Publications by authors named "Pengcheng Xu"

120 Publications

Comprehensive evaluation of the efficacy and safety of LPV/r drugs in the treatment of SARS and MERS to provide potential treatment options for COVID-19.

Aging (Albany NY) 2021 04 20;13(8):10833-10852. Epub 2021 Apr 20.

Peking University Shenzhen Hospital, Clinical College of Anhui Medical University, Shenzhen 518036, Guangdong, China.

Coronavirus disease 2019 (COVID-19) experienced an outbreak that expanded worldwide. Lopinavir/ritonavir (LPV/r), which is used effectively for severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronavirus infections, was applied for COVID-19 treatment given similarities in the molecular structures of these viruses. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of lopinavir/ritonavir antiviral treatment in patients with SARS, MERS, and COVID-19. After registration with INPLASY, a search was conducted in PubMed, Embase, China National Knowledge Infrastructure (CNKI), Cochrane Library, WanFang Data, China Biomedical Literature Database (CBM) and other databases for all relevant literature on lopinavir/ritonavir treatment of SARS, MERS and COVID-19. The Cochrane Collaboration's bias risk assessment tool and the Newcastle-Ottawa Scale (NOS) were used to evaluate the quality of the literature, and RevMan 5.3 software was used to evaluate the relevant outcome indicators of the efficacy and safety of lopinavir/ritonavir in the treatment of COVID-19. A total of 18 eligible studies (including randomized controlled studies, cohort studies, and case-control studies) were retrieved and included with a total of 2273 patients. The lopinavir/ritonavir group exhibited an increased nucleic acid conversion rate (P=0.004), higher virus clearance rate (P<0.0001), lower mortality rate (P=0.002), and reduced incidence of acute respiratory distress syndrome (ARDS) (P=0.02) compared with the control group. No significant benefit in the improvement rate of chest CT (P=0.08) or incidence of adverse events (P=0.45) was noted. The lopinavir/ritonavir group had a lower incidence of acute respiratory distress syndrome (P=0.02). According to the clinical prognostic results, the incidence of adverse events between the two groups was not statistically significant (P<0.0001). The efficacy of lopinavir/ritonavir in the treatment of patients with SARS, MERS and COVID-19 was significantly better than that of the control. Furthermore, the incidence of adverse events did not significantly increase. Lopinavir/ritonavir is effective in the treatment of COVID-19, and this combination should be further assessed in RCT studies. In addition, when we analyzed the differences in age and sex, we found that the differences were statistically significant in the safety and effectiveness of lopinavir/ritonavir in patients with COVID-19, and both of these factors played a significant role in the trial.
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http://dx.doi.org/10.18632/aging.202860DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8109137PMC
April 2021

Low-dose decitabine modulates T cell homeostasis and restores immune tolerance in immune thrombocytopenia.

Blood 2021 Apr 19. Epub 2021 Apr 19.

Qilu hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.

Our previous clinical study demonstrated that low-dose decitabine showed sustained responses in nearly half of refractory immune thrombocytopenia (ITP) patients. The long-term efficacy of decitabine in ITP is not likely due to its simple role in increasing platelet production. Whether decitabine has the potential to restore immune tolerance in ITP is unknown. In this study, we analyzed the effect of decitabine on T cell subpopulations in ITP in vitro and in vivo. We found that low-dose decitabine promoted the generation and differentiation of regulatory T (Treg) cells, and augmented their immunosuppressive function. Splenocytes from CD61 knockout mice immunized with CD61+ platelets were transferred into severe combined immunodeficient (SCID) mouse recipients to induce a murine model of ITP. Low-dose decitabine alleviated thrombocytopenia and restored the balance between Treg and helper T (Th) cells in active ITP mice. Treg deletion and depletion offset the effect of decitabine in restoring CD4+ T cell subpopulations in ITP mice. For patients who received low-dose decitabine, the quantity and function of Treg cells were substantially improved, whereas Th1 and Th17 cells were suppressed compared with the pretreatment levels. Next-generation RNA sequencing and cytokine analysis showed that low-dose decitabine rebalanced T cell homeostasis, decreased proinflammatory cytokines, and down-regulated phosphorylated STAT3 in ITP patients. STAT3 inhibition analysis suggested that low-dose decitabine might restore Treg cells by inhibiting STAT3 activation. In conclusion, our data indicated that the immunomodulatory effect of decitabine provided one possible mechanistic explanation for the sustained response achieved by low-dose decitabine in ITP.
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http://dx.doi.org/10.1182/blood.2020008477DOI Listing
April 2021

Lack of cross-transmission of SARS-CoV-2 between passenger's cabins on the cruise ship.

Build Environ 2021 Jul 15;198:107839. Epub 2021 Apr 15.

Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.

An outbreak of COVID-19 occurred on the cruise ship in January and February 2020 in Japan. We analysed information on the cases of infection to infer whether airborne transmission of SARS-CoV-2, the causative agent of COVID-19, had occurred between cabins. We infer from our analysis that most infections in passengers started on 28 January and were completed by 6 February, except in those who shared a cabin with another infected passenger. The distribution of the infected cabins was random, and no spatial cluster of the infected can be identified. We infer that the ship's central air-conditioning system for passenger's cabins did not play a role in SARS-CoV-2 transmission, i.e. airborne transmission did not occur between cabins during the outbreak, suggesting that the sufficient ventilation was provided. We also infer that the ship's cabin drainage system did not play a role. Most transmission appears to have occurred in the public areas of the cruise ship, likely due to crowding and insufficient ventilation in some of these areas.
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http://dx.doi.org/10.1016/j.buildenv.2021.107839DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8046742PMC
July 2021

A DM1-doped porous gold nanoshell system for NIR accelerated redox-responsive release and triple modal imaging guided photothermal synergistic chemotherapy.

J Nanobiotechnology 2021 Mar 19;19(1):77. Epub 2021 Mar 19.

Department of Pharmaceutics, China Pharmaceutical University, Nanjing, China.

