Publications by authors named "Xiao-Bing Zhang"

272 Publications

therapeutic response monitoring by a self-reporting upconverting covalent organic framework nanoplatform.

Chem Sci 2019 Dec 3;11(5):1299-1306. Epub 2019 Dec 3.

Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Life Sciences, Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University Changsha Hunan 410082 China

The real-time and monitoring of reactive oxygen species (ROS) generation is critical for minimizing the nonspecific damage derived from the high doses of ROS required during the photodynamic therapy (PDT) process. However, phototherapeutic agents that can generate ROS-related imaging signals during PDT are rare, hampering the facile prediction of the future therapeutic outcome. Herein, we develop an upconverting covalent organic framework (COF) nanoplatform a core-mediated strategy and further functionalized it with a singlet oxygen reporter for the efficient near-infrared activated and self-reporting of PDT. In this work, the COF photodynamic efficacy is greatly improved (12.5 times that of irregular COFs) tailoring the size. Furthermore, this nanoplatform is able to not only produce singlet oxygen for PDT, but it can also emit singlet oxygen-correlated luminescence, allowing the real-time and monitoring of the therapeutic process for cancer cells or solid tumors near-infrared luminescence imaging. Thus, our core-mediated synthetic and size-tailored strategy endows the upconverting COF nanoplatform with promising abilities for high-efficacy, deep-tissue, precise photodynamic treatment.
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http://dx.doi.org/10.1039/c9sc04875hDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8148386PMC
December 2019

Tumor-Specific Multipath Nucleic Acid Damages Strategy by Symbiosed [email protected] with Synergistic Self-Cyclic Catalysis.

Small 2021 Jun 10:e2100766. Epub 2021 Jun 10.

State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, China.

The high proliferation efficiency, redox imbalance, and elevated nucleic acid repair capabilities of tumor cells severely restrict the theranostic efficacy. Selectively interference chaotic tumors with devastating nucleic acid damages (NUDs) properties are expected to overcome theranostic barriers. Here, an exquisite catalytic-based strategy with comprehensive NUDs mechanisms is demonstrated. In this regard, enzyme (glucose oxidase, GOD) symbioses nanozyme Cu (PO ) through biomineralization (abbreviated as [email protected]), GOD can disorder the metabolism by consuming glucose, thereby inhibiting the nutrition supply for nucleic acid repair. GOD-catalyzed H O guarantees the self-cyclic glutathione depletion and reactive oxygen species generation caused by Cu (PO ) , resulted the reduced antioxidation defense and enhanced oxidation assault, ensures an indiscriminate NUDs ability. Moreover, the high photothermal effect of Cu (PO ) induces effective tumor inhibition. Consequently, this substantial multipath NUDs strategy, with potentials of suppressing the cytoprotective mechanisms, amplifying the cellular oxidative stress, and disrupting the redox balance to ensure substantial irreversible NUDs, completely breaks the obstacle of chaotic tumors, providing new conceptual thinking for tumor proliferation inhibition.
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http://dx.doi.org/10.1002/smll.202100766DOI Listing
June 2021

Ratiometric Semiconducting Polymer Nanoparticle for Reliable Photoacoustic Imaging of Pneumonia-Induced Vulnerable Atherosclerotic Plaque in Vivo.

Nano Lett 2021 05 12;21(10):4484-4493. Epub 2021 May 12.

State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.

Acute pneumonia can greatly increase the vulnerable risk of atherosclerotic plaque and contribute to the mortality of cardiovascular disease. To accurately assess the rupture risk caused by acute pneumonia, we developed a novel kind of ratiometric semiconducting polymer nanoparticle (RSPN) for photoacoustic imaging of vulnerable plaque in apolipoprotein E-deficient mice complicated with pneumonia. Specifically, RSPN can react with O and exhibit the enhanced photoacoustic signals at about 690 nm, while 800 nm is regarded as an internal photoacoustic reference. As a result, RSPN can provide reliable determination of O within aortic atherosclerosis by analyzing the ratios of photoacoustic signals, which can successfully reflect the oxidative stress level in vulnerable plaque. Therefore, RSPN enable to specifically distinguish plaque-bearing mice and plaque-bearing mice complicated with pneumonia from healthy mice, which provides a promising tool to predict the vulnerability of plaque for reducing the mortality of atherosclerotic-induced cardiovascular disease.
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http://dx.doi.org/10.1021/acs.nanolett.1c01359DOI Listing
May 2021

Gene knockout in highly purified mouse hematopoietic stem cells by CRISPR/Cas9 technology.

J Immunol Methods 2021 May 4;495:113070. Epub 2021 May 4.

State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China. Electronic address:

The CRISPR/Cas9 system has been used for genome editing of human and mouse cells. In this study, we established a protocol for gene knockout (KO) in mouse hematopoietic stem cells (HSCs). HSCs were highly purified from the bone marrow of tamoxifen-treated Cas9-EGFP/Cre-ER transgenic mice, maintained in serum-free polyvinyl alcohol culture with cytokines, lentivirally transduced with sgRNA-Crimson, and transplanted into lethally irradiated mice with competitor cells. Previous studies of Pax5 KO mice have shown B cell differentiation block. To verify our KO HSC strategy, we deleted Pax5 gene in 600 CD201CD150CD48c-KitSca-1Lin cells (HSC1 cells), highly enriched in myeloid-biased HSCs, and CD201CD150CD48 c-KitSca-1Lin cells (HSC2 cells), highly enriched in lymphoid-biased HSCs. As predicted, both Pax5 KO HSC1 and HSC2 cells showed few B cells in the peripheral blood and the accumulation of pro-B cells in the bone marrow of recipient mice. Our data suggesetd that myeloid-biased and lymphoid-biased HSCs share a common B cell differentiation pathway. This population-specific KO strategy will find its applications for gene editing in a varity of somatic cells, particuarly rare stem and progenitor cells from different tissues.
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http://dx.doi.org/10.1016/j.jim.2021.113070DOI Listing
May 2021

Precipitated Fluorophore-Based Molecular Probe for Imaging of Aminopeptidase N in Living Cells and Tumors.

