Membrane reorganization after photochemical internalization to release transferrin-biofunctionalized polystyrene microparticles.

Therapeutic drug carriers can drive their cargo to their target cells. However, an obstacle is usually the entrapment of the drug inside the endolysosomal compartment, which physically impedes its actuation by the impossibility of reaching its molecular site of action. To overcome this hurdle, photochemical internalization (PCI) has been proposed, but the extent of PCI-induced membrane disruption and its capability to allow the release of microparticles is unknown. The aim of the present study was to determine if PCI allows the release of microparticles from the endolysosomal compartment to the cytosol and to analyze at the ultrastructural level the effect of PCI on the membrane surrounding the particles. Confocal microscope allowed us to detect that endolysosomal membranes suffered some disruption after PCI, evidenced by the diffusion of soluble transferrin from the endolysosomes to the cytosol and by a decrease of LAMP1-microparticles co-localization. Transmission electron microscopy (TEM) showed a decrease in the number of well-defined membranes around microparticles after PCI, and scanning TEM combined with energy dispersive x-ray revealed an increase in the width of endolysosomal membranes after treatment. These results suggest that endolysosomal membranes suffered an ultrastructure alteration after PCI, enough to liberate soluble transferrin but not the entire microparticles.

Uncertainty of fast biological radiation dose assessment for emergency response scenarios.

PURPOSE: Reliable dose estimation is an important factor in appropriate dosimetric triage categorization of exposed individuals to support radiation emergency response. MATERIALS AND METHODS: Following work done under the EU FP7 MULTIBIODOSE and RENEB projects, formal methods for defining uncertainties on biological dose estimates are compared using simulated and real data from recent exercises. RESULTS: The results demonstrate that a Bayesian method of uncertainty assessment is the most appropriate, even in the absence of detailed prior information. The relative accuracy and relevance of techniques for calculating uncertainty and combining assay results to produce single dose and uncertainty estimates is further discussed. CONCLUSIONS: Finally, it is demonstrated that whatever uncertainty estimation method is employed, ignoring the uncertainty on fast dose assessments can have an important impact on rapid biodosimetric categorization.

The RENEB operational basis: complement of established biodosimetric assays.

PURPOSE: To set up an operational basis of the Realizing the European Network of Biodosimetry (RENEB) network within which the application of seven established biodosimetric tools (the dicentric assay, the FISH assay, the micronucleus assay, the PCC assay, the gamma-H2AX assay, electron paramagnetic resonance and optically stimulated luminescence) will be compared and standardized among the participating laboratories. METHODOLOGY: Two intercomparisons were organized where blood samples and smartphone components were irradiated, coded and sent out to participating laboratories for dosimetric analysis. Moreover, an accident exercise was organized during which each RENEB partner had the chance to practice the procedure of activating the network and to handle large amounts of dosimetric results. RESULTS: All activities were carried out as planned. Overall, the precision of dose estimates improved between intercomparisons 1 and 2, clearly showing the value of running such regular activities. CONCLUSIONS: The RENEB network is fully operational and ready to act in case of a major radiation emergency. Moreover, the high capacity for analyzing radiation-induced damage in cells and personal electronic devices makes the network suitable for large-scale analyses of low doses effects, where high numbers of samples must be scored in order to detect weak effects.

RENEB - Running the European Network of biological dosimetry and physical retrospective dosimetry.

PURPOSE: A European network was initiated in 2012 by 23 partners from 16 European countries with the aim to significantly increase individualized dose reconstruction in case of large-scale radiological emergency scenarios. RESULTS: The network was built on three complementary pillars: (1) an operational basis with seven biological and physical dosimetric assays in ready-to-use mode, (2) a basis for education, training and quality assurance, and (3) a basis for further network development regarding new techniques and members. Techniques for individual dose estimation based on biological samples and/or inert personalized devices as mobile phones or smart phones were optimized to support rapid categorization of many potential victims according to the received dose to the blood or personal devices. Communication and cross-border collaboration were also standardized. To assure long-term sustainability of the network, cooperation with national and international emergency preparedness organizations was initiated and links to radiation protection and research platforms have been developed. A legal framework, based on a Memorandum of Understanding, was established and signed by 27 organizations by the end of 2015. CONCLUSIONS: RENEB is a European Network of biological and physical-retrospective dosimetry, with the capacity and capability to perform large-scale rapid individualized dose estimation. Specialized to handle large numbers of samples, RENEB is able to contribute to radiological emergency preparedness and wider large-scale research projects.

Surface modification of microparticles causes differential uptake responses in normal and tumoral human breast epithelial cells.

The use of micro- and nanodevices as multifunctional systems for biomedical applications has experienced an exponential growth during the past decades. Although a large number of studies have focused on the design and fabrication of new micro- and nanosystems capable of developing multiple functions, a deeper understanding of their interaction with cells is required. In the present study, we evaluated the effect of different microparticle surfaces on their interaction with normal and tumoral human breast epithelial cell lines. For this, AlexaFluor488 IgG functionalized polystyrene microparticles (3 µm) were coated with Polyethyleneimine (PEI) at two different molecular weights, 25 and 750 kDa. The effect of microparticle surface properties on cytotoxicity, cellular uptake and endocytic pathways were assessed for both normal and tumoral cell lines. Results showed a differential response between the two cell lines regarding uptake efficiency and mechanisms of endocytosis, highlighting the potential role of microparticle surface tunning for specific cell targeting.

