Sensitive detection of human breast cancer cells based on aptamer–cell–aptamer sandwich architecture

Breast cancer is one of the most critical threats to the health of women, and the development of new methods for early diagnosis is urgently required, so this paper reports a method to detect Michigan cancer foundation-7 (MCF-7) human breast cancer cells with considerable sensitivity and selectivity by using electrochemical technique. In this method, a mucin 1 (MUC1)-binding aptamer is adopted to recognize MCF-7 human breast cancer cells, while enzyme labeling is employed to produce amplified catalytic signals. The molecular recognition and the signal amplification are elaborately integrated by fabricating an aptamer–cell–aptamer sandwich architecture on an electrode surface, thus a biosensor for the detection of MCF-7 is fabricated based on the architecture. The detection range can be from 100 to 1 × 10⁷ cells, and the detection limit can be as low as 100 cells. The method is also cost-effective and conveniently operated, implying potential help for the development of early diagnosis of breast cancer.     

Versatile lipid profiling by liquid chromatography–high resolution mass spectrometry using all ion fragmentation and polarity switching. Preliminary application for serum samples phenotyping related to canine mammary cancer

Lipids represent an extended class of substances characterized by such high variety and complexity that makes their unified analyses by liquid chromatography coupled to either high resolution or tandem mass spectrometry (LC–HRMS or LC–MS/MS) a real challenge. In the present study, a new versatile methodology associating ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC–HRMS/MS) have been developed for a comprehensive analysis of lipids. The use of polarity switching and “all ion fragmentation” (AIF) have been two action levels particularly exploited to finally permit the detection and identification of a multi-class and multi-analyte extended range of lipids in a single run. For identification purposes, both higher energy collision dissociation (HCD) and in-source CID (collision induced dissociation) fragmentation were evaluated in order to obtain information about the precursor and product ions in the same spectra. This approach provides both class-specific and lipid-specific fragments, enhancing lipid identification. Finally, the developed method was applied for differential phenotyping of serum samples collected from pet dogs developing spontaneous malignant mammary tumors and health controls. A biological signature associated with the presence of cancer was then successfully revealed from this lipidome analysis, which required to be further investigated and confirmed at larger scale.     

Synthesis and Characterization of Iron Nanowires

The iron nanowires can be fabricated via the process in which sodium borohydride reduces iron salts in external magnetic field. The iron nanowires are found to be covered by passivated layers of iron oxide which prevent the oxidation of iron nanowires. In this process, the boron will include in iron nanowires. The average length and diameter of iron nanowires is around 1.2 micrometers and 60 nanometers, respectively. According to ICP results, the contents of B and Fe are about 1.98 wt% and 87.04 wt%, respectively, in iron nanowires. A wide variety of equipment is used to investigate the morphological, microchemical, and structural characteristics of the newly synthesized iron nanowires ––– e.g., XRD, FE‐SEM, HR‐TEM, VSM and XANES. XANES analysis indicates the boron in iron nanowires exists in the form of B₂O₃. The saturation magnetization and the coercive force of iron nanowires are 157.93 emu/g and 9.74 Oe, respectively. In‐situ images of synthesized iron nanowires during reduction process in magnetic field are observed by NSRRC transmission X‐ray microscope. Thus, this study develop a novel process to produce iron nanowires with large quantitates and can control its length and diameter by various the concentration of precursors for various applications.     

The cytotoxic activities of imidazole derivatives prepared from various guanylhydrazone and phenylglyoxal monohydrate

Abstract

A series of imidazole derivatives were synthesized from two-component condensation reaction of phenylgloxal monohydrate with guanylhydrazone. They were characterized by spectroscopic and analytical techniques. The in vitro anticancer evaluation of these compounds was done on human breast cancer (MCF-7) and human liver cancer (HepG2) cell lines using the MTT assay method. Most of the newly synthesized compounds displayed cytotoxic activity against these cancerous cells. In fact, compounds 3a, 3e, and 3?h exhibited more cytotoxic activities than the positive control drugs, fluro-5, and irinocam, against the MCF-7 cell line. Almost all the compounds, except for three, 3b, 3d, and 3f, gave more cytotoxic results than cisplatin. Therefore, these compounds could be considered for further development as anticancer drug candidates.     

A microfluidic chip‐based fluorescent biosensor for the sensitive and specific detection of label‐free single‐base mismatch via magnetic beads‐based “sandwich” hybridization strategy

A novel microfluidic chip‐based fluorescent DNA biosensor, which utilized the electrophoretic driving mode and magnetic beads‐based “sandwich” hybridization strategy, was developed for the sensitive and ultra‐specific detection of single‐base mismatch DNA in this study. In comparison with previous biosensors, the proposed DNA biosensor has much more robust resistibility to the complex matrix of real saliva and serum samples, shorter analysis time, and much higher discrimination ability for the detection of single‐base mismatch. These features, as well as its easiness of fabrication, operation convenience, stability, better reusability, and low cost, make it a promising alternative to the SNPs genotyping/detection in clinical diagnosis. By using the biosensor, we have successfully determined oral cancer‐related DNA in saliva and serum samples without sample labeling and any preseparation or dilution with a detection limit of 5.6 × 10^?11 M, a RSD (n = 5) < 5% and a discrimination factor of 3.58–4.54 for one‐base mismatch.     