Anal Chem 2021 04 14;93(16):6463-6471. Epub 2021 Apr 14.

State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.

Aminopeptidase N (APN) is capable of cleaving N-terminal amino acids from peptides with alanine in the N-terminal position and plays a key role in the growth, migration, and metastasis of cancer. However, reliable information is hard to be obtained with the current APN-responsive molecular probes because the released fluorophores are cytoplasmic soluble and thus rapidly depart from the enzymatic reaction sites and spread out all over the cytoplasm. Here, we report a precipitated fluorophore, , which is completely insoluble in water and shows strong yellow solid emission when excited with a 405 nm laser. Owing to the controllable solid fluorescence of by the protection-deprotection of phenolic hydroxyl, we further utilized to design an APN-responsive fluorogenic probe () for the imaging of intracellular APN. Importantly, can not only perform imaging of APN in different organelles (, lysosomes, mitochondria, endoplasmic reticula, and so forth) but also display a stable and indiffusible fluorescent signal for reliable mapping of the distribution of APN in living cells. In addition, through real-time imaging of APN in 4T1 tumors, we found that the fluorescent signal with high fidelity generated by could remain constant even after 12 h, which further confirmed its diffusion-resistant ability and long-term reliable imaging ability. We believe that the precipitated fluorophore may have great potential for long-term imaging.
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http://dx.doi.org/10.1021/acs.analchem.1c00280DOI Listing
April 2021

Intellectual Capital and Financial Performance: Comparison With Financial and Pharmaceutical Industries in Vietnam.

Front Psychol 2021 25;12:595615. Epub 2021 Mar 25.

North China University of Water Resources and Electric Power, Zhengzhou, China.

This study investigates the impacts of intellectual capital through Value-Added Intellectual Capital (VAIC) and its components: human capital efficiency (HCE) and structural capital efficiency (SCE) on financial performance in terms of return on assets (ROA) and return on equity (ROE). In addition, this study compares the effects between firms from financial and pharmaceutical industries. A total of 149 Vietnamese firms comprising of 108 financial firms and 41 pharmaceutical firms were examined. Based on the findings, VAIC and HCE show beneficial impacts on both financial performance measures, ROA, and ROE. However, SCE shows adverse and beneficial implications on ROA and ROE, respectively. In terms of industry comparison, VAIC has positive effects on ROA and ROE among the firms from financial industry, whereas it has no effect in the firms from pharmaceutical industry. The effect of HCE on ROA is stronger in the firms from financial industry than firms from pharmaceutical industry while the effect of HCE on ROE is stronger in the firms from pharmaceutical industry than firms from financial industry. The effect of SCE on ROA is stronger in the pharmaceutical firms than financial firms while the effect of SCE on ROE is stronger in the financial firms than pharmaceutical firms. Lastly, the implications of the importance of knowledge-based resources on value creation were elaborated.
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http://dx.doi.org/10.3389/fpsyg.2021.595615DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8029978PMC
March 2021

Activatable NIR-II Fluorescent Probes Applied in Biomedicine: Progress and Perspectives.

ChemMedChem 2021 Mar 29. Epub 2021 Mar 29.

Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China.

With the advantage of inherent responsiveness that can change the spectroscopic signals from "off" to "on" state in responding to targets (e. g. biological analytes/microenvironmental factors), activatable fluorescent probes have attracted extensive attention and made significant progress in the field of bioimaging and biosensing. Due to the high depth of tissue penetration, minimal tissue damage and negligible background signal at longer wavelengths, the development of second near-infrared window (NIR-II) fluorescent materials provides a new opportunity to develop activable fluorescent probes. Here, we summarized properties, advantages and disadvantages of mainly NIR-II fluorophores (such as rare earth-doped nanoparticles, quantum dots, single-walled carbon nanotubes, small molecule dyes, conjugated polymers and gold nanoclusters), then overviewed current role and development of activatable NIR-II fluorescent probes (AFPs) for biomedical applications including biosensing, bioimaging and therapeutic. The potential challenges and perspectives of AFPs in deep-tissue imaging and clinical application are also discussed.
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http://dx.doi.org/10.1002/cmdc.202100142DOI Listing
March 2021

Dual-Stimulus Responsive Near-Infrared Reversible Ratiometric Fluorescent and Photoacoustic Probe for Tumor Imaging.

Anal Chem 2021 04 22;93(13):5420-5429. Epub 2021 Mar 22.

State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.

