Combining the Photocatalysis and Absorption Properties of Core-Shell Cu-BTC@TiO2 Microspheres: Highly Efficient Desulfurization of Thiophenic Compounds from Fuel.

A core-shell Cu-benzene-1,3,5-tricarboxylic acid (Cu-BTC)@TiO2 was successfully synthesized for photocatalysis-assisted adsorptive desulfurization to improve adsorptive desulfurization (ADS) performance. Under ultraviolet (UV) light irradiation, the TiO2 shell on the surface of Cu-BTC achieved photocatalytic oxidation of thiophenic S-compounds, and the Cu-BTC core adsorbed the oxidation products (sulfoxides and sulfones). The photocatalyst and adsorbent were combined using a distinct core-shell structure. The morphology and structure of the fabricated Cu-BTC@TiO2 microspheres were verified by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray powder diffraction, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy analyses. A potential formation mechanism of Cu-BTC@TiO2 is proposed based on complementary experiments. The sulfur removal efficiency of the microspheres was evaluated by selective adsorption of benzothiophene (BT) and dibenzothiophene (DBT) from a model fuel with a sulfur concentration of 1000 ppmw. Within a reaction time of 20 min, the BT and DBT conversion reached 86% and 95%, respectively, and achieved ADS capacities of 63.76 and 59.39 mg/g, respectively. The BT conversion and DBT conversion obtained using Cu-BTC@TiO2 was 6.5 and 4.6 times higher, respectively, than that obtained using Cu-BTC. A desulfurization mechanism was proposed, the interaction between thiophenic sulfur compounds and Cu-BTC@TiO2 microspheres was discussed, and the kinetic behavior was analyzed.

A novel self-assembled pH-sensitive targeted nanoparticle platform based on antibody-4arm-polyethylene glycol-pterostilbene conjugates for co-delivery of anticancer drugs.

Recently, antibody-drug conjugates (ADC) have shown potential for cancer immunotherapy by tumor-targeted delivery of anticancer drugs. However, the development of ADC is subject to many restrictions, such as the payloads, stabilities and intracellular uptake of the drugs, which has greatly restricted their clinical application. To overcome these hurdles, in this study, a novel pH-sensitive targeted nanoparticle platform based on a newly synthesized amphipathic antibody-drug conjugate (antibody-4arm-polyethylene glycol-pterostilbene, mAb-4arm-PEG-PS) was fabricated for co-delivery of another anticancer drug (10-hydroxy camptothecin, HCPT). The prepared mAb-4arm-PEG-PS/HCPT nanoparticles (NPs) had a moderate particle size (∼120 nm), a high drug to antibody ratio (∼22.4) and relatively high binary drug loading capacity (∼24.2 wt% HCPT, ∼2.9 wt% PS). Moreover, the mAb-4arm-PEG-PS/HCPT NPs exhibited enhanced intracellular uptake (∼5 fold that of mAb-4arm-PEG-PS conjugates) and excellent cytotoxicity in vitro. In subsequent Daudi lymphoma xenograft assays, compared with free drugs and mAb-4arm-PEG-PS conjugates, the mAb-4arm-PEG-PS/HCPT NPs inhibited tumor growth more efficiently. Our results indicated the great potential of mAb-4arm-PEG-PS/HCPT NPs for targeted co-delivery of anticancer drugs to solid tumors.

Self-Assembled pH and Redox Dual Responsive Carboxymethylcellulose-Based Polymeric Nanoparticles for Efficient Anticancer Drug Codelivery.

To face the growing demand of polymeric nanoparticles with biocompatibility and a drug release profile, in this work, a novel carboxymethylcellulose-based pH and redox dual-responsive polymeric nanoparticle, carboxymethyl cellulose-dithiopropionate hydrazide-8arm-polyethylene glycol-pterostilbene/10-hydroxy camptothecin (CTPP/HCPT), was prepared for efficient drug codelivery. These well-dispersed CTPP/HCPT NPs were prepared with a dimension of around 144 nm and exhibited high binary drug loading capacity and good biocompatibility. The biggest advantage of this design is that these nanoparticles can rapidly release the drug payload responding to intracellular acidic or reductive stimuli, while maintaining sufficient stability under normal physiological conditions. The in vitro drug release study revealed that the HCPT payload released from nanoparticles in a weakly acidic environment with 10 mM reductive glutathione was about 74.8%, which was 3.8-fold higher than under normal physiological conditions (∼19.6%). Further in vitro and in vivo investigation demonstrated that such dual-responsive CTPP/HCPT NPs could potently kill cancer cells and suppress tumor growth with lower adverse effects. All these results suggested that CTPP/HCPT NPs were suitable as potential and effective candidates for cancer therapy.

A novel self-assembled targeted nanoparticle platform based on carboxymethylcellulose co-delivery of anticancer drugs.

