Feasibility of Raman spectroscopic identification of gall bladder cancer using extracellular vesicles extracted from bile.

Extracellular vesicles (EVs), which are heterogeneous membrane-based vesicles with bilayer cell membrane structures, could be versatile biomarkers for the identification of diverse diseases including cancers. With this potential, this study has attempted the Raman spectroscopic identification of gall bladder (GB) cancer by directly measuring the EV solution extracted from human bile without further sample drying. For this purpose, bile samples were obtained from four normal individuals and 21 GB polyp, eight hepatocellular carcinoma (HCC), and five GB cancer patients, and EVs were extracted from each of the bile samples. The Raman peak shapes of the EVs extracted from the GB cancer samples, especially the relative intensities of peaks in the 1560-1340 cm-1 range, were dissimilar to those of the samples from the normal, GB polyp, and HCC groups. The intensity ratios of peaks at 1537 and 1453 cm-1 and at 1395 and 1359 cm-1 of the GB cancer samples were lower and higher, respectively, than those of the samples of the remaining three groups. The differences of peak intensity ratios were statistically significant based on the Mann-Whitney U test. DNA/RNA bases, amino acids, and bile salts contributed to the spectra of EVs, and their relative abundances seemed to vary according to the occurrence of GB cancer. The varied metabolite compositions and/or structures of EVs were successfully demonstrated by the dissimilar peak intensity ratios in the Raman spectra, thereby enabling the discrimination of GB cancer.

Feasibility for SERS-based discrimination of gallbladder cancer from polyp by indirect recognition of components in bile.

The aqueous solution extracted from raw bile juice is composed primarily of bile salts, with lower levels of bilirubin and its derivatives. Among them, the bilirubin and bilirubin-derived metabolites are the only surface-enhanced Raman scattering (SERS)-active components. An analytical scheme indirectly responsive and able to utilize all bile components, including SERS-inactive bile salts, was explored for SERS-based discrimination of gallbladder (GB) polyp and GB cancer. Initially, the surface of a SERS substrate (Au nanodendrite on Ni foil (AuND@NiF)) was covered with an alkanethiol molecule to generate a SERS signal and attract bile components by mutual interaction. For more effective recognition of bile components, 4 independent substrates covered with 4 different alkanethiols with various functional groups (SH(CH2)2CH3, SH(CH2)2NH2, SH(CH2)2COOH, and SH(CH2)2OH) were prepared. The SERS peaks of each substrate clearly varied on interaction with pure bile components as well as aqueous bile samples, and the SERS peaks in each substrate were individually characteristic. When the principal component (PC) scores of spectra obtained using the SH(CH2)2CH3- and SH(CH2)2OH-covered substrates were combined, the k-Nearest Neighbor-based discrimination accuracy was 100%, superior to those (90.6-96.9%) using individual substrates. The use of complementary bile component-induced spectral information provided by the two substrates was responsible for accurate discrimination. On the other hand, when bare AuND@NiF recognizing only SERS-active bilirubin derivatives was used, discrimination was unsatisfactory (accuracy: 75.0%).

Development of Universal and Lineage-Specific Primer Sets for Rapid Detection of the Zika Virus (ZIKV) in Blood and Urine Samples Using One-Step Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP).

Zika is a mosquito-borne disease that has been posing a significant threat to public health in recent years. The Zika virus (ZIKV), the causative agent of this disease, is classified into 2 distinct genetic lineages, namely Asian and African. While molecular nucleic acid analysis methods have been shown to be useful for the diagnosis of ZIKV infection, the development of assays based on one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) offers several advantages, such as shorter incubation times, ease of handling, and rapid detection. In this study, a universal LAMP primer set was developed to target conserved sequences of known ZIKV lineages. Additionally, the Af7462 and As1788 primer sets were designed based on LAMP-based single-nucleotide polymorphism (SNPs) typing for the specific detection of the African and Asian lineages. The developed RT-LAMP assays could specifically detect the African and Asian lineages of ZIKV, with a detection limit ranging from 0.17 FFU/mL to 2.3×102 FFU/mL. As ZIKV viremia ranges between 102 to 106 PFU/mL or 103 to 106 copies/mL, the data indicate that the viremia range of clinical samples is within the detection range of our assay. Due to the high specificity and sensitivity, as well as the ease of use of our assay, it could potentially be used for early clinical diagnosis applications.

Adsorption of Polyelectrolyte onto Nanosilica Synthesized from Rice Husk: Characteristics, Mechanisms, and Application for Antibiotic Removal.

Adsorption of the polyelectrolyte polydiallyldimethylammonium chloride (PDADMAC) onto nanosilica (SiO2) fabricated from rice husk was studied in this work. Nanosilica was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Adsorption of PDADMAC onto SiO2 increased with increasing pH because the negative charge of SiO2 is higher at high pH. Adsorption isotherms of PDADMAC onto silica at different KCl concentrations were fitted well by a two-step adsorption model. Adsorption mechanisms of PDADMAC onto SiO2 are discussed on the basis of surface charge change, evaluation by ζ potential, surface modification by FTIR measurements, and the adsorption isotherm. The application of PDADMAC adsorption onto SiO2 to remove amoxicillin antibiotic (AMX) was also studied. Experimental conditions such as contact time, pH, and adsorbent dosage for removal of AMX using SiO2 modified with PDADMAC were systematically optimized and found to be 180 min, pH 10, and 10 mg/mL, respectively. The removal efficiency of AMX using PDADMAC-modified SiO2 increased significantly from 19.1% to 92.3% under optimum adsorptive conditions. We indicate that PDADMAC-modified SiO2 rice husk is a novel adsorbent for removal of antibiotics from aqueous solution.

Preparation and properties of silver nanoparticles loaded in activated carbon for biological and environmental applications.

Silver nanoparticles colloid has been prepared by a modified sonoelectrodeposition technique in which a silver plate was used as the source of silver ions. This technique allows producing Ag nanoparticles with the size of 4-30 nm dispersed in a non-toxic solution. The Ag nanoparticles were loaded in a high surface activated carbon produced from coconut husk, a popular agricultural waste in Vietnam by thermal activation. The surface area of the best activated carbon is 890 m(2)/g. The presence of Ag nanoparticles does not change significantly properties of the activated carbon in terms of morphology and methylene blue adsorption ability. The Ag nanoparticle-loaded activated carbon shows a good antibacterial activity against Escherichia coli with very low minimal inhibitory concentration of 16 µg/ml and strong As(V) adsorption. The materials are potential for prevention and treatment of microbial infection and contamination for environmental applications.