Background: Although many treatments for breast cancer are available, poor tumour targeting limits the effectiveness of most approaches. Consequently, it is difficult to achieve satisfactory results with monotherapies. The lack of accurate diagnostic and monitoring methods also limit the benefits of cancer treatment. The aim of this study was to design a nanocarrier comprising porous gold nanoshells (PGNSs) co-decorated with methoxy polyethylene glycol (mPEG) and trastuzumab (Herceptin®, HER), a therapeutic monoclonal antibody that binds specifically to human epidermal receptor-2 (HER2)-overexpressing breast cancer cells. Furthermore, a derivative of the microtubule-targeting drug maytansine (DM1) was incorporated in the PGNSs.

Methods: Prepared PGNSs were coated with mPEG, DM1 and HER via electrostatic interactions and Au-S bonds to yield DM1-mPEG/HER-PGNSs. SK-BR-3 (high HER2 expression) and MCF-7 (low HER2) breast cancer cells were treated with DM1-mPEG/HER-PGNSs, and cytotoxicity was evaluated in terms of cell viability and apoptosis. The selective uptake of the coated PGNSs by cancer cells and subsequent intracellular accumulation were studied in vitro and in vivo using inductively coupled plasma mass spectrometry and fluorescence imaging. The multimodal imaging feasibility and synergistic chemo-photothermal therapeutic efficacy of the DM1-mPEG/HER-PGNSs were investigated in breast cancer tumour-bearing mice. The molecular mechanisms associated with the anti-tumour therapeutic use of the nanoparticles were also elucidated.

Result: The prepared DM1-mPEG/HER-PGNSs had a size of 78.6 nm and displayed excellent colloidal stability, photothermal conversion ability and redox-sensitive drug release. These DM1-mPEG/HER-PGNSs were taken up selectively by cancer cells in vitro and accumulated at tumour sites in vivo. Moreover, the DM1-mPEG/HER-PGNSs enhanced the performance of multimodal computed tomography (CT), photoacoustic (PA) and photothermal (PT) imaging and enabled chemo-thermal combination therapy. The therapeutic mechanism involved the induction of tumour cell apoptosis via the activation of tubulin, caspase-3 and the heat shock protein 70 pathway. M2 macrophage suppression and anti-metastatic functions were also observed.

Conclusion: The prepared DM1-mPEG/HER-PGNSs enabled nanodart-like tumour targeting, visibility by CT, PA and PT imaging in vivo and powerful tumour inhibition mediated by chemo-thermal combination therapy in vivo. In summary, these unique gold nanocarriers appear to have good potential as theranostic nanoagents that can serve both as a probe for enhanced multimodal imaging and as a novel targeted anti-tumour drug delivery system to achieve precision nanomedicine for cancers.
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http://dx.doi.org/10.1186/s12951-021-00824-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7976706PMC
March 2021

Phosphoproteome and Biological Evidence Revealed Abnormal Calcium Homeostasis in Keloid Fibroblasts and Induction of Aberrant Platelet Aggregation.

J Proteome Res 2021 May 12;20(5):2521-2532. Epub 2021 Mar 12.

MOE Key Laboratory of Tumor Molecular Biology and Institute of Life and Health Engineering, Jinan University, Guangzhou, Guangdong 510632, China.

Keloid is a benign tumor characterized by persistent inflammation, increased fibroblast proliferation, and abnormal deposition of collagen in the wound. The etiology of keloid is unclear. Here, we explored the phospho-signaling changes in human keloid fibroblasts via phosphoproteome mass spectrometry analysis. We found that comparative phosphoproteomics could statistically distinguish keloid from control fibroblasts. Differentially expressed phosphoproteins could predict the activation of known keloid-relevant upstream regulators including transforming growth factor-β1, interleukin (IL)-4, and IL-5. With multiple bioinformatics analyses, phosphorylated FLNA, TLN1, and VCL were significantly enriched in terms of calcium homeostasis and platelet aggregation. We biologically verified that keloid fibroblasts had a higher level of Ca influx than the control fibroblasts upon ionomycin stimulation. Via co-cultivation analysis, we found that human keloid fibroblasts could directly promote platelet aggregation. As suggested by PhosphoPath and gene set enrichment analysis, pFLNA was centered as the top phosphoproteins associated with keloid phenotypes. We validated that pFLNA was upregulated both in keloid fibroblasts and keloid tissue section, implicating its biomarker potential. In conclusion, we reported the first phosphoproteome on keloid fibroblasts, based on which we revealed that keloid fibroblasts had aberrant calcium homeostasis and could directly induce platelet aggregation.
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http://dx.doi.org/10.1021/acs.jproteome.0c00984DOI Listing
May 2021

Low-Dose Decitabine Inhibits Cytotoxic T Lymphocytes-Mediated Platelet Destruction Modulating PD-1 Methylation in Immune Thrombocytopenia.

Front Immunol 2021 17;12:630693. Epub 2021 Feb 17.

Department of Hematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.

Cytotoxic T lymphocytes (CTLs)-mediated platelet destruction plays an important role in the pathogenesis of primary immune thrombocytopenia (ITP). The programmed cell death protein 1 (PD-1) signaling can turn off autoreactive T cells and induce peripheral tolerance. Herein, we found that the expression of PD-1 and its ligand PD-L1 on CD8 T cells from ITP patients was decreased. Activating PD-1 pathway by PD-L1-Fc fusion protein inhibited CTLs-mediated platelet destruction in ITP . PD-1 promoter hypermethylation in CD8 T cells was found in ITP patients, resulting in decreased PD-1 expression. The demethylating agent decitabine at a low dose was proved to restore the methylation level and expression of PD-1 on CD8 T cells and reduce the cytotoxicity of CTLs of ITP patients. The phosphorylation levels of phosphatidylinositol 3-kinase (PI3K) and AKT in CD8 T cells were significantly downregulated by low-dose decitabine. Furthermore, blocking PD-1 could counteract the effect of low-dose decitabine on CTLs from ITP patients. Therefore, our data suggest that the aberrant PD-1/PD-L1 pathway is involved in the pathophysiology of ITP and enhancing PD-1/PD-L1 signaling is a promising therapeutic approach for ITP management. Our results reveal the immunomodulatory mechanism of low-dose decitabine in ITP by inhibiting CTLs cytotoxicity to autologous platelets through PD-1 pathway.
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http://dx.doi.org/10.3389/fimmu.2021.630693DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7925841PMC
February 2021

Differences in Calcium Clearance at Inner Hair Cell Active Zones May Underlie the Difference in Susceptibility to Noise-Induced Cochlea Synaptopathy of C57BL/6J and CBA/CaJ Mice.