Tumor-specific imaging is a major challenge in clinical tumor resection. To overcome this problem, several activatable probes have been developed for use in tumor imaging. However, most of these probes are activated based on a single-factor stimulation and are irreversible. Therefore, false signals that make tumor-specific imaging difficult are easily generated. We have developed a new dual-stimulus responsive near-infrared (NIR) reversible adenosine 5'-triphosphate (ATP)-pH probe for fluorescence and photoacoustic ratiometric imaging of tumors. Since the H and ATP content is significantly higher in the tumor microenvironment than that in normal tissues, the Förster resonance energy transfer-based probe ATP-pH was constructed with silicon rhodamine as the donor, CS dye as the acceptor, and ATP/H recognition units that could only be activated when both H and ATP were connected to the acceptor. The ATP-pH probe is reversibly activated by both the H and ATP, which effectively reduces the cumulative response of the probe in circulation after intravenous injection. Further, the NIR ratiometric property of the probe makes it suitable for imaging. Finally, our probe was successfully utilized in ratiometric photoacoustic and fluorescence tumor imaging and ratiometric fluorescence imaging-guided tumor resection.
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http://dx.doi.org/10.1021/acs.analchem.0c04804DOI Listing
April 2021

Probing Dynamic Features of Phagosome Maturation in Macrophage using [email protected] @SiO Nanoparticles as pH-Sensitive Plasmonic Nanoprobes.

Chem Asian J 2021 May 31;16(9):1150-1156. Epub 2021 Mar 31.

Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China.

Phagosome maturation in macrophage is essential to the clearance of pathogenic materials in host defence but the dynamic features remain difficult to be measured in real time. Herein, we reported the multilayered [email protected] @SiO nanoparticle as a robust pH-sensitive plasmonic nanosensor for monitoring the dynamic acidification features over the phagosome maturation process in macrophage under darkfield microscopy. For this multilayered nanosensor, the gold nanoparticle core plays a role of signal reporter, the MnO shell and the outmost SiO act as the sensing layer and the protecting layer, respectively. After subject to the acidic buffer solution, the MnO layer in the multilayered nanoprobe could be decomposed rapidly, resulting in a remarkable spectral shift and color change under darkfield microscopy. We demonstrated this nanosensor for the investigation of single phagosome acidification dynamics by monitoring the color changes of nanoprobes after phagocytosis over time. The nanoprobes after phagocytosized in macrophage displayed a slight color change within the first hour and then cost several minutes to change from red to green in the next stage, indicating the phagosome undergoes a slow first and then fast acidification feature as well as a slow-to-fast acidification translation over the phagosome maturation process. Moreover, we validated that the slow-to-fast acidification translation was dependent on the activation of V-ATPase from the ATP depletion assay. We believed that this nanosensor is promising for studying the dynamic acidification features as well as disorders in phagosome maturation in phagocytic cells, which might provide valuable information for understanding the disease pathogenesis related to phagosome dysfunctions.
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http://dx.doi.org/10.1002/asia.202100031DOI Listing
May 2021

Exploring the Trans-Cleavage Activity of CRISPR/Cas12a on Gold Nanoparticles for Stable and Sensitive Biosensing.

Anal Chem 2021 03 11;93(11):4967-4974. Epub 2021 Mar 11.

Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.

Taking advantage of the excellent trans-cleavage activity, CRISPR-based diagnostics (CRISPR-Dx) has shown great promise in molecular diagnostics. However, the single-stranded DNA reporter of the current CRISPR-Dx suffers from poor stability and limited sensitivity, which make their application in complex biological environments difficult. Herein, we, for the first time, explore the trans-cleavage activity of CRISPR/Cas12a toward the substrate on gold nanoparticles and apply the new phenomenon to develop a spherical nucleic acid (SNA) reporter for stable and sensitive CRISPR-Dx biosensing. By anchoring the DNA substrate on gold nanoparticles, we discovered different trans-cleavage activities of different types of the Cas12a system (e.g., LbCas12a and AsCas12a) on a nanoparticle surface. The further study suggests that the trans-cleavage activity of LbCas12a on the nanoparticle surface is highly dependent on the density and length of DNA strands. Based on these interesting discoveries, we furthermore develop SNA reporter-based fluorescent CRISPR-Dx for stable and sensitive biosensing application. Compared to traditional ssDNA reporters, the SNA reporter exhibits improved stability, which enables the stable application in a complex serum environment. In addition, the SNA reporter system with tunable density exhibits high sensitivity with a detection limit of 10 fM, which is about 2 orders of magnitude lower than that of the ssDNA reporter system. Finally, the practical application of SNA reporter-based CRISPR-Dx in clinical serum was successfully achieved. These results indicate their significant potential in future research on biology science and medical diagnoses.
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http://dx.doi.org/10.1021/acs.analchem.1c00027DOI Listing
March 2021

Nucleic Acid Immunotherapeutics for Cancer.

ACS Appl Bio Mater 2020 May 16;3(5):2838-2849. Epub 2020 Mar 16.

Department of Pharmaceutics, Center for Pharmaceutical Engineering and Sciences-School of Pharmacy; Massey Cancer Center; Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23298, United States.

The past decade has witnessed the blossom of two fields: nucleic acid therapeutics and cancer immunotherapy. Unlike traditional small molecule medicines or protein biologics, nucleic acid therapeutics have characteristic features such as storing genetic information, immunomodulation, and easy conformational recovery. Immunotherapy uses the patients' own immune system to treat cancer. A variety of strategies have been developed for cancer immunotherapy including immune checkpoint blockade, adoptive cell transfer therapy, therapeutic vaccines, and oncolytic virotherapy. Interestingly, nucleic acid therapeutics have emerged as a pivotal class of regimen for cancer immunotherapy. Examples of such nucleic acid immunotherapeutics include immunostimulatory DNA/RNA, mRNA/plasmids that can be translated into immunotherapeutic proteins/peptides, and genome-editing nucleic acids. Like many other therapeutic nucleic acids, nucleic acid immunotherapeutics often require chemical modifications to protect them from enzymatic degradation and need drug delivery systems for optimal delivery to target tissues and cells and subcellular locations. In this review, we attempted to summarize recent advancement in the interfacial field of nucleic acid immunotherapeutics for cancer treatment.
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http://dx.doi.org/10.1021/acsabm.0c00101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7932307PMC
May 2020

Size-selective DNA nanocage-based activatable CRISPR-Cas12a for sensitive and accurate detection of mature microRNA.

