The effect of deep eutectic solvent (DES) modified silica on the properties of nature rubber (NR) composites were investigated. The DES is an environment-friendly and low-cost solvent, which was prepared by mixing choline chloride and urea in a 1:2 molar ratio. The NR composites filled with DES modified silica were prepared and the properties were tested. The interaction between the DES and silica were characterized by Fourier transform infrared spectroscopy (FTIR), the interaction between silica and silica were tested by differential scanning calorimetry (DSC). The dynamic properties, such as rolling resistance and wet skid resistance, and were tested by dynamic mechanical analysis (DMA). Morphologies of the composites were characterized by scanning electron microscopy (SEM). The results indicate that the DES can interact with silica by hydrogen bond to improve the compatibility between the rubber and silica. When the content of DES was 3 phr, the tensile strength, modulus at 300%, tear strength, and the crosslinking density of the composites was increased. At the same time, the proper content of DES can reduce the rolling resistance of the vulcanized rubber while maintaining good wet skid resistance.

The indirect enzyme-linked immunosorbent assay (ELISA) is the gold standard method for monoclonal antibody (McAb) detection and plays a unique role in the preparation of bacterial antibodies. To solve the laborious issues associated with indirect ELISA, a novel bacterial coloration immunofluorescence strip (BCIFS) for antibody detection using colored bacteria instead of a labeled antibody as the antigen and tracer simultaneously and goat anti-mouse IgG as the test line was developed. The affinity range survey of BCIFS indicated that hybridoma cell cultures of E. coli O157:H7 (D3, E7) and Vibrio parahemolyticus (H7, C9) were detected, which complied with the results of indirect ELISA. Compared with the traditional indirect ELISA, the BCIFS sensitivity for E7 cell cultures, ascites, and purified antibodies was at least 4-fold more sensitive, and the BCIFS cross-reactivity for E7 cell cultures was almost consistent with that of indirect ELISA. In addition, the BCIFS isotypes for E. coli O157:H7 cell cultures and Vibrio parahemolyticus were IgG2a and IgG1, respectively, which were identical to the indirect ELISA. Furthermore, the BCIFS method was confirmed by McAb preparation, effective antibody use, and targeted antibody-secreted hybridoma preparation and screening, which showed excellent performance and substitution of the indirect ELISA method. Combined with methylcellulose semisolid medium, BCIFS offers a novel, easy to operate, rapid preparation method for antigen-specific hybridomas. This is the first report using BCIFS instead of indirect ELISA for bacterial antibody detection and application in different samples, which demonstrates a rapid and powerful tool for antibody engineering.

Salmonella Typhimurium (S. Typhimurium) is an important foodborne pathogen that can cause severe enteric disease. Thus, the timely detection of S. Typhimurium is crucial to prevent infections and reduce the losses caused by Salmonella. In this study, we combined recombinase polymerase amplification (RPA) and lateral flow dipstick (LFD) to establish a rapid, sensitive, and visual method for the detection of S. Typhimurium. Through the optimization of the RPA reaction, the best primer concentration, reaction temperature, and reaction time were determined to be 5 μmol/L, 39 °C, and 20 min, respectively. After the RPA reaction was completed, the test results could be read within 5 min using LFD. The specificity of the detection system was improved by adding the RPA probe, and the established method shared high sensitivity with the detection limit of 102 CFU/mL of bacterial concentration and 4.5 fg/μL of bacterial DNA. Milk, egg, and chicken samples were selected as the spiked food samples with bacteria, and the method could detect S. Typhimurium in these food samples with the initial inoculation bacteria concentration of 1 CFU/mL after 2 h enrichment. In short, the method developed in this study was expected to realize the detection of S. Typhimurium in low resource areas, and provided a new idea for the rapid detection of foodborne pathogens.

Outbreaks of Salmonella infections have always attracted world-wide attention in food industry. Therefore, it is particularly important to detect Salmonella. In this study, we aimed to develop a rapid, simple, sensitive, and broad-spectrum colloidal gold immunochromatographic test strip (ICTS) for detecting Salmonella. The prepared monoclonal antibody (mAb) 1B4 was labeled with colloidal gold and used as the capture antibody, as it can pair with itself to form a sandwich detection platform. The sensitivity of the test strip for Salmonella typhimurium was 4 ? 105 CFU/mL with naked eye and the pathogen was detected in 5?15 min. The colloidal gold ICTS can be used to detect 18 stains of Salmonella and there was no cross-reaction with 14 other food-borne pathogens. Salmonella typhimurium, Salmonella paratyphi B, and Salmonella enterica in chicken were detected after 7 h, 7 h and 6 h of incubation, respectively, and the detection limit was as low as 1 CFU/mL. In short, this is important reports of colloidal gold ICTS for detecting so many stains of Salmonella, and this will be a huge improvement for detecting multiple Salmonella in food samples.

