The Graphene Quantum Dots Gated Nanoplatform for Photothermal-Enhanced Synergetic Tumor Therapy.

Currently, the obvious side effects of anti-tumor drugs, premature drug release, and low tumor penetration of nanoparticles have largely reduced the therapeutic effects of chemotherapy. A drug delivery vehicle (MCN-SS-GQDs) was designed innovatively. For this, the mesoporous carbon nanoparticles (MCN) with the capabilities of superior photothermal conversion efficiency and high loading efficiency were used as the skeleton structure, and graphene quantum dots (GQDs) were gated on the mesopores via disulfide bonds. The doxorubicin (DOX) was used to evaluate the pH-, GSH-, and NIR-responsive release performances of DOX/MCN-SS-GQDs. The disulfide bonds of MCN-SS-GQDs can be ruptured under high glutathione concentration in the tumor microenvironment, inducing the responsive release of DOX and the detachment of GQDs. The local temperature of a tumor increases significantly through the photothermal conversion of double carbon materials (MCN and GQDs) under near-infrared light irradiation. Local hyperthermia can promote tumor cell apoptosis, accelerate the release of drugs, and increase the sensitivity of tumor cells to chemotherapy, thus increasing treatment effect. At the same time, the detached GQDs can take advantage of their extremely small size (5-10 nm) to penetrate deeply into tumor tissues, solving the problem of low permeability of traditional nanoparticles. By utilizing the photothermal properties of GQDs, synergistic photothermal conversion between GQDs and MCN was realized for the purpose of synergistic photothermal treatment of superficial and deep tumor tissues.

Customized multi-stimuli nanovehicles with dissociable 'bomblets' for photothermal-enhanced synergetic tumor therapy.

Recently, the therapeutic effect of chemotherapy has been obviously impaired due to premature drug release, low tumor penetration, and multidrug resistance of nanoplatforms. In this paper, a novel multiple-sensitive drug delivery system (MC-ss-CDs) was developed by gating long-wavelength emitting carbon dots (CDs) on the openings of mesoporous carbon nanoparticles (MC) through disulfide bonds. The MC with excellent photothermal transition efficiency and high drug storage capacity for doxorubicin (DOX) was used as the delivery carrier. The CDs had multiple functions, including intelligent switching to hinder unwanted release, photothermal therapy (PTT) agents to improve the heat generation effect of MCs and bioimaging trackers to monitor drug delivery. The disulfide bonds, as the linkers between MC carriers and CDs, are stable under normal physical conditions and relatively labile under high GSH concentrations in the cytoplasm of tumor cells. After arriving at the tumor microenvironment, DOX/MC-ss-CDs can rapidly break into DOX/MC and CDs under high GSH concentrations. DOX/MC could realize efficient integration of PTT and chemotherapy on the surface of the tumor by stimuli-responsive DOX release and synergetic heating of MC and CDs. The small-sized CDs with excellent penetrating ability could effectively enter the deep tumor and realize NIR-triggered photothermal ablation. The DOX/MC-ss-CDs showed a chemophotothermal effect with a combination index of 0.38 in vitro and in vivo. Therefore, the DOX/MC-ss-CDs could be employed as a trackable nanovehicle for synergistic chemotherapy and PTT at different depths.

Cancer cell membrane-coated mesoporous silica loaded with superparamagnetic ferroferric oxide and Paclitaxel for the combination of Chemo/Magnetocaloric therapy on MDA-MB-231 cells.

To effectively inhibit the growth of breast cancer cells (MDA-MB-231 cells) by the combination method of chemotherapy and magnetic hyperthermia, we fabricated a biomimetic drug delivery (CSiFePNs) system composed of mesoporous silica nanoparticles (MSNs) containing superparamagnetic ferroferric oxide and Paclitaxel (PTX) coated with MDA-MB-231 cell membranes (CMs). In the in vitro cytotoxicity tests, the MDA-MB-231 cells incubated with CSiFePNs obtained IC50 value of 0.8 µgL-1, 3.5-fold higher than that of SiFePNs. The combination method of chemotherapy and magnetic hyperthermia can effectively inhibit the growth of MDA-MB-231 cells.

Development of a matrix solid-phase dispersion extraction combined with high-performance liquid chromatography for determination of five lignans from the Schisandra chinensis.

