Antimicrobial Silver-Polyethyleneimine-Polylactic Acid Polymer Composite Film for Coating Methacrylate-Based Denture Surfaces

To prepare an antimicrobial polymer composite composed of silver- (Ag-) polyethyleneimine- (PEI-) polylactic acid (PLA) in chloroform, for coating the mucosal surfaces of methacrylate-based dentures as a prospective therapy for denture stomatitis. The water-insoluble, tightly bound, hard, micrometre-thin, and colourless film exerts its effects by direct contact with the pathogens and via the active constituents (Ag, PEI, and Ag-PEI) released slowly into the mucosa’s salivary layer. Silver and PEI were blended at 140°C, then bound to PLA. The Ag-PEI complex was characterised by dynamic light scattering and transmission electron microscopy, and the Ag-PEI-PLA composite was examined by atomic force microscopy and micro-computed tomography. The characteristic was measured by atomic force microscopy (AFM) and micro-computed tomography (micro-CT). The quantity of water-soluble Ag-PEI complex released from the composite film was measured with gravimetry. The cellular physiological effects were analysed by impedimetry and computer-based morphometry using human gingival epithelial cells. A real-time cell proliferation assay revealed moderate toxic effects of Ag-PEI on the epithelium. The viscous Ag-PEI-PLA solution produced could be applied as a thin film on methacrylate surfaces. Active antimicrobial components (Ag, PEI, and Ag-PEI) were released from the hard, tightly bound Ag-PEI-PLA coating. This study’s findings verified the applicability of the antimicrobial Ag-PEI-PLA composite for coating the inner surfaces of acrylate dentures. Owing to the well-known antimicrobial effects of silver and PEI and the supplementary effects of chloroform, this composite provides a new therapeutic method for denture stomatitis that can be easily performed by dentists

Epitópok illetve antimikrobiális hatású peptidek, peptidszármazékok célzott bevitele makrofág típusú sejtekbe = Targeting of epitope or antimicrobial peptides and derivatives to macrophages

A kutatás során számos olyan új vegyület készült el, amelyek segítségével tisztázni lehet epitóp peptidek és hatóanyagok célsejtbe (makrofágba) juttatásának szerkezeti illetve funkcionális feltételeit. Vizsgálataink fontos eredménye olyan biokonjugátumok előállítása volt, amelyekben az alkotórészek a kémiai kötés kialakítása után is megtartották biológiai funkciójukat (pl. T-sejt válasz indukció, ellenanyagfelismerés, antituberkulotikus hatás). A nagyrészt nívós nemzetközi folyóiratokban közölt eredmények közül kiemelkedik annak a jelenségnek a leírása és sokoldalú bizonyítása, amely szerint a makrofágok polianionos szintetikus makromolekulák felvételére scavenger A receptort ?használnak?. Kimutattuk, hogy efféle molekulához kovalensen kapcsolt riporter egység (fluorofor) bekerül a sejtbe. Ez a megfigyelés, valamint a kemotaxis alapú célbajuttatás jelenségének leírása lényegesek lehetnek makromolekulára alapozott célbajuttató rendszerek kifejlesztésében (makromolekula kiválasztás, intracelluláris kötés stabilitás stb.) és segíthetik új gyógyszerek kifejlesztését. | We have prepared a number of new bioconjugates and their components. These compounds proved to be useful for understanding and identification of structural and functional requirements for targeting macrophages. The components of new conjugates prepared preserved their funcional properties (e.g. T cell response provoking capacity, antibody recognition, antituberculotic activity). Among the most important findings we describe that macrophages could internalize polyanionic, synthetic compounds as well as their conjugates. We found that for this purpose scavenger A receptors are utilised. As another important result of the last few years we also proposed and provided experimental evidence concerning the principle of chemotaxis based drug/epitop delivery. Results achieved were presented in International journals and conferences. Our findings could be considered as useful contribution to the development of macromolecule based targeting for drug research and/or immundiagnostics

Metastasis-associated S100A4 is a specific amine donor and an activity-independent binding partner of transglutaminase-2.

