Publications by authors named "Xudong Cao"

68 Publications

Honeycomb-like activated carbon with microporous nanosheets structure prepared from waste biomass cork for highly efficient dye wastewater treatment.

J Hazard Mater 2021 08 20;416:125896. Epub 2021 Apr 20.

Key Laboratory of Wood Material Science and Utilization (Beijing Forestry University), Ministry of Education, Beijing 100083, PR China. Electronic address:

Cork, a porous biomass material, is consist of thin-walled hollow prismatic cells arranged into a compact and orderly honeycomb-like structure and could be applied as an adsorption material. Here, cork-activated carbons (CACs) with a fluffy honeycomb-like structure were synthesized by two-step pyrolysis with solid KOH chemical activation to rapidly and efficiently adsorb methylene blue (MB) (maximum wavelength: 664 nm). The structure, morphology and surface functional groups of the CACs were characterized using BET, SEM, and FTIR analysis. The results show that the CACs have a well-developed hierarchical porous structure and an ultra-high specific surface area of 2864.9 m/g, which would facilitate the efficient diffusion and adsorption of MB molecules onto CACs. MB adsorption performance results show that the CACs have an outstanding maximum MB adsorption capacity (1103.68 mg/g) and fast adsorption kinetics (800 mg/L, 99.8% in 10 min), indicating that CACs possess significant advantages compared with most other adsorbents previously reported. The adsorption mechanism was studied by various kinetic models, isothermal models and thermodynamic models. Langmuir model is the most adapted to describe the adsorption process, indicating that the MB molecules are uniformly adsorbed on CAC's surface in a single layer. Moreover, MB adsorption by the CACs was an endothermic, spontaneous and randomly increasing adsorption. The regeneration test showed that the uptake of MB onto CACs can still reached 580 mg/g after three adsorption-desorption cycles, demonstrating the excellent reusability of CACs. The continuous adsorption performance of MB onto CACs was evaluated by a packed column test, which further confirmed its potential as an adsorbent for dye wastewater purification.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125896DOI Listing
August 2021

A Genetically Engineered Mouse Model of Venous Anomaly and Retinal Angioma-like Vascular Malformation.

Bio Protoc 2021 Aug 5;11(15):e4117. Epub 2021 Aug 5.

Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, National Clinical Research Center for Hematologic Diseases, State Key Laboratory of Radiation Medicine and Protection, Cam-Su Genomic Resources Center, Soochow University, Suzhou 215123, China.

Characterization of key regulators in vein development will advance our understanding of mechanisms underlying venous anomalies and provide therapeutic targets for the treatment of vascular malformations. Here, we provide a detailed protocol for the generation of genetically engineered mouse models targeting the gene for the analysis of vein formation and vein-associated vascular diseases at the embryonic and postnatal stages. It includes steps involved in the whole-mount processing of mouse skin, mesentery, and retina for the examination of vascular malformation during embryonic and postnatal development.
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http://dx.doi.org/10.21769/BioProtoc.4117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8376502PMC
August 2021

In situ rolling circle amplification surface modifications to improve E. coli O157:H7 capturing performances for rapid and sensitive microfluidic detection applications.

Anal Chim Acta 2021 Mar 22;1150:338229. Epub 2021 Jan 22.

Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, ON, K1N 6N5, Canada. Electronic address:

We investigated the application of rolling circle amplification (RCA) to modify microfluidic channels for potential sensitive detection applications. To this end, a novel in situ capturing RCA (cRCA) strategy was used to modify the inner surfaces of microfluidic channels with cRCA products that featured repeating tandem capturing aptamers specific for E. coli O157:H7 cells. We showed that the in situ cRCA reaction modified microfluidic channels demonstrated significantly enhanced capturing efficiency in a wide range of flow rates when compared with the unit-aptamer approach. We demonstrated for the first time that microfluidic surfaces modified with the in situ cRCA products showed peak capturing performances both in terms of target capturing efficiency and specificity, and this was likely due to unexpected base-pairing that resulted in altered secondary structures of the capturing aptamers. Our data suggest that the in situ cRCA surface modification is a promising strategy to improve capturing performances in microfluidic devices in sensitive detection applications that also require high throughput. However, cRCA reaction conditions, particularly reaction time and concentrations of initial circular template, must be carefully investigated before the potentials of the in situ cRCA surface modification approach can be fully realized.
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http://dx.doi.org/10.1016/j.aca.2021.338229DOI Listing
March 2021

[Engineering ω-transaminase by random mutagenesis and semi-rational design for the synthesis of (R)-(+)-1-(1-naphthyl)ethylamine].

Sheng Wu Gong Cheng Xue Bao 2020 Sep;36(9):1828-1837

School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, China.

(R)-(+)-1-(1-naphthyl)ethylamine is a key chiral intermediate for the synthesis of calcimimetic drug cinacalcet hydrochloride. ω-Transaminase has been considered to be potential for producing (R)-(+)-1-(1-naphthyl)ethylamine by asymmetric reduction of 1-acetonaphthone. Here, ω-transaminase from Arthrobacter sp. was engineered by combinatorial strategies of random mutagenesis and semi-rational design. Variants F225M, C281I, F225M/C281I with improved catalytic efficiency and thermostability were obtained. Compared with WT, variant F225M/C281I showed 85% increased kcat, 56% decreased Km and 3.42-fold kcat/Km. Furthermore, 22% higher conversion rate was achieved by F225M/C281I at 10 mmol/L 1-acetonaphthone after 24 h. Based on molecular docking and molecular dynamics simulation, improved catalytic efficiency of F225M/C281I could be attributed to its increased Pi-Pi T-shaped interaction with substrate 1-acetonaphthone. Additionally, a slightly higher half-life of F225M/C281I was validated by its lower root-mean-square fluctuation (RMSF) value of loop 134-139 compared with WT.
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http://dx.doi.org/10.13345/j.cjb.200032DOI Listing
September 2020

High-Throughput Screening Method for Directed Evolution and Characterization of Aldol Activity of D-Threonine Aldolase.