Chem Commun (Camb) 2021 Apr 3;57(26):3291-3294. Epub 2021 Mar 3.

Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China.

The sensitive and accurate detection of mature miRNA without the signal interference by pre-miRNAs is highly important. Herein, a size-selective DNA nanocage-based activatable CRISPR/Cas12a system was developed to achieve this goal.
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http://dx.doi.org/10.1039/d1cc00178gDOI Listing
April 2021

A de novo strategy to develop NIR precipitating fluorochrome for long-term in situ cell membrane bioimaging.

Proc Natl Acad Sci U S A 2021 Feb;118(8)

Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082 Changsha, P. R. China.

Cell membrane-targeted bioimaging is a prerequisite for studying the roles of membrane-associated biomolecules in various physiological and pathological processes. However, long-term in situ bioimaging on the cell membrane with conventional fluorescent probes leads to diffusion into cells from the membrane surface. Therefore, we herein proposed a de novo strategy to construct an antidiffusion probe by integrating a fluorochrome characterized by strong hydrophobicity and low lipophilicity, with an enzyme substrate to meet this challenge. This precipitating fluorochrome HYPQ was designed by conjugating the traditionally strong hydrophobic solid-state fluorochrome 6-chloro-2-(2-hydroxyphenyl) quinazolin-4(3H)-one (HPQ) with a 2-(2-methyl-4H-chromen-4-ylidene) malononitrile group to obtain closer stacking to lower lipophilicity and elongate emission to the far-red to near-infrared wavelength. As proof-of-concept, the membrane-associated enzyme γ-glutamyltranspeptidase (GGT) was selected as a model enzyme to design the antidiffusion probe HYPQG. Then, benefiting from the precipitating and stable signal properties of HYPQ, in situ imaging of GGT on the membrane was successfully realized. Moreover, after HYPQG was activated by GGT, the fluorescence signal on the cell membrane remained unchanged, with incubation time even extending to 6 h, which is significant for in situ monitoring of enzymatic activity. In vivo testing subsequently showed that the tumor region could be accurately defined by this probe after long-term in situ imaging of tumor-bearing mice. The excellent performance of HYPQ indicates that it may be an ideal alternative for constructing universal antidiffusion fluorescent probes, potentially providing an efficient tool for accurate imaging-guided surgery in the future.
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http://dx.doi.org/10.1073/pnas.2018033118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7923636PMC
February 2021

Finite element analysis of wedge and biconcave deformity in four different height restoration after augmentation of osteoporotic vertebral compression fractures.

J Orthop Surg Res 2021 Feb 15;16(1):138. Epub 2021 Feb 15.

Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China.

Purpose: Biomechanical comparison of wedge and biconcave deformity of different height restoration after augmentation of osteoporotic vertebral compression fractures was analyzed by three-dimensional finite element analysis (FEA).

Methods: Three-dimensional finite element model (FEM) of T11-L2 segment was constructed from CT scan of elderly osteoporosis patient. The von Mises stresses of vertebrae, intervertebral disc, facet joints, displacement, and range of motion (ROM) of wedge and biconcave deformity were compared at four different heights (Genant 0-3 grade) after T12 vertebral augmentation.

Results: In wedge deformity, the stress of T12 decreased as the vertebral height in neutral position, flexion, extension, and left axial rotation, whereas increased sharply in bending at Genant 0; L1 and L2 decreased in all positions excluding flexion of L2, and T11 increased in neutral position, flexion, extension, and right axial rotation at Genant 0. No significant changes in biconcave deformity. The stress of T11-T12, T12-L1, and L1-L2 intervertebral disc gradually increased or decreased under other positions in wedge fracture, whereas L1-L2 no significant change in biconcave fracture. The utmost overall facet joint stress is at Genant 3, whereas there is no significant change under the same position in biconcave fracture. The displacement and ROM of the wedge fracture had ups and downs, while a decline in all positions excluding extension in biconcave fracture.

Conclusions: The vertebral restoration height after augmentation to Genant 0 affects the von Mises stress, displacement, and ROM in wedge deformity, which may increase the risk of fracture, whereas restored or not in biconcave deformity.
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http://dx.doi.org/10.1186/s13018-021-02225-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7885256PMC
February 2021

HDAC inhibitors improve CRISPR-mediated HDR editing efficiency in iPSCs.

Sci China Life Sci 2021 Jan 6. Epub 2021 Jan 6.

State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, 300020, China.