A method based on a simplified sample extraction by matrix solid phase dispersion (MSPD) followed by HPLC determination is validated for analysis of five lignans in Schisandra chinensis. The MSPD parameters that affect the extraction efficiency of lignans from S. chinensis were examined and optimized. The optimal extraction conditions were determined to be that silica gel was used as dispersing sorbent, the ratio of silica gel to sample mass was selected to be 2:1, and 4mL of methanol was used as elution solvent. The method recoveries were determined to be from 92.25 to 101.17% and the RSDs from 1.3 to 4.9%. The extraction yields of five lignans obtained by the MSPD were higher than those of traditional reflux and sonication extraction with reduced requirements on sample, solvent and time. In addition, the optimized method was applied for analyzing five real S. chinensis samples obtained from different cultivated areas.

Multiwalled-carbon-nanotubes-based matrix solid-phase dispersion extraction coupled with high-performance liquid chromatography for the determination of honokiol and magnolol in Magnoliae Cortex.

In this paper, multiwalled-carbon-nanotube-based matrix solid-phase dispersion coupled to HPLC with diode array detection was used to extract and determine honokiol and magnolol from Magnoliae Cortex. The extraction efficiency of the multiwalled-carbon-nanotube-based matrix solid-phase dispersion was studied and optimized as a function of the amount of dispersing sorbent, volume of elution solvent, and flow rate of elution solvent, with the aid of response surface methodology. An amount of 0.06 g of carboxyl-modified multiwalled carbon nanotubes and 1.5 mL of methanol at a flow rate of 1.1 mL/min were selected. The method obtained good linearity (r(2) > 0.9992) and precision (RSD < 4.7%) for honokiol and magnolol, with limits of detection of 0.045 and 0.087 µg/mL, respectively. The recoveries obtained from analyzing in triplicate spiked samples were determined to be from 90.23 to 101.10% and the RSDs from 3.5 to 4.8%. The proposed method that required less samples and reagents was simpler and faster than Soxhlet and maceration extraction methods. The optimized method was applied for analyzing five real samples collected from different cultivated areas.

Matrix solid-phase dispersion extraction followed by HPLC-diode array detection method for the determination of major constituents in a traditional Chinese medicine Folium isatidis (Da-qing-ye).

A simple and low-cost method based on matrix solid-phase dispersion (MSPD) extraction, HPLC separation, and diode array detection has been developed for the determination of indigo and indirubin in Folium isatidis. The experimental parameters that may affect the MSPD method, including dispersing sorbent, ratio of dispersing sorbent to sample, elution solvent, and volume of the elution solvent were examined and optimized. The optimized conditions were determined to be that C18 was used as dispersing sorbent, the ratio of C18 to sample mass was selected to be 4:1, and 10 mL of N,N-dimethyl formamide was used as elution solvent. The highest extraction yields of the two compounds were obtained under the optimized conditions. The method showed good linearity (r > 0.9995) and precision (RSD < 3.0%) for indigo and indirubin, with the limits of detection of 18 and 22.5 ng/mL, respectively. The recoveries were in the range of 90.33-100.74% with RSD values ranging from 1.7 to 3.6%. Comparing to ultrasonic and Soxhlet methods, the proposed MSPD procedure was more convenient and less time-consuming with reduced requirements on sample and solvent amounts. The proposed procedure was applied to analyzed three real samples that were collected from different localities.

Matrix solid-phase dispersion extraction coupled with HPLC-diode array detection method for the analysis of sesquiterpene lactones in root of Saussurea lappa C.B.Clarke.

We developed a reliable and effective method to determine costunolide and dehydrocostuslactone in the root of Saussurea lappa C. B.Clarke using matrix solid-phase dispersion (MSPD) extraction, HPLC separation and diode array detection (DAD). Several extraction parameters for the MSPD were optimized. Florisil was chosen as dispersing adsorbent with methanol as elution solvent. The ratio of Florisil to sample was selected to be 4:1 and no additional clean-up steps were needed. Linearities (r>0.9995) were determined to be in the range of 22.5-360.0 µg/mL for costunolide and 25.0-400.0 µg/mL for dehydrocostuslactone. Intra- and inter-day precisions were also determined with a relative standard deviation (RSD) less than 3.2%. The limits of detection were found to be 0.122 µg/mL for costunolide and 0.135 µg/mL for dehydrocostuslactone. The recoveries were in the range of 92.5-99.8% with relative standard deviations ranged from 1.2% to 3.5%. The proposed MSPD method required shorter time and lower solvent volume than maceration-ultrasonic and Soxhlet extraction methods.