Functionalized mesoporous carbon nanoparticles for targeted chemo-photothermal therapy of cancer cells under near-infrared irradiation

Chemo-photothermal therapy with the combination of chemotherapy and photothermal therapy has emerged as a promising anticancer treatment for its synergistic effects. In this work, the functionalized mesoporous carbon nanoparticles (FA/PEI/O-MCN) were constructed by modifying the mesoporous carbon nanoparticles (MCN) with polyethylenimine (PEI) and folic acid (FA) for the targeted chemophotothermal therapy. The FA/PEI/O-MCN exhibited strong light absorption and high photothermal conversion efficiency in the near-infrared (NIR) region due to the graphitic structure of MCN. Meanwhile, FA/PEI/O-MCN displayed high drug loading capacity using doxorubicin hydrochloride (DOX) as a model drug. Flow cytometry analysis and competitive binding experiments verified that the FA modification could significantly enhance the uptake of FA/PEI/O-MCN by HeLa cells with folate receptors (FR) over-expressing. Comparing with chemotherapy or photothermal therapy alone, the DOX-loaded FA/PEI/OMCN demonstrated the synergistic effects and resulted in the higher therapeutic efficacy. We believe that the FA/PEI/O-MCN could be applied as an efficient chemo-photothermal platform to realize the targeted synergistic therapy

Preparation of organic-silica hybrid monolithic columns via crosslinking of functionalized mesoporous carbon nanoparticles for capillary liquid chromatography

An organic-silica hybrid monolithic capillary column was fabricated by crosslinking (3-aminopropyl)trimethoxysilane (APTMS) modified mesoporous carbon nanoparticles (AP-MCNs) with tetramethoxysilane (TMOS) and n-butyltrimethoxysilane (C4-TriMOS). Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, mercury intrusion porosimetry and inverse size-exclusion chromatography characterization proved the successful immobilization of mesoporous carbon nanoparticles (MCNs). The crosslinking of AP-MCNs into the hybrid monolithic matrix has significantly increased the reversed-phase retention of alkylbenzenes and chromatographic performance for small molecules separations in comparison with the neat one without MCNs. The resulting column efficiency of the mesoporous carbon nanoparticle-based butyl-silica hybrid monolithic column (MCN-C4-monolith) was up to ca. 116,600 N/m for the capillary liquid chromatography (cLC) separation of butylbenzene. Enhanced performance of proteins separation was achieved on the MCN-C4-monolith in comparison with the butyl-silica hybrid monolithic column without MCN (C4-monolith). The separation of peptides from bovine serum albumin (BSA) digest was carried out on the MCN-C4-monolith by capillary liquid chromatography-tandem mass spectrometry (cLC-MS/MS) with protein sequence coverage of 81.9%, suggesting its potential application in proteomics. (C) 2017 Elsevier B.V. All rights reserved

Structural isomer and high-yield of Pt1Ag28 nanocluster via one-pot chemical wet method

In order to understand the structure-property correlation and explore the application of metal nanoclusters, it is important and intriguing to determine their crystal structure and obtain high-yield. At the same time, this is also a challenge in nanoscience and technology. Here, we report the highly efficient synthesis of Pt1Ag28 nanocluster via one-pot chemical wet method. The crystal structure of Pt1Ag28 nanocluster was determined by X-ray crystallography to be a face centered cubic (FCC) kernel. This novel structure is the structural isomerization of Pt1Ag28 nanocluster reported before. This phenomenon is first discovered in the synthesis of alloy nanoclusters. In addition, Pt1Ag28 nanocluster has high yield and exhibits potential optics in the near infrared (NIR) fluorescent imaging. The time-dependent density functional theory (TD-DFT) calculation implied that the optical property of Pt1Ag28 was sensitive to its structure. This work provides a simple method to synthesize alloy nanoclusters with structural isomerization

A homogeneous carbon nanosphere film-spot: For highly efficient laser desorption/ionization of small biomolecules

In this work, a novel strategy for highly efficient detection of small molecules with a homogeneous carbon nanosphere film-spot (HCNFs) was carried out for the first time by negative surface-assisted laser desorption/ionization time-of-flight mass spectroscopy (SALDI-TOF MS). The HCNFs was fabricated by monolayer oxidized carbon nanospheres (OCS) self-assembling on laser desorption/ionization (LDI) target. With the HCNFs, no background interference and exclusive deprotonated ([M-H] ) peaks of analytes were obtained for a wide range of small biomolecules including fatty acids, amino acids, nucleobases, traditional Chinese medicines, and anti-cancer drugs in the negative SALDI-TOF MS. Comparing with other carbon-based matrices as well as the organic matrix, the monolayer OCS film exhibited various advantages including fewer interfering fragments, stronger signal intensities, and higher detection sensitivity. Moreover, with the improved spotting homogeneity of the HCNFs, "sweetspot" searching on LDI target was avoided and good reproducibility was obtained in the LDI-TOF MS analysis. This study is expanding the application of carbon nanospheres and providing a promising approach for rapid analysis of small molecules with none-interference and good reproducibility. (C) 2017 Elsevier Ltd. All rights reserved

In vivo detection of magnetic labeled oxidized multi-walled carbon nanotubes by magnetic resonance imaging