In this study, the four nanomaterials: Traditional colloidal gold (AuNP), New colloidal gold (N-AuNP), Multi-branched gold nanoflowers (AuNF) and Luminol-reduced Au nanoparticles (L-AuNP) were respectively labeled with the monoclonal antibody against Vibrio parahaemolyticus (V. parahaemolyticus). We aimed to develop lateral flow immunoassays (LFIAs) with these nanomaterial labels and determine their performance in visual detection of V. parahaemolyticus. The results of four colloidal gold particle-labeled LFIAs and polymerase chain reaction (PCR) simultaneously detected in actual samples were to be highly consistent, indicating that strips have high accuracy. The four strips were also found to be stable up to 14 weeks under laboratory conditions. In terms of sensitivity, the N-AuNP-based strip was slightly better than the other three. For the N-AuNP-based strips, the difference between the results obtained for different batches was high consistency, and the stability was much better than that of the AuNP-, AuNF-and L-AuNP-based ones. Our results indicate that the N-AuNP can be better used as labels in immunochromatographic tests. It can also reduce the based antibodies, improve the detection sensitivity and reduce the production cost, thereby expanding the scale of production. The use of LFIA labeled with N-AuNP can be more effective, rapid and inexpensive methods for V. parahaemolyticus assay in on-site applications.

Reconciling the conflicting needs for a prolonged circulation time, enhanced cellular uptake by bulk tumor cells and cancer stem cells (CSCs), and extensive tumor tissue penetration remains a major challenge for current nano drug delivery systems. Here we describe smart poly(N-isopropylacrylamide)-based nanogels with a fast adaptive hydrophobicity to solve these contradictory requirements for enhanced cancer chemotherapy. The nanogels are hydrophilic in the blood to prolong their circulation time. Once they accumulate at tumor sites, they rapidly become hydrophobic in response to tumor extracellular acidity. The adaptive hydrophobicity of the nanogels facilitates tumor accumulation, deep tumor penetration, and efficient uptake by bulk tumor cells and CSCs, resulting in a greater in vivo enrichment in tumor cells and side population cells. Together with lysosomal pH-regulated charge reversal and redox-responsive intracellular drug release, the nanogels escape from lysosomes and release their cargo doxorubicin. Thus, the nanogels significantly improve the in vivo anticancer efficacy and decrease side effects of doxorubicin. Strikingly, the ratio of CSCs is greatly decreased after treatment with the nanogels loaded with doxorubicin. Our current study provides new insights into designing effective anticancer drug delivery systems.

The enhanced permeability and retention (EPR) effect of tumors is much more complex than initially defined, and it alone is not sufficient for targeted delivery of nanosized agents. Meanwhile, poor tumor penetration is another major challenge for the treatment of solid tumors using nanoparticles. Development of delivery systems for SN38, the active metabolite of CPT-11 in human and a very potent anticancer molecule, has become an attractive research area. PEGx -p(HEMASN38)y (x and y are viable), a prodrug synthesized by using polyethylene glycol (PEG) as initiator and SN38 as monomer through atom transfer radical polymeration (ATRP) method, is previously reported. Using PEG2.4K -p(HEMASN38)3K as a model prodrug, herein an active-targeted strategy decorated with cys-arg-gly-asp-lys (CRGDK), a peptide specifically binds to neuropilin-1 overexpressed by tumor vessels and tumor cells, is successfully established to further improve the delivery and efficacy of SN38. CRGDK-functionalized PEG2.4K -p(HEMASN38)3K (C-SN38) nanoparticles and nonfunctionalized control (B-SN38) are prepared with two distinct sizes, 30 and 100 nm. Their physiochemical and biological characteristics are investigated in vitro and in vivo with multiple tumor models. It is demonstrated for the first time that CRGDK functionalization can be a promising strategy for efficient delivery of SN38, and C-SN38 is a potent drug candidate for the treatment of neuropilin-1 overexpressing tumors.

