172 research outputs found
Boron-loaded liposomes in the treatment of hepatic metastases: preliminary investigation by autoradiography analysis.
Boronophenylalanine (BPA)-loaded conventional and stabilized liposomes were prepared by the reversed phase evaporation method to treat liver metastases by boron neutron capture therapy. Conventional vesicles were composed of phosphatidylcholine and cholesterol, molar ratio 1:1. To obtain stealth liposomes, GM1 or PEG were included in the lipidic bilayer at a concentration of 6.67 or 5 mol%, respectively. Large unilamellar vesicles were formulated encapsulating BPA in the liposome aqueous compartment as a complex with fructose; BPA free base also was embedded into the lipidic bilayer. In vivo experiments were carried out after intravenous injection of liposome suspensions in BD-IX strain rats in which liver metastases had been induced. Alpha particle spectroscopy associated with histological analysis was performed to visualize boron spatial distribution in liver. Simultaneously, tissue boron concentrations were determined using inductively coupled plasma-mass spectroscopy. Results showed that PEG-modified liposomes accumulated boron in therapeutic concentrations (30 micrograms boron/g tissue) in metastatic tissue. The PEG-liposomes could be further explored in enhancing boron delivery to tumor cells
Effects of Single or Combined Treatments with Radiation and Chemotherapy on Survival and Danger Signals Expression in Glioblastoma Cell Lines
The success of chemo-and radiotherapy in glioblastoma multiforme, the most common and lethal primary brain tumour, could rely on the induction of immunogenic tumour cell death and on the induction of anticancer immune response. In this study we investigated cell survival to single treatments or combination of X-rays and temozolomide in glioblastoma cell lines (T98G and U251MG) and we attempted to identify danger signals (HMGB1 and HSP70) released by dying cells in the microenvironment that could activate antitumour immunity contributing to the therapeutic efficacy of conventional treatments. Our data suggest that HSP70 translocates from cytoplasm to extracellular environment after an increase in radiation dose and HMGB1 translocates from the nucleus to the cytoplasm and subsequently is released into the extracellular space, confirming a role of these proteins as signals released after radiation-induced damage in glioblastoma cells. We also could state that TMZ had limited effectiveness in activating HMGB1 and HSP70 signalling and, instead, an adjuvant effect was observed in some combined treatments, depending on schedule, cell line, and timing. A big challenge in tumour therapy is, therefore, to identify the most beneficial combination and chronology of multiple treatment options to contribute to the improvement of the therapeutic outcome
NMR as evaluation strategy for cellular uptake of nanoparticles
Advanced nanostructured materials, such as gold nanoparticles, magnetic nanoparticles, and multifunctional materials, are nowadays used in many state-of-the-art biomedical application. However, although the engineering in this field is very advanced, there remain some fundamental problems involving the interaction mechanisms between nanostructures and cells or tissues. Here we show the potential of 1H NMR in the investigation of the uptake of two different kinds of nanostructures, that is, maghemite and gold nanoparticles, and of a chemotherapy drug (Temozolomide) in glioblastoma tumor cells. The proposed experimental protocol provides a new way to investigate the general problem of cellular uptake for a variety of biocompatible nanostructures and drugs. © 2014 American Chemical Society
Matrix metalloprotease activity is enhanced in the compensated but not in the decompensated phase of pressure overload hypertrophy
BACKGROUND: During the transition of pressure overload hypertrophy (POH) to heart failure (HF) there is intense interstitial cardiac remodeling, characterized by a complex balance between collagen deposition and degradation by matrix metalloproteases (MMPs). This study was aimed at investigating the process of cardiac remodeling during the different phases of the transition of POH to HF. METHODS: Guinea pigs underwent thoracic descending aortic banding or sham operation. Twelve weeks after surgery, left-ventricular (LV) end-diastolic internal dimension and ventricular systolic pressure were measured by combined M-mode echocardiography and micromanometer cathetherization. The MMP activity, tissue-specific MMP inhibitors (TIMPs), and collagen fraction were evaluated in LV tissue samples by zymography, ELISA, and computer-aided analysis, respectively. RESULTS: Banded animals were divided by lung weight values into either compensated left-ventricular hypertrophy (LVH) or HF groups, as compared with sham-operated controls. All HF animals exhibited a restrictive pattern of Doppler transmitral inflow, indicative of diastolic dysfunction, and developed lung congestion. Compensated LVH was associated with increased MMP-2 activity, which was blunted after transition to HF, at a time when TIMP-2 levels and collagen deposition were increased. CONCLUSIONS: The cardiac remodeling process that accompanies the development of POH is a phase-dependent process associated with progressive deterioration of cardiac function
Dendritic cells and interleukin-2: cytochemical and ultrastructural study
The aim of the present study was to verify the effect of IL-2 on dendritic cell (DC) differentiation. Various cytokines have been indicated as factors inducing DC differentiation, but no data about the interleukin-2 (IL-2) effect on DC differentiation have been reported. Monocytes isolated from peripheral blood were treated in vitro with the following factors: IL-2, IL- 4, GM-CSF and G-CSF alone or in combination. Morphological (also ultrastructural) and cytochemical observations were carried out starting from 3 to 21 days of treatment. The results indicate that the differentiation of cells showing dendritic pattern is related to the presence of IL-2. Moreover a synergic effect of IL-2 and GM-CSF was observed. The enzymatic features changed with the culture time: before the differentiation into DC, the stimulated cells expressed the typical pattern of monocytes. On the contrary, at advanced stage of differentiation, some enzyme activities changed and in terminally differentiated dendritic cells the reactions for peroxidase and serine esterase were negative.Considering the morphological features, the ability to interact with lymphocytes and the enzymatic pattern observed, we suppose that IL-2 may act as a maturative factor rather than as a growth factor in the DC differentiation
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