1
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Jin Y, Mikhailova E, Lei M, Cowley SA, Sun T, Yang X, Zhang Y, Liu K, Catarino da Silva D, Campos Soares L, Bandiera S, Szele FG, Molnár Z, Zhou L, Bayley H. Integration of 3D-printed cerebral cortical tissue into an ex vivo lesioned brain slice. Nat Commun 2023; 14:5986. [PMID: 37794031 PMCID: PMC10551017 DOI: 10.1038/s41467-023-41356-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 09/01/2023] [Indexed: 10/06/2023] Open
Abstract
Engineering human tissue with diverse cell types and architectures remains challenging. The cerebral cortex, which has a layered cellular architecture composed of layer-specific neurons organised into vertical columns, delivers higher cognition through intricately wired neural circuits. However, current tissue engineering approaches cannot produce such structures. Here, we use a droplet printing technique to fabricate tissues comprising simplified cerebral cortical columns. Human induced pluripotent stem cells are differentiated into upper- and deep-layer neural progenitors, which are then printed to form cerebral cortical tissues with a two-layer organization. The tissues show layer-specific biomarker expression and develop a structurally integrated network of processes. Implantation of the printed cortical tissues into ex vivo mouse brain explants results in substantial structural implant-host integration across the tissue boundaries as demonstrated by the projection of processes and the migration of neurons, and leads to the appearance of correlated Ca2+ oscillations across the interface. The presented approach might be used for the evaluation of drugs and nutrients that promote tissue integration. Importantly, our methodology offers a technical reservoir for future personalized implantation treatments that use 3D tissues derived from a patient's own induced pluripotent stem cells.
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Affiliation(s)
- Yongcheng Jin
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | | | - Ming Lei
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Sally A Cowley
- James and Lillian Martin Centre for Stem Cell Research, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
| | - Tianyi Sun
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Xingyun Yang
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Yujia Zhang
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Kaili Liu
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | | | - Luana Campos Soares
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Sara Bandiera
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Francis G Szele
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.
| | - Zoltán Molnár
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK.
| | - Linna Zhou
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK.
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7DQ, UK.
| | - Hagan Bayley
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK.
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2
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Zhang Y, Riexinger J, Yang X, Mikhailova E, Jin Y, Zhou L, Bayley H. A microscale soft ionic power source modulates neuronal network activity. Nature 2023; 620:1001-1006. [PMID: 37648756 PMCID: PMC10468398 DOI: 10.1038/s41586-023-06295-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 06/07/2023] [Indexed: 09/01/2023]
Abstract
Bio-integrated devices need power sources to operate1,2. Despite widely used technologies that can provide power to large-scale targets, such as wired energy supplies from batteries or wireless energy transduction3, a need to efficiently stimulate cells and tissues on the microscale is still pressing. The ideal miniaturized power source should be biocompatible, mechanically flexible and able to generate an ionic current for biological stimulation, instead of using electron flow as in conventional electronic devices4-6. One approach is to use soft power sources inspired by the electrical eel7,8; however, power sources that combine the required capabilities have not yet been produced, because it is challenging to obtain miniaturized units that both conserve contained energy before usage and are easily triggered to produce an energy output. Here we develop a miniaturized soft power source by depositing lipid-supported networks of nanolitre hydrogel droplets that use internal ion gradients to generate energy. Compared to the original eel-inspired design7, our approach can shrink the volume of a power unit by more than 105-fold and it can store energy for longer than 24 h, enabling operation on-demand with a 680-fold greater power density of about 1,300 W m-3. Our droplet device can serve as a biocompatible and biological ionic current source to modulate neuronal network activity in three-dimensional neural microtissues and in ex vivo mouse brain slices. Ultimately, our soft microscale ionotronic device might be integrated into living organisms.
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Affiliation(s)
- Yujia Zhang
- Department of Chemistry, University of Oxford, Oxford, UK.
| | | | - Xingyun Yang
- Department of Chemistry, University of Oxford, Oxford, UK
| | | | - Yongcheng Jin
- Department of Chemistry, University of Oxford, Oxford, UK
| | - Linna Zhou
- Department of Chemistry, University of Oxford, Oxford, UK.
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Hagan Bayley
- Department of Chemistry, University of Oxford, Oxford, UK.