Multibiodose radiation emergency triage categorization software.

In this note, the authors describe the MULTIBIODOSE software, which has been created as part of the MULTIBIODOSE project. The software enables doses estimated by networks of laboratories, using up to five retrospective (biological and physical) assays, to be combined to give a single estimate of triage category for each individual potentially exposed to ionizing radiation in a large scale radiation accident or incident. The MULTIBIODOSE software has been created in Java. The usage of the software is based on the MULTIBIODOSE Guidance: the program creates a link to a single SQLite database for each incident, and the database is administered by the lead laboratory. The software has been tested with Java runtime environment 6 and 7 on a number of different Windows, Mac, and Linux systems, using data from a recent intercomparison exercise. The Java program MULTIBIODOSE_1.0.jar is freely available to download from http://www.multibiodose.eu/software or by contacting the software administrator: MULTIBIODOSE-software@gmx.com.

Detection of circulating cancer cells using electrocatalytic gold nanoparticles.

A rapid cancer cell detection and quantification assay, based on the electrocatalytic properties of gold nanoparticles towards the hydrogen evolution reaction, is described. The selective labeling of cancer cells is performed in suspension, allowing a fast interaction between the gold nanoparticle labels and the target proteins expressed at the cell membrane. The subsequent electrochemical detection is accomplished with small volumes of sample and user-friendly equipment through a simple electrochemical method that generates a fast electrochemical response used for the quantification of nanoparticle-labeled cancer cells. The system establishes a selective cell-detection assay capable of detecting 4 × 10(3) cancer cells in suspension that can be extended to several other cells detection scenarios.

Simple monitoring of cancer cells using nanoparticles.

Here we present a new strategy for a simple and fast detection of cancer circulating cells (CTCs) using nanoparticles. The human colon adenocarcinoma cell line (Caco2) was chosen as a model CTC. Similarly to other adenocarcinomas, colon adenocarcinoma cells have a strong expression of EpCAM, and for this reason this glycoprotein was used as the capture target. We combine the capturing capability of anti-EpCAM functionalized magnetic beads (MBs) and the specific labeling through antibody-modified gold nanoparticles (AuNPs), with the sensitivity of the AuNPs-electrocatalyzed hydrogen evolution reaction (HER) detection technique. The fully optimized process was used for the electrochemical detection of Caco2 cells in the presence of monocytes (THP-1), other circulating cells that could interfere in real blood samples. Therefore we obtained a novel and simple in situ-like sensing format that we applied for the rapid quantification of AuNPs-labeled CTCs in the presence of other human cells.

Internalization and cytotoxicity analysis of silicon-based microparticles in macrophages and embryos.

Microchips can be fabricated, using semiconductor technologies, at microscopic level to be introduced into living cells for monitoring of intracellular parameters at a single cell level. As a first step towards intracellular chips development, silicon and polysilicon microparticles of controlled shape and dimensions were fabricated and introduced into human macrophages and mouse embryos by phagocytosis and microinjection, respectively. Microparticles showed to be non-cytotoxic for macrophages and were found to be localized mainly inside early endosomes, in tight association with endosomal membrane, and more rarely in acidic compartments. Embryos with microinjected microparticles developed normally to the blastocyst stage, confirming the non-cytotoxic effect of the particles. In view of these results silicon and polysilicon microparticles can serve as the frame for future intracellular chips development and this technology opens the possibility of real complex devices to be used as sensors or actuators inside living cells.

Radiation effects in interventional radiology using biological and physical dosimetry methods: a case-control study.

Interventional radiologists and staff members are frequently exposed to protracted and fractionated low doses of ionizing radiation, which extend during all their professional activities. These exposures can derive, due to the irradiation of skin tissues and peripheral blood, in deterministic effects (radiodermitis, aged skin, hands depilation) or stochastic ones (skin and non-solid cancers incidence). Epidemiological studies of population exposed to ionizing radiation provide information of radio-induced effects. The radiation risk or radiological detriment has been estimated from a group of six exposed interventionist radiologists of the Hospital La Fe (Valencia, Spain). Dosimetry has been periodically registered from TLDs and wrist dosimeters (physical methods) and estimated through translocations in lymphocytes of peripheral blood (biological methods), by extrapolating the yield of translocations to their respective dose-effect curves. The probability of non-melanoma skin cancer and leukaemia (acute myelogenous, acute lymphocytic and chronic myelogenous leukaemia) incidence has been estimated through the software RADRISK. This software is based on a transport model from epidemiological studies of population exposed to external low-LET ionizing radiation [1]. Other non-solid carcinomas have not been considered due to their low statistical power, such as myeloid and non-Hodgkin lymphomas. The discrepancies observed between the physically recorded doses and biological estimated doses could indicate that exposed workers did not always wear their dosimeters or these dosimeters were not always exposed to the radiation field.