Front Cell Dev Biol 2020 5;8:635201. Epub 2021 Feb 5.

Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Noise exposure of a short period at a moderate level can produce permanent cochlear synaptopathy without seeing lasting changes in audiometric threshold. However, due to the species differences in inner hair cell (IHC) calcium current that we have recently discovered, the susceptibility to noise exposure may vary, thereby impact outcomes of noise exposure. In this study, we investigate the consequences of noise exposure in the two commonly used animal models in hearing research, CBA/CaJ (CBA) and C57BL/6J (B6) mice, focusing on the functional changes of cochlear IHCs. In the CBA mice, moderate noise exposure resulted in a typical fully recovered audiometric threshold but a reduced wave I amplitude of auditory brainstem responses. In contrast, both auditory brainstem response threshold and wave I amplitude fully recovered in B6 mice at 2 weeks after noise exposure. Confocal microscopy observations found that ribbon synapses of IHCs recovered in B6 mice but not in CBA mice. To further characterize the molecular mechanism underlying these different phenotypes in synaptopathy, we compared the ratio of Bax/Bcl-2 with the expression of cytochrome-C and found increased activity in CBA mice after noise exposure. Under whole-cell patch clamped IHCs, we acquired two-photon calcium imaging around the active zone to evaluate the Ca clearance rate and found that CBA mice have a slower calcium clearance rate. Our results indicated that excessive accumulation of calcium due to acoustic overexposure and slow clearance around the presynaptic ribbon might lead to disruption of calcium homeostasis, followed by mitochondrial dysfunction of IHCs that cause susceptibility of noise-induced cochlear synaptopathy in CBA mice.
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http://dx.doi.org/10.3389/fcell.2020.635201DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7902005PMC
February 2021

Quantitative Structure-Activity Relationship of Nanowire Adsorption to SO Revealed by TEM Technique.

Nano Lett 2021 Feb 3;21(4):1679-1687. Epub 2021 Feb 3.

State Key Lab of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.

A quantitative structure-activity relationship (QSAR) is revealed based on the real-time sulfurization processes of ZnO nanowires observed via gas-cell transmission electron microscopy ( TEM). According to the TEM observations, the ZnO nanowires with a diameter of 100 nm (ZnO-100 nm) gradually transform into a core-shell nanostructure under SO atmosphere, and the shell formation kinetics are quantitatively determined. However, only sparse nanoparticles can be observed on the surface of the ZnO-500 nm sample, which implies a weak solid-gas interaction between SO and ZnO-500 nm. The QSAR model is verified with heat of adsorption (-Δ°) and aberration-corrected TEM characterization. With the guidance of the QSAR model, the following adsorbing/sensing applications of ZnO nanomaterials are explored: (i) breakthrough experiment demonstrates the application potential of the ZnO-100 nm sample for SO capture/storage; (ii) the ZnO-500 nm sample features good reversibility (RSD = 1.5%, = 3) for SO sensing, and the detection limit reaches 70 ppb.
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http://dx.doi.org/10.1021/acs.nanolett.0c04481DOI Listing
February 2021

A composite hydrogel with co-delivery of antimicrobial peptides and platelet-rich plasma to enhance healing of infected wounds in diabetes.

Acta Biomater 2021 04 30;124:205-218. Epub 2021 Jan 30.

The Graduate School of Southern Medical University, Guangzhou 510515, China; Department of Burn and Plastic Surgery, General Hospital of Southern Theater Command, PLA, Guangzhou 510010, China. Electronic address:

Diabetic wound healing remains a major challenge due to its vulnerability to bacterial infection, as well as the less vascularization and prolonged inflammatory phase. In this study, we developed a hydrogel system for the treatment of chronic infected wounds, which can regulate inflammatory (through the use of antimicrobial peptides) and enhance collagen deposition and angiogenesis (through the addition of platelet-rich plasma (PRP)). Based on the formation of Schiff base linkage, the ODEX/HA-AMP/PRP hydrogel was prepared by mixing oxidized dextran (ODEX), antimicrobial peptide-modified hyaluronic acid (HA-AMP) and PRP under physiological conditions, which exhibited obvious inhibition zones against three pathogenic bacterial strains (E. coli, S. aureus and P. aeruginosa) and slow release ability of antimicrobials and growth factors. Moreover, CCK-8, live/dead fluorescent staining and scratch test confirmed that ODEX/HA-AMP/PRP hydrogel could facilitate the proliferation and migration of L929 fibroblast cells. More importantly, in vivo experiments further demonstrated that the prepared hydrogels could significantly improve wound healing in a diabetic mouse infection by regulating inflammation, accelerating collagen deposition and angiogenesis. In addition, prepared hydrogel showed a significant antibacterial activity against S. aureus and P. aeruginosa, inhibited pro-inflammatory factors (TNF-α, IL-1β and IL-6), enhanced anti-inflammatory factors (TGF-β1) and vascular endothelial growth factor (VEGF) production. The findings of this study suggested that the composite hydrogel with AMP and PRP controlled release ability could be used as a promising candidate for chronic wound healing and infection-related wound healing.
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http://dx.doi.org/10.1016/j.actbio.2021.01.046DOI Listing
April 2021

Palladium-catalyzed dearomative cyclocarbonylation of allyl alcohol for the synthesis of quinolizinones.

Org Biomol Chem 2021 02;19(6):1274-1277

State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China. and Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry, Center for Excellence in Molecular Synthesis, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, P. R. China.

