Safe and cost-effective method for application of liquid ethyl formate (FumateTM) as a methyl bromide alternative for perishable commodities: Poster

The cylinderized liquid ethyl formate (EF) formulated with CO2 is one of the great potential fumigants to replace methyl bromide (MeBr) for fresh fruit. However, it is too expensive to adapt commercial practices, and also involves work place safety issue including handling of heavy cylinders as well as restrict emission of CO2, particularly for use in large scale commercial fumigationw. Therefore, it is urgently needed to develop environmental friendly, safe for workers and cost-effective alternative method for application of liquid ethyl formate as a MeBr alternative for perishable commodities. Recently, the environmentally friendly, cost-effective and practically safe use of liquid EF (FumateTM, registered name) with nitrogen gas has been developed and commercialized in Republic of Korea and Australia. The new technology for application of liquid EF is 100 times safer than MeBr in terms of threshold values (EF, TLV = 100 ppm). Ethyl formate is known as food additive and naturally occurred substances as well as a non-ozone depletion chemical. In this report, we demonstrate the liquid EF application technology that offers a clean environment (no ozone depletions and CO2 emissions), safe to fumigators and related workers and practically cost-effective technology to fumigation industry.The cylinderized liquid ethyl formate (EF) formulated with CO2 is one of the great potential fumigants to replace methyl bromide (MeBr) for fresh fruit. However, it is too expensive to adapt commercial practices, and also involves work place safety issue including handling of heavy cylinders as well as restrict emission of CO2, particularly for use in large scale commercial fumigationw. Therefore, it is urgently needed to develop environmental friendly, safe for workers and cost-effective alternative method for application of liquid ethyl formate as a MeBr alternative for perishable commodities. Recently, the environmentally friendly, cost-effective and practically safe use of liquid EF (FumateTM, registered name) with nitrogen gas has been developed and commercialized in Republic of Korea and Australia. The new technology for application of liquid EF is 100 times safer than MeBr in terms of threshold values (EF, TLV = 100 ppm). Ethyl formate is known as food additive and naturally occurred substances as well as a non-ozone depletion chemical. In this report, we demonstrate the liquid EF application technology that offers a clean environment (no ozone depletions and CO2 emissions), safe to fumigators and related workers and practically cost-effective technology to fumigation industry

Simultaneous Detection of EGFR and VEGF in Colorectal Cancer using Fluorescence-Raman Endoscopy

Fluorescence endomicroscopy provides quick access to molecular targets, while Raman spectroscopy allows the detection of multiple molecular targets. Using a simultaneous fluorescence-Raman endoscopic system (FRES), we herein demonstrate its potential in cancer diagnosis in an orthotopically induced colorectal cancer (CRC) xenograft model. In the model, epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) were targeted with antibody-conjugated fluorescence and surface-enhanced Raman scattering (F-SERS) dots. FRES demonstrated fast signal detection and multiplex targeting ability using fluorescence and Raman signals to detect the F-SERS dots. In addition, FRES showed a multiplex targeting ability even on a subcentimeter-sized CRC after spraying with a dose of 50 µg F-SERS dots. In conclusion, molecular characteristics of tumor cells (EGFR in cancer cell membranes) and tumor microenvironments (VEGF in the extracellular matrix) could be simultaneously investigated when performing a colonoscopy

Three-Dimensional Macroporous Alginate Scaffolds Embedded with Akaganeite Nanorods for the Filter-Based High-Speed Preparation of Arsenic-Free Drinking Water