Genome-edited human induced pluripotent stem cells (iPSCs) hold great promise for therapeutic applications. However, low editing efficiency has hampered the applications of CRISPR-Cas9 technology in creating knockout and homology-directed repair (HDR)-edited iPSC lines, particularly for silent genes. This is partially due to chromatin compaction, inevitably limiting Cas9 access to the target DNA. Among the six HDAC inhibitors we examined, vorinostat, or suberoylanilide hydroxamic acid (SAHA), led to the highest HDR efficiency at both open and closed loci, with acceptable toxicity. HDAC inhibitors equally increased non-homologous end joining (NHEJ) editing efficiencies (∼50%) at both open and closed loci, due to the considerable HDAC inhibitor-mediated increase in Cas9 and sgRNA expression. However, we observed more substantial HDR efficiency improvement at closed loci relative to open chromatin (2.8 vs. 1.1-fold change). These studies provide a new strategy for HDR-editing of silent genes in iPSCs.
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http://dx.doi.org/10.1007/s11427-020-1855-4DOI Listing
January 2021

Precipitated Fluorophore-Based Probe for Accurate Detection of Mitochondrial Analytes.

Anal Chem 2021 02 5;93(4):2235-2243. Epub 2021 Jan 5.

Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Life Sciences, Hunan University, Changsha 410082, China.

Mitochondria-targeted fluorescent probes are highly important to obtain mitochondrial function information. However, the accuracy of the current mitochondria-targeted fluorescent probes is unsatisfactory owing to the following two reasons. In the first case, some probes that always have a mitochondria-targeting group, thus, would react with the analytes outside of mitochondria and enter mitochondria with the generated fluorophore signal, which leads to a false-positive result. In the other case, after response to the analytes in mitochondria, some probes could diffuse from mitochondria to other organelles, thus triggering a false-negative result. To avoid the two problems, herein, we develop a precipitated fluorophore-based probe, which precipitates in situ after reacting with analytes, for the accurate detection of mitochondrial analytes. The probe was modified with HQPQ, a novel solid-state fluorophore that is insoluble in water. As a proof of concept, we designed and synthesized a probe (HQPQ-B) for HO detection. Based on the different mitochondria-targeting capacities of quinoline salts and quinolone, HQPQ loses the mitochondria-targeting ability after reacting with analytes outside of mitochondria, thus avoiding a false-positive result. On the contrary, when the probe first localized in mitochondria and then reacted with analytes, HQPQ would precipitate and remain in mitochondria without diffusing to other sites, thus avoiding a false-negative result. Therefore, HQPQ enables the accurate detection of mitochondrial analytes. We believe that the novel strategy based on HQPQ will be a general strategy for accurate detection of mitochondrial analytes without interference from other sites, which enables an accurate study on mitochondrial function.
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http://dx.doi.org/10.1021/acs.analchem.0c04094DOI Listing
February 2021

Dynamics and competition of CRISPR-Cas9 ribonucleoproteins and AAV donor-mediated NHEJ, MMEJ and HDR editing.

Nucleic Acids Res 2021 01;49(2):969-985

State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China.

Investigations of CRISPR gene knockout editing profiles have contributed to enhanced precision of editing outcomes. However, for homology-directed repair (HDR) in particular, the editing dynamics and patterns in clinically relevant cells, such as human iPSCs and primary T cells, are poorly understood. Here, we explore the editing dynamics and DNA repair profiles after the delivery of Cas9-guide RNA ribonucleoprotein (RNP) with or without the adeno-associated virus serotype 6 (AAV6) as HDR donors in four cell types. We show that editing profiles have distinct differences among cell lines. We also reveal the kinetics of HDR mediated by the AAV6 donor template. Quantification of T50 (time to reach half of the maximum editing frequency) indicates that short indels (especially +A/T) occur faster than longer (>2 bp) deletions, while the kinetics of HDR falls between NHEJ (non-homologous end-joining) and MMEJ (microhomology-mediated end-joining). As such, AAV6-mediated HDR effectively outcompetes the longer MMEJ-mediated deletions but not NHEJ-mediated indels. Notably, a combination of small molecular compounds M3814 and Trichostatin A (TSA), which potently inhibits predominant NHEJ repairs, leads to a 3-fold increase in HDR efficiency.
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http://dx.doi.org/10.1093/nar/gkaa1251DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7826255PMC
January 2021

Design Strategy of Fluorescent Probes for Live Drug-Induced Acute Liver Injury Imaging.

Acc Chem Res 2021 01 31;54(2):403-415. Epub 2020 Dec 31.

State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.

Drug-induced acute liver injury (DIALI) is increasingly recognized as a significant cause of acute liver injury (ALI), which is characterized by a rapid loss of hepatocyte function in patients without pre-existing liver diseases. Evaluation of corresponding biomarkers, including alanine transaminase and aspartate amino transferase, is available as a diagnostic tool for hepatotoxicity. However, these blood tests have certain limitations: (1) they are generally not available for early estimation; (2) it is difficult to visualize and identify hepatotoxicity unambiguously in real-time; and (3) the biomarkers are not unique and are usually influenced by a variety of diseases, leading to potential false results. It is of grave importance and burgeoning demand to develop an early diagnostic approach for such diseases, but the ideal toolkit remains an unresolved challenge.As an alternative, molecular optical probes (fluorescence, chemiluminescence, bioluminescence, etc.) display a lot of advantages, such as high sensitivity, noninvasive fast analysis, and real-time in situ detection. They have emerged as potent and promising tools for the biomedical study of DIALI in living system. Until now, a number of optical probes for DIALI have been reported with some great potential for clinical trials. However, most of the probes still suffer from false signals because of the limitations in clinical application, including poor selectivity, low sensitivity, and biocompatibility. One key challenge that probes face in the ALI environment is the excessive exposure to reactive oxygen/nitrogen species and diffusivity, which may lead to false-positive or negative signals.Our group has employed multiple rational approaches to engineer high-performance optical probes for DIALI. With such development, we have successfully achieved the accurate detection of DIALI with minimal false signals both ex vivo and in vivo. While marching firmly toward understanding the biogenesis and progression of DIALI, we ultimately aim at the early stage clinical diagnosis of the disease, as well as mechanism understanding for clinical trials. In this Account, we summarize and present our three new approaches for the development of high-fidelity optical probes: (1) a combined screening and rational design strategy, (2) a double-locked probe design strategy, and (3) in situ imaging based on the release of a precipitating fluorochrome strategy. Using these strategies, we have formulated probes for a range of biological species that are biomarkers of DIALI, including reactive nitrogen species (ONOO), reactive sulfur species (HS and HS), and enzymes (LAP, MAO, and ALP). We have highlighted the rationale for our design and screening strategy and methods to achieve high-fidelity optical probes. Some recent examples of optical probes developed by our laboratory and collaborations are mainly illustrated herein. We anticipate the strategies summarized here to inspire future molecular optical probe design, to contribute to studies of the detailed molecular mechanisms underlying liver diseases, and to improve the efficiency of the diagnosis and treatment of these diseases in clinical settings.
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http://dx.doi.org/10.1021/acs.accounts.0c00646DOI Listing
January 2021