Improving the intratumoral distribution of anticancer agents remains the critical challenge for developing efficient cancer chemotherapy. Luminescent porous silicon nanoparticles (PSiNPs) have attracted considerable attention in the biomedical field especially in drug delivery. Here, we described the lysosomal exocytosis-mediated domino-like intercellular delivery of undecylenic acid-conjugated PSiNPs (UA-PSiNPs) for deep tumor penetration. UA-PSiNPs with significantly improved stability in physiological conditions were internalized into tumor cells by macropinocytosis-, caveolae-, and clathrin-mediated endocytosis and mainly colocalized with Golgi apparatus and lysosomes. Substantial evidence showed that UA-PSiNPs was excreted from cells via lysosomal exocytosis after cellular uptake. The exocytosed UA-PSiNPs induced a domino-like infection of adjacent cancer cells and allowed encapsulated doxorubicin (DOX) to deeply penetrate into both three-dimensional tumor spheroids and in vivo tumors. In addition, DOX-loaded UA-PSiNPs exhibited strong antitumor activity and few side effects in vivo. This study demonstrated that UA-PSiNPs as a drug carrier might be applied for deep tumor penetration, offering a new insight into the design of more efficient delivery systems of anticancer drugs.

Ideal anticancer nano drug delivery systems (NDDSs) need to overcome a series of physiological barriers including blood circulation, tumor accumulation, tumor penetration, internalization by cancer cells, lysosomal escape, and on-demand intracellular drug release following systemic administration. However, it remains a big challenge to construct NDDSs that can overcome all the barriers at the same time. Here, we develop zwitterionic temperature/redox-sensitive nanogels loaded with near-infrared (NIR) dye Indocyanine green (ICG) and anticancer drug doxorubicin (I/D@NG). I/D@NG exhibits enhanced photothermal effects, and NIR irradiation markedly decreases its diameter. NIR irradiation at tumor sites significantly enhances tumor accumulation, tumor penetration, and cellular uptake of I/D@NG with prolonged blood circulation time. Furthermore, I/D@NG can effectively escape from lysosomes by singlet oxygen-induced lysosomal disruption, and DOX is then sufficiently released from the nanogels to the nucleus in response to high intracellular GSH and photothermal effects. This nanoplatform for thermo-chemotherapy not only efficiently exerts synergistic cytotoxicity but also overcomes all the physiological barriers of therapeutic agent, thereby providing a substantial in vivo anticancer effect. The multiple functions of I/D@NG provide new insights into designing nanoplatforms for synergistic cancer therapy.

Abstract Long circulation in blood, enhanced tumor accumulation and penetration, efficient cellular internalization and intracellular drug release are major challenges in the development of ideal anticancer drug delivery systems. Although several strategies have been reported to improve therapeutic efficacy, they mainly meet one or a few features which can not circumvent all the barriers. Here the stimuli-responsive zwitterionic nanogels were developed to overcome the sequential physiological barriers in cancer chemotherapy. The nanogels were constructed via a simple precipitation polymerization method by using temperature-sensitive monomer N-isopropylacrylamide (NIPAM) pH-responsive monomer methylallyl amine (MAA) and betaine-based zwitterionic monomer sulfobetaine methacrylate (SBMA) with in vivo anti-protein adsorption property as comonomers, and disulfide bonds-containing N, N'-bis(acryloyl) cystamine (BAC) as crosslinker. Volume phase transition temperature (VPTT) and surface charge of the prepared nanogels were precisely controlled by altering the feeding molar ratio of these comonomers. Remarkably, The nanogels possess ultra-pH sensitive hydrophilicity/hydrophobicity reversible property, in which the nanogels were hydrophilic in the blood (pH 7.4, 37 °C) for prolonged circulation, while they were rapidly switched to hydrophobic with similar size and surface charge at acidic tumor pH, resulting in enhanced tumor accumulation and penetration and strong internalization by normal cancer cells and CSCs. For efficient lysosomal escape and intracellular drug release, the nanogels were positively charged at lysosome pH, which allowed them to be transported into the cytosol where the loaded cargo DOX was released from the nanogels with the introduction of intracellular high GSH concentration to exert cytotoxicity. This study indicated that pH-dependent hydrophilicity/hydrophobicity-, surface charge-reversible and redox sensitive nanogels might be used as potential carriers for anticancer drugs, which provided a foundation for designing an effective drug delivery system for cancer therapy. Note: This abstract was not presented at the meeting. Citation Format: Hao Yang, Qin Wang, Fuying Li, Yanhong Zhu, Lu Gan, Xiangliang Yang. pH-regulated hydrophilicity/hydrophobicity-, surface charge-reversible and redox sensitive nanogels for anticancer drug delivery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3099. doi:10.1158/1538-7445.AM2017-3099