Separation of arsenic from water is an urgent worldwide issue because of its serious toxic effect on human health and aquatic life. In this study, a filter device composed of three-dimensional (3D) macroporous alginate/akaganeite composite (MAAC) scaffolds is proposed for the convenient separation of arsenic from contaminated water. Akaganeite nanorods with superior arsenic adsorption capability are incorporated and distributed within the macroporous alginate scaffold, without significant aggregation. The micron-sized pores and oxygen functional groups in the MAAC scaffold offer enhanced mass transport of the contaminated water throughout the scaffold without the need for input of any force and allow easy contact of arsenic with the active adsorption sites of the scaffold. The high mechanical strength of the MAAC facilitates structural stability of the materials in aqueous solutions. Moreover, the scaffold is capable of excellent arsenic adsorption and can reduce the concentration of arsenic in contaminated water to the acceptable drinking-water level (10 μg L^–1). We also demonstrate that a column filter device constructed by stacking several MAAC scaffolds enables a continuous supply of drinking water with a permissible limit of arsenic according to the World Health Organization in a high-purification speed (∼22–25 mL min^–1 under gravity), which could potentially provide an appropriate technology to obtain arsenic-free drinking water in developing countries

Extra-Large Pore Mesoporous Silica Nanoparticles Enabling Co-Delivery of High Amounts of Protein Antigen and Toll-like Receptor 9 Agonist for Enhanced Cancer Vaccine Efficacy

Cancer vaccine aims to invoke antitumor adaptive immune responses to detect and eliminate tumors. However, the current dendritic cells (DCs)-based cancer vaccines have several limitations that are mostly derived from the <i>ex vivo</i> culture of patient DCs. To circumvent the limitations, direct activation and maturation of host DCs using antigen-carrying materials, without the need for isolation of DCs from patients, are required. In this study, we demonstrate the synthesis of extra-large pore mesoporous silica nanoparticles (XL-MSNs) and their use as a prophylactic cancer vaccine through the delivery of cancer antigen and danger signal to host DCs in the draining lymph nodes. Extra-large pores of approximately 25 nm and additional surface modification of XL-MSNs resulted in significantly higher loading of antigen protein and toll-like receptor 9 (TLR9) agonist compared with conventional small-pore MSNs. <i>In vitro</i> study showed the enhanced activation and antigen presentation of DCs and increased secretion of proinflammatory cytokines. <i>In vivo</i> study demonstrated efficient targeting of XL-MSNs co-delivering antigen and TLR9 agonist to draining lymph nodes, induction of antigen-specific cytotoxic T lymphocytes (CTLs), and suppression of tumor growth after vaccination. Furthermore, significant prevention of tumor growth after tumor rechallenge of the vaccinated tumor-free mice resulted, which was supported by a high level of memory T cells. These findings suggest that mesoporous silica nanoparticles with extra-large pores can be used as an attractive platform for cancer vaccines

Injectable Macroporous Ferrogel Microbeads with a High Structural Stability for Magnetically Actuated Drug Delivery

Macroporous hydrogels are an attractive material platform that can provide shortened interfacial diffusion pathways and high biomacromolecule loading. Recently, macroporous ferrogels have shown high potential for use in the on-demand delivery of bioactive molecules, resulting from their reversible and large volumetric deformation upon magnetic stimulation. However, these macroporous ferrogels require surgical placement in the body due to their large size; an injectable form of macroporous ferrogels has not yet been reported. In this study, injectable macroporous ferrogel microbeads loaded with iron oxide nanoparticles have been prepared on the basis of alginate microbeads for on-demand drug release. A simple solvent exchange and subsequent covalent cross-linking of the alginate chains in hydrogel microbeads induced a high polymer density on the hydrogel network and led to enhanced mechanical properties even after the generation of macropores in the microbeads. The macroporous ferrogel microbeads exhibited good mechanical stability and were stable during needle injection. The increased loading of large biomolecules due to the macroporosity of the microbeads and their large reversible volumetric deformation response to the external magnetic field enabled their potential for use in the on-demand delivery of drugs of assorted sizes by magnetic actuation. As a result of their structural stability, injectable size, and ability for on-demand drug delivery, ferrogel microbeads have promising potential for application in many biomedical fields

Extra-Large Pore Mesoporous Silica Nanoparticles for Directing in Vivo M2 Macrophage Polarization by Delivering IL‑4