Appl Biochem Biotechnol 2021 Feb 5;193(2):417-429. Epub 2020 Oct 5.

The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China.

A rapid and reliable method for the determination of aldol condensation activity of threonine aldolases (TAs) toward aldehydes and glycine was developed. This 2,4-dinitrophenylhydrazine (DNPH) method has high sensitivity and low background disturbance and can be spectrophotometrically measured for high-throughput screening and characterization of TAs. For 4-methylsulfonyl benzaldehyde (MSB), the maximum absorbance peak was observed at around 485 nm. Site-directed saturation mutagenesis libraries of D-threonine aldolase from Alcaligenes xylosoxidans CGMCC 1.4257 (AxDTA) was constructed and screened with this DNPH method for increased aldol activity toward MSB. Two beneficial variants AxDTA and AxDTA were identified. Substrate specificity of AxDTA and variants toward nineteen aldehydes with different substituents was facilely characterized employing this DNPH method. Furthermore, AxDTA variants displayed enhanced catalytic performance and selectivity in aldol reaction. Consequently, our study provides a rapid screening and characterization method for TAs with potential applications in preparation of chiral β-hydroxy-α-amino acids.
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http://dx.doi.org/10.1007/s12010-020-03447-yDOI Listing
February 2021

Isoquinolinone derivatives as potent CNS multi-receptor D/5-HT/5-HT/5-HT/5-HT agents: Synthesis and pharmacological evaluation.

Eur J Med Chem 2020 Dec 20;207:112709. Epub 2020 Aug 20.

Jiangsu Key Laboratory of Marine Biological Resources and Environment, Jiangsu Key Laboratory of Marine Pharmaceutical Compound Screening, School of Pharmacy, Jiangsu Ocean University, Lianyungang, 222005, China. Electronic address:

In this study, a series of novel Isoquinolinone derivatives were synthesized as potential multi-target antipsychotics. Among these, compound 13 showed high affinity for dopamine D and serotonin 5-HT, 5-HT, 5-HT, and 5-HT receptors, showed low affinity for off-target receptors (5-HT, H, and α), and negligible effects on ether-a-gogo-related gene (hERG; i.e., reduced QT interval prolongation). An animal behavioral study revealed that compound 13 reversed APO-induced hyperlocomotion, MK-801-induced hyperactivity, and DOI-induced head twitch. Moreover, compound 13 exhibited a high threshold for acute toxicity, a lack of tendency to induce catalepsy, and did not cause prolactin secretion or weight gain when compared to risperidone. Furthermore, in the forced swim test, tail suspension test, and novel object recognition test, treatment with compound 13 resulted in improvements in depression and cognitive impairment. In addition, compound 13 had a favorable pharmacokinetic profile in rats. Thus, the antipsychotic drug-like effects of compound 13 indicate that it may be useful for developing a novel class of drugs for the treatment of schizophrenia.
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http://dx.doi.org/10.1016/j.ejmech.2020.112709DOI Listing
December 2020

Developing a dual-RCA microfluidic platform for sensitive E. coli O157:H7 whole-cell detections.

Anal Chim Acta 2020 Aug 6;1127:79-88. Epub 2020 Jul 6.

Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, ON, K1N 6N5, Canada; Ottawa-Carleton Institute of Biomedical Engineering, University of Ottawa, Ottawa, ON, K1N 6N5, Canada. Electronic address:

Aptamer based microfluidic platforms have been developed rapidly in recent years, and strategies to improve detection sensitivities of such platforms have attracted a significant amount of attention. To achieve whole cell sensitive detections by microfluidic devices, a new dual-rolling circle amplification (RCA) detection approach is presented in this study. This dual-RCA approach includes a capturing RCA (cRCA) reaction that is designed to modify microfluidic channel surfaces with long tandem repeating aptamers (i.e. poly-aptamers) to effectively capture target E. coli O157:H7 cells. We demonstrate that this poly-aptamers modified microchannels capture 3-fold more target cells in comparison with microchannels modified with mono-aptamers against the target cells. In addition, signalling RCA (sRCA) is employed in the dual-RCA design to further enhance detection signals. Our results show that the detection signals are enhanced by up to 50 times by sRCA when compared with those with single fluorescence probes. Furthermore, by combing both the cRCA and the sRCA in one dual-RCA detection system, we demonstrate that the detection signals can be significantly enhanced by ∼250-fold. We also show that E. coli O157:H7 detections with the dual-RCA approach can be used in different food matrices, including orange juice and milk where the limit of detection of 80 cells/mL is achieved. In conclusion, this microfluidic device in combination with a dual-RCA to enhance both target capturing and detection signals is a simple and promising approach to sensitive whole-cell detections for food safety inspections.
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http://dx.doi.org/10.1016/j.aca.2020.06.046DOI Listing
August 2020

Revisit ligand-receptor interaction at the human vasopressin V receptor: A kinetic perspective.

