Microencapsulation technology by nature: Cell derived extracellular vesicles with therapeutic potential

Cell derived extracellular vesicles are submicron structures surrounded by phospholipid bilayer and released by both prokaryotic and eukaryotic cells. The sizes of these vesicles roughly fall into the size ranges of microbes, and they represent efficient delivery platforms targeting complex molecular information to professional antigen presenting cells. Critical roles of these naturally formulated units of information have been described in many physiological and pathological processes. Extracellular vesicles are not only potential biomarkers and possible pathogenic factors in numerous diseases, but they are also considered as emerging therapeutic targets and therapeutic vehicles. Strikingly, current drug delivery systems, designed to convey therapeutic proteins and peptides (such as liposomes), show many similarities to extracellular vesicles. Here we review some aspects of therapeutic implementation of natural, cell-derived extracellular vesicles in human diseases. Exploration of molecular and functional details of extracellular vesicle release and action may provide important lessons for the design of future drug delivery systems

Az OKKR kialakításával kapcsolatos hazai munkálatok történeti áttekintése

Jelen tanulmány keretében kísérletet teszünk az OKKR létrehozásával összefüggő hazai munkálatok 5 éves történetének áttekintésére, az egyes fázisok során elért eredmények számbavételére, a felvetődött és nem megoldott problémák bemutatására. Az eltelt időszak öt egymástól jól elkülönülő periódust ölel fel – ezek mindegyikének külön fejezetet szenteltünk

Hisztamin hatása a sejtdifferenciációra, összehasonlító vizsgálatok tumor - és embrionális őssejteken = Effect of histamine on cell differentiation, comparative study of tumor-and embronic stem cells

Célkitűzésünk a genetikailag hisztamin hiányos és WT dermatofibrosarcoma tumorsejtek és embrionális őssejtek differenciációs markereinek összehasonlítása volt. Az indukált tumorokból alapított sejttenyészetekből tumor spheroid formájában fenntartható klónokat hoztunk létre, melyek jellemzőikben hasonlítottak az embrionális testet (EB) képző őssejtekre. A továbbiakban microarray analízissel a letapadó, illetve spheroidként/EB-ként növő sejtek génexpressziós mintázatát vizsgáltuk, különös tekintettel az egyedfejlődésben szerepet játszó, és a sejt önmegújulásért felelős transzkripciós faktorokra. Mivel az array adatok igen nagyszámú gén aktivitásában mutattak különbséget, ezért az Ingenuity pathway analízis nyomán csak a Wnt jelátviteli útra koncentráltunk a továbbiakban. Az így kiemelt Id2, Sox2, Nestin, Col2A1 génhálózat expressziós tendenciáit real-time PCR-rel és Western blottal próbáltuk validálni, azonban a 3 módszerrel detektált változások tendenciái nem vagy csak részben mutattak egyezést. Mivel a spheroid- és EB-képzésben a sejt-mátrix kapcsolatoknak is szerepe van (erre utalhat a Col2A1) ezért ebbe az irányba terjesztettük ki kutatásainkat, az adherens és spheroid/EB sejtek adhéziós viselkedését vizsgálva, különös tekintettel egy másik (a hisztaminnal összefüggésben már igazolt szerepű) mátrix komponensre, a fibulin5-re. A HDC KO sejtek fokozottabb adhézióval és fibulin5 expresszióval rendelkeznek, ez összhangban áll a korábban melanoma sejteken tett megfigyelésünkkel. | Our aim was to compare the differentiation markers of BalB/c WT and HDC KO dermatofibrosarcoma tumor cells and embryonic stem cells with the same genetic background. From the induced tumors cell cultures and non-adhesive spheroid forming clones were established, which were similar embryoid bodies (EBs). Subsequently microarray analyses on Agilent platform were carried out to determine the gene expression patterns of the adherent and spheroid or EB forming cells. We focused our interest to those transcription factors involved in cellular self-renewal and in early embryogenesis. As the array data showed differences in hundreds of genes, we concentrated our efforts - after using Ingenuity pathway analysis - the Wnt pathway, important in self-renewal and tumorigenesis. Id2, Sox2, Nestin and Col2A1 elements of this network were used for validation via real-time PCR and Western blotting. Unfortunately the tendencies observed here did not fit well the data derived from microarray analysis. Since cell-matrix connections are important in both spheroid and EB formation (reflected by the Col2A1 expression, too) we expand our efforts to study the adhesive behaviour of adherent and spheroid/body forming cells in connection with an other matrix component fibulin5, its role related to histamine has been proven earlier by us. The HDC KO cells had better adhesion characteristics and increased FBLN5 expression, which is in good correlation our earlier observations made on melanoma cells

Length scale dependence of dynamical heterogeneity in a colloidal fractal gel

We use time-resolved dynamic light scattering to investigate the slow dynamics of a colloidal gel. The final decay of the average intensity autocorrelation function is well described by $g\_2(q,\tau)-1 \sim \exp[-(\tau/\tau\_\mathrm{f})^p]$, with $\tau\_\mathrm{f} \sim q^{-1}$ and $p$ decreasing from 1.5 to 1 with increasing $q$. We show that the dynamics is not due to a continuous ballistic process, as proposed in previous works, but rather to rare, intermittent rearrangements. We quantify the dynamical fluctuations resulting from intermittency by means of the variance $\chi(\tau,q)$ of the instantaneous autocorrelation function, the analogous of the dynamical susceptibility $\chi\_4$ studied in glass formers. The amplitude of $\chi$ is found to grow linearly with $q$. We propose a simple --yet general-- model of intermittent dynamics that accounts for the $q$ dependence of both the average correlation functions and $\chi$.Comment: Revised and improved, to appear in Europhys. Let

Magnetic Fluctuations, Precursor Phenomena and Phase Transition in MnSi under Magnetic Field

The reference chiral helimagnet MnSi is the first system where skyrmion lattice correlations have been reported. At zero magnetic field the transition at $T_C$ to the helimagnetic state is of first order. Above $T_C$, in a region dominated by precursor phenomena, neutron scattering shows the build up of strong chiral fluctuating correlations over the surface of a sphere with radius $2\pi/\ell$, where $\ell$ is the pitch of the helix. It has been suggested that these fluctuating correlations drive the helical transition to first order following a scenario proposed by Brazovskii for liquid crystals. We present a comprehensive neutron scattering study under magnetic fields, which provides evidence that this is not the case. The sharp first order transition persists for magnetic fields up to 0.4 T whereas the fluctuating correlations weaken and start to concentrate along the field direction already above 0.2 T. Our results thus disconnect the first order nature of the transition from the precursor fluctuating correlations. They also show no indication for a tricritical point, where the first order transition crosses over to second order with increasing magnetic field. In this light, the nature of the first order helical transition and the precursor phenomena above $T_C$, both of general relevance to chiral magnetism, remain an open question