Laser-induced breakdown spectroscopy (LIBS) is a promising technique for the readout of immunochemical assays utilizing indirect detection of labels (Tag-LIBS), typically based on nanoparticles. We have previously demonstrated that Tag-LIBS immunoassay employing yttrium-based photon-upconversion nanoparticles (UCNPs) can reach sensitivity similar to commonly used enzyme and fluorescence immunoassays. In this study, we report on further increasing the sensitivity of UCNP-based Tag-LIBS immunoassay by employing magnetic microbeads (MBs) as the solid phase in the determination of cancer biomarker prostate-specific antigen. Due to the possibility of analyte preconcentration, MBs enabled achieving a limit of detection (LOD) of 4.0 pg·mL-1, representing two orders of magnitude improvement compared with equivalent microtiter plate-based assay (LOD of 460 pg·mL-1). In addition, utilizing MBs opens up the possibility of an internal standardization of the LIBS readout by employing iron spectral lines, which improves the assay robustness by compensating for LIBS signal fluctuations and bead-bound immunocomplexes lost throughout the washing steps. Finally, the practical applicability of the technique was confirmed by the successful analysis of clinical samples, showing a strong correlation with the standard electrochemiluminescence immunoassay. Overall, MB-based Tag-LIBS was confirmed as a promising immunoassay approach, combining fast readout, multiplexing possibilities, and high sensitivity approaching upconversion luminescence scanning while avoiding the requirement of luminescence properties of labels.
- MeSH
- imunoanalýza metody MeSH
- lasery * MeSH
- lidé MeSH
- limita detekce * MeSH
- mikrosféry MeSH
- prostatický specifický antigen * analýza imunologie krev MeSH
- spektrální analýza metody MeSH
- ytrium chemie účinky záření MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The main task of the research is to acquire fundamental knowledge about the effect of polymer structure on the physicochemical properties of films. A novel meta-material that can be used in manufacturing sensor layers was developed as a model. At the first stage, poly(sodium 4-styrenesulfonate) (PNaSS) cross-linked microspheres are synthesized (which are based on strong polyelectrolytes containing sulfo groups in each monomer unit), and at the second stage, PNaSS@PEDOT microspheres are formed. The poly(3,4-ethylenedioxythiophene) (PEDOT) shell was obtained by the acid-assisted self-polymerization of the monomer; this process is biologically safe and thus suitable for biomedical applications. The suitability of electrochemical impedance spectroscopy for E. coli detection was tested; it was revealed that the attached bacterial wall was destroyed upon application of constant oxidation potential (higher than 0.5 V), which makes the PNaSS@PEDOT microsphere particles promising materials for the development of antifouling coatings. Furthermore, under open-circuit conditions, the walls of E. coli bacteria were not destroyed, which opens up the possibility of employing such meta-materials as sensor films. Scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle, and wide-angle X-ray diffraction methods were applied in order to characterize the PNaSS@PEDOT films.
- MeSH
- bicyklické sloučeniny heterocyklické chemie MeSH
- Escherichia coli * MeSH
- mikrosféry MeSH
- polymery * chemie MeSH
- Publikační typ
- časopisecké články MeSH
Primary liver tumours (i.e. hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC)) are among the most frequent cancers worldwide. However, only 10-20% of patients are amenable to curative treatment, such as resection or transplant. Liver metastases are most frequently caused by colorectal cancer, which accounts for the second most cancer-related deaths in Europe. In both primary and secondary tumours, radioembolization has been shown to be a safe and effective treatment option. The vast potential of personalized dosimetry has also been shown, resulting in markedly increased response rates and overall survival. In a rapidly evolving therapeutic landscape, the role of radioembolization will be subject to changes. Therefore, the decision for radioembolization should be taken by a multidisciplinary tumour board in accordance with the current clinical guidelines. The purpose of this procedure guideline is to assist the nuclear medicine physician in treating and managing patients undergoing radioembolization treatment. PREAMBLE: The European Association of Nuclear Medicine (EANM) is a professional non-profit medical association that facilitates communication worldwide among individuals pursuing clinical and research excellence in nuclear medicine. The EANM was founded in 1985. These guidelines are intended to assist practitioners in providing appropriate nuclear medicine care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by medical professionals taking into account the unique circumstances of each case. Thus, there is no implication that an approach differing from the guidelines, standing alone, is below the standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set out in the guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources or advances in knowledge or technology subsequent to publication of the guidelines. The practice of medicine involves not only the science but also the art of dealing with the prevention, diagnosis, alleviation and treatment of disease. The variety and complexity of human conditions make it impossible to always reach the most appropriate diagnosis or to predict with certainty a particular response to treatment. Therefore, it should be recognised that adherence to these guidelines will not ensure an accurate diagnosis or a successful outcome. All that should be expected is that the practitioner will follow a reasonable course of action based on current knowledge, available resources and the needs of the patient to deliver effective and safe medical care. The sole purpose of these guidelines is to assist practitioners in achieving this objective.