Eur J Pharmacol 2020 Aug 30;880:173157. Epub 2020 Apr 30.

Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China. Electronic address:

The vasopressin V receptor belongs to the superfamily of G protein-coupled receptors (GPCRs) and is a potential drug target for water balance disorders such as polycystic kidney disease. Traditionally, the discovery of novel agents for the vasopressin V receptor has been guided by evaluating their receptor affinity, largely ignoring the binding kinetics. However, the latter is receiving increasing attention in the drug research community and has been proved to be a more complete descriptor of the dynamic process of ligand-receptor interaction. Herein we aim to revisit the molecular basis of ligand-vasopressin V receptor interaction from the less-investigated kinetic perspective. A homogenous time-resolved fluorescence resonance energy transfer (TR-FRET) assay was set up and optimized, which enabled accurate kinetic profiling of unlabeled vasopressin V receptor ligands. Receptor occupancy profiles of two representative antagonists with distinct target residence time were simulated. Their functional effects were further explored in cAMP assays. Our results showed that the antagonist with longer receptor residence time (lixivaptan) displayed sustained target occupancy than the antagonist with shorter receptor residence time (mozavaptan). In accordance, lixivaptan displayed insurmountable antagonism and wash-resistant inhibitory effect on the cellular cAMP level, while not so for mozavaptan. Together, our data provide evidence that binding kinetics, next to their affinity, offers additional information for the dynamic process of ligand-receptor interaction. Hopefully, this study may lead to more kinetics-directed medicinal chemistry efforts and aid the design and discovery of different-in-class of vasopressin V receptor ligands for clinical applications.
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http://dx.doi.org/10.1016/j.ejphar.2020.173157DOI Listing
August 2020

Modified SEIR and AI prediction of the epidemics trend of COVID-19 in China under public health interventions.

J Thorac Dis 2020 Mar;12(3):165-174

National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, First Affiliated Hospital of Guangzhou Medical University, State Key Laboratory of Respiratory Disease (Guangzhou Medical University), Guangzhou 510230, China.

Background: The coronavirus disease 2019 (COVID-19) outbreak originating in Wuhan, Hubei province, China, coincided with , the period of mass migration for the annual Spring Festival. To contain its spread, China adopted unprecedented nationwide interventions on January 23 2020. These policies included large-scale quarantine, strict controls on travel and extensive monitoring of suspected cases. However, it is unknown whether these policies have had an impact on the epidemic. We sought to show how these control measures impacted the containment of the epidemic.

Methods: We integrated population migration data before and after January 23 and most updated COVID-19 epidemiological data into the Susceptible-Exposed-Infectious-Removed (SEIR) model to derive the epidemic curve. We also used an artificial intelligence (AI) approach, trained on the 2003 SARS data, to predict the epidemic.

Results: We found that the epidemic of China should peak by late February, showing gradual decline by end of April. A five-day delay in implementation would have increased epidemic size in mainland China three-fold. Lifting the Hubei quarantine would lead to a second epidemic peak in Hubei province in mid-March and extend the epidemic to late April, a result corroborated by the machine learning prediction.

Conclusions: Our dynamic SEIR model was effective in predicting the COVID-19 epidemic peaks and sizes. The implementation of control measures on January 23 2020 was indispensable in reducing the eventual COVID-19 epidemic size.
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http://dx.doi.org/10.21037/jtd.2020.02.64DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7139011PMC
March 2020

Design and evaluation of a biosynthesized cellulose drug releasing duraplasty.

Mater Sci Eng C Mater Biol Appl 2020 May 21;110:110677. Epub 2020 Jan 21.

Department of Chemical and Biological Engineering, Faculty of Engineering, University of Ottawa, Canada; Biomedical Engineering, Faculty of Engineering, University of Ottawa, Canada. Electronic address:

Decompressive craniectomy (DC) is a standard surgical procedure performed on stroke patients in which a portion of a skull is removed and a duraplasty membrane is applied onto the brain. While DC can significantly reduce the risk of death, it does not reverse the stroke damage. In this study, a novel biosynthesized cellulose (BC)-based drug releasing duraplasty was developed and studied. The BC duraplasty fabrication process allowed readily incorporation of growth factors (GFs) in a sterile manner and control of physical and mechanical properties of the resulting duraplasty. Our results showed that BC duraplasty containing the highest amount of dry cellulose presented swelling ratio of 496 ± 27%, Young's modulus of 0.37 ± 0.02 MPa, ultimate tensile strength of 0.96 ± 0.02 MPa, while releasing GFs for over 10 days. In addition, neural stem/progenitor cell (NSPC) cultures demonstrated that the GFs released from the BC duraplasty promoted NSPC proliferation and differentiation in vitro. Finally, animal studies revealed that the BC duraplasty did not cause any inflammatory reactions after the DC procedure in vivo. In summary, this newly developed GF loaded BC membrane demonstrates a promising potential as drug releasing duraplasty, not only for stroke treatments but also for traumatic brain injuries and spinal cord injuries.
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http://dx.doi.org/10.1016/j.msec.2020.110677DOI Listing
May 2020

Intracranial Pressure Monitoring-Aided Management Associated with Favorable Outcomes in Patients with Hypertension-Related Spontaneous Intracerebral Hemorrhage.

Transl Stroke Res 2020 12 6;11(6):1253-1263. Epub 2020 Mar 6.

Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China.