An approach for the synthesis of quinolizinone with potential bioactivity has been developed via palladium-catalytic dearomative cyclocarbonylation of allyl alcohol. Diverse quinolizinone compounds could be attained with good efficiencies. A feasible reaction pathway could be a successive procedure of allylation, dearomatization, CO insertion and the Heck reaction.
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http://dx.doi.org/10.1039/d0ob02529aDOI Listing
February 2021

Tumor Necrosis Factor-α Blockade Corrects Monocyte/Macrophage Imbalance in Primary Immune Thrombocytopenia.

Thromb Haemost 2021 Jan 14. Epub 2021 Jan 14.

Department of Haematology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.

Primary immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder. Monocytes and macrophages are the major cells involved in autoantibody-mediated platelet clearance in ITP. In the present study, we found increased percentages of peripheral blood proinflammatory CD16 monocytes and elevated frequencies of splenic tumor necrosis factor-α (TNF-α)-expressing macrophages in ITP patients compared with healthy controls. Concurrently, we observed elevated TNF-α secretion in plasma as well as higher TNF-α mRNA expression in total peripheral blood mononuclear cells and CD14 monocytes of ITP patients. Of note, in vitro TNF-α blockade with neutralizing antibody remarkably reduced polarization to M1 macrophages by inhibiting the nuclear factor kappa B (NF-κB) signaling pathway. Moreover, TNF-α blockade dampened macrophage phagocytosis and T cell stimulatory capacity. Finally, in passive and active murine models of ITP, anti-TNF-α therapy reduced the number of nonclassical monocytes and M1 macrophages, ameliorated the retention of platelets in spleen and liver, and increased the platelet count of ITP mice. Taken together, TNF-α blockade decreased the number and function of proinflammatory subsets of monocytes and macrophages by inhibiting the NF-κB signaling pathway, leading to remarkable attenuation of antibody-mediated platelet destruction. Thus, TNF-α blockade may be a promising therapeutic strategy for the management of ITP.
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http://dx.doi.org/10.1055/s-0040-1722186DOI Listing
January 2021

Machine Learning Aided Design of Polymer with Targeted Band Gap Based on DFT Computation.

J Phys Chem B 2021 01 7;125(2):601-611. Epub 2021 Jan 7.

Materials Genome Institute, Shanghai University, and Shanghai Materials Genome Institute, Shanghai 200444, China.

Polymer band gap is one of the most important properties associated with electric conductivity. In this work, the machine learning model called support vector regression (SVR) was developed to predict the polymer band gap, where the training data of the polymer band gap were obtained from DFT computation while the descriptors were generated from Dragon. After feature selection with the maximum relevance minimum redundancy, the SVR model using 16 key features as inputs gave the optimal performance for predicting polymer band gaps. The determination coefficient () of the SVR model between the DFT computations and SVR predictions of polymer band gaps reached as high as 0.824 for the leave-one-out cross-validation and 0.925 for the independent test. Besides, the 16 key features were explored through correlation analysis and sensitivity analysis. The available model can be used to screen out the polymers with targeted band gaps before experiments, which is very helpful for rapid design of new polymers.
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http://dx.doi.org/10.1021/acs.jpcb.0c08674DOI Listing
January 2021

Thermodynamic Phase-like Transition Effect of Molecular Self-assembly.

J Phys Chem Lett 2021 Jan 14;12(1):126-131. Epub 2020 Dec 14.

State Key Lab of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.

The technique of self-assembled monolayers (SAMs) is frequently applied for grafting functional groups or area-selective deposition of thin films on a material surface. The formation and quality of SAMs are fundamentally determined by thermodynamic data, which are difficult to measure with available experimental methods. This work quantitatively extracted thermodynamic parameters including Δ°, Δ°, and Δ° during the SAMs construction process with an ultrasensitive resonant microcantilever as molecule-surface interactions real-time recording tool. By correlating the thermodynamic parameters with self-assembling temperatures, a new thermodynamic phase-like transition effect of molecular self-assembly has been first revealed. The sharp transition of the thermodynamic parameters defines the critical condition for SAMs formation. The thermodynamic data further provide optimized reaction conditions for constructing high-quality SAMs. The explored quantitative thermodynamic analysis method not only plays as criterion for SAM growth but also helps to fundamentally elucidate physicochemical mechanism of spontaneous self-assembly.
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http://dx.doi.org/10.1021/acs.jpclett.0c03248DOI Listing
January 2021

Bioaerosol in a typical municipal wastewater treatment plant: concentration, size distribution, and health risk assessment.

Water Sci Technol 2020 Oct;82(8):1547-1559

International Science and Technology Cooperation Center for Urban Alternative Water Resources Development; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education; Engineering Technology Research Center for Wastewater Treatment and Reuse, Shaanxi Province; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China E-mail:

An investigation on bioaerosol in a wastewater treatment plant (WWTP) located in Xi'an, China, was conducted to understand the characteristics of bioaerosol released from wastewater and sludge treatment facilities because the bioaerosols may pose a threat to human health. Using the Andersen impactor sampler collection and colony-counting method, bioaerosol concentrations and size distributions were detected. The risk quotient method was used to evaluate the health risks associated with inhalation of bioaerosol for WWTP staff, based on the average daily dose rates of exposure. The health risk in relation to Legionella pneumophila was quantitatively calculated using quantitative microbial risk assessment (QMRA), based on the assumption of the percentage. The maximum concentration of airborne bacteria (3,767 ± 280 colony forming units (CFU)/m) and fungi (8,775 ± 406 CFU/m) occurred from the aerated grit chamber and sludge thickening house, respectively, which all exceeded 500 CFU/m as the acceptable guideline proposed by the American Conference of Governmental Industrial Hygienists. The particle size of airborne bacteria was mainly distributed in the first three stages (>3.3 µm), while that of airborne fungi was from the second to the fourth stage (2.1-7.0 µm). The hazard index exposure to bioaerosol for adult males and females by inhalation were higher than 1. The proportion of L. pneumophila should be strictly controlled below 10, based on the QMRA approach.
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http://dx.doi.org/10.2166/wst.2020.416DOI Listing
October 2020

Severity and Consolidation Quantification of COVID-19 From CT Images Using Deep Learning Based on Hybrid Weak Labels.