DNA origami-based protein networks: from basic construction to emerging applications.

Chem Soc Rev 2021 Feb;50(3):1846-1873

Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China.

Natural living systems are driven by delicate protein networks whose functions are precisely controlled by many parameters, such as number, distance, orientation, and position. Focusing on regulation rather than just imitation, the construction of artificial protein networks is important in many research areas, including biomedicine, synthetic biology and chemical biology. DNA origami, sophisticated nanostructures with rational design, can offer predictable, programmable, and addressable scaffolds for protein assembly with nanometer precision. Recently, many interdisciplinary efforts have achieved the precise construction of DNA origami-based protein networks, and their emerging application in many areas. To inspire more fantastic research and applications, herein we highlight the applicability and potentiality of DNA origami-based protein networks. After a brief introduction to the development and features of DNA origami, some important factors for the precise construction of DNA origami-based protein networks are discussed, including protein-DNA conjugation methods, networks with different patterns and the controllable parameters in the networks. The discussion then focuses on the emerging application of DNA origami-based protein networks in several areas, including enzymatic reaction regulation, sensing, bionics, biophysics, and biomedicine. Finally, current challenges and opportunities in this research field are discussed.
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http://dx.doi.org/10.1039/d0cs00255kDOI Listing
February 2021

Nucleic Acids Analysis.

Sci China Chem 2020 Dec 2:1-33. Epub 2020 Dec 2.

Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 Canada.

Nucleic acids are natural biopolymers of nucleotides that store, encode, transmit and express genetic information, which play central roles in diverse cellular events and diseases in living things. The analysis of nucleic acids and nucleic acids-based analysis have been widely applied in biological studies, clinical diagnosis, environmental analysis, food safety and forensic analysis. During the past decades, the field of nucleic acids analysis has been rapidly advancing with many technological breakthroughs. In this review, we focus on the methods developed for analyzing nucleic acids, nucleic acids-based analysis, device for nucleic acids analysis, and applications of nucleic acids analysis. The representative strategies for the development of new nucleic acids analysis in this field are summarized, and key advantages and possible limitations are discussed. Finally, a brief perspective on existing challenges and further research development is provided.
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http://dx.doi.org/10.1007/s11426-020-9864-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7716629PMC
December 2020

Episomal Reprogramming of Human Peripheral Blood Mononuclear Cells into Pluripotency.

Methods Mol Biol 2021 ;2239:117-133

State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China.

Peripheral blood is an easily accessible cell resource for reprogramming into pluripotency by episomal vectors. Here, we describe an approach for efficient generation of integration-free induced pluripotent stem cells (iPSCs) under feeder or feeder-free conditions. Additionally, in combination with the CRISPR-Cas9 genome-editing system, we can directly generate edited iPSCs from blood cells. With this protocol, one can easily generate either integration-free iPSCs or genetically edited iPSCs from peripheral blood at high efficiency.
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http://dx.doi.org/10.1007/978-1-0716-1084-8_8DOI Listing
April 2021

Single-Cell RNA-Seq Reveals that CD9 Is a Negative Marker of Glucose-Responsive Pancreatic β-like Cells Derived from Human Pluripotent Stem Cells.

Stem Cell Reports 2020 11 22;15(5):1111-1126. Epub 2020 Oct 22.

Department of Chemical Pathology; Li Ka Shing Institute of Health Sciences, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China. Electronic address:

To date, it remains unclear if there are specific cell-surface markers for purifying glucose-responsive pancreatic β-like cells derived from human pluripotent stem cells (hPSCs). In searching for this, we generated an efficient protocol for differentiating β-like cells from human embryonic stem cells. We performed single-cell RNA sequencing and found that CD9 is a negative cell-surface marker of β-like cells, as most INS cells are CD9. We purified β-like cells for spontaneous formation of islet-like organoids against CD9, and found significantly more NKX6.1MAFAC-PEPTIDE β-like cells in the CD9 than in the CD9 population. CD9 cells also demonstrate better glucose responsiveness than CD9 cells. In humans, we observe more CD9C-PEPTIDE β cells in the fetal than in the adult cadaveric islets and more Ki67 proliferating cells among CD9 fetal β cells. Taken together, our experiments show that CD9 is a cell-surface marker for negative enrichment of glucose-responsive β-like cells differentiated from hPSCs.
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http://dx.doi.org/10.1016/j.stemcr.2020.09.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7663789PMC
November 2020

A two-photon fluorescence self-reporting black phosphorus nanoprobe for the monitoring of therapy response.