Transglutaminase-2 (TG2) is best known as a Ca(2+)-dependent cross-linking enzyme; however, some of its extracellular matrix-related functions are independent of its catalytic activity and include matrix remodelling, adhesion and migration. S100A4 belongs to the Ca(2+)-binding EF-hand S100 protein family and acts both intra- and extra-cellularly through binding to various partners. It regulates cell migration and its overexpression is strongly associated with metastasis and poor survival in various cancers. It has recently been suggested that TG2 mediates S100A4-dependent tumour cell migration. In the present study we provide evidence that S100A4 is an interacting partner and also a specific amine donor of TG2. TG2 incorporates a glutamine donor peptide to Lys(100) in the C-terminal random coil region of S100A4. Importantly, the enzyme activity is not necessary for the interaction: S100A4 also binds to TG2 in the presence of a specific inhibitor that keeps the enzyme in an open conformation, or to an enzymatically inactive mutant. We also found that S100A4 considerably enhances TG2-mediated adhesion of A431 epithelial carcinoma cells to the extracellular matrix. This role is independent of enzyme activity and requires the open conformation of TG2. We propose that S100A4 stabilizes the open conformation of TG2, which binds to its cell-surface receptor in this state and increases cell adhesion

Development of Cyclic NGR Peptides with Thioether Linkage:Structure and Dynamics Determining Deamidation and Bioactivity

NGR peptides that recognize CD13 receptors in tumor neovasculature are of high interest, in particular due to their potential applications in drug targeting. Here we report the synthesis and structural analysis of novel thioether bond-linked cyclic NGR peptides. Our results show that their chemostability (resistance against spontaneous decomposition forming isoAsp and Asp derivatives) strongly depends on both sample handling conditions and structural properties. A significant correlation was found between chemostability and structural measures, such as NHGly−COAsn‑sc distances. The sidechain orientation of Asn is a key determining factor; if it is turned away from HNGly, the chemostability increases. Structure stabilizing factors (e.g., H-bonds) lower their internal dynamics, and thus biomolecules become even more resistant against spontaneous decomposition. The effect of cyclic NGR peptides on cell adhesion was examined in A2058 melanoma cell lines. It was found that some of the investigated peptides gradually increased cell adhesion with long-term characteristics, indicating time-dependent formation of integrin binding isoAsp derivatives that are responsible for the adhesion-inducing effect

Célzott terápiára alkalmas új peptidkonjugátumok szintézise és alkalmazása rosszindulatú daganatok kezelésében. = Development of new peptide conjugates for targeted therapy of cancer.

Célunk az volt, hogy olyan hatóanyag szállító rendszereket állítsunk elő, amelyek a tumornövekedést gátló hatóanyagokat szelektíven juttatják a tumoros sejtekbe. Ennek érdekében előállítottunk több mint 70 vegyületet, ezen belül kb. 50 GnRH illetve oligotuftsin hordozó – hatóanyag konjugátumot. Vizsgáltuk a konjugátumok in vitro tumorellenes hatását, sejtbe jutásukat, enzim stabilitásukat, metabolizmusukat és a metabolitok DNS kötődését. Összehasonlítottuk néhány vegyület receptorkötődési képességét. Szerkezet-hatás összefüggések vizsgálatával megállapítottuk, hogy milyen szekvencia módosítások, peptid-hatóanyag közötti kötéstípusok (pl. oxim, észter, hidrazon,) eredményeznek hatékonyabb konjugátumokat. A tumorellenes hatást több hatóanyag sejtbe juttatásával is fokozni kívántuk. Ezért a konjugátumok dimerjeit, illetve több drog molekulát tartalmazó konjugátumot is előállítottunk. Vizsgáltuk a vegyületek kemotaxisát és sejtadhézióra gyakorolt hatását, amelyek fontosak a tumor metasztázisában. Az vizsgálatok megkönnyítése érdekében saját fejlesztésű kemotaxis chippet készítettünk. A tumorsejtekben kezelés hatására lejátszódó, fehérje és RNS szintű változások tanulmányozására proteomikai és RT-PCR módszereket alkalmaztunk. A kutatás adott fázisában az aktuálisan leghatékonyabb vegyületek in vivo tumorellenes hatását vizsgáltuk vastagbél tumorral beoltott egereken. Az eredményekből olyan következtetéseket vontunk le, amelyek jelentősek a további kísérletek szempontjából. | The aim of our project was the development of drug delivery systems that target anticancer drugs selectively to the tumor cells. For this purpose more than 70 new compounds, among them ca. 50 GnRH and oligotuftsin based carrier – drug conjugates, were prepared. In vitro antitumor activity, cellular uptake, enzyme stability and metabolism of the conjugates were studied. The DNA binding of the metabolites was also investigated. The receptor binding activity of several compounds was checked and compared. The structure – activity relationship studies showed the allowed substitutions in the peptide sequences. The influence of types of bond (e.g. oxime, ester, hydrazone) between the drug and carrier molecule on efficient drug release was identified. The antitumor activity of the compounds could be increased by the elevation of drug molecules (identical or different) on carrier molecules or by dimerization of the drug containing monomer conjugates. For the development of metastasis preventing compounds the chemotactic activity of the conjugates and their influence on cell adhesion were also studied. For these studies new chemotactic chips were developed. The protein or RNA based changes in the treated cells compared to untreated cells were studied by proteome analysis or by RT-PCR. The best compounds were selected for in vivo studies. The antitumor activity of the compounds was measured on colon cancer bearing mice. The results of the project are useful for the further research

