Recently, the appeal of 2D black phosphorus (BP) has been rising due to its unique optical and electronic properties with a tunable band gap (≈0.3–1.5 eV). While numerous research efforts have ...recently been devoted to nano‐ and optoelectronic applications of BP, no attention has been paid to promising medical applications. In this article, the preparation of BP‐nanodots of a few nm to <20 nm with an average diameter of ≈10 nm and height of ≈8.7 nm is reported by a modified ultrasonication‐assisted solution method. Stable formation of nontoxic phosphates and phosphonates from BP crystals with exposure in water or air is observed. As for the BP‐nanodot crystals’ stability (ionization and persistence of fluorescent intensity) in aqueous solution, after 10 d, ≈80% at 1.5 mg mL−1 are degraded (i.e., ionized) in phosphate buffered saline. They showed no or little cytotoxic cell‐viability effects in vitro involving blue‐ and green‐fluorescence cell imaging. Thus, BP‐nanodots can be considered a promising agent for drug delivery or cellular tracking systems.
Black phosphorus (BP)‐nanodots are prepared using a simple ultrasonication‐assisted solution method. Compared to conventional semiconductor quantum dots, BP‐nanodots present little in vitro cytotoxicity and further blue‐ and green‐fluorescent bioimaging roles under excitations of UV and visible light, showing potential as novel drug delivery carriers in biomedical applications.
Growth of large-scale patterned, wrinkle-free graphene and the gentle transfer technique without further damage are most important requirements for the practical use of graphene. Here we report the ...growth of wrinkle-free, strictly uniform monolayer graphene films by chemical vapor deposition on a platinum (Pt) substrate with texture-controlled giant grains and the thermal-assisted transfer of large-scale patterned graphene onto arbitrary substrates. The designed Pt surfaces with limited numbers of grain boundaries and improved surface perfectness as well as small thermal expansion coefficient difference to graphene provide a venue for uniform growth of monolayer graphene with wrinkle-free characteristic. The thermal-assisted transfer technique allows the complete transfer of large-scale patterned graphene films onto arbitrary substrates without any ripples, tears, or folds. The transferred graphene shows high crystalline quality with an average carrier mobility of ∼5500 cm2 V–1 s–1 at room temperature. Furthermore, this transfer technique shows a high tolerance to variations in types and morphologies of underlying substrates.
Multifunctional carbon-based nanodots (C-dots) are synthesized using atmospheric plasma treatments involving reactive gases (oxygen and nitrogen). Surface design was achieved through one-step plasma ...treatment of C-dots (AC-paints) from polyethylene glycol used as a precursor. These AC-paints show high fluorescence, low cytotoxicity and excellent cellular imaging capability. They exhibit bright fluorescence with a quantum yield twice of traditional C-dots. The cytotoxicity of AC-paints was tested on BEAS2B, THLE2, A549 and hep3B cell lines. The in vivo experiments further demonstrated the biocompatibility of AC-paints using zebrafish as a model, and imaging tests demonstrated that the AC-paints can be used as bio-labels (at a concentration of <5 mg mL
). Particularly, the oxygen plasma-treated AC-paints (AC-paints-O) show antibacterial effects due to increased levels of reactive oxygen species (ROS) in AC-paints (at a concentration of >1 mg mL
). AC-paints can effectively inhibit the growth of Escherichia coli (E. coli) and Acinetobacter baumannii (A. baumannii). Such remarkable performance of the AC-paints has important applications in the biomedical field and environmental systems.