Chem Commun (Camb) 2020 Nov;56(90):14007-14010

State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China.

The in situ and real-time supervision of reactive oxygen species (ROS) generated during photodynamic therapy (PDT) is of great significance for lessening nonspecific damage and guiding personalized therapy. However, photosensitizers frequently fail to deliver successful treatment accompanying the ROS-related imaging signals produced, impeding simple treatment outcome predictions and therapeutic schedule adjustments. Here, we report a two-photon fluorescence self-reporting strategy for the in situ and real-time monitoring of treatment response via a novel black phosphorus-based two-photon nanoprobe (TPBP). TPBP effectively generated singlet oxygen (1O2) under near-infrared laser irradiation for PDT, and 1O2 stimulated a two-photon molecule to emit fluorescence signals for feedback of 1O2 generation, which facilitated the regulation of treatment parameters to achieve precise and personalized medicine in deep tissue.
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http://dx.doi.org/10.1039/d0cc05335jDOI Listing
November 2020

Peroxidase-like [email protected] nanozyme as an integrated nanosensor for Ag detection by LSPR spectroscopy.

Talanta 2021 Jan 12;221:121627. Epub 2020 Sep 12.

College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China. Electronic address:

Here we report the peroxidase-like [email protected] nanozyme as an integrated nanosensor for selective detection of silver ions (Ag), where the nanozyme plays the roles as both the signal trigger and reporter simultaneously. This method relies on two critical chemical reactions, including (1) the unique inhibitory effect of Ag on the nanozyme triggered HO decomposition at weak acid environment and (2) HO induced Ag reduction onto the nanozyme surface at basic environment, leading to a blueshift in the localized surface plasmonic resonance wavelength (LSPR λ) of the nanosensor. With this simple strategy, we demonstrated the sensitive and selective detection of Ag over a dynamic range from 0.5 to 1000 μM with a limit of detection (LOD) of 500 nM by UV-visible spectroscopy, which is below the permitted level of Ag in drinking water by U.S. Environmental Protection Agency (EPA). This method also exhibits satisfying recovery efficiency for Ag detection both in tap water and spring water from the Yuelu Mountain. With this satisfying sensing performance and excellent stability of nanoprobes, this strategy is promising for the detection of Ag in environment monitoring and food safety analysis.
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http://dx.doi.org/10.1016/j.talanta.2020.121627DOI Listing
January 2021

The threshold of a deterministic and a stochastic SIQS epidemic model with varying total population size.

Appl Math Model 2021 Mar 8;91:749-767. Epub 2020 Oct 8.

Department of Applied Mathematics, Lanzhou University of Technology, Lanzhou 730050, People's Republic of China.

In this paper, a stochastic and a deterministic SIS epidemic model with isolation and varying total population size are proposed. For the deterministic model, we establish the threshold . When is less than 1, the disease-free equilibrium is globally stable, which means the disease will die out. While is greater than 1, the endemic equilibrium is globally stable, which implies that the disease will spread. Moreover, there is a critical isolation rate *, when the isolation rate is greater than it, the disease will be eliminated. For the stochastic model, we also present its threshold . When is less than 1, the disease will disappear with probability one. While is greater than 1, the disease will persist. We find that stochastic perturbation of the transmission rate (or the valid contact coefficient) can help to reduce the spread of the disease. That is, compared with stochastic model, the deterministic epidemic model overestimates the spread capacity of disease. We further find that there exists a critical the stochastic perturbation intensity of the transmission rate *, when the stochastic perturbation intensity of the transmission rate is bigger than it, the disease will disappear. At last, we apply our theories to a realistic disease, pneumococcus amongst homosexuals, carry out numerical simulations and obtain the empirical probability density under different parameter values. The critical isolation rate * is presented. When the isolation rate is greater than *, the pneumococcus amongst will be eliminated.
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http://dx.doi.org/10.1016/j.apm.2020.09.050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7543952PMC
March 2021

Matrix reverses immortalization-mediated stem cell fate determination.

Biomaterials 2021 01 16;265:120387. Epub 2020 Sep 16.

Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, WV, USA; WVU Cancer Institute, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, USA. Electronic address:

Primary cell culture in vitro suffers from cellular senescence. We hypothesized that expansion on decellularized extracellular matrix (dECM) deposited by simian virus 40 large T antigen (SV40LT) transduced autologous infrapatellar fat pad stem cells (IPFSCs) could rejuvenate high-passage IPFSCs in both proliferation and chondrogenic differentiation. In the study, we found that SV40LT transduced IPFSCs exhibited increased proliferation and adipogenic potential but decreased chondrogenic potential. Expansion on dECMs deposited by passage 5 IPFSCs yielded IPFSCs with dramatically increased proliferation and chondrogenic differentiation capacity; however, this enhanced capacity diminished if IPFSCs were grown on dECM deposited by passage 15 IPFSCs. Interestingly, expansion on dECM deposited by SV40LT transduced IPFSCs yielded IPFSCs with enhanced proliferation and chondrogenic capacity but decreased adipogenic potential, particularly for the dECM group derived from SV40LT transduced passage 15 cells. Our immunofluorescence staining and proteomics data identify matrix components such as basement membrane proteins as top candidates for matrix mediated IPFSC rejuvenation. Both cell proliferation and differentiation were endorsed by transcripts measured by RNASeq during the process. This study provides a promising model for in-depth investigation of the matrix protein influence on surrounding stem cell differentiation.
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http://dx.doi.org/10.1016/j.biomaterials.2020.120387DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7944411PMC
January 2021

DNAzyme-gold nanoparticle-based probes for biosensing and bioimaging.