Over the past decade, mesoporous silica nanoparticles (MSNs) smaller than 200 nm with a high colloidal stability have been extensively studied for systemic drug delivery. Although small molecule delivery via MSNs has been successful, the encapsulation of large therapeutic biomolecules, such as proteins or DNA, is limited due to small pore size of the conventional MSNs obtained by soft-templating. Here, we report the synthesis of mesoporous silica nanoparticles with extra-large pores (XL-MSNs) and their application to in vivo cytokine delivery for macrophage polarization. Uniform, size-controllable XL-MSNs with 30 nm extra-large pores were synthesized using organic additives and inorganic seed nanoparticles. XL-MSNs showed significantly higher loadings for the model proteins with different molecular weights compared to conventional small pore MSNs. XL-MSNs were used to deliver IL-4, which is an M2-polarizing cytokine and very quickly degraded in vivo, to macrophages and polarize them to anti-inflammatory M2 macrophages in vivo. XL-MSNs induced a low level of reactive oxygen species (ROS) production and no pro-inflammatory cytokines in bone marrow-derived macrophages (BMDMs) and in mice injected intravenously with XL-MSNs. We found that the injected XL-MSNs were targeted to phagocytic myeloid cells, such as neutrophils, monocytes, macrophages, and dendritic cells. Finally, we demonstrated that the injection of IL-4-loaded XL-MSNs successfully triggered M2 macrophage polarization in vivo, suggesting the clinical potential of XL-MSNs for modulating immune systems via targeted delivery of various cytokines

Carbohydrate-Functionalized rGO as an Effective Cancer Vaccine for Stimulating Antigen-Specific Cytotoxic T Cells and Inhibiting Tumor Growth

Efficient delivery of antigens to dendritic cells (DCs), potent antigen-presenting cells, and subsequent antigen presentation to initiate the production of activated cytotoxic T cells are vital parameters that determine the success of cancer immunotherapy. Here, we report dextran-functionalized reduced graphene oxide (rGO-dextran) as an antigen delivery carrier for cancer immunotherapy. We synthesized dextran-functionalized rGO, where the dextran component facilitated good colloidal stability by exposing hydroxyl groups on the surface of reduced graphene oxide (rGO) and also enhanced cellular uptake via interaction with carbohydrate receptors present on DCs. High surface area and intrinsic hydrophobic surface of rGO facilitated high loading of the model antigen, ovalbumin (OVA). We found that rGO-dextran efficiently delivered OVA to DCs and enhanced the antigen presentation via major histocompatibility complex class I (MHC-I). In addition, the release of inflammatory cytokines, IL-12 and TNF-α, for DCs incubated with OVA-loaded rGO-dextran was remarkably higher than that for those incubated with soluble OVA. We also demonstrated that OVA-loaded rGO-dextran induced production of antigen-specific cytotoxic T cells in vivo and significantly inhibited tumor growth. Therefore, the proposed rGO-dextran could be a potent candidate for cancer vaccine and other immunotherapy

Self-Position of Au NPs in Perovskite Solar Cells: Optical and Electrical Contribution

Metallic nanoparticles (NPs) exhibit a localized surface plasmon resonance (LSPR) and act as scattering centers and subwavelength antennas, so metallic NPs can be incorporated into perovskite solar cells (PSCs) to effectively improve the light absorption of light harvesting devices. Here, we have embedded Au nanoparticles (NPs) into the hole transport layer (HTL) of the PSCs to investigate the photovoltaic effect of the PSCs with Au NPs. Interestingly, it was found that Au NPs dispersed spiro-OMeTAD HTL solution could naturally end up located near the perovskite layer as the result of the spin-coating step. Solar cell performance observations indicate that the LSPR and electrical effects of Au NPs enhance the photovoltaic response of PSCs, in spite of a slight decrease in the open-circuit voltage (<i>V</i>_OC), by causing an incredible improvement in the photocurrent density as a dominant factor