IEEE J Biomed Health Inform 2020 12 4;24(12):3529-3538. Epub 2020 Dec 4.

Early and accurate diagnosis of Coronavirus disease (COVID-19) is essential for patient isolation and contact tracing so that the spread of infection can be limited. Computed tomography (CT) can provide important information in COVID-19, especially for patients with moderate to severe disease as well as those with worsening cardiopulmonary status. As an automatic tool, deep learning methods can be utilized to perform semantic segmentation of affected lung regions, which is important to establish disease severity and prognosis prediction. Both the extent and type of pulmonary opacities help assess disease severity. However, manually pixel-level multi-class labelling is time-consuming, subjective, and non-quantitative. In this article, we proposed a hybrid weak label-based deep learning method that utilize both the manually annotated pulmonary opacities from COVID-19 pneumonia and the patient-level disease-type information available from the clinical report. A UNet was firstly trained with semantic labels to segment the total infected region. It was used to initialize another UNet, which was trained to segment the consolidations with patient-level information using the Expectation-Maximization (EM) algorithm. To demonstrate the performance of the proposed method, multi-institutional CT datasets from Iran, Italy, South Korea, and the United States were utilized. Results show that our proposed method can predict the infected regions as well as the consolidation regions with good correlation to human annotation.
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http://dx.doi.org/10.1109/JBHI.2020.3030224DOI Listing
December 2020

Long-Circulating Thermosensitive Liposomes for the Targeted Drug Delivery of Oxaliplatin.

Int J Nanomedicine 2020 11;15:6721-6734. Epub 2020 Sep 11.

China Pharmaceutical University, Center for Research Development and Evaluation of Pharmaceutical Excipients and Generic Drugs, Nanjing 210009, People's Republic of China.

Introduction: Oxaliplatin (L-OHP) is a well-known third-generation platinum anticancer drug with severe systemic- and neuro-toxicity. The main objective of the current research was to develop a targeted long-circulating thermosensitive smart-release liposome (LCTL) system for better therapeutic efficacy and less toxicity.

Methods: The reverse-phase evaporation method (REV) was used to prepare L-OHP loaded LCTL (L-OHP/LCTL). The physical characteristics were evaluated including encapsulation efficiency (EE), size, zeta potential and stability. The release behavior, cytotoxicity and in vivo evaluation were also carried out.

Results: EE of LCTL was around 25% with a uniform size distribution, and LCTL achieved almost complete release at 42°C while it was only 10% at 37°C. Moreover, the LCTL showed significantly higher cytotoxicity at 42°C than that at 37°C. The in vivo results indicated LCTL could target tumors and enhance retention for more than 24 h, thereby enhancing anti-tumor efficacy on 4T1-bearing mice.

Discussion: These results indicated that LCTL not only possessed a prolonged circulation time but it also enhanced accumulation and achieved selective release at the tumor sites. Conclusively, LCTL could serve as a promising carrier for oxaliplatin delivery to treat solid tumors.
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http://dx.doi.org/10.2147/IJN.S250773DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7494235PMC
November 2020

A polyoxyethylene sorbitan oleate modified hollow gold nanoparticle system to escape macrophage phagocytosis designed for triple combination lung cancer therapy via LDL-R mediated endocytosis.

Drug Deliv 2020 Dec;27(1):1342-1359

Department of Pharmaceutics, Center for Research Development and Evaluation of Pharmaceutical Excipients and Generic Drugs, China Pharmaceutical University, Nanjing, China.

Presently, a combination of chemotherapy, radiotherapy, thermotherapy, and other treatments has become a hot topic of research for the treatment of cancer, especially lung cancer. In this study, novel hollow gold nanoparticles (HGNPs) were used as drug carriers, and in order to improve the targeting ability of HGNPs to a lung tumor site, polyoxyethylene sorbitol oleate (PSO) was chosen here as a target ligand since it can be specifically recognized by the low-density lipoprotein (LDL) receptor which is usually over expressed on A549 lung cancer cells. In this way, a PSO-modified doxorubicin-loaded HGNP drug delivery system (PSO-HGNPs-DOX) was constructed and its physicochemical properties, photothermal conversion ability, and drug release of PSO-HGNPs-DOX was investigated. Further, the effects of triple combination therapy, the intracellular uptake, and the ability to escape macrophage phagocytosis of PSO-HGNPs-DOX were also studied using A549 cells . In addition, an mouse model was also used to study the targeting of PSO-HGNPs-DOX to lung cancer. PSO-HGNPs-DOX demonstrated a good triple therapeutic effect for lung cancer (A549 cell viability was only 10% at 500 μM) by LDL receptor mediated endocytosis and was able to escape macrophage phagocytosis to enhance its accumulation at the target site. Therefore, PSO-HGNPs-DOX is a novel, safe, promising, and targeted drug carrier designed for triple combination lung cancer therapy which should be further studied for such applications.
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http://dx.doi.org/10.1080/10717544.2020.1822459DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7534200PMC
December 2020

Platelet-rich plasma accelerates skin wound healing by promoting re-epithelialization.

Burns Trauma 2020 14;8:tkaa028. Epub 2020 Aug 14.

Department of Burn and Plastic Surgery, General Hospital of Southern Theater Command, PLA, Guangzhou, China.

Background: Autologous platelet-rich plasma (PRP) has been suggested to be effective for wound healing. However, evidence for its use in patients with acute and chronic wounds remains insufficient. The aims of this study were to comprehensively examine the effectiveness, synergy and possible mechanism of PRP-mediated improvement of acute skin wound repair.

Methods: Full-thickness wounds were made on the back of C57/BL6 mice. PRP or saline solution as a control was administered to the wound area. Wound healing rate, local inflammation, angiogenesis, re-epithelialization and collagen deposition were measured at days 3, 5, 7 and 14 after skin injury. The biological character of epidermal stem cells (ESCs), which reflect the potential for re-epithelialization, was further evaluated and .

