Facile preparation of full-color emissive carbon dots and their applications in imaging of the adhesion of erythrocytes to endothelial cells.

Full-color emissive CDs (F-CDs) are synthesized by a green method, which avoids toxic reagents, harsh reaction conditions and multistep processes. The water-soluble, 6 ± 1 nm uniform-sized F-CDs exhibit tunable multicolor emission in gradient colors from blue to red. The emission wavelength and intensity of the fluorescence and the wavelength of the absorption peak can be tuned by controlling the concentration of the F-CD aqueous dispersions.

Gold nanoprobes-based resonance Rayleigh scattering assay platform: Sensitive cytosensing of breast cancer cells and facile monitoring of folate receptor expression.

A rapid, facile assay for sensitive cytosensing of breast cancer cells should help to guide potential medical evaluation for breast cancer. Here, we report development of novel resonance Rayleigh scattering (RRS) cytosensor for cell recognitions and folate (FA) receptor expression analyses on living cells. Using FA-conjugated gold nanoparticles (FA-AuNPs) as nanoprobes, the constructed nanoprobes-assembled recognition interface could increase the binding capacity for cell recognition, amplify Au-aggregates-enhanced RRS signal, and then enhance the sensitivity for membrane antibody assay.

Synthesis and synergetic anti-tumor activity evaluation of dihydroartemisinin-organogermanium(IV) compound.

Dihydroartemisinin (DHA), a semi-synthetic derivative of the herb artemisinin, has shown commendable bioactivity. In this paper, a novel dihydroartemisinin-organogermanium (DHA-Ge) compound was synthesized, characterized and its potential anti-tumor activity was evaluated by various methods. MTT results demonstrated that DHA-Ge could effectively inhibit the proliferation of HepG2 cells and showed their dose-dependent properties.

Facile synthesis of multifunctional germanium nanoparticles as a carrier of quercetin to achieve enhanced biological activity.

A simple method for preparing quercetin surface-functionalized germanium nanoparticles (Qu-GeNPs) with enhanced antioxidant and anticancer activity is reported. Spherical germanium nanoparticles (GeNPs) were capped by quercetin (Qu) with a mean particle size of approximately 33 nm and were characterized by TEM, AFM, UV-visible absorption spectroscopy, FTIR, and XRD measurements. The in vitro drug release of Qu from the Qu-GeNPs indicated that Qu could principally be distributed around tumor tissues rather than in the normal section and Qu-GeNPs were internalized by MCF-7 cells.

A novel strategy for real-time and in situ detection of cytochrome c and caspase-9 in Hela cells during apoptosis.

Cytochrome c (cyt c) and caspase-9 were critical biomarkers in mitochondria-mediated apoptosis. A novel electrochemical immunosensor was developed for in situ analysis of cyt c and caspase-9 in the cytosol. Gold nanoparticle-polydopamine (AuNP/PDA) composites were used to fabricate the interface of the sensor.

In-situ detection of resveratrol inhibition effect on epidermal growth factor receptor of living MCF-7 cells by Atomic Force Microscopy.

A new method based on Atomic Force Microscopy (AFM) was developed to real-time and in-situ detect epidermal growth factor receptor (EGFR) expression levels on living MCF-7 cells for evaluating the anticancer activity of resveratrol. Here, the inhibition effect of resveratrol on EGFR expression levels on MCF-7 cells was probed by epidermal growth factor (EGF)-functionalized tips for the first time. Changes in morphology and stiffness of single cell stimulated by resveratrol at different concentrations were detected by AFM.

Highly sensitive detection of chromium (III) ions by resonance Rayleigh scattering enhanced by gold nanoparticles.

Simple and sensitive determination of chromium (III) ions (Cr(3+)) has potential applications for detecting trace contamination in environment. Here, the assay is based on the enhancement of resonance Rayleigh scattering (RRS) by Cr(3+)-induced aggregation of citrate-capped gold nanoparticles (AuNPs). Transmission electron microscopy (TEM) and UV-vis absorption spectroscopy were employed to characterize the nanostructures and spectroscopic properties of the Cr(3+)-AuNP system.

Anti-tumor activity evaluation of novel chrysin-organogermanium(IV) complex in MCF-7 cells.

Chrysin (5,7-dihydroxylflavone, Chry) is a natural product extracted from plants, honey, and propolis. In this work, a novel chrysin-organogermanium(IV) complex (Chry-Ge) with enhanced anticancer activities was synthesized, and its potential anticancer effects against cancer cells were measured using various methods. MTT results showed that Chry-Ge had significant inhibition effects on the proliferation of MCF-7, HepG2 and Colo205 human cancer cell lines in a dose-dependent manner while had little cytotoxic effects on MCF-10A human normal cells (MCF-10A cells) with the same treatment of Chry-Ge.

Synthesis and synergetic effects of chrysin-organogermanium (IV) complex as potential anti-oxidant.

Organogermanium(IV) (Ge) is considered to play an important role in the anti-oxidative activities of some Chinese medicines. Here, a new chrysin-organogermanium (Chry-Ge) complex was synthesized and investigated for its potential biological activities. The radicals-sensitive Ge-O bond was introduced to Chry-Ge complex to enhance bioactivities of organic Ge or Chry.

