Preparation of nanoparticles by the self-organization of polymers consisting of hydrophobic and hydrophilic segments: Potential applications

AbstractThis review describes the preparation of core-corona type polymeric nanoparticles and their applications in various technological and biomedical fields. Over the past two decades, we have studied the synthesis and clinical applications of core-corona polymeric nanoparticles composed of hydrophobic polystyrene and hydrophilic macromonomers. These nanoparticles were utilized as catalyst carriers, carriers for oral peptide delivery, virus capture agents, and vaccine carriers, and so on. Moreover, based on this research, we attempted to develop novel biodegradable nanoparticles composed of hydrophobic poly(γ-glutamic acid) (γ-PGA) derivatives (γ-hPGA). Various model proteins were efficiently entrapped on/into the nanoparticles under different conditions: encapsulation, covalent immobilization, and physical adsorption. The encapsulation method showed the most promising results for protein loading. It is expected that biodegradable γ-hPGA nanoparticles can encapsulate and immobilize various biomacromolecules. Nanoparticles consisting of hydrophobic and hydrophilic segments have great potential as multifunctional carriers for pharmaceutical and biomedical applications, such as drug, protein, peptide or DNA delivery systems

Novel 600 V Low Reverse Recovery Loss Vertical PiN Diode with Hole Pockets by Bosch Deep Trench

The performance of a novel diode with characteristic trench shape is predicted by TCAD simulation. A novel 600 V vertical PiN diode with hole pockets by the Bosch deep trench process is proposed for a better trade-off curve between reverse recovery loss and forward voltage. The reverse recovery loss is reduced to a half. In addition, the active chip size of the novel diode is reduced to two-thirds that of the conventional PiN diode in the same forward voltage. The novel diode structure is a strong candidate when the simple fabrication process under development is established.ISPSD 2016 28th International Symposium on Power Semiconductor Devices and ICs., Jun 12-16, 2016, Žofín Palace, Prague, Czech Republi

High-performance vertical Si PiN diode by hole remaining mechanism

A novel diode with a unique trench shape is predicted by TCAD simulation to have high performance. The novel 600 V vertical PiN diode with hole pockets by the Bosch deep trench process shows a better trade-off curve between reverse recovery loss and forward voltage. The reverse recovery loss is reduced by half. In addition, the active chip size of the novel diode is reduced to two-thirds that of the conventional PiN diode in the same forward voltage. Thanks to the hole pockets with an electric field in the diagonal direction, the remaining hole suppresses the surge voltage with noise for high performance. In this paper, we specially focus on the analysis of phenomenon and the noise suppression mechanism during reverse recovery. The novel diode structure is a strong candidate when developing the fabrication process after silicon trench etching is established

Novel 600 V Low Reverse Recovery Loss Vertical PiN Diode with Hole Pockets by Bosch Deep Trench

ISPSD 2016 28th International Symposium on Power Semiconductor Devices and ICs., Jun 12-16, 2016, Žofín Palace, Prague, Czech RepublicThe performance of a novel diode with characteristic trench shape is predicted by TCAD simulation. A novel 600 V vertical PiN diode with hole pockets by the Bosch deep trench process is proposed for a better trade-off curve between reverse recovery loss and forward voltage. The reverse recovery loss is reduced to a half. In addition, the active chip size of the novel diode is reduced to two-thirds that of the conventional PiN diode in the same forward voltage. The novel diode structure is a strong candidate when the simple fabrication process under development is established

Methane Production Using Cattle Rumen Fluids and Its Application to Reduce Volume of Radiation-polluted Biomass

Poster Presentatio

Production of Functionally Deficient Dendritic Cells from HTLV-I-Infected Monocytes: Implications for the Dendritic Cell Defect in Adult T Cell Leukemia