- MeSH
- hepatocelulární karcinom * farmakoterapie radioterapie MeSH
- lidé MeSH
- mikrosféry MeSH
- nádory jater * diagnostické zobrazování radioterapie MeSH
- nádory žlučových cest * farmakoterapie MeSH
- radioizotopy ytria terapeutické užití MeSH
- terapeutická embolizace * MeSH
- žlučové cesty intrahepatální patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Current in vitro drug-release testing of the sustained-release parenterals represents the in vivo situation insufficiently. In this work, a thin agarose hydrogel layer surrounding the tested dosage form was proposed to mimic the tissue. The method was applied on implantable formulations of different geometries (films, microspheres, and cylindrical implants); prepared from various polymers (several Resomer® grades or ethyl cellulose) and loaded with different model drugs: flurbiprofen, lidocaine or risperidone. The hydrogel layer did not possess any retarding effect on the released drug and acted as a physical restriction to swelling and/or plastic deformation of the tested dosage forms. This led to a different surface area available for drug-release compared with testing in release medium alone and correspondingly to significantly different release profiles of the majority of the formulations obtained between the two methods (e.g. t50% = 18 days in pure release medium vs. t50% = 26 days in gel-setup for risperidone loaded Resomer® 503 H films or t50% = 7 days vs. t50% = 19 days for risperidone loaded Resomer® 503 H microspheres). The limited space for swelling and the rigidity of the agarose gel might mimic the tight encapsulation of the dosage form in the tissue better than the conventional liquid medium.
We firstly identified 48 kDa molecular form of the unconventional myosin 1c (p48/Myo1C), and isolated it from blood serum of multiple sclerosis patients. The amount of p48/Myo1C in human blood serum correlated with some autoimmune, hemato-oncological and neurodegenerative diseases and thus may serve as a potential molecular biomarker. The biological functions of this protein in human blood remain unknown. Previously, we used the monodisperse magnetic poly (glycidyl methacrylate)(mag-PGMA-NH2 ) microspheres with immobilized 48/Myo1C and western-blot analysis, which allowed us to identify IgM and IgG immunoglobulins presenting an affinity to this protein. Here, we used mass spectrometry followed by the western blotting in order to identify other blood serum proteins with affinity to 48/Myo1C. The obtained data demonstrate that 48/Myo1C binds to component 3 of the complement and the antithrombin-III proteins. A combination of magnetic microparticle-based affinity chromatography with MALDI-TOF mass spectrometry and an in silico analysis provided an opportunity to identify the partners of interaction of 48/Myo1C with other proteins, in particular those participating in complement and coagulation cascades.
- MeSH
- chromatografie afinitní metody MeSH
- krevní proteiny analýza chemie metabolismus MeSH
- lidé MeSH
- magnety MeSH
- mikrosféry MeSH
- molekulární modely MeSH
- myosin typu I chemie metabolismus MeSH
- prognóza MeSH
- roztroušená skleróza krev MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- vazba proteinů MeSH
- western blotting MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Long-term delivery of growth factors and immunomodulatory agents is highly required to support the integrity of tissue in engineering constructs, e.g., formation of vasculature, and to minimize immune response in a recipient. However, for proteins with a net positive charge at the physiological pH, controlled delivery from negatively charged alginate (Alg) platforms is challenging due to electrostatic interactions that can hamper the protein release. In order to regulate such interactions between proteins and the Alg matrix, we propose to complex proteins of interest in this study - CXCL12, FGF-2, VEGF - with polyanionic heparin prior to their encapsulation into Alg microbeads of high content of α-L-guluronic acid units (high-G). This strategy effectively reduced protein interactions with Alg (as shown by model ITC and SPR experiments) and, depending on the protein type, afforded control over the protein release for at least one month. The released proteins retained their in vitro bioactivity: CXCL12 stimulated the migration of Jurkat cells, and FGF-2 and VEGF induced proliferation and maturation of HUVECs. The presence of heparin also intensified protein biological efficiency. The proposed approach for encapsulation of proteins with a positive net charge into high-G Alg hydrogels is promising for controlled long-term protein delivery under in vivo conditions.
- MeSH
- algináty chemie MeSH
- chemokin CXCL12 chemie MeSH
- endoteliální buňky pupečníkové žíly (lidské) MeSH
- fibroblastový růstový faktor 2 chemie MeSH
- heparin chemie MeSH
- lidé MeSH
- mikrosféry MeSH
- nádorové buněčné linie MeSH
- tkáňové inženýrství MeSH
- vaskulární endoteliální růstový faktor A chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
Despite the importance of drug release testing of parenteral depot formulations, the current in vitro methods still require ameliorations in biorelevance. We have investigated here the use of muscle tissue components to better mimic the intramuscular administration. For convenient handling, muscle tissue was used in form of a freeze-dried powder, and a reproducible process of incorporation of tested microspheres to an assembly of muscle tissue of standardized dimensions was successfully developed. Microspheres were prepared from various grades of poly(lactic-co-glycolic acid) (PLGA) or ethyl cellulose, entrapping flurbiprofen, lidocaine, or risperidone. The deposition of microspheres in the muscle tissue or addition of only isolated lipids into the medium accelerated the release rate of all model drugs from microspheres prepared from ester-terminated PLGA grades and ethyl cellulose, however, not from the acid-terminated PLGA grades. The addition of lipids into the release medium increased the solubility of all model drugs; nonetheless, also interactions of the lipids with the polymer matrix (ad- and absorption) might be responsible for the faster drug release. As the in vivo drug release from implants is also often faster than in simple buffers in vitro, these findings suggest that interactions with the tissue lipids may play an important role in these still unexplained observations.