Two zinc-aminoclays ZnACs with functionalized primary amines (-CH2)3NH2 were prepared by a simple sol-gel reaction using cationic metal precursors of ZnCl2 and Zn(NO3)2 with 3-aminopropyl ...triethoxysilane APTES under ambient conditions. Due to the facile interaction of heavy metals with primary amine sites and Zn-related intrinsic antimicrobial activity, toxicity assays of ZnACs nanoparticles (NPs) prior to their environmental and human-health applications are essential. However, such reports remain rare. Thus, in the present study, a cell viability assay of in-vitro HeLa cells comparing ZnCl2, Zn(NO3)2 salts, and ZnO (~50nm average diameter) NPs was performed. Interestingly, compared with the ZnCl2, and Zn(NO3)2 salts, and ZnO NPs (18.73/18.12/51.49µg/mL and 18.12/15.19/46.10µg/mL of IC50 values for 24 and 48h), the two ZnACs NPs exhibited the highest toxicity (IC50 values of 21.18/18.36µg/mL and 18.37/17.09µg/mL for 24 and 48h, respectively), whose concentrations were calculated on Zn elemental composition. This might be due to the enhanced bioavailability and uptake into cells of ZnAC NPs themselves and their positively charged hydrophilicity by reactive oxygen species (ROS) generation, particularly as ZnACs exist in cationic NP's form, not in released Zn2+ ionic form (i.e., dissolved nanometal). However, in an in-vivo embryotoxicity assay in zebrafish, ZnACs and ZnO NPs showed toxic effects at 50–100µg/mL (corresponding to 37.88–75.76 of Zn wt% µg/mL). The hatching rate (%) of zebrafish was lowest for the ZnO NPs, particularly where ZnAC-(NO3)2 is slightly more toxic than ZnAC-Cl2. These results are all very pertinent to the issue of ZnACs’ potential applications in the environmental and biomedical fields.
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•Two 3-aminopropyl functionalized zinc phyllosilicates were prepared.•Two ZnACs exhibited more toxic effect in HeLa cells than did ZnO.•ZnO showed more embryonic toxic effect in zebrafish than did two ZnACs.•ZnACs’ toxicity is crucial to the success of environmental and biomedical applications.
We compared 4-year efficacy and safety of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in patients with diabetes mellitus (DM).
Four-year comparison of SES with PES in diabetic ...patients has not been evaluated in a randomized manner.
This prospective, multicenter, randomized study compared SES (n = 200) and PES (n = 200) implantation in diabetic patients. We evaluated 4-year major adverse cardiac events (MACE) including death, myocardial infarction (MI), and target lesion revascularization (TLR).
The 2 groups had similar baseline characteristics. At 2 years, TLR (3.5% vs. 11.0%, log-rank, p < 0.01) and MACE (3.5% vs. 12.5%, log-rank, p < 0.01) were significantly lower in SES versus PES group with no difference of death or MI. At 4 years there were no differences in death (3.0% vs. 5.0%, p = 0.45) or MI (1.5% vs. 1.0%, p = 0.99) between SES and PES group. The TLR (7.5% vs. 12.0%, log-rank, p = 0.10) and MACE (11.0% vs. 16.0%, log-rank, p = 0.10) were statistically not different between SES and PES group. At multivariate Cox regression, post-procedural minimal lumen diameter (hazard ratio HR: 0.44, 95% confidence interval CI: 0.24 to 0.81, p < 0.01), hypercholesterolemia (HR: 2.21, 95% CI: 1.29 to 3.79, p < 0.01), and use of intravascular ultrasound (HR: 0.51, 95% CI: 0.26 to 0.99, p = 0.049) were independent predictors of 4-year MACE.
Superiority of SES over PES during 2 years was attenuated between 2 years and 4 years in diabetic patients. Use of intravascular ultrasound and larger post-procedural minimal lumen diameter were independent predictors of the improved long-term clinical outcomes.
The objectives of this paper are to develop advanced hybrid GAX cycles (HGAX) using NH3–H2O by combining absorption and vapor compression cycles, and to perform parametric analysis of system ...pressures and component sizes for performance enhancement. Four different HGAX cycles are developed—Type A (Performance improvement), Type B (Low temperature applications) Type C (Reduction of desorption temperature) and Type D (Hot water temperature applications). A compressor is placed between the evaporator and the absorber in Type A and Type B, and placed between the desorber and the condenser in Type C and Type D. It is found that the COP can be improved by 24% compared with the standard GAX cycle (in Type A) and the evaporation temperature of as low as −80 °C can be obtained from the HGAX cycle (Type B). In Type C, the maximum desorption temperature can be reduced down to 164 °C. Therefore, the corrosion problem, which becomes severe at higher temperature 200 °C, can be completely removed. The maximum desorption temperature for the standard GAX cycle ranges 190–200 °C. In Type D, the hot water temperature of as high as 106 °C could be obtained. Therefore, Type D can be applied for space heating and panel or floor heating applications.