Functionalized carbon nanotubes (f-CNTs) have been widely used in bio-medicine as drug carriers, bio-sensors, imaging agents and tissue engineering additives, which demands better understanding of their in vivo behavior because of the increasing exposure potential to humans. However, there are limited studies to investigate the in vivo biodistribution and elimination of f-CNTs. In this study, superparamagnetic iron oxides (SPIOs) were used to label oxidized multiwalled carbon nanotubes (o-MWCNTs) for in vivo distribution study of o-MWCNTs by magnetic resonance imaging (MRI). SPIO labeled o-MWCNTs (((SPIO))o-MWCNTs) were prepared by a hydrothermal reaction process, and characterized by TEM, XRD and magnetometer. ((SPIO))o-MWCNTs exhibited superparamagnetic property, excellent biocompatibility and stability. The intravenously injected ((SPIO))o-MWCNTs were observed in liver, kidney and spleen, while the subcutaneously injected ((SPIO))o-MWCNTs could be only detected in sub mucosa. Most of the intravenously injected ((SPIO))o-MWCNTs could be eliminated from liver, spleen, kidney and sub mucosa on 4 d post injection (P.I.). However, the residual o-MWCNTs could induce 30-40% MRI signal-to-noise ratio changes in these tissues even on 30 d P.I. This in vivo biodistribution and elimination information of o-MWCNTs will greatly facilitate the application of f-CNT based nanoproducts in biomedicine. In addition, the magnetic labeling method provides an approach to investigate the in vivo biodistribution and clearance of other nanomaterials

Preparation of phenyl-silica hybrid monolithic column with "one-pot" process for capillary liquid chromatography

A phenyl-silica hybrid monolithic column for capillary liquid chromatography (cLC) was prepared through "one-pot" process by con-currently using benzyl methacrylate and alkoxysilanes. The effects of the molar ratio of tetramethoxysilane/vinyltrimethoxysilane (TMOS/VTMS), polycondensation temperature, content of supramolecule template (cetyltrimethylammonium bromide, CTAB), ratio of N,N'-dimethylformamide/methanol (v/v), the volume of benzyl methacrylate on the morphologies of the prepared phenyl-silica hybrid monolithic columns were investigated in detail. The permeability of the hybrid monolithic column was calculated as 3.23 x 10(-13) m(2), and the minimum plate height was determined as 8.38 mu m which corresponding to 119,000 theoretical plates per meter. Separation of various neutral, polar and basic analytes as well as small peptides on the hybrid monolithic column was achieved by cLC and showed high efficiency and satisfactory reproducibility. Moreover, the prepared hybrid monolithic column was also applied for the analysis of Cryptic digests of bovine serum albumin (BSA), ovalbumin, a-casein, cytochrome C and myoglobin by cLC tandem mass spectrometry (cLC-MS/MS), and the results showed that the separation performance was close to that of the octadecylsilane (C18) packed capillary column which demonstrating its potential in proteome analysis. Moreover, since the prepolymerization system was mainly consisted of organic solvents (methanol and N,N'-dimethylformamide). various hydrophobic monomers could be potentially used to prepare organic-silica hybrid monolithic columns through "one-pot" approach. (C) 2011 Elsevier B.V. All rights reserved

Facile one-pot synthesized hydrothermal carbon from cyclodextrin: A stationary phase for hydrophilic interaction liquid chromatography

A new hydrothermal carbon was prepared by a "one-pot" hydrothermal transformation of beta-cyclodextrin on silica microspheres (noted as silica@HTC microspheres), which was featuring as anew stationary phase for the hydrophilic interaction liquid chromatography (HILIC). The synthesized silica@HTC possessed polar groups of hydroxyl, carbonyl and carboxyl groups arising from the carbonization transformation of beta-cyclodextrin. As demonstrating great hydrophilicity, the silica@HTC was applied as an excellent HILIC stationary phase for the separation of polar compounds including phenols and the endocrine disrupting chemicals (EDCs). In comparison with commercial available HILIC stationary phases, the separation performance of the silica@HTC stationary phase was superior in the separation of phenols and EDCs. The mild hydrothermal carbon transformation of the beta-cyclodextrin on the silica microspheres in the "one-pot" manner would represent a new and simple approach to prepare a new class of saccharide-derived stationary phases by using sacharides as precursors. (C) 2018 Elsevier B.V. All rights reserved

Highly Specific Enrichment of Multi-phosphopeptides by the Diphosphorylated Fructose-Modified Dual-Metal-Centered Zirconium-Organic Framework

Multisite phosphorylation of a protein, generally occurring in biological processes, plays important roles in the regulation of cellular functions. However, the identification of multi-phosphopeptides especially at low abundance is a big challenge as the extreme hydrophilicity and poor ionization efficiency of the multiphosphorylated peptides restrict the deep inspection of multisite phosphorylation processes. In this study, the highly specific enrichment of multiphosphorylated peptides was achieved via the modification of the dual-metal-centered zirconium-organic framework with the diphosphorylated fructose. The diphosphorylated fructose-modified dual-metal-centered zirconium-organic framework (DZMOF-FDP) demonstrated the highly specific affinity to the multiple phosphorylated peptides, with the density functional theory calculations explaining the plausible mechanism for multi-phosphopeptides on the DZMOF-FDP. The selective capture of multi-phosphopeptides from mimic samples confirmed the superior performance of the DZMOF-FDP, with comprehensive comparisons to other modification agents, such as orthophosphate and pyrophosphate. A number of 1871 multiphosphorylated peptides captured by DZMOF-FDP from tryptic digests of HeLa cell lysate could be identified, significantly higher than that by the pristine DZMOF. The deliberately designed modification with diphosphorylated fructose for the dual-zirconium-centered metal-organic framework materials suggests an efficient strategy to develop new enrichment methods in the selective capture of target analytes by judiciously optimizing specific modifiers for adsorbents