Unravelling the Role of Trophoblastic-Derived Extracellular Vesicles in Regulatory T Cell Differentiation

Regulatory T cells (Treg) are mandatory elements in the maintenance of human pregnancy, but their de novo differentiation has not been completely exposed. HSPE1 chaperone expressing trophoblast cells may have a role in it. Trophoblast-derived extracellular vesicles (EVs), either at the feto–maternal interface or in circulation, target CD4+ T cells. We hypothesized that HSPE1-associated trophoblastic cell line (BeWo)-derived EVs are active mediators of Treg cell differentiation. We proved at first that recombinant HSPE1 promote human Treg cell differentiation in vitro. Developing a CRISPR-Cas9 based HSPE1 knockout BeWo cell line we could also demonstrate, that EV-associated HSPE1 induces Treg development. Next-generation sequencing of miRNA cargo of BeWo-EVs characterized the regulatory processes of Treg polarization. By the use of single-cell transcriptomics analysis, seven Treg cell subtypes were distinguished and we demonstrated for the first time that the expression level of HSPE1 was Treg subtype dependent, and CAPG expression is characteristic to memory phenotype of T cells. Our data indicate that HSPE1 and CAPG may be used as markers for identification of Treg subtypes. Our results suggest, that trophoblastic-derived iEVs-associated HSPE1 and miRNA cargo have an important role in Treg cell expansion in vitro and HSPE1 is a useful marker of Treg subtype characterization

Neutrophil-to-Lymphocyte Ratio Is an Independent Risk Factor for Coronary Artery Disease in Central Obesity

Several inflammatory biomarkers were found to be associated with an increased risk of cardiovascular disease. Neutrophil-to-lymphocyte ratio (NLR) is a marker of subclinical inflammation that increases with the stress response. Visceral adiposity index (VAI) calculated as a combination of anthropometric and metabolic parameters reflects both the extent and function of visceral adipose tissue. Given the association of subclinical inflammation with both obesity and cardiovascular diseases, it is plausible that the inflammation-CVD association is modulated by the amount and function of adipose tissue. Thus, our aim was to examine the association between NLR and coronary artery calcium score (CACS), an intermediate marker of coronary artery disease in asymptomatic patients across VAI tertiles. Methods: Data from 280 asymptomatic participants of a cardiovascular screening program were analysed. In addition to the collection of lifestyle and medical history, a non-contrast cardiac CT scan and laboratory tests were performed on all participants. Multivariate logistic regression was conducted with CACS > 100 as the outcome and with conventional cardiovascular risk factors and NLR, VAI, and NLR by VAI tertile as predictors. Results: We found an interaction between VAI tertiles and NLR; NLR values were similar in the lower VAI tertiles, while they were higher in the CACS > 100 in the 3rd VAI tertile (CACS ≤ 100: 1.94 ± 0.58 vs. CACS > 100: 2.48 ± 1.1, p = 0.008). According to multivariable logistic regression, the interaction between NLR and VAI tertiles remained: NLR was associated with CACS > 100 in the 3rd VAI tertile (OR = 1.67, 95% CI 1.06-2.62, p = 0.03) but not in the lower tertiles even after adjustment for age, sex, smoking, history of hypertension, hyperlipidaemia, and diabetes mellitus, as well as high-sensitivity C-reactive protein. Our findings draw attention to the independent association between subclinical, chronic, systemic inflammation and subclinical coronary disease in obesity

Blood flow kinetics of a xenogeneic collagen matrix following a vestibuloplasty procedure in the human gingiva-An explorative study

The aim of the present study was to investigate temporal and spatial blood flow patterns following vestibuloplasty procedures using a collagen matrix (CM) to get an insight into the timing and direction of neovascularization in the CM.Five patients were treated using a modified apically repositioned flap combined with a CM. Intraoral photographs and blood flow measurements by laser speckle contrast imaging were taken for 12 months. Thirty regions of interest in the graft and the surrounding mucosa were evaluated. The clinical parameters were assessed after 6 and 12 months. VEGF expression was analyzed in the wound fluid on days 2 and 4.At 6 months, the mean width of keratinized gingiva increased, but the thickness was unchanged. Scar formation was observed in all cases. Perfusion in the graft began to increase at the lateral and coronal edges and then spread concentrically toward the center. The apical side showed a significant delay in perfusion, the highest VEGF expression, and wound fluid production as well as the most abundant scar formation.Neovascularization occurs mainly from the lateral and coronal edges, which may limit the extent of the surgical area. Abundant scar formation may be explained by increased VEGF expression induced by prolonged ischemia in this area