Human mesenchymal stem cells (hMSCs) have generated a great deal of interest in clinical application due to their ability to undergo multi-lineage differentiation. Recently, ex vivo genetic ...modification of hMSCs was attempted to increase their differentiation potential. The present study was conducted to evaluate the biodistribution and in vivo efficacy of genetically modified hMSCs. To accomplish this, Runx2, which is a key transcription factor associated with osteoblast differentiation, was transduced into hMSCs using lentiviral vectors expressing green fluorescent protein (GFP) or luciferase. Here, we developed an experimental fracture in mice femur to investigate the effects of Runx2-transduced hMSCs on bone healing and migration into injury site. We conducted bio-luminescence imaging (BLI) using luciferase-tagged vector and quantitative real-time PCR using GFP probe to investigate the biodistribution of Runx2-transduced hMSCs in the fracture model. The biodistribution of hMSC cells in the fractured femur was observed at 14 days post-transplantation upon both BLI imaging and real-time PCR. Moreover, the fractured mice transplanted with Runx2-transduced hMSCs showed superior bone healing when compared to mock-transduced hMSC and MRC5 fibroblasts which were used as control. These data suggested that transplanted genetically modified hMSCs systemically migrate to the fractured femur, where they contribute to bone formation in vivo.
Lumazine protein is a member of the riboflavin synthase superfamily and the intense fluorescence is caused by non-covalently bound to 6,7-dimethyl 8-ribityllumazine. To figure out the binding modes ...and the structure of the N-terminal domain of lumazine protein, the wild type of protein extending to amino acid 118 (N-LumP 118 Wt) and mutants of N-LumP 118 V41W, S48W, T50W, D64W, and A66W from Photobacterium leiognathi were purified. The biochemical properties of the wild type and mutants of N-LumP 118 proteins were analyzed by absorbance and fluorescence spectroscope. The peak of absorbance and fluorescence of lumazine ligand were shifted to longer wavelength on binding to N-LumPs. The observed absorbance value at 410 nm of lumazine bound to N-LumP 118 proteins indicate that one mole of N-LumP 118 proteins bind to one mole of ligand of lumazine. Fluorescence analysis show that the maximum peak of fluorescence of N-LumP S48W was shifted to the longest wavelength by binding with 6,7-dimethyl 8-ribityllumazine and was shown to the greatest quench effect by acrylamide among all tryptophan mutants. KCI Citation Count: 1
Enzyme-linked immunosorbent assays (ELISAs) have most widely been applied in immunoassays for several decades. However, several unavoidable limitations (e.g., instability caused by structural ...unfolding) of natural enzymes have hindered their widespread applications. Here, we describe a new nanohybrid consisting of Fe₃O₄ magnetic nanoparticles (MNPs) and platinum nanoparticles (Pt NPs), simultaneously immobilized on the surface of graphene oxide (GO). By synergistically integrating highly catalytically active Pt NPs and MNPs on GO whose frameworks possess high substrate affinity, the nanohybrid is able to achieve up to a 30-fold higher maximal reaction velocity (V(max)) compared to that of free GO for the colorimetric reaction of the peroxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB), and enable rapid detection of target cancer cells. Specifically, using this new assay system, clinically important breast cancer cells are detected in a 5 min time period at room temperature with high specificity and sensitivity. The remarkably high capability to catalyze oxidation reactions could allow the nanohybrid to replace conventional peroxidase-based immunoassay systems as part of new, rapid, robust and convenient assay systems which can be widely utilized for the identification of important target molecules.
Development of drug-delivery systems that allow simultaneous in vivo imaging has gained much interest. We report a novel strategy to encapsulate metal nanoparticles (NPs) within alginate gel for in ...vivo imaging. The cell lysate of recombinant Escherichia coli strain, expressing Arabidopsis thaliana phytochelatin synthase and Pseudomonas putida metallothionein genes, was encapsulated within the alginate gel. Incubation of alginate gel with metal ion precursors followed by UV irradiation resulted in the synthesis of high concentrations of metal NPs, such as Au, Ag, CdSe, and EuSe NPs, within the gel. The alginate gel with metal NPs was used as a drug-delivery system by further co-encapsulating doxorubicin and rifampicin, the release of which was made to be pH-dependent. This system can be conveniently and safely used for in vitro and in vivo bioimaging, enabled by the metal NPs formed within the gel matrix without using toxic reducing reagents or surfactants.
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