Single-drug therapy for cancer is greatly hampered by its non-specific delivery to the target tissue, limited efficacies, poor tolerability, and resistance profiles. In order to overcome these limitations, we developed a new targeted nanoparticle platform for co-delivery of two different anticancer drugs. A conjugate based on carboxymethylcellulose (CMC) was first synthesized by introducing hydrophilic molecules (PEG), target molecules (folate), and drug molecules (betulinic acid) into CMC. Then another anticancer drug hydroxycamptothecine (HCPT) was encapsulated into the nanoparticles from the conjugate using a simple nanoprecipitation method. The obtained nanoparticles possessed appropriate size (∼180 nm), high drug loading efficiency (∼23 wt% BA, 21.15 wt% HCPT), a slow drug release rate, higher blood circulation half-time of free BA (6.4-fold) and HCPT (6.0-fold), and high synergetic activity of BA and HCPT toward cancer cells. Furthermore, the targeted nanoparticles showed rapid cellular uptake by tumor cells. The antitumor effect of the nanoparticles in a mouse tumor xenograft model exhibited a much better tumor inhibition efficacy and fewer side effects than that of BA and HCPT, strongly supporting their application as efficient carriers for anticancer therapy.

Self-assembled targeted folate-conjugated eight-arm-polyethylene glycol-betulinic acid nanoparticles for co-delivery of anticancer drugs.

In this study, a targeted nanoparticle platform for co-delivery of anticancer drugs based on folate-conjugated eight-arm-polyethylene glycol-betulinic acid (F-8arm-PEG-BA) was first presented. F-8arm-PEG-BA was synthesized by introducing target molecules (folate) and drug molecules (betulinic acid, BA) to hydrophilic molecules (8arm-PEG). Then another anticancer drug, hydroxycamptothecin (HCPT), was encapsulated into the self-assembled nanoparticles from the conjugate by a simple nanoprecipitation method. These F-8arm-PEG-BA/HCPT nanoparticles (NPs) had a small size (∼120 nm), acceptable critical aggregation concentration (∼64.8 µg mL-1), and high drug loading (∼18 wt% BA and ∼16 wt% HCPT). Compared to the free drugs, the nanoparticles significantly improved the cellular cytotoxicity and exhibited an obvious synergistic effect by the co-delivery of two different anticancer drugs, BA and HCPT. Pharmacokinetics study revealed the nanoparticles could prolong the circulation of BA and HCPT in the blood. In vivo studies indicated that the nanoparticles enhanced tumor targeting and antitumor activity with lower systemic toxicity. In conclusion, F-8arm-PEG-BA/HCPT NPs have great potential for targeted chemotherapy for cancer.

[Molecular imprinting-flow injection chemiluminescence method for determination of doxycycline hydrochloride].

Doxycycline hydrochloride can enhance the chemiluminescence of potassium ferricyanide and luminol in alkaline medium. So a molecular imprinting-flow-injection chemiluminescence method for the determination of doxycycline hydrochloride was established by using doxycycline hydrochloride-imprinted polymers as recognition material and potassium ferricyanide and luminol as detection system. Doxycycline hydrochloride-imprinted polymer was synthesized using methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker. The linear range is 9.0 x 10(-7)-6.0 x 10(-5) g x mL(-1) and the detection limit is 3.2 x 10(-7) g x mL(-1). The relative standard deviation for 6.0 X 10(-6) g x mL(-1) of doxycycline hydrochloride was 3.5% (n = 9). This method has been successfully applied to the determination of doxycycline hydrochloride in tablets and in urine samples.

Immunosorbent assay microchip system for analysis of human immunoglobulin G on MagnaBind carboxyl derivatized beads.

An immunosorbent assay system was integrated into a PMVS microchip. MagnaBind carboxyl derivatized beads were introduced into a microchannel, and then human immunoglobulin G (IgG) was bound to the bead surface in the microchannel of the chip. Immunoreaction was conducted in the microchannel for the bead-bounded antigen IgG with the antibody FITC-labelled IgG. On-chip detection was performed using a laser-induced fluorescence (LIF) system. The integration shortened the overall analysis time from 7 h to less than 40 min.

Preparation of Z-L-Phe-OH-NBD imprinted microchannel and its molecular recognition study.

An integrated microchip was presented for selective recognition of Z-L-Phe-OH-NBD, using molecular imprinting technique. Molecularly imprinted polymer (MIP) were prepared by copolymerization in the presence of template molecule Z-L-Phe-OH-NBD, in which methacrylic acid and 4-vinylpyridine were used as functional monomers and ethylene dimethacrylate used as crosslinker. Imprinted polymer particles were introduced into a microchannel fabricated with a new material i.e. poly(methylvinylsiloxane) by simply rapid prototyping method. Imprinted effects were evaluated by laser-induced fluorescence (LIF) detection where the results indicated that good selective recognition for Z-L-Phe-OH-NBD in the imprinted polymer was obtained; the adsorption percentage of Z-L-Phe-OH-NBD was 61%. In contrast to conventional molecular imprinting analysis, integration shortened overall analysis time from 4h to 10 min.

[Study on rhG-CSF modified with polyethylene glycol].

Monomethoxy Polyethylene Glycol(mPEG20000) was activated by N-hydroxysuccinimede and analyzed by infrared spectrum and hydrolysis kinetics. In order to propose the optimized reaction conditions of mono-PEGylated rhG-CSF, orthogonal design of the experiment was investigated. Ion exchange chromatography was used to separate and purify PEGylated rhG-CSF from unPEGylated rhG-CSF. The purity of mono-PEGylated rhG-CSF was analyzed by high performance liquid chromatography (HPLC) to be 97%.