMF) exposure on the growth of subcutaneous mouse melanomas (B16-F10) was evaluated. Bimagnetic Fe/Fe3O4 core/shell nanoparticles were designed for cancer targeting after intratumoral or intravenous administration. Their inorganic center was protected against rapid biocorrosion by organic dopamine-oligoethylene glycol ligands. TCPP (4-tetracarboxyphenyl porphyrin) units were attached to the dopamine-oligoethylene glycol ligands. Results The magnetic hyperthermia results obtained after intratumoral injection indicated that micromolar concentrations of iron given within the modified core-shell Fe/Fe3O4 nanoparticles caused a significant anti-tumor effect on murine B16-F10 melanoma with three short 10-minute AMF exposures. We also observed a decrease in tumor size after intravenous administration of the MNPs followed by three consecutive days of AMF exposure 24 hrs after the MNPs injection. Conclusions These results indicate that intratumoral administration of surface modified MNPs can attenuate mouse melanoma after AMF exposure. Moreover, we have found that after intravenous administration of micromolar concentrations, these MNPs are capable of causing an anti-tumor effect in a mouse melanoma model after only a short AMF exposure time. This is a clear improvement to state of the art.

Purpose: Integrating small-animal experimental hyperthermia instrumentation with magnetic resonance imaging (MRI) affords real-time monitoring of spatial temperature profiles. This study reports on the development and preliminary in vivo characterisation of a 2.45 GHz microwave hyperthermia system for pre-clinical small animal investigations, integrated within a 14 T ultra-high-field MRI scanner. Materials and methods: The presented system incorporates a 3.5 mm (OD) directional microwave hyperthermia antenna, positioned adjacent to the small-animal target, radiating microwave energy for localised heating of subcutaneous tumours. The applicator is integrated within the 30 mm bore of the MRI system. 3D electromagnetic and biothermal simulations were implemented to characterise hyperthermia profiles from the directional microwave antenna. Experiments in tissue mimicking phantoms were performed to assess hyperthermia profiles and validate MR thermometry against fibre-optic temperature measurements. The feasibility of delivering in vivo hyperthermia exposures to subcutaneous 4T1 tumours in experimental mice under simultaneous MR thermometry guidance was assessed. Results: Simulations and experiments in tissue mimicking phantoms demonstrated the feasibility of heating 21-982 mm3 targets with 8-12 W input power. Minimal susceptibility and electrical artefacts introduced by the hyperthermia applicator were observed on MR imaging. MR thermometry was in excellent agreement with fibre-optic temperatures measurements (max. discrepancy ≤0.6 °C). Heating experiments with the reported system demonstrated the feasibility of heating subcutaneous tumours in vivo with simultaneous MR thermometry. Conclusions: A platform for small-animal hyperthermia investigations under ultra-high-field MR thermometry was developed and applied to heating subcutaneous tumours in vivo. [ABSTRACT FROM AUTHOR]