J Mater Chem B 2020 10;8(41):9449-9465

Molecular Sciences and Biomedicine Laboratory, State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China.

The deoxyribozyme (DNAzyme) is a specific nucleic acid with high catalytic activity in the presence of coenzyme factors. Because of its good programmability, high stability and excellent activity, DNAzyme is considered to be a promising material in many fields, such as environmental monitoring, food regulation, biosensing and gene therapy. Gold nanoparticles exhibit excellent photoelectric properties, and can also provide DNAzyme with enhanced cell transfection and excellent resistance to nuclease degradation. Therefore, DNAzyme-gold nanoparticle complexes have attracted much attention in many areas, particularly in biosensing and bioimaging. In this review, we first provide a brief introduction of the structure and catalytic activity of DNAzymes, as well as several methods for preparing DNAzyme-gold nanoparticles. Then, the discussion focuses on applications of DNAzyme-gold nanoparticle-based probes in biosensing and bioimaging in recent years (especially in the past five years). Based on their output signals, these sensors are divided into fluorescence sensors, colorimetric sensors, electrochemical sensors, photoelectrochemical sensors and other sensors. Finally, we discuss several challenges and opportunities in this emerging field.
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http://dx.doi.org/10.1039/d0tb01750gDOI Listing
October 2020

A General Strategy for Development of Activatable NIR-II Fluorescent Probes for In Vivo High-Contrast Bioimaging.

Angew Chem Int Ed Engl 2021 01 3;60(2):800-805. Epub 2020 Nov 3.

Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, P. R. China.

Organic dye based NIR-II fluorescent probes, owing to their high signal-to-background ratio and deeper penetration, are highly useful for deep-tissue high-contrast imaging in vivo. However, it is still a challenge to design activatable NIR-II fluorescent probes. Here, a novel class of polymethine dyes (NIRII-RTs), with bright (quantum yield up to 2.03 %), stable, and anti-solvent quenching NIR-II emission, together with large Stokes shifts, was designed. Significantly, the novel NIR-II dyes NIRII-RT3 and NIRII-RT4, equipped with a carboxylic acid group, can serve as effective NIR-II platforms for the design of activatable bioimaging probes with high contrast. As a proof of concept, a series of target-activatable NIRII-RT probes (NIRII-RT-pH, NIRII-RT-ATP and NIRII-RT-Hg) for pH, adenosine triphosphate (ATP), and metal-ion detection, were synthesized. By applying the NIRII-RT probe, the real-time monitoring of drug-induced hepatotoxicity was realized.
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http://dx.doi.org/10.1002/anie.202009986DOI Listing
January 2021

Engineering of a dual-site molecular probe for logical bioimaging of lysosomal HS and pH.

Talanta 2020 Nov 13;219:121286. Epub 2020 Jun 13.

Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University, Changsha, 410082, China. Electronic address:

Lysosomes contains numerous enzymes and proteins closely linked with cellular metabolism. The variation of lysosomal pH is closely related to cell homeostasis while hydrogen sulfide (HS) has been regarded as an important gasotransmitter. Herein, via rational design, a high-sensitivity fluorescent probe ANp-Rh-Lys was synthesized for logical detection and bioimaging of HS and pH in lysosomes of living cells. The probe showed different fluorescence signals towards HS and lysosomal pH. Significantly, ANp-Rh-Lys is membrane-permeable and suitable for visualization of both pH variations and endogenous HS in lysosomes. This logical design strategy may have great potential for detection of multiple analytes in complicated biological systems.
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http://dx.doi.org/10.1016/j.talanta.2020.121286DOI Listing
November 2020

Single-Particle Mobility Analysis Enables Ratiometric Detection of Cancer Markers under Darkfield Tracking Microscopy.

Anal Chem 2020 08 21;92(15):10233-10240. Epub 2020 Jul 21.

Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China.

Here, we introduced a single-particle mobility analysis-based ratiometric strategy for quantitative detection of disease-related biomarkers using antibody-conjugated gold nanoparticles (AuNPs) as probes under darkfield tracking microscopy (DFTM). On the basis of the capability of discriminating nanoparticles with different hydrodynamic sizes and detecting the changes in hydrodynamic effect, single-particle mobility analysis enables us to determine the amount of aggregated and monodispersed nanoprobes for the sandwich-like immunoassay strategy, making it possible to quantify the biotargets by analyzing the relative changes in the aggregate-to-monomer ratio of nanoprobes. By using capture antibody and detection antibody conjugated AuNPs as nanoprobes, we demonstrated ratiometric detection of carcinoembryonic antigen (CEA) over a linear dynamic range from 50 to 750 pM, which is acceptable for clinical diagnostic analysis of CEA in tumor patients. This ratiometric detection technique exhibited excellent anti-interference ability in the presence of nonspecific proteins or complicated protein mixtures. It can be anticipated that this robust technique is promising for the accurate detection of disease biomarkers and other biomolecules for biochemical and diagnostic applications.
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http://dx.doi.org/10.1021/acs.analchem.9b05512DOI Listing
August 2020