To investigate the effect of intracranial pressure (ICP) monitoring on the functional outcome of patients with hypertension-related spontaneous intracerebral hemorrhage (ICH). We included 196 patients with Glasgow Coma Scale (GCS) scores of 3-12 in this observational study, of which 103 underwent ICP monitors. Binary and ordinal regression analyses were used to estimate the effect of ICP monitoring on the functional outcome. The rate of adverse events, blood pressure control, and length of hospitalization were compared between the two groups. ICP monitoring had a significant impact on the clinical outcome of patients by shifting the Extended Glasgow Outcome Scale (GOS-E) scores in a favorable direction (p = 0.027) and reducing mortality at discharge (p = 0.004) and 6 months later (p = 0.02). The rate of favorable outcome at 6 months was higher in the ICP-monitored group (p = 0.03). However, subgroup analysis showed that no relationship between ICP monitoring and clinical outcome was found for patients with GCS scores of 3-8. For patients with GCS scores of 9-12, the distribution of GOS-E scores at 6 months shifted in a favorable direction in the ICP-monitored group (p = 0.001). The rate of favorable outcome at 6 months was higher in the ICP-monitored group (p = 0.01). The mortality at discharge and 6 months later was also lower in the ICP-monitored group. Thus, our study supports the value of ICP monitoring in hypertension-related ICH patients with GCS scores of 3-12, especially those with GCS scores of 9-12.
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http://dx.doi.org/10.1007/s12975-020-00798-wDOI Listing
December 2020

Production and evaluation of biosynthesized cellulose tubes as promising nerve guides for spinal cord injury treatment.

J Biomed Mater Res A 2020 06 6;108(6):1380-1389. Epub 2020 Mar 6.

Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario, Canada.

Spinal cord injury (SCI) is a central nervous disorder that can result in permanent motor and sensory damage due to a severed communication pathway. Although there is currently no effective treatment, nerve guide tubes have been used to bridge the injured stumps and act as drug delivery systems. In this study, biosynthesized cellulose (BC) nerve guides were prepared, and nerve growth factor (NGF)-a model growth factor-was incorporated into the tubular nerve guide in order to obtain a nerve guide/drug delivery system to assist the regeneration. To achieve this, Gluconacetobacter hansenii was cultivated in a special bioreactor to produce biosynthesized cellulose tubes (BCTs) in situ, and the physical and mechanical properties of the BCTs obtained from different cultivation time points were evaluated. Our results showed that the properties of the BCTs were comparable to those of the native human neural tissues, and that the NGF released from the BCTs was bioactive for at least 7 days as evaluated by PC12 cell cultures in vitro. In summary, this study evaluated the use of BCT as a drug releasing nerve guide, and our results showed that the BCT is an attractive strategy to enhance nerve regeneration after the SCI.
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http://dx.doi.org/10.1002/jbm.a.36909DOI Listing
June 2020

Enabling long-lived organic room temperature phosphorescence in polymers by subunit interlocking.

Nat Commun 2019 Sep 18;10(1):4247. Epub 2019 Sep 18.

Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing, 211816, China.

Long-lived room temperature phosphorescence (LRTP) is an attractive optical phenomenon in organic electronics and photonics. Despite the rapid advance, it is still a formidable challenge to explore a universal approach to obtain LRTP in amorphous polymers. Based on the traditional polyethylene derivatives, we herein present a facile and concise chemical strategy to achieve ultralong phosphorescence in polymers by ionic bonding cross-linking. Impressively, a record LRTP lifetime of up to 2.1 s in amorphous polymers under ambient conditions is set up. Moreover, multicolor long-lived phosphorescent emission can be procured by tuning the excitation wavelength in single-component polymer materials. These results outline a fundamental principle for the construction of polymer materials with LRTP, endowing traditional polymers with fresh features for potential applications.
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http://dx.doi.org/10.1038/s41467-019-11749-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6751207PMC
September 2019

Target capturing performance of microfluidic channel surface immobilized aptamers: the effects of spacer lengths.

Biomed Microdevices 2019 06 15;21(3):54. Epub 2019 Jun 15.

Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada.

Aptamers have been widely used to recognize and capture their targets in sensitive detection applications, such as in detections of circulating tumor cells. In this study, we investigate the effects of different lengths of oligo-T spacers on surface tethered sgc8 aptamers and their target capturing performances. To achieve this, sgc8 aptamers were immobilized onto microfluidic channel surfaces via oligo-T spacers of different lengths, and the target capturing performances of these immobilized aptamers were studied using CCRF-CEM cells. We demonstrate that the capturing performances of the immobilized aptamers were significantly affected by steric hindrance. Our results also show that aptamers immobilized on surfaces via spacers of ten Ts demonstrated the best cell capturing performances; aptamers with either too short or too long oligo-T spacers showed reduced cell capturing performances. Therefore it can be concluded that spacer optimizations are critically important for surface tethered aptamers that are commonly used in microfluidic devices for sensitive target sensing and detections.
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http://dx.doi.org/10.1007/s10544-019-0403-zDOI Listing
June 2019

Synthesis and evaluation of histamine H receptor ligand based on lactam scaffold as agents for treating neuropathic pain.

Bioorg Med Chem Lett 2019 06 8;29(12):1492-1496. Epub 2019 Apr 8.

Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address:

The synthesis and H receptor ligand of a new series of lactam derivatives are reported. The new compounds were evaluated in vitro in H and H receptor-binding assays. The structure-activity relationship led us to the promising derivative 2-methyl-7-(3-morpholinopropoxy)-3,4-dihydroisoquinolin-1(2H)-one (11). The compound with highest affinity and greatest selectivity were further profiled, In addition, compound 11 exerted dose-dependent anti-nociceptive effects in the formalin test. These characteristics suggested that the potent and selective compound 11 could be a potent candidate for pain treatment.
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http://dx.doi.org/10.1016/j.bmcl.2019.04.015DOI Listing
June 2019

Aptamer surface functionalization of microfluidic devices using dendrimers as multi-handled templates and its application in sensitive detections of foodborne pathogenic bacteria.

Anal Chim Acta 2019 May 29;1056:96-107. Epub 2019 Jan 29.

Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada; Ottawa-Carlton Institute of Biomedical Engineering, Ottawa, Ontario, K1N 6N5, Canada. Electronic address:

A microfluidic system that incorporates both dendrimers and aptamers to detect E. coli O157:H7 is developed. To achieve this, generation 7-polyamidoamine dendrimers were immobilized onto the detection surfaces of PDMS microfluidic channels; subsequently aptamers against E. coli O157:H7 were conjugated onto the microchannel surfaces via the immobilized dendrimers as templates. Surface modifications were characterized by FTIR, XPS, water contact angles, fluorescence microscopy and AFM to confirm the success of each surface modification steps. The efficacy of this simple microchannel in detection was investigated using E. coli O157:H7 spiked samples. Our results showed that this interesting approach significantly increased the amount of aptamers available on the microfluidic channel surfaces to capture E. coli O157:H7 cells to allow sensitive detection, which in turn resulted in detections of E. coli O157:H7 cells at a low limit of detection of 10 cells mL. The results also demonstrated that in comparison with the generation 4-polyamidoamine dendrimers (G4) modified microchannels, those modified with G7 showed enhanced detection signals, improved target capturing efficiencies, and at higher throughput. This simple whole cell detection design has not been reported in the literature and it is an interesting and effective approach to developing a sensitive and rapid detection platform for foodborne pathogenic bacteria.
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http://dx.doi.org/10.1016/j.aca.2019.01.035DOI Listing
May 2019

A cyclometalating organic ligand with an Iridium center toward dramatically improved photovoltaic performance in organic solar cells.

Chem Commun (Camb) 2019 Feb;55(18):2640-2643

Key Lab for Flexible Electronics and Institute of Advanced Materials, Nanjing Tech University, 30 South Puzhu Road, Nanjing, 211816, P. R. China.

Organometallic compounds as photoactive materials are relatively new in organic solar cells. Upon cyclometalation, the octahedral heteroleptic Ir complex TBzIr exhibits significantly enhanced optical-absorption and improved film-morphology compared to the planar organic 2-(5''-hexyl-[2,2':5',2''-terthiophen]-5-yl)benzo[d]thiazole (TBz) ligand. Thus, a dramatically improved power conversion efficiency (PCE) from ∼0 to 3.81% is attained when combined with PC71BM.
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http://dx.doi.org/10.1039/c9cc00173eDOI Listing
February 2019

Association of human leukocyte antigens-DQB2/DPA1/DPB1 polymorphism and pulmonary tuberculosis in the Chinese Uygur population.

Mol Genet Genomic Med 2019 03 1;7(3):e544. Epub 2019 Jan 1.

Key Laboratory of Xinjiang Endemic and Ethnic Diseases Cooperated by Education Ministry with Xinjiang Province, Shihezi University, Shihezi, China.

Background: Tuberculosis (TB) is the second-leading cause of death globally. Genetic polymorphisms in human leukocyte antigens (HLA)-DQB2, HLA-DPA1, and HLA-DPB1 may partly explain individual differences in TB susceptibility.

Methods: We performed a hospital-based case-control study to assess the genetic influence of single-nucleotide polymorphisms (SNPs) in the HLA (HLA-DPA, HLA-DPB, and HLA-DQB) on the development of TB. There were 248 TB-infected cases and 340 healthy controls in this study.

Results: The HLA-DQB2 rs7453920 genotype GG was applied as the reference group, the GA genotype was related to a considerably magnified risk of TB (GA vs. GG: adjusted OR = 1.547, 95% CI = 1.039-2.304, p = 0.032). Nevertheless, the other two SNPs were not associated with TB risk. Stratified analyses suggested that tobacco was associated with an increased risk of TB in HLA-DQB2 rs7453920 G>A.

Conclusion: These results suggested that the functional HLA-DQB2 rs7453920 G>A polymorphism may contribute to the genetic susceptibility to TB. Nevertheless, the results were based on a limited sample size, and larger well-designed studies are expected to confirm these preliminary findings.
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http://dx.doi.org/10.1002/mgg3.544DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6418356PMC
March 2019

Synthesis and Biological Evaluation of Sigma-1 (σ ) Receptor Ligands Based on Phenyl-1,2,4-oxadiazole Derivatives.

Chem Biodivers 2019 Mar 18;16(3):e1800599. Epub 2019 Feb 18.

Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China.