- MeSH
- celulosa analogy a deriváty MeSH
- flurbiprofen aplikace a dávkování MeSH
- kopolymer kyseliny glykolové a mléčné MeSH
- léky s prodlouženým účinkem * MeSH
- lidokain aplikace a dávkování MeSH
- mikrosféry MeSH
- nosiče léků MeSH
- parenterální infuze * MeSH
- pomocné látky MeSH
- prasata MeSH
- příprava léků MeSH
- risperidon aplikace a dávkování MeSH
- svaly metabolismus MeSH
- techniky in vitro MeSH
- uvolňování léčiv MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: This study aims to study the preparation method of arsenic trioxide (As2O3) polylactic-co-glyconlic acid (PLGA) microspheres and 10-hydroxycamptothecin (HCPT) PLGA microspheres and explore their therapeutic effects as embolic agents for VX2 hepatocellular carcinoma in rabbits. METHODS: As2O3 and HCPT PLGA microspheres were prepared by multiple emulsion solvent evaporation method. Scanning electron microscopy (SEM) and particle size distribution were used to analyze the morphology, the drug sustained release ability was observed by the release of microspheres in vitro. The rabbit model of VX2 hepatocellular carcinoma was established and the hepatocellular carcinoma was treated with combined microspheres. The therapeutic effects were detected by qPCR, western blotting, HE staining and immunohistochemical methods. RESULTS: The PLGA microspheres loaded with As2O3 and HCPT were successfully prepared by optimizing the ratio. The particle size was between 30 and 50 μm. In vitro release results showed that PLGA microspheres loaded with As2O3 released completely in 10 days and PLGA microspheres loaded with HCPT released completely in 12 days. Western blotting and qPCR results showed that the expression of ALDH1A1 and Nanog decreased significantly in treatment group. HE staining and immunohistochemical analysis showed that the expression of CD31, HIF and VEGF decreased significantly and the apoptosis of tissues was obvious. CONCLUSION: The combination of As2O3 and HCPT PLGA microspheres as embolization for VX2 hepatocellular carcinoma in rabbits has significant therapeutic effect.
- MeSH
- hepatocelulární karcinom farmakoterapie MeSH
- kamptothecin aplikace a dávkování analogy a deriváty MeSH
- kopolymer kyseliny glykolové a mléčné * MeSH
- králíci MeSH
- mikrosféry * MeSH
- modely nemocí na zvířatech MeSH
- nádory jater farmakoterapie MeSH
- oxid arsenitý aplikace a dávkování MeSH
- protinádorové látky aplikace a dávkování MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
In this work, a hybrid organic-inorganic adsorbent based on polyelectrolyte copolymers of poly(4-vinylbenzyl trimethylammonium chloride-co-2-hydroxyethyl methacrylate) microspheres mixed with a hydrous zirconium oxide phase were applied to remove arsenic species from aqueous solutions. The hybrid adsorbent was synthesized in a two-step procedure: first, the polymeric microspheres were obtained through emulsion radical copolymerization, and then, the microspheres were impregnated with a zirconium oxide precursor followed by the subsequent sol-gel reaction. The purpose of this hybrid material was to combine properties of each component in the interaction with arsenic oxoanions and compare its performance with commercial adsorbents. The polymer hybrid microspheres were shown to remove arsenate, and the presence of the inorganic phase also allowed for the removal of arsenite. The hybrid adsorbent exhibited arsenic sorption independent of pH, is able to regenerate, displays fast kinetics and has the ability to reduce arsenic concentration in treated water below 10 μg L-1 even in real samples with an initial concentration as high as 380 μg L-1.
The cytopoxic effect of RL2 lactaptin (the recombinant analog of proteolytic fragment of human kappa-casein) toward tumor cells in vitro and in vivo presents it as a novel promising antitumor drug. The binding of any drug with serum proteins can affect their activity, distribution, rate of excretion and toxicity in the human body. Here, we studied the ability of RL2 to bind to various blood serum proteins. Using magnetic microparticles bearing by RL2 as an affinity matrix, in combination with mass spectrometry and western blot analysis, we found a number of blood serum proteins possessing affinity for RL2. Among them IgA, IgM and IgG subclasses of immunoglobulins, apolipoprotein A1 and various cortactin isoforms were identified. This data suggests that in the bloodstream RL2 lactaptin takes part in complicate protein-protein interactions, which can affect its activity.
- MeSH
- chromatografie afinitní metody MeSH
- kaseiny metabolismus MeSH
- krevní proteiny analýza izolace a purifikace metabolismus MeSH
- kyseliny polymethakrylové chemie MeSH
- lidé MeSH
- magnety chemie MeSH
- mikrosféry MeSH
- protinádorové látky metabolismus MeSH
- rekombinantní proteiny metabolismus MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