Efficient accumulation and intracellular drug release in cancer cells remain a crucial challenge in developing ideal anticancer drug delivery systems. Here, poly(N-isopropylacrylamide)-ss-acrylic acid (P(NIPAM-ss-AA)) nanogels based on NIPAM and AA cross-linked by N,N'-bis(acryloyl)cystamine (BAC) were constructed by precipitation polymerization. The nanogels exhibited pH/redox dual responsive doxorubicin (DOX) release behavior in vitro and in tumor cells, in which DOX release from nanogels was accelerated in lysosomal pH (pH 4.5) and cytosolic reduction (10 mM GSH) conditions. Moreover, intracellular tracking of DOX-loaded nanogels confirmed that after the nanogels and the loaded DOX entered the cells simultaneously mainly via lipid raft/caveolae-mediated endocytosis, DOX-loaded nanogels were transported to lysosomes and then the loaded DOX was released to nucleus triggered by lysosomal pH and cytoplasmic high GSH. MTT analysis showed that DOX-loaded nanogels could efficiently inhibit the proliferation of HepG2 cells. In vivo animal studies demonstrated that DOX-loaded nanogels were accumulated and penetrated in tumor tissues more efficiently than free DOX. Meanwhile, DOX-loaded nanogels exhibited stronger tumor inhibition activity and fewer side effects. This study indicated that pH/redox dual-responsive nanogels might present a prospective platform for intracellular drug controlled release in cancer therapy.

Drug resistance is the major cause of failure of cancer chemotherapy in ovarian cancer. However, the molecular mechanisms on the regulation of drug resistance are not fully understood. Here we showed that Trx1 and FOXO1 were involved in paclitaxel (PTX)-induced drug resistance in ovarian cancer A2780 cells. PTX induced reactive oxygen species (ROS) and resulted in Trx1 and FOXO1 nuclear translocation. We further found that Trx1 bound to FOXO1 and enhanced FOXO1 transcriptional activity; however Trx1 C69S mutant which is barely detected in the nucleus downregulated Trx1–FOXO1 interaction and Trx1-induced FOXO1 transcriptional activation. Silencing of FOXO1 abrogated Trx1-induced drug resistance. Trx1 increased FOXO1-induced drug resistance, while Trx1 C69S mutant completely abolished the regulation of FOXO1-mediated drug resistance by Trx1. These findings provided a novel mechanism on Trx1/FOXO1 signaling in drug resistance in ovarian cancer cells.

Atmospheric pressure cold plasma showed selective killing efficiency on cancer cells in vitro and in vivo, which makes plasma a potential option for cancer therapy. However, the plasma effects on chemotherapeutic drugs-resistant cells are rarely to be found. In this paper, the effects of plasma on human hepatocellular carcinoma Bel7402 cells and 5-fluorouracil (5-FU) resistant Bel7402/5FU cells were intensively investigated. The results showed that plasma induced superior toxicity to Bel7402 cells compared with Bel7402/5FU cells. Incubation with plasma-treated medium for 20 s induced more than 85% death rate in Bel7402 cells, while the same death ratio was achieved when Bel7402/5FU cells were treated for as long as 300 s. The hydrogen peroxide in the medium played a leading role in the cytotoxicity effects. Further studies implicated that when the treatment time was shorter than 60 s, the depolarization of mitochondrial membrane potential and apoptosis occurred through the intracellular reactive oxygen species accumulation in Bel7402 cells. Molecular analysis showed an increase in the transcription factor activity for AP-1, NF-кB, and p53 in Bel7402 cells. No obvious damage could be detected in plasma-treated Bel7402/5FU cells due to the strong intracellular reactive oxygen stress scavenger system.