A novel gold nanoparticle-doped polyaniline nanofibers-based cytosensor confers simple and efficient evaluation of T-cell activation.

A rapid, easy assay for monitoring dynamics of T-cell activation should help to guide potential medical evaluation of immune responses or immunopathogenesis. Here, we report development of novel electrochemical cytosensors for dynamic analyses of T-cell activation markers on living cells. Gold nanoparticles-doped polyaniline nanofiber (Au/PANI-NFs) composite was greenly prepared by in situ one-step chemical inertness of PANI-NFs with gold nanoparticles to fabricate impedance-based electrochemical biosensors.

A label-free electrochemiluminescence cytosensors for specific detection of early apoptosis.

A novel electrochemiluminescence (ECL) cytosensors was developed for the detection of early apoptotic cells by the specific interaction between Annexin V and phosphatidylserine(PS) based on ECL signal of CdS-QDs. Immobilization of Annexin V on a L-cysteine-capped CdS-QDs/Polyaniline nanofibers (PANI-NF) resulted in the stable and high loading of Annexin V on the sensor surface and the possibility of sensitivity enhancement. Early apoptotic cells showed an increased exposure of PS on the cell membrane caused by physiological and pathological response reactions, leading to a strong interaction between the apoptotic cells and the sensor surface, which could be probed by the ECL.

Synthesis and biological evaluation of Germanium(IV)-polyphenol complexes as potential anti-cancer agents.

Germanium (Ge) is considered to play a key role in the pharmacological effects of some medicinal plants. Here, two new Ge(IV)-polyphenol complexes were synthesized and measured for their potential biological activities. The results indicated that these Ge(IV)-polyphenol complexes possessed great anti-oxidative activities, both showing stronger hydroxyl scavenging effects than their corresponding ligands.

Hydroxyl radical scavenging mechanism of human erythrocytes by quercetin-germanium (IV) complex.

Quercetin is a popular flavonoid in plant foods, herbs, and dietary supplement. Germanium, a kind of trace elements, can enhance the body immunity. This study investigated the hydroxyl-radical-scavenging mechanism of the quercertin-germanium (IV) (Qu-Ge) complex to human erythrocytes, especially the effects on ultrastructure and mechanical properties of cell membrane, plasma membrane potential and intracellular free Ca(2+) concentration.

[Immobilization of anti-transferrin on nano-gold and its immune recognition of transferrin].

A novel strategy based on antigen-antibody interaction was developed by means of backfilling transferrin on antibody functionalized gold nanoparticles surfaces in the present study. Nano gold particles were immobilized with cysteamine layer by self-assembly, whose surfaces were chemically coupled with anti-transferrin antibodies by using EDCX, forming the anti-transferrin-Au immuno-probes. The particles and the nano-probes were characterized by the integrated tools of resonance Rayleigh scattering (RRS), UV-Vis absorption spectra, transmission electron microscopy (TEM) and laser light scattering.

Electrochemical activity of holotransferrin and its electrocatalysis-mediated process of artemisinin.

Holotransferrin, the iron (III) transport protein in the blood, can significantly increase the anticancer activity of artemisinin, which is isolated from the Chinese plant qinghaosu. This paper investigates the action process of holotransferrin-induced electrocatalytic reduction of artemisinin by spectroscopic and electrochemical techniques. Results show that holotransferrin(Fe(III)) is the electrochemical sites of holotransferrin, which can catalyze the reduction of artemisinin through lowering the overpotential by about 80 mV.

[Study of DNA damage induced by potassium dichromate and glutathione with atomic force microscope].

Objective: To observe calf thymus DNA damage induced by potassium dichromate in combination with glutathione (GSH).

Methods: Atomic force microscope and ultraviolet spectrum (UV) were used to observe the alterations of the DNA ultrastructure and absorption spectrum.

Results: Atomic force microscopy revealed no breaks of the DNA strand in response to treatment with potassium dichromate alone, but when coupled with GSH at proper concentrations, potassium dichromate induced alterations in the DNA structure and DNA fragmentation.

The stepwise process of chromium-induced DNA breakage: characterization by electrochemistry, atomic force microscopy, and DNA electrophoresis.

DNA conformational change and breakage induced by Cr(VI)-GSH interaction were characterized by the integrated tools of electrochemistry, atomic force microscopy (AFM), and DNA electrophoresis. While electrochemistry confirmed the formation of the active species generated from Cr(VI)-GSH reduction, which causes the DNA conformational changes, AFM imaging vividly demonstrated the stepwise process of the DNA denaturation and breakage for the first time. Our DNA electrophoresis further validated that the DNA breakage occurs unevenly at both of the single strands of the molecule.

Transferrin-mediated gold nanoparticle cellular uptake.

Targeted drug delivery is an important research area in specific therapy. Transferrin-conjugated nanoparticles are an attractive formulation as a vehicle for specific cellular uptake and targeted drug delivery. In this report, atomic force microscopy imaging was used to visualize the process of cellular uptake of transferrin-coupled gold nanoparticles on the surfaces of live cells for the first time.