In this study, a series of phenyl-1,2,4-oxadiazole derivatives were synthesized and evaluated for anti-allodynic activity. Structure-activity relationship studies identified 1-{4-[3-(2,4-dichlorophenyl)-1,2,4-oxadiazol-5-yl]butyl}piperidine (39) with excellent affinity for the σ receptor and selectivity for the σ receptor, with poor activity to other central nervous system neurotransmitter receptors and transporters associated with pain. Compound 39 exhibited dose-dependent efficacy in suppressing the formalin-induced flinching and attenuating mechanical allodynia in chronic constriction injury-induced neuropathic rats. These results suggest that compound 39 exerts potent antihyperalgesic activity and could be considered as a promising candidate for treating neuropathic pain.
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http://dx.doi.org/10.1002/cbdv.201800599DOI Listing
March 2019

polymorphism was associated with an increased risk of tuberculosis in the Chinese Uygur population.

Int J Mol Epidemiol Genet 2018 20;9(5):64-70. Epub 2018 Oct 20.

Key Laboratory of Xinjiang Endemic and Ethnic Diseases Cooperated by Education Ministry with Xinjiang Province Xinjiang Province, China.

Introduction: Tuberculosis (TB) is a foremost infectious disease in most parts of the world. Globally, tuberculosis is the second-leading cause of infectious diseases. This has become a significant world-wide social and public health issue, and one of the major diseases in China. In addition to environmental risk factors, genetic factors may play an important role in the development of tuberculosis.

Methods: We conducted a case-control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs): MBL2 rs1800450 C > T, MBL2 rs7095891 G > A and MBL2 rs7096206 C > G, and their influences on the development of tuberculosis. A total of 231 tuberculosis cases and 240 controls were included in this study. Genotypes were determined using a custom-designed 48-Plex SNPscanTM kit.

Results: The MBL2 rs7095891 G > A polymorphism was associated with an increased risk of TB. However, there were no significant links with the other two SNPs. In any subgroup, there was no relvant risk of TB associated with MBL2 rs7095891 G > A polymorphism.

Conclusion: These findings suggest that functional polymorphism MBL2 rs7095891 G > A may be positively correlated with susceptibility to tuberculosis. These findings may be somewhat limited by sample size. A further study with more focus on different regions, ethnic groups and larger sample sizes is therefore suggested.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6261923PMC
October 2018

Synthesis and Biological Evaluation of Fused Tricyclic Heterocycle Piperazine (Piperidine) Derivatives As Potential Multireceptor Atypical Antipsychotics.

J Med Chem 2018 11 9;61(22):10017-10039. Epub 2018 Nov 9.

Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan 430074 , China.

Herein, a novel series of multireceptor ligands was developed as polypharmacological antipsychotic agents using the designed multiple ligand approach between dopamine receptors and serotonin receptors. Among them, compound 47 possessed unique pharmacological features, exhibiting high affinities for D, D, 5-HT, 5-HT, and 5-HT receptors and low efficacy at the off-target receptors (5-HT, histamine H, and adrenergic α receptor). Compound 47 showed dose-dependent inhibition of apomorphine- and MK-801-induced motor behavior, and the conditioned avoidance response with low cataleptic effect. Moreover, compound 47 resulted nonsignificantly serum prolactin levels and weight gain change compared with risperidone. Additionally, compound 47 possessed a favorable pharmacokinetic profile with oral bioavailability of 58.8% in rats. Furthermore, compound 47 displayed procognition properties in a novel object recognition task in rats. Taken together, compound 47 may constitute a novel class of atypical antipsychotic drugs for schizophrenia.
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http://dx.doi.org/10.1021/acs.jmedchem.8b01096DOI Listing
November 2018

Subunits of human condensins are potential therapeutic targets for cancers.

Cell Div 2018 20;13. Epub 2018 Feb 20.

3Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, K1N 6N5 Canada.

The main role of condensins is to regulate chromosome condensation and segregation during cell cycles. Recently, it has been suggested in the literatures that subunits of condensin I and condensin II are involved in some human cancers. This paper will first briefly discuss discoveries of human condensins, their components and structures, and their multiple cellular functions. This will be followed by reviews of most recent studies on subunits of human condensins and their dysregulations or mutations in human cancers. It can be concluded that many of these subunits have potentials to be novel targets for cancer therapies. However, hCAP-D2, a subunit of human condensin I, has not been directly documented to be associated with any human cancers to date. This review hypothesizes that hCAP-D2 can also be a potential therapeutic target for human cancers, and therefore that all subunits of human condensins are potential therapeutic targets for human cancers.
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http://dx.doi.org/10.1186/s13008-018-0035-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5819170PMC
February 2018

A fluorescent immunochromatographic strip test using a quantum dot-antibody probe for rapid and quantitative detection of 1-aminohydantoin in edible animal tissues.

Anal Bioanal Chem 2018 Jan 28;410(2):565-572. Epub 2017 Nov 28.

Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.

A rapid, simple, and sensitive fluorescent immunochromatographic strip test (ICST) based on quantum dots (QDs) has been developed to detect 1-aminohydantoin (AHD), a major metabolite of nitrofurantoin in animal tissues. To achieve this, QD-labeled antibody conjugates, which consist of CdSe/ZnS QDs and monoclonal antibodies, were prepared by an activated ester method. Under optimal conditions, with the nitrophenyl derivative of AHD as the target, the ICST had a linear range from 0.1 to 100 ng/mL, with a correlation coefficient of 0.9656 and a 50% inhibitory concentration of 4.51 ng/mL. The limit of detection was 0.14 ng/g, which was below the minimum required performance limit of 1 μg/kg for AHD established by the European Commission. The recoveries for AHD ranged from 81.5% to 108.2%, with coefficients of variation below 13%, based on intraday and interday analysis. Furthermore, for AHD in real samples, the ICST showed high reliability and high correlation with liquid chromatography-tandem mass spectrometry (correlation coefficient of 0.9916). To the best of our knowledge, this is the first report of a novel and sensitive method based on a fluorescent ICST to detect AHD below the minimum required performance limit. The ICST demonstrated high reliability, and could be ideally suited for rapid, simple, and on-site screening of AHD contamination in animal tissues. Graphical abstract A rapid, simple, and sensitive fluorescent immunochromatographic strip test that is based on quantum dots was developed to detect 1-aminohydantoin (AHD), a major metabolite of nitrofurantoin in animal tissues. 2-NBA 2-nitrobenzaldehyde, NP nitrophenyl.
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http://dx.doi.org/10.1007/s00216-017-0756-1DOI Listing
January 2018