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3
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Samarin A, Savelev A, Toropov A, Dzestelova A, Malykh V, Mikhailova E, Motyko A. One-Staged Attention-Based Neoplasms Recognition Method for Single-Channel Monochrome Computer Tomography Snapshots. Pattern Recognit Image Anal 2022. [DOI: 10.1134/s1054661822030361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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4
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Pulcu GS, Galenkamp NS, Qing Y, Gasparini G, Mikhailova E, Matile S, Bayley H. Single-Molecule Kinetics of Growth and Degradation of Cell-Penetrating Poly(disulfide)s. J Am Chem Soc 2019; 141:12444-12447. [DOI: 10.1021/jacs.9b00387] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Gökçe Su Pulcu
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | | | - Yujia Qing
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Giulio Gasparini
- Department of Chemistry, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Ellina Mikhailova
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Stefan Matile
- Department of Chemistry, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Hagan Bayley
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
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5
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D'Haens GR, Sandborn WJ, Zou G, Stitt LW, Rutgeerts PJ, Gilgen D, Jairath V, Hindryckx P, Shackelton LM, Vandervoort MK, Parker CE, Muller C, Pai RK, Levchenko O, Marakhouski Y, Horynski M, Mikhailova E, Kharchenko N, Pimanov S, Feagan BG. Randomised non-inferiority trial: 1600 mg versus 400 mg tablets of mesalazine for the treatment of mild-to-moderate ulcerative colitis. Aliment Pharmacol Ther 2017; 46:292-302. [PMID: 28568974 DOI: 10.1111/apt.14164] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 01/16/2017] [Accepted: 05/04/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND High concentration mesalazine formulations are more convenient than conventional low concentration formulations for the treatment of ulcerative colitis (UC). AIM To compare the efficacy and safety of 1600 mg and 400 mg tablet mesalazine formulations. METHODS Patients with mild-to-moderate active UC (Mayo Clinic Score >5; N=817) were randomised to 3.2 g of oral mesalazine, administered as two 1600 mg tablets once, or four 400 mg tablets twice daily. We hypothesised that treatment with the 1600 mg tablet was non-inferior (within a 10% margin) to the 400 mg tablet for induction of clinical and endoscopic remission at week 8. Open-label treatment with the 1600 mg tablet continued for 26-30 weeks based on induction response. Predictors of treatment response were also explored. RESULTS At week 8, remission occurred in 22.4% and 24.6% of patients receiving the 1600 mg and 400 mg tablets, respectively (absolute difference -2.2%, 95% CI: -8.1% to 3.8%, non-inferiority P=.005). Endoscopic and histopathologic disease activity, leucocyte concentration and age were significantly associated with clinical remission (P=.022, .042, .014 and .023, respectively). At week 38, 43.9% (296/675) of patients who continued treatment with the 1600 mg formulation were in remission, including 70.3% (142/202) of patients who received a reduced dose of mesalazine (1.6 g/d). The overall incidence of serious adverse events was low. CONCLUSIONS Induction therapy with 3.2 mg mesalazine using two 1600 mg tablets once-daily was statistically and clinically non-inferior to a twice-daily regimen using four 400 mg tablets (NCT01903252).