AbstractAdult T cell leukemia (ATL) is induced by an infection with human T lymphotropic virus type I (HTLV-I) and is accompanied by immunodeficiency. Monocyte-derived immature dendritic cells (DCs) donated by 11 ATL patients were suppressed in the ability to take up fluorescein isothiocyanate (FITC)–dextran and were down-regulated in the expression of CD1a and CD86 antigens (Ags). Monocytes from the patients showed impaired expression of CD14 and HLA-DR Ags. These results suggest intrinsic abnormalities of monocytes and a defect of DC maturation in ATL patients. Therefore, we examined the influence of HTLV-I infection of monocytes on their differentiation to DCs. Monocytes obtained from healthy donors were susceptible to HTLV-I infection in vitro. HTLV-I-infected monocytes were down-regulated in the expression of CD14 Ags, and immature DCs obtained from them expressed CD1a poorly and were impaired in the ability to take up FITC–dextran. Mature DCs differentiated from these cells could not stimulate autologous CD4+ T cell or CD8+ T cell proliferation, even after being secondarily pulsed with HTLV-I at an immature DC stage. These results suggest that HTLV-I-infected monocytes cannot properly differentiate to DCs and that this might be one of the important mechanisms producing dysfunctional DCs in ATL patients

Uptake of biodegradable poly(γ-glutamic acid) nanoparticles and antigen presentation by dendritic cells in vivo

AbstractPoly(γ-glutamic acid) (γ-PGA) nanoparticles (NPs) carrying antigens have been shown to induce potent antigen-specific immune responses. However, in vivo delivery of γ-PGA NPs to dendritic cells (DCs), a key regulator of immune responses, still remains unclear. In this study, γ-PGA NPs were examined for their uptake by DCs and subsequent migration from the skin to the regional lymph nodes (LNs) in mice. After subcutaneous injection of fluorescein 5-isothiocyanate (FITC)-labeled NPs or FITC-ovalbumin (OVA)-carrying NPs (FITC-OVA-NPs), DCs migrated from the skin to the LNs and maturated, resulting in the upregulation of the costimulatory molecules CD80 and CD86 and the chemokine receptor CCR7. However, the migrated DCs were not detected in the spleen. FITC-OVA-NPs were found to be taken up by skin-derived CD103+ DCs, and the processed antigen peptides were cross-presented by the major histocompatibility complex (MHC) class I molecule of DCs. Furthermore, significant activation of antigen-specific CD8+ T cells was observed in mice immunized with OVA-carrying NPs (OVA-NPs) but not with OVA alone or OVA with an aluminum adjuvant. The antigen-specific CD8+ T cells were induced within 7 days after immunization with OVA-NPs. Thus, γ-PGA NPs carrying various antigens may have great potential as an antigen-delivery system and vaccine adjuvant in vivo

Selective inhibition of hepatitis C virus replication by alpha-zam, a Nigella sativa seed formulation

Background: Hepatitis C virus (HCV) infection became curable because of the development of direct acting antivirals (DAAs). However, the high cost of DAAs has greatly impeded their potential impact on the treatment of HCV infection. As a result, hepatitis C will continue to cause substantial morbidity, and mortality among chronically infected individuals in low and middle income countries. Thus, urgent need exists for developing cheaper drugs available to hepatitis C patients in these countries.Materials and Methods: Alpha-zam, an indigenous herbal formulation from Nigella sativa seed, was examined for its anti-HCV activity and cytotoxicity in genotype 1b HCV replicon cells. The antiviral activity was determined by luciferase expression and viral RNA synthesis, while the cytotoxicity was assessed by viable cell number and glyceraldehyde-3-phosphate dehydrogenase RNA synthesis in the replicon cells.Results: Alpha-zam was found to be a selective inhibitor of HCV replication. The 50% effective dilution and 50% cytotoxic dilution of Alpha-zam were 761- and < 100-fold, respectively, in the subgenomic replicon cells LucNeo#2. Its selective inhibition of HCV was also confirmed by HCV RNA levels in LucNeo#2 and in the full-genome HCV replicon cells NNC#2 using real-time reverse transcriptase polymerase chain reaction. Furthermore, the anti-HCV activity of Alpha-zam was not due to the induction of interferon.Conclusion: Alpha-zam selectively inhibits HCV replication and therefore has potential for a novel antiviral agent against HCV infection.Keywords: Alpha-zam, chronic hepatitis, hepatitis C virus, antiviral assay, Nigella sativ