Results: PRP strongly improved skin wound healing, which was associated with regulation of local inflammation, enhancement of angiogenesis and re-epithelialization. PRP treatment significantly reduced the production of inflammatory cytokines interleukin-17A and interleukin-1β. An increase in the local vessel intensity and enhancement of re-epithelialization were also observed in animals with PRP administration and were associated with enhanced secretion of growth factors such as vascular endothelial growth factor and insulin-like growth factor-1. Moreover, PRP treatment ameliorated the survival and activated the migration and proliferation of primary cultured ESCs, and these effects were accompanied by the differentiation of ESCs into adult cells following the changes of CD49f and keratin 10 and keratin 14.

Conclusion: PRP improved skin wound healing by modulating inflammation and increasing angiogenesis and re-epithelialization. However, the underlying regulatory mechanism needs to be investigated in the future. Our data provide a preliminary theoretical foundation for the clinical administration of PRP in wound healing and skin regeneration.
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http://dx.doi.org/10.1093/burnst/tkaa028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7427034PMC
August 2020

Compound Heterozygous Mutations in and Are Associated with Autosomal Recessive Nonsyndromic Hearing Loss in Two Chinese Han Families.

Neural Plast 2020 1;2020:8872185. Epub 2020 Aug 1.

Department of Otorhinolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.

Genetic hearing loss is a common sensory disorder, and its cause is highly heterogeneous. In this study, by targeted next-generation sequencing of 414 known deafness genes, we identified compound heterozygous mutations p.R34X/p.M413T in and p.S3417del/p.R1407T in in two recessive Chinese Han deaf families. Intrafamilial cosegregation of the mutations with the hearing phenotype was confirmed in both families by the Sanger sequencing. Auditory features of the affected individuals are consistent with that previously reported for recessive mutations in and . The two novel mutations identified in this study, p.M413T in and p.R1407T in , are classified as likely pathogenic according to the guidelines of ACMG. Our study expanded the mutation spectrums of and and illustrated that genotype-phenotype correlation in combination with next-generation sequencing may improve the accuracy for genetic diagnosis of deafness.
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http://dx.doi.org/10.1155/2020/8872185DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7416276PMC
August 2020

Generic Approach to Boost the Sensitivity of Metal Oxide Sensors by Decoupling the Surface Charge Exchange and Resistance Reading Process.

ACS Appl Mater Interfaces 2020 Aug 6;12(33):37295-37304. Epub 2020 Aug 6.

Anhui Provincial Key Laboratory of Photonic Devices and Materials, Anhui Institute of Optics and Fine Mechanics, and Key Lab of Photovoltaic and Energy Conservation Materials, Chinese Academy of Sciences, Hefei 230031, China.

As one of the bottleneck parameters for practical applications of metal oxide semiconductor-based gas sensors, sensitivity enhancement has attracted significant attention in the past few decades. In this work, alternative to conventional strategies for designing sensitive surfaces via morphology/defect/heterojunction control (then operating at an optimized isothermal temperature with a maximal response), a facile enhancement approach by decoupling surface charge exchange and resistance reading process (possessing different temperature-dependent behaviors) through pulsed temperature modulation (PTM) is reported. Substantially magnifying electrical responses of a generic metal oxide (e.g., WO) micro-electromechanical systems sensor toward diverse analyte molecules are demonstrated. Under the optimal PTM condition, the response toward 10 ppm NO can be boosted from (isothermal) 99.7 to 842.7, and the response toward 100 ppm acetone is increased from (isothermal) 2.7 to 425, which are comparable to or even better than most of the state-of-the-art WO-based sensors. In comparison to conventional (isothermal) operation, PTM allows to sequentially manipulate the physisorption/chemisorption of analyte molecules, generation of surface reactive oxygen species, and sensor resistance reading and thus provides additional opportunities in boosting the electrical response of oxide sensors for advanced health and/or environment monitoring in future.
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http://dx.doi.org/10.1021/acsami.0c07626DOI Listing
August 2020

Resonant-Cantilever-Detected Kinetic/Thermodynamic Parameters for Aptamer-Ligand Binding on a Liquid-Solid Interface.

Anal Chem 2020 08 1;92(16):11127-11134. Epub 2020 Jul 1.

State Key Lab of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, China.

Nucleic acid aptamers have been widely used as recognition elements on various biosensing interfaces, but quantitative kinetic/thermodynamic analysis for revealing the aptamer-ligand binding mechanism, which occurs on a liquid-solid interface, has not been realized due to a lack of usable biophysical tools. Herein we apply a resonant microcantilever sensor to continuously record the frequency shift according to the binding-induced mass change on the liquid-solid interface. The frequency-shift curve is used for tracing the reaction process and is fitted with classic equations to calculate a set of kinetic/thermodynamic parameters, such as rate constants ( = 902.95 M s, = 0.000141 s), equilibrium constants ( = 1.55 μM), the Gibbs free energy ( = -32.57 kJ/mol), and the activation energy ( = 38.03 kJ/mol) for the immobilized aptamer and free ATP. This quantitative analysis method is label-free, calibration-free, and highly sensitive. The kinetic/thermodynamic parameter detection method provides new resolution to the in-depth understanding of the ligand-aptamer interaction on the liquid-solid interface for biosensing or lab-on-a-chip applications.
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http://dx.doi.org/10.1021/acs.analchem.0c01142DOI Listing
August 2020

Bacterial viability and diversity in a landscape lake replenished with reclaimed water: a case study in Xi'an, China.

Environ Sci Pollut Res Int 2020 Sep 9;27(26):32796-32808. Epub 2020 Jun 9.

International Science and Technology Cooperation Center for Urban Alternative Water Resources Development, Xi'an University of Architecture and Technology, Xi'an, 710055, China.