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Affiliation(s)
- G R D'Haens
- Amsterdam, The Netherlands.,London, ON, Canada
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Ma S, Mukherjee N, Mikhailova E, Bayley H. Gel Microrods for 3D Tissue Printing. ACTA ACUST UNITED AC 2017; 1:e1700075. [DOI: 10.1002/adbi.201700075] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 05/31/2017] [Indexed: 01/28/2023]
Affiliation(s)
- Shaohua Ma
- Chemistry Research Laboratory; University of Oxford; 12 Mansfield Road Oxford OX1 3TA UK
| | - Nobina Mukherjee
- Chemistry Research Laboratory; University of Oxford; 12 Mansfield Road Oxford OX1 3TA UK
| | - Ellina Mikhailova
- Chemistry Research Laboratory; University of Oxford; 12 Mansfield Road Oxford OX1 3TA UK
| | - Hagan Bayley
- Chemistry Research Laboratory; University of Oxford; 12 Mansfield Road Oxford OX1 3TA UK
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7
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Kunts T, Karpukhina K, Mikhailova E, Varaksin N, Autenshlyus A. P64. European Journal of Cancer Supplements 2015. [DOI: 10.1016/j.ejcsup.2015.08.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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8
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Sosnina A, Vankhalsky A, Mikhailova E, Kunts T, Varaksin N, Autenshlyus A. P64. European Journal of Cancer Supplements 2015. [DOI: 10.1016/j.ejcsup.2015.08.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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10
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Pulcu GS, Mikhailova E, Choi LS, Bayley H. Continuous observation of the stochastic motion of an individual small-molecule walker. Nat Nanotechnol 2015; 10:76-83. [PMID: 25486119 PMCID: PMC5011421 DOI: 10.1038/nnano.2014.264] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 10/15/2014] [Indexed: 05/23/2023]
Abstract
Motion--whether it the ability to change shape, rotate or translate--is an important potential asset for functional nanostructures. For translational motion, a variety of DNA-based and small-molecule walkers have been created, but observing the translational motion of individual molecules in real time remains a significant challenge. Here, we show that the movement of a small-molecule walker along a five-foothold track can be monitored continuously within a protein nanoreactor. The walker is an organoarsenic(III) molecule with exchangeable thiol ligands, and the track a line of cysteine residues 6 Å apart within an α-haemolysin protein pore that acts as the nanoreactor. Changes in the flow of ionic current through the pore reflect the individual steps of a single walker, which require the making and breaking of As-S bonds, and occur in aqueous solution at neutral pH and room temperature. The walker moves considerably faster (∼0.7 s per step) than previous walkers based on covalent chemistry and is weakly processive (6 ± 1 steps per outing). It shows weak net directional movement, which can be described by a thermodynamic sink arising from the different environments of the cysteines that constitute the track.
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Affiliation(s)
- Gökçe Su Pulcu
- Correspondence and requests for materials should be addressed to G.S.P () or H.B ()
| | | | | | - Hagan Bayley
- Correspondence and requests for materials should be addressed to G.S.P () or H.B ()
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11
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Abstract
Post-transcriptional modifications of the 3'-ends of RNA molecules have a profound impact on their stability and processing in the cell. Uridylation, the addition of uridines to 3'-ends, has recently been found to be an important regulatory signal to stabilize the tagged molecules or to direct them toward degradation. Simple and cost-effective methods for the detection of this post-transcriptional modification are not yet available. Here, we demonstrate the selective and transient binding of 3'-uridylated ssRNAs inside the β barrel of the staphylococcal α-hemolysin (αHL) nanopore and investigate the molecular basis of uridine recognition by the pore. We show the discrimination of 3'-oligouridine tails on the basis of their lengths and propose the αHL nanopore as a useful sensor for this biologically relevant RNA modification.
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Affiliation(s)
- Massimiliano Clamer
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Laboratory of Translational Genomics, Center for Integrative Biology, University of Trento, Via delle Regole, 101 38123 Mattarello (TN), Italy
| | - Lajos Höfler
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Ellina Mikhailova
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Gabriella Viero
- Laboratory of Translational Genomics, Center for Integrative Biology, University of Trento, Via delle Regole, 101 38123 Mattarello (TN), Italy
- Institute of Biophysics, CNR, Via alla Cascata 56/C, 38123 (Povo) Trento, Italy
| | - Hagan Bayley
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Corresponding Author: Hagan Bayley
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12
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Bagatskaya N, Mikhailova E, Proskurina T, Sweedan E, Matkovskaya H, Matkovskaya T. EPA-0730 – Some features of spontaneous mutagenesis in children with depressive disorders. Eur Psychiatry 2014. [DOI: 10.1016/s0924-9338(14)78082-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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13
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Evstegneeva N, Mikhailova E. 2188 – Cognitive decline and somatic complaints in war veterans and former young prisoners of nazi concentration camps. Eur Psychiatry 2013. [DOI: 10.1016/s0924-9338(13)77062-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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14
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Franceschini L, Mikhailova E, Bayley H, Maglia G. Nucleobase recognition at alkaline pH and apparent pKa of single DNA bases immobilised within a biological nanopore. Chem Commun (Camb) 2011; 48:1520-2. [PMID: 22089628 DOI: 10.1039/c1cc16124e] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The four DNA bases are recognized in immobilized DNA strands at high alkaline pH by nanopore current recordings. Ionic currents through the biological nanopores are also employed to measure the apparent pK(a) values of single nucleobases within the immobilised DNA strands.