Development of multifunctional nanoparticles towards applications in non-invasive magnetic resonance imaging and axonal tracing.

J Biol Inorg Chem 2017 Dec 25;22(8):1305-1316. Epub 2017 Oct 25.

Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur Street, Ottawa, ON, K1N 6N5, Canada.

A multifunctional nanobiomaterial has been developed by deliberately combining functions of superparamagnetism, fluorescence, and axonal tracing into one material. Superparamagnetic iron oxide nanoparticles were first synthesized and coated with a silica layer to prevent emission quenching through core-dye interactions; a fluorescent molecule, fluorescein isothiocyanate, was doped inside second layer of silica shell to improve photo-stability and to enable further thiol functionalization. Subsequently, biotinylated dextran amine, a sensitive axonal tracing reagent, was immobilized on the thiol-functionalized nanoparticle surfaces. The resulting nanoparticles were characterized by transmission electron microscopy, dynamic light scattering, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis spectroscopy, magnetic resonance imaging and fluorescence confocal microscopy. In vitro cell experiments using both undifferentiated and differentiated Neuro-2a cells showed that the cells were able to take up the nanoparticles intracellularly and that the nanoparticles showed good biocompatibilities. In summary, this new material demonstrated promising performances for both optical and magnetic resonance imaging modalities, suggesting its promising potentials in applications such as in non-invasive imaging, particularly in neuronal tracing.
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http://dx.doi.org/10.1007/s00775-017-1503-yDOI Listing
December 2017

In situ and ex situ modifications of bacterial cellulose for applications in tissue engineering.

Mater Sci Eng C Mater Biol Appl 2018 Jan 30;82:372-383. Epub 2016 Nov 30.

Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada. Electronic address:

Bacterial cellulose (BC) is secreted by a few strains of bacteria and consists of a cellulose nanofiber network with unique characteristics. Because of its excellent mechanical properties, outstanding biocompatibilities, and abilities to form porous structures, BC has been studied for a variety of applications in different fields, including the use as a biomaterial for scaffolds in tissue engineering. To extend its applications in tissue engineering, native BC is normally modified to enhance its properties. Generally, BC modifications can be made by either in situ modification during cell culture or ex situ modification of existing BC microfibers. In this review we will first provide a brief introduction of BC and its attributes; this will set the stage for in-depth and up-to-date discussions on modified BC. Finally, the review will focus on in situ and ex situ modifications of BC and its applications in tissue engineering, particularly in bone regeneration and wound dressing.
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http://dx.doi.org/10.1016/j.msec.2016.11.121DOI Listing
January 2018

Facile synthesis of Gd-doped CdTe quantum dots with optimized properties for optical/MR multimodal imaging.

J Biol Inorg Chem 2017 Dec 1;22(8):1151-1163. Epub 2017 Sep 1.

Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur Private, Ottawa, ON, K1N 6N5, Canada.

Each imaging modality has its own merits and intrinsic limitations; therefore, combining two or more complementary imaging modalities has become an interesting area of research. Recently, magnetic ion-doped quantum dots have become an increasingly promising class of optical/magnetic resonance multimodal imaging probes due to their excellent physical and chemical properties. In this work, Gd-doped CdTe quantum dots (QDs) were successfully synthesized via a facile one-step refluxing route,and their optimal synthesis conditions were investigated. The prepared CdTe:Gd QDs were shown to exhibit good optical properties with high quantum yields up to 69%, high longitudinal relaxivity (r  = 3.8 mM s), and good crystalline structures. In addition, after further QD surface modification with dextran amine (DA), the resulting DA-modified QDs (i.e. DA-CdTe:Gd QDs) showed strong magnetic resonance imaging contrast (r  = 3.5 mM s) and improved biocompatibility when tested with cell cultures in vitro. Taken together, this new material demonstrated promising performances for both optical and magnetic resonance imaging modalities, suggesting its promising potential applications in non-invasive imaging, particularly in neuronal tracing.
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http://dx.doi.org/10.1007/s00775-017-1491-yDOI Listing
December 2017

Angiopoietin receptor Tie2 is required for vein specification and maintenance via regulating COUP-TFII.

Elife 2016 12 22;5. Epub 2016 Dec 22.

Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China.