To understand the characteristics of bacterial viability and diversity in landscape waters replenished with reclaimed water, the typical landscape lake using reclaimed water was investigated in this study. Samples were collected from a reclaimed water inlet (P1), a reclaimed water distribution outlet (P2), and a landscape lake replenished by reclaimed water (P3). By means of measuring adenosine triphosphate (ATP), flow cytometry (FCM), and 16S rRNA gene high-throughput sequencing, the bacterial viability and diversity in reclaimed water distribution system and landscape lake were illustrated. The bacterial ATP contents at P1, P2, and P3 were 3.55 ± 1.79 ng/L, 3.31 ± 1.43 ng/L, and 18.97 ± 6.39 μg/L, and the intact bacterial cell concentrations were 5.91 ± 0.52 × 10 cells/mL, 7.95 ± 2.58 × 10 cells/mL, and 5.65 ± 2.10 × 10 cells/mL, respectively. These results indicated a significant increase of bacterial viability in the landscape lake. The Shannon diversity index of 6.535, 7.05, and 6.886 at P1, P2, and P3, respectively, demonstrated no notable change of bacterial diversity from reclaimed water distribution system to landscape lake. However, the relative abundance of Pseudomonas sp. at P3 was significantly higher than that at P1. These findings indicated that viable but non-culturable (VBNC) bacteria could be revived in the landscape lake. The bacterial viability during reclaimed water reuse should deserve special attention.
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http://dx.doi.org/10.1007/s11356-020-08910-1DOI Listing
September 2020

Electrolyte Membranes with Biomimetic Lithium-Ion Channels.

Nano Lett 2020 07 23;20(7):5435-5442. Epub 2020 Jun 23.

Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States.

High-performance lithium-ion batteries (LIBs) demand efficient and selective transport of lithium ions. Inspired by ion channels in biology systems, lithium-ion channels are constructed by chemically modifying the nanoporous channels of metal-organic frameworks (MOFs) with negatively charged sulfonate groups. Analogous to the biological ion channels, such pendant anionic moieties repel free anions while allowing efficient transport of cations through the pore channels. Implementing such MOFs as an electrolyte membrane doubly enhances the lithium-ion transference number, alleviates concentration polarization, and affords striking durability of high-rate LIBs. This work demonstrates an ion-selective material design that effectively tunes the ion-transport behavior and could assist with more efficient operation of LIBs.
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http://dx.doi.org/10.1021/acs.nanolett.0c01910DOI Listing
July 2020

Antibiotic-loaded chitosan-gelatin scaffolds for infected seawater immersion wound healing.

Int J Biol Macromol 2020 Sep 17;159:1140-1155. Epub 2020 May 17.

Department of Nuclear Medicine, The First Clinical Hospital of Guangzhou Medical University, Guangzhou 510120, China; Department of Plastic Surgery, General Hospital of Southern Theater Command, PLA, Guangzhou 510010, China. Electronic address:

Skin damaged during sea battles is vulnerable to seawater immersion and bacterial infection. Scaffolds with effective biological function are highly desired for treatment of naval combat wound injuries. Herein, we prepared composite scaffolds of CS/GEL/GMs-CIP. The chitosan (CS) and gelatin (GEL) were cross-linked by genipin as matrix, and then gelatin microspheres loading ciprofloxacin hydrochloride (GMs-CIP) were add. From in vitro characterization results, CS/GEL/GMs-CIP had high water absorption ability, proper porosity, satisfactory fracture resistance, and flexibility. Furthermore, CS/GEL/GMs-CIP composite scaffold had excellent biocompatibility. Antibacterial experiments confirmed that CS/GEL/GMs-CIP had a significant inhibitory effect on E. coli, S. aureus and P. aeruginosa. The in vivo wound healing was evaluated using animal wound infection model of seawater immersion, and it was observed that the prepared composite scaffolds accelerated wound healing, reepithelialization, collagen deposition. Further analysis of wound tissue indicated that the expression of anti-inflammatory factor (TGF-β1) was up-regulated, but the serum endotoxin levels and expression of pro-inflammatory factor (TNF-a, IL-6, and IL-1β) were down-regulated. In summary, we believe that CS/GEL/GMs-CIP composite scaffold may serve as a promising multifunctional dressing for healing with open trauma wound infections and wound with seawater immersion.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.05.126DOI Listing
September 2020

Effects of polymer aging on sorption of 2,2',4,4'-tetrabromodiphenyl ether by polystyrene microplastics.

Chemosphere 2020 Aug 9;253:126706. Epub 2020 Apr 9.

Qingdao Engineering Research Center for Rural Environment, Qingdao Agricultural University, Qingdao, 266109, China. Electronic address:

The sorption behavior of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) on aged polystyrene (PS) microplastics via seawater soaking, ultraviolet (UV) irradiation, seawater soaking and UV irradiation together was investigated. The effects of environmental factors including salinity, pH, and dissolved organic matter (DOM) on sorption of BDE-47 by the aged PS microplastics were analyzed. The equilibrium sorption capacity of BDE-47 by virgin PS, aged PS with seawater soaking, aged PS with UV irradiation and aged PS with seawater soaking and UV irradiation was 6.16, 4.96, 3.53, and 3.75 ng/g, respectively. The decrease in sorption capacity was related to the increase of surface crystallinity and the appearance of surface oxygen-containing functional groups. The kinetic and isotherm models suggested that aging did not change the sorption mechanism of BDE-47 on PS microplastics. pH had negligible impacts on BDE-47 sorption by virgin and aged PS. Sorption capacity of BDE-47 on aged PS in water with high salinity was lower than that on virgin PS, and DOM has less effect on the sorption of BDE-47 on aged PS.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126706DOI Listing
August 2020

Cantharidin-loaded functional mesoporous titanium peroxide nanoparticles for non-small cell lung cancer targeted chemotherapy combined with high effective photodynamic therapy.

Thorac Cancer 2020 06 4;11(6):1476-1486. Epub 2020 Apr 4.

Department of Pharmaceutical Engineering, College of Pharmacy, Inner Mongolia Medical University, Hohhot, China.

Background: Although photodynamic therapy (PDT) has emerged as a potential alternative to conventional chemotherapy, the low reactive oxygen species (ROS) yield of the photosensitizer such as TiO nanoparticles has limited its application. In addition, it is difficult to achieve effective tumor treatment with a single tumor therapy.