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15
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Rincon-Restrepo M, Mikhailova E, Bayley H, Maglia G. Controlled translocation of individual DNA molecules through protein nanopores with engineered molecular brakes. Nano Lett 2011; 11:746-50. [PMID: 21222450 PMCID: PMC3391008 DOI: 10.1021/nl1038874] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Protein nanopores may provide a cheap and fast technology to sequence individual DNA molecules. However, the electrophoretic translocation of ssDNA molecules through protein nanopores has been too rapid for base identification. Here, we show that the translocation of DNA molecules through the α-hemolysin protein nanopore can be slowed controllably by introducing positive charges into the lumen of the pore by site directed mutagenesis. Although the residual ionic current during DNA translocation is insufficient for direct base identification, we propose that the engineered pores might be used to slow down DNA in hybrid systems, for example, in combination with solid-state nanopores.
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16
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Raychaudhuri P, Li Q, Mason A, Mikhailova E, Heron AJ, Bayley H. Fluorinated Amphiphiles Control the Insertion of α-Hemolysin Pores into Lipid Bilayers. Biochemistry 2011; 50:1599-606. [DOI: 10.1021/bi1012386] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Pinky Raychaudhuri
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Qiuhong Li
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Amy Mason
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Ellina Mikhailova
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Andrew J. Heron
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Hagan Bayley
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
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17
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Wallace EVB, Stoddart D, Heron AJ, Mikhailova E, Maglia G, Donohoe TJ, Bayley H. Identification of epigenetic DNA modifications with a protein nanopore. Chem Commun (Camb) 2010; 46:8195-7. [PMID: 20927439 PMCID: PMC3147113 DOI: 10.1039/c0cc02864a] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Two DNA bases, 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (hmC), marks of epigenetic modification, are recognized in immobilized DNA strands and distinguished from G, A, T and C by nanopore current recording. Therefore, if further aspects of nanopore sequencing can be addressed, the approach will provide a means to locate epigenetic modifications in unamplified genomic DNA.
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Affiliation(s)
- Emma V. B. Wallace
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, OX1 3TA, Oxford, UK
| | - David Stoddart
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, OX1 3TA, Oxford, UK
| | - Andrew J. Heron
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, OX1 3TA, Oxford, UK
| | - Ellina Mikhailova
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, OX1 3TA, Oxford, UK
| | - Giovanni Maglia
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, OX1 3TA, Oxford, UK
| | - Timothy J. Donohoe
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, OX1 3TA, Oxford, UK
| | - Hagan Bayley
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, OX1 3TA, Oxford, UK
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18
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Stoddart D, Heron AJ, Klingelhoefer J, Mikhailova E, Maglia G, Bayley H. Nucleobase recognition in ssDNA at the central constriction of the alpha-hemolysin pore. Nano Lett 2010; 10:3633-7. [PMID: 20704324 PMCID: PMC2935931 DOI: 10.1021/nl101955a] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Nanopores are under investigation for single-molecule DNA sequencing. The alpha-hemolysin (alphaHL) protein nanopore contains three recognition points capable of nucleobase discrimination in individual immobilized ssDNA molecules. We have modified the recognition point R(1) by extensive mutagenesis of residue 113. Amino acids that provide an energy barrier to ion flow (e.g., bulky or hydrophobic residues) strengthen base identification, while amino acids that lower the barrier weaken it. Amino acids with related side chains produce similar patterns of nucleobase recognition providing a rationale for the redesign of recognition points.