Long circulation in the blood, efficient cellular internalization, and intracellular drug release in the tumor cells are major challenges in the development of ideal anticancer drug delivery systems. In this paper, hydrophilicity/hydrophobicity reversable and redox-sensitive poly(oligo(ethylene glycol) methacrylates-ss-acrylic acid) (P(OEGMAs-ss-AA)) nanogels were constructed as drug carriers for cancer therapy. The nanogels underwent a pH-dependent hydrophilic/hydrophobic change. The nanogels were hydrophilic under physiological conditions (pH 7.4, 37 °C), resulting in fewer opsonization of proteins and less phagocytosis by macrophage RAW264.7 cells, while they were hydrophobic in the tumor tissues (pH 6.5, 37 °C), resulting in strong internalization by Bel7402 cells. The doxorubicin (DOX) release from DOX-loaded nanogels was increased in intracellular reductive and lysosome acidic environments. DOX-loaded nanogels exhibited higher cellular proliferation inhibition to GSH-OEt-pretreated Bel7402 cells at pH 6.5 than to unpretreated cells at pH 7.4. Further studies showed that the loaded DOX and nanogels were internalized into the cells together via both lipid raft/caveolae- and clathrin-mediated endocytic pathways. After internalization, the DOX-loaded nanogels were transported via the specific route in endo/lysosomal system. The loaded DOX was released from the nanogels with the introduction of intracellular GSH and entered the nucleus. This study indicated that the hydrophilicity/hydrophobicity reversable and redox-sensitive nanogels might be used as potential carriers for anticancer drugs, which provided a foundation for designing an effective drug delivery system for cancer therapy.

A strategy is described to prepare epoxy resin nanofibers by combining coaxial electrospinning and traditional hot-curing processes. Core/sheath nanofibers with diameters of 480 +/- 80nm are prepared at flow rates of 0.1 and 2mL h-1 for the core (20%w/v EP and 6% w/v curing agent in ethanol/acetone) and sheath (10% PVP in ethanol) fluids. After the curing of the nanofibers and selective removal of the sheath PVP, EP nanofibers with an average diameter of 210 +/- 60nm are obtained. ATR-FTIR analysis shows that the EP nanofibers display no obvious difference compared with an EP film cast from the core solution. The method presented allows to develop functional EP nanoproducts and to prepare heat-cured resin nanofibers.

A modified coaxial electrospinning process is developed for producing thinner methacrylate-based copolymer nanofibers. With Eudragit® L-100 (EL100) as a model and using a poor volatile solvent N, N-dimethylacetamide (DMAc) as sheath fluid, high quality EL100 nanofibers have been successfully generated using the developing coaxial process. SEM observations demonstrate that the nanofibers by the modified process have better quality than those produced by a single fluid electrospinning in terms of surface smoothness, nanofiber diameters and their distributions. The former has an average diameter of 240±30 nm while the later 490±170 nm. The mechanism is proposed that an appropriate DMAc surrounding to the core polymer jet helps to retain it in a fluid state to experience a longer time and more stable electrical drawing. The modified coaxial electrospinning process described here extends the capability of electrospinning process and opens a new way to obtain thinner polymer nanofibers with fine structural uniformity.

Use polydimethylsiloxane(PDMS) fabricate a microfluidic chip as the sample channel in Ultraviolet integrated biological chip, By re-molding method using the PDMS of the ratio of matrix and curing agent is 10:1 fabricate the substrate of microfluidic chip, using the PDMS of the ratio of matrix and curing agent is 5:1 fabricate the cover sheet and complete the seal of the microfluidic chip. Fabricate the microfluidic chip with the channel width is 100μm, 50μm, 1mm and 2mm.

Understanding the processes involved in the cellular uptake of nanoparticles is critical for developing effective nano drug delivery systems. In this paper we found that PEG-b-PLA polymeric micelles firstly interacted with cell membrane using atomic force microscopy (AFM) and then released their core-loaded agents into the cell membrane by fluorescence resonance energy transfer (FRET). The released agents were internalized into the cells via lipid raft/caveolae-mediated endocytosis using total internal reflection fluorescence microscopy (TIRFM) and endocytic inhibitors. Further studies revealed that paclitaxel (PTX)-loaded PEG-b-PLA micelles (M-PTX) increased the cellular accumulation of PTX in PTX-resistant human ovarian cell line A2780/T which resulted in more apoptosis as measured by flow cytometry and the cleavage of poly (ADP-ribose) polymerase (PARP) compared with free PTX. PEG-b-PLA micelles inhibited P-glycoprotein (Pgp) function and Pgp ATPase activity but had no effect on Pgp protein expression. The membrane microenvironment studies showed that PEG-b-PLA micelles induced cell membrane depolarization and enhanced membrane microviscosity. These results suggested that PEG-b-PLA micelles might inhibit Pgp function to reverse multidrug resistance (MDR) via interaction with cell membrane to affect the membrane microenvironment. This study provides a foundation for understanding the mechanism of reversing MDR by nanoparticles better and designing more effective nano drug carriers.

A series of functionalized resins were synthesized from Merrifield resin by virtue of microwave irradiation. A significant reduction in reaction time was achieved. This method provides a rapid transformation of functionalized resin in solid-phase synthesis.