Mechanisms underlying the vein development remain largely unknown. Tie2 signaling mediates endothelial cell (EC) survival and vascular maturation and its activating mutations are linked to venous malformations. Here we show that vein formation are disrupted in mouse skin and mesentery when Tie2 signals are diminished by targeted deletion of either ubiquitously or specifically in embryonic ECs. Postnatal Tie2 attenuation resulted in the degeneration of newly formed veins followed by the formation of haemangioma-like vascular tufts in retina and venous tortuosity. Mechanistically, Tie2 insufficiency compromised venous EC identity, as indicated by a significant decrease of COUP-TFII protein level, a key regulator in venogenesis. Consistently, angiopoietin-1 stimulation increased COUP-TFII in cultured ECs, while Tie2 knockdown or blockade of Tie2 downstream PI3K/Akt pathway reduced COUP-TFII which could be reverted by the proteasome inhibition. Together, our results imply that Tie2 is essential for venous specification and maintenance via Akt mediated stabilization of COUP-TFII.
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http://dx.doi.org/10.7554/eLife.21032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5218530PMC
December 2016

Developing a non-fouling hybrid microfluidic device for applications in circulating tumour cell detections.

Colloids Surf B Biointerfaces 2017 Mar 6;151:39-46. Epub 2016 Dec 6.

Department of Chemical and Biological Engineering, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada; Ottawa-Carleton Institute of Biomedical Engineering, Ottawa, Ontario K1N 6N5, Canada. Electronic address:

Non-specific cell adsorption is a challenge in sensitive detections using microfluidic systems, such as detecting circulating tumour cells from blood samples. In this report, we present a new strategy to study the combined effects of surface hydrophilicity/hydrophobicity, electric charges and roughness on surface non-fouling properties of a PDMS/SU-8 microfluidic system. To achieve this, microchannel surfaces were modified by poly(amidoamine) generation 4 and generation 7, dendrimers that rendered surfaces negatively and positively charged at pH 7.4, respectively. Water contact angle, atomic force microscopy (AFM) and microscopy were used to characterize and confirm surface modifications, and the non-fouling performance of the resulting surfaces was tested using both live and dead CCRM-CEM cancer cells. Our results show that for live cells, electric charges of a surface is the most important factor affecting the non-fouling features of the surface in microfluidic systems; in contrast, for dead cells, surface hydrophilicity is the most important factor affecting surface non-fouling properties. However, surface roughness does not seem to be as important for both live and dead cells under the experimental conditions used in this study. These results also highlight the importance of different considerations when designing a lab-on-a-chip microfluidic system for high sensitivity biosensing and detection applications.
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http://dx.doi.org/10.1016/j.colsurfb.2016.12.003DOI Listing
March 2017

Synthesis and biological evaluation of new 6-hydroxypyridazinone benzisoxazoles: Potential multi-receptor-targeting atypical antipsychotics.

Eur J Med Chem 2016 Nov 4;124:713-728. Epub 2016 Sep 4.

Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; Jiangsu Nhwa Pharmaceutical Co., Ltd., 69 Democratic South Road, Xuzhou, Jiangsu 221116, China. Electronic address:

In recent years, multi-targeting directed ligands have attracted great interest as possible new atypical antipsychotics. Combinations of dopamine and serotonin receptor ligands within single molecules might afford new therapeutic opportunities. Herein, we describe the synthesis of a novel series of 6-hydroxypyridazinone benzisoxazoles and their binding behaviors to different receptors in terms of atypical antipsychotic behaviors. The most potent compound (46) exhibited excellent affinities for certain receptors (D, K = 0.5 ± 0.07 nM; 5-HT, K = 5.9 ± 0.8 nM; 5-HT, K = 0.3 ± 0.01 nM; 5-HT, K = 0.5 ± 0.04 nM) and combined with low affinities for the H, 5-HT, and adrenergic α receptors. In contrast to risperidone, compound 46 exhibited a high cataleptic threshold; this may be useful in the development of a novel class of drugs treating schizophrenia.
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http://dx.doi.org/10.1016/j.ejmech.2016.09.008DOI Listing
November 2016

Loop-mediated isothermal amplification assay targeting the mpb70 gene for rapid differential detection of Mycobacterium bovis.

Arch Microbiol 2016 Nov 7;198(9):905-11. Epub 2016 Jun 7.

College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang Province, 832000, People's Republic of China.

Loop-mediated isothermal amplification (LAMP) is a highly sensitive, rapid, cost-effective nucleic acid amplification method. Tuberculosis (TB) is widely popular in the world and it is difficult to cure. The fundamental treatment is to clear the types of TB pathogens such as Mycobacterium bovis (M. bovis), Mycobacterium tuberculosis (M. tuberculosis). In order to detect and diagnose TB early, we constructed the differential diagnostic method of TB. In this study, we used LAMP for detection of M. bovis, based on amplification of the mpb70 gene which is a unique gene in M. bovis strain. The LAMP assay was able to detect only seven copies of the gene per reaction, whereas for the conventional PCR, it was 70 copies. The LAMP was evaluated for its specificity using six strains of five Mycobacterium species and 18 related non-Mycobacterium microorganism strains as controls. The target three Mycobacterium strains were all amplified, and no cross-reaction was found with 18 non-Mycobacterium microorganism strains. TB was detected by two methods, LAMP and conventional PCR (based on mpb70 gene); the positive rates of the two methods were 9.55 and 7.01 %, respectively. Our results indicate that the LAMP method should be a potential tool with high convenience, rapidity, sensitivity and specificity for the diagnosis of TB caused by M. bovis. Most importance is that the use of LAMP as diagnostic method in association with diagnostic tests based on mpb70 gene would allow the differentiation between M. bovis and other Mycobacterium in humans or animals. The LAMP method is actually in order to detect human TB, and it can be used for differential diagnosis in this paper.
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http://dx.doi.org/10.1007/s00203-016-1232-6DOI Listing
November 2016
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