Methods: We used TiOx nanocomposite (YSA-PEG-TiO ) instead of TiO as a photosensitizer to solve the problem of insufficient ROS generation in PDT. Benefiting from the desired mesoporous structure of TiOx, Cantharidin (CTD), one of the active components of mylabris, is loaded into TiOx for targeted combination of chemotherapy and PDT. The cellular uptake in human non-small cell lung carcinoma cell line (A549) and human normal breast cell line (MCF 10A) was evaluated by confocal microscopy. in vitro cytotoxicity was evaluated using Cell Counting Kit-8 assay. The ROS was detected via a chemical probe DCFH-DA and the photodynamic treatment effect of YSA-PEG-TiOx was further evaluated by a living-dead staining. The cell apoptosis was detected by the flow cytometry.

Results: Our findings showed that the modification of YSA peptide improved the cytotoxicity of YSA-PEG-TiO /CTD to EphA2 overexpressing A549 non-small cell lung cancer (NSCLC) than non-YSA modified counterparts. In addition, TiOx generated adequate ROS under X-ray irradiation to further kill cancer cells. Flow analysis results also proved the superiority of this combined treatment.

Conclusions: YSA-PEG-TiO nanoparticles could significantly increase ROS production under X-ray exposure and provide a new drug delivery nanocarrier for CTD in combination with PDT to achieve effective NSCLC treatment.
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http://dx.doi.org/10.1111/1759-7714.13414DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7262929PMC
June 2020

Multi-functional anodes boost the transient power and durability of proton exchange membrane fuel cells.

Nat Commun 2020 Mar 4;11(1):1191. Epub 2020 Mar 4.

Chemical and Biomolecular Engineering, University of California, Los Angeles, CA, 90095, USA.

Proton exchange membrane fuel cells have been regarded as the most promising candidate for fuel cell vehicles and tools. Their broader adaption, however, has been impeded by cost and lifetime. By integrating a thin layer of tungsten oxide within the anode, which serves as a rapid-response hydrogen reservoir, oxygen scavenger, sensor for power demand, and regulator for hydrogen-disassociation reaction, we herein report proton exchange membrane fuel cells with significantly enhanced power performance for transient operation and low humidified conditions, as well as improved durability against adverse operating conditions. Meanwhile, the enhanced power performance minimizes the use of auxiliary energy-storage systems and reduces costs. Scale fabrication of such devices can be readily achieved based on the current fabrication techniques with negligible extra expense. This work provides proton exchange membrane fuel cells with enhanced power performance, improved durability, prolonged lifetime, and reduced cost for automotive and other applications.
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http://dx.doi.org/10.1038/s41467-020-14822-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7055244PMC
March 2020

Erythrocyte-mimicking paclitaxel nanoparticles for improving biodistributions of hydrophobic drugs to enhance antitumor efficacy.

Drug Deliv 2020 Dec;27(1):387-399

Institute of Systems Biomedicine, Beijing Key Laboratory of Tumor Systems Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.

Recent decades have witnessed several nanocrystal-based hydrophobic drug formulations because of their excellent performance in improving drug loading and controlling drug release as mediate drug forms in tablets or capsules. However, the intravenous administration of drug nanocrystals was usually hampered by their hydrophobic surface properties, causing short half-life time in circulation and low drug distribution in tumor. Here, we proposed to enclose nanocrystals (NC) of hydrophobic drug, such as paclitaxel (PTX) into erythrocyte membrane (EM). By a series of formulation optimizations, spherical PTX nanoparticles (PN) with the particle size of around 280 nm were successfully cloaked in erythrocyte membrane, resulting in a PTX-NP-EM (PNM) system. The PNM could achieve high drug loading of PTX (>60%) and stabilize the particle size significantly compared to PN alone. Besides, the fluorescence-labeling PNM presented better tumor cell uptake, stronger cytotoxicity, and higher drug accumulation in tumor compared to PN. Finally, the PNM was found to be the most effective against tumor growth among all PTX formulations in tumor-bearing mice models, with much lower system toxicity than control formulation. In general, the PNM system with high drug-loading as well as superior bio-distributions could be served as a promising formulation.
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http://dx.doi.org/10.1080/10717544.2020.1731862DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7054973PMC
December 2020

Pentagram-Shaped Ag@Pt Core-Shell Nanostructures as High-Performance Catalysts for Formaldehyde Detection.

ACS Appl Mater Interfaces 2020 Feb 3;12(7):8091-8097. Epub 2020 Feb 3.

State Key Lab of Transducer Technology, Shanghai Institute of Microsystem and Information Technology , Chinese Academy of Sciences , 865 Changning Road , Shanghai 200050 , China.

High-performance HCHO sensors are of great importance in various application fields such as indoor air quality assessments. Herein, bimetallic Ag-Pt nanoparticles are synthesized as high-performance catalysts for ZnO-based gas sensors. Spherical aberration (Cs)-corrected transmission electron microscopy images with atomic resolution clearly indicate that the prepared nanoparticles exhibit a novel Ag@Pt core-shell nanostructure with a pentagram shape. For high-performance HCHO sensor construction, integrated micro-electrodes are first fabricated with the microelectromechanical system (MEMS) technology. Then, the hydrothermal route is used to self-assemble well-aligned ZnO nanowire arrays onto the sensing microregion. After that, the pentagram-shaped Ag@Pt nanoparticles are loaded onto the surface of ZnO nanowires with the inkjet printing technique to form MEMS sensors with Ag@Pt@ZnO as the sensing material. The thoroughly sensing experiments indicate that the Ag@Pt nanoparticles exhibit satisfied catalytic activation to HCHO molecules. The experimental observed detection limit of our sensor to HCHO reaches the parts per billion level. To elucidate the HCHO-sensing mechanism, the online mass spectrum (online MS) is utilized to analyze the components of exhaust gas stream of HCHO flowing through the Ag@Pt@ZnO material. The online MS indicates that with the Ag@Pt catalyst, HCHO molecules are partially oxidized to HCOOH molecules at low temperatures and are completely oxidized to CO molecules at high temperatures.
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http://dx.doi.org/10.1021/acsami.9b17201DOI Listing
February 2020