Characterization of a hybrid dielectrophoresis and immunocapture microfluidic system for cancer cell capture

The capture of circulating tumor cells (CTCs) from cancer patient blood enables early clinical assessment as well as genetic and pharmacological evaluation of cancer and metastasis. Although there have been many microfluidic immunocapture and electrokinetic techniques developed for isolating rare cancer cells, these techniques are often limited by a capture performance tradeoff between high efficiency and high purity. We present the characterization of shear‐dependent cancer cell capture in a novel hybrid DEP–immunocapture system consisting of interdigitated electrodes fabricated in a Hele‐Shaw flow cell that was functionalized with a monoclonal antibody, J591, which is highly specific to prostate‐specific membrane antigen expressing prostate cancer cells. We measured the positive and negative DEP response of a prostate cancer cell line, LNCaP, as a function of applied electric field frequency, and showed that DEP can control capture performance by promoting or preventing cell interactions with immunocapture surfaces, depending on the sign and magnitude of the applied DEP force, as well as on the local shear stress experienced by cells flowing in the device. This work demonstrates that DEP and immunocapture techniques can work synergistically to improve cell capture performance, and it will aid in the design of future hybrid DEP–immunocapture systems for high‐efficiency CTC capture with enhanced purity.     

Novel monofunctionalized electron-deficient anthraquinone-based discotic liquid crystals

A series of electron-deficient 1-hydroxy-2,3,5,6,7-pentaalkoxyanthra-9,10-quinones has been synthesized. All nine members of the series were found to be liquid crystalline, forming columnar mesophases over a broad temperature range. Such supramolecular building blocks can be used for the preparation of novel discotic dimers, oligomers, polymers and metallomesogens.     

Formation of Glyco-Functionalized Platinum Complexes by Cross-Metathesis and Evaluation of Their Efficacy in Inhibition of Lung Tumor Cell Lines

Syntheses of carbohydrate-functionalized platinum complexes resembling presently employed cytostatics were performed. Mono-allylated sugar substrates obtained in two steps from glucose and galactose were connected with 2-allyl diethyl malonate by cross-metathesis. Following hydrogenation and acidic cleavage of the ester and alkylidene functionalities gave dicarboxylated glycoconjugates, which were transformed into their diammine platinum complexes. The antitumor activities of these platinum complexes were checked by sensitivity testing with 11 lung cancer cell lines. The novel glucose-platinum complex proved to be comparable to the drug carboplatin.     

A Designed 5‐Fluorouracil‐Based Bridged Silsesquioxane as an Autonomous Acid‐Triggered Drug‐Delivery System

Two new prodrugs, bearing two and three 5‐fluorouracil (5‐FU) units, respectively, have been synthesized and were shown to efficiently treat human breast cancer cells. In addition to 5‐FU, they were intended to form complexes through H‐bonds to an organo‐bridged silane prior to hydrolysis‐condensation through sol–gel processes to construct acid‐responsive bridged silsesquioxanes (BS). Whereas 5‐FU itself and the prodrug bearing two 5‐FU units completely leached out from the corresponding materials, the prodrug bearing three 5‐FU units was successfully maintained in the resulting BS. Solid‐state NMR (²⁹Si and ¹³C) spectroscopy show that the organic fragments of the organo‐bridged silane are retained in the hybrid through covalent bonding and the ¹H NMR spectroscopic analysis provides evidence for the hydrogen‐bonding interactions between the prodrug bearing three 5‐FU units and the triazine‐based hybrid matrix. The complex in the BS is not affected under neutral medium and operates under acidic conditions even under pH as high as 5 to deliver the drug as demonstrated by HPLC analysis and confirmed by FTIR and ¹³C NMR spectroscopic studies. Such functional BS are promising materials as carriers to avoid the side effects of the anticancer drug 5‐FU thanks to a controlled and targeted drug delivery.     

Multifunctional Core‐Shell‐Corona‐Type Polymeric Micelles for Anticancer Drug‐Delivery and Imaging

We have developed core‐shell‐corona‐type polymeric micelles that can integrate multiple functions in one system, including the capability of accommodating hydrophobic dyes into core and hydrophilic drug into the shell, as well as pH‐triggered drug‐release. The neutral and hydrophilic corona sterically stabilizes the multifunctional polymeric micelles in aqueous solution. The mineralization of calcium phosphate (CaP) on the PAA domain not only enhances the diagnostic efficacy of organic dyes, but also works as a diffusion barrier for the controlled release.