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Affiliation(s)
- David Stoddart
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom
| | - Andrew J. Heron
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom
| | - Jochen Klingelhoefer
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
| | - Ellina Mikhailova
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom
| | - Giovanni Maglia
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom
| | - Hagan Bayley
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom
- To whom correspondence may be addressed: , Hagan Bayley, PhD, Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, England, UK, Tel: +44 1865 285101, Fax: +44 1865 275708
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Stoddart D, Maglia G, Mikhailova E, Heron AJ, Bayley H. Multiple base-recognition sites in a biological nanopore: two heads are better than one. Angew Chem Int Ed Engl 2010; 49:556-9. [PMID: 20014084 DOI: 10.1002/anie.200905483] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- David Stoddart
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK
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20
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Stoddart D, Maglia G, Mikhailova E, Heron A, Bayley H. Multiple Base-Recognition Sites in a Biological Nanopore: Two Heads are Better than One. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200905483] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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21
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Maglia G, Heron AJ, Hwang WL, Holden MA, Mikhailova E, Li Q, Cheley S, Bayley H. Droplet networks with incorporated protein diodes show collective properties. Nat Nanotechnol 2009; 4:437-40. [PMID: 19581896 DOI: 10.1038/nnano.2009.121] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Accepted: 04/28/2009] [Indexed: 05/02/2023]
Abstract
Recently, we demonstrated that submicrolitre aqueous droplets submerged in an apolar liquid containing lipid can be tightly connected by means of lipid bilayers to form networks. Droplet interface bilayers have been used for rapid screening of membrane proteins and to form asymmetric bilayers with which to examine the fundamental properties of channels and pores. Networks, meanwhile, have been used to form microscale batteries and to detect light. Here, we develop an engineered protein pore with diode-like properties that can be incorporated into droplet interface bilayers in droplet networks to form devices with electrical properties including those of a current limiter, a half-wave rectifier and a full-wave rectifier. The droplet approach, which uses unsophisticated components (oil, lipid, salt water and a simple pore), can therefore be used to create multidroplet networks with collective properties that cannot be produced by droplet pairs.
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Affiliation(s)
- Giovanni Maglia
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
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22
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Maglia G, Heron AJ, Hwang WL, Holden MA, Mikhailova E, Li Q, Cheley S, Bayley H. Electrical Communication In Droplet Interface Bilayers Networks. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.2947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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23
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Abstract
Molecular adapters are crucial for the stochastic sensing of organic analytes with alpha-hemolysin (alphaHL) protein nanopores when direct interactions between analytes and the pore cannot readily be arranged by conventional protein engineering. In our earlier studies, cyclodextrin adapters were lodged noncovalently within the lumen of the alphaHL pore. In the present work, we have realized the controlled covalent attachment of a beta-cyclodextrin (betaCD) adapter in the two possible molecular orientations inside alphaHL pores prepared by genetic engineering. There are two advantages to such a covalent system. First, the adapter cannot dissociate, which means there are no gaps during stochastic detection, a crucial advance for single-molecule exonuclease DNA sequencing where the continuous presence of a molecular adapter will be essential for reading individual nucleotides. Second, the ability to orient the adapter allows analytes to bind through only one of the two entrances to the betaCD cavity. We demonstrate that the covalently attached adapters can be used to alter the ion selectivity of the alphaHL pore, examine binding events at elevated temperatures, and detect analytes with prolonged dwell times.
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Affiliation(s)
- Hai-Chen Wu
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom
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Mazneikova V, Dimitrova V, Karag'ozova Z, Ivanova M, Mikhailova E, Stefanova A, Sl'ncheva B, Tsekova K, Lekova S, Furnadzhieva T. [Pregnancy with Rh-isoimmunization. Results of a retrospective analysis in the maternity hospital "Maichin Dom"]. Akush Ginekol (Sofiia) 2002; 40:3-7. [PMID: 11785364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
UNLABELLED The aim of the study is to analyze the outcome of pregnancies complicated by Rh-isoimmunization for the period 1996-2001 and to outline the aspects of optimization of the obstetrical conduct. MATERIAL AND METHODS The current study includes 39 pregnant women with Rh-isoimmunisation to whom amniocentesis and cordocentesis was performed. All cases were analyzed using medical history, serology (indirect Coombs, PAP test), ultrasound examination, amniocentesis, cordocentesis, NST. RESULTS From 39 pregnancies, complicated by severe Rh-isoimmunization 36 resulted in a live delivery, 2 resulted in intrauterine death of the fetus and 1 in early neonatal death. The titre of the antibodies is of prognostical value only in the first isoimmunised pregnancy. In this case there is a reliable correlation between the condition of the newborn and the zone from the Liley curve, antenatally found. With history of former immune pregnancies with unfavourable perinatal outcome most precise information about the condition of the foetus gives the cordocentesis. CONCLUSION In all of the discussed cases the Rh-isoimmunization is a result of no andi-D immunoglobulin profilaxis post partum or following abortion. That is why the efforts should be directed towards conduction of proper profilaxis to all Rh-negative pregnant women.
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