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Sitsanidis ED, Kasapidou PM, Hiscock JR, Gubala V, Castel H, Popoola PIA, Hall AJ, Edwards AA. Probing the self-assembly and anti-glioblastoma efficacy of a cinnamoyl-capped dipeptide hydrogelator. Org Biomol Chem 2022; 20:7458-7466. [PMID: 36094013 DOI: 10.1039/d2ob01339h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 01/19/2023]
Abstract
Herein, we introduce the first diphenylalanine dipeptide hydrogelator capped with the cinnamoyl functional group (Cin-L-F-L-F). We evaluate the effects of the cinnamoyl moiety on molecular self-assembly events and resultant physical properties of the hydrogel formed. In addition, we report our preliminary results of this dipeptide's cytotoxicity against glioblastoma (GBM) cancer cells.
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Affiliation(s)
- E D Sitsanidis
- Medway School of Pharmacy, Universities of Kent and Greenwich at Medway, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014, Finland
| | - P M Kasapidou
- Medway School of Pharmacy, Universities of Kent and Greenwich at Medway, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.
- Melville Laboratory for Polymer Synthesis, Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - J R Hiscock
- Supramolecular, Interfacial and Synthetic Chemistry Group, School of Physical Sciences, University of Kent, Canterbury, Kent, CT2 7NZ, UK
| | - V Gubala
- Medway School of Pharmacy, Universities of Kent and Greenwich at Medway, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.
| | - H Castel
- Normandie Univ, UNIROUEN, INSERM U1245, CBG, 76000 Rouen, France
| | - P I A Popoola
- Supramolecular, Interfacial and Synthetic Chemistry Group, School of Physical Sciences, University of Kent, Canterbury, Kent, CT2 7NZ, UK
| | - A J Hall
- Medway School of Pharmacy, Universities of Kent and Greenwich at Medway, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.
| | - A A Edwards
- Medway School of Pharmacy, Universities of Kent and Greenwich at Medway, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK.
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2
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Kasapidou PM, de Montullé EL, Dembélé KP, Mutel A, Desrues L, Gubala V, Castel H. Hyaluronic acid-based hydrogels loaded with chemoattractant and anticancer drug - new formulation for attracting and tackling glioma cells. Soft Matter 2021; 17:10846-10861. [PMID: 34806746 DOI: 10.1039/d1sm01003d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Over the last few years, significant interest has emerged in the development of localised therapeutic strategies for the treatment of glioblastoma (GBM). The concept of attracting and trapping residual tumour cells within a confined area to facilitate their eradication has developed progressively. Herein, we propose a new design of hyaluronic acid-based hydrogel which can be utilized as a matrix containing a soluble chemoattractant to attract residual glioma cells and chemotherapeutic agents to eradicate them in a less invasive and more efficient way compared to the currently available methods. Hydrogels were prepared at different crosslinking densities, e.g. low and high density, by crosslinking hyaluronic acid with various concentrations of adipic acid dihydrazide and U87MG GBM cell morphology, survival and CD44 expression were evaluated. As a proof-of-concept, hydrogels were loaded with a small peptide chemokine, human urotensin II (hUII), and the migration and survival of U87MG GBM cells were studied. Chemoattractant-containing hydrogels were also loaded with chemotherapeutic drugs to promote cell death in culture. The results showed that U87MG cells were able to invade the hydrogel network and to migrate in response to the chemoattractant hUII. In addition, in static condition, hydrogels loaded with doxorubicin demonstrated significant cytotoxicity leading to less than 80% U87MG cell viability after 48 hours when compared to the control sample. In addition, in in vitro invasive assays, it was originally shown that the chemoattractant effect of hUII can be effective before the cytotoxic action of doxorubicin on the U87MG cells trapped in the hydrogel. Our results provide new insights into a promising approach which can be readily translated in vivo for the treatment of one of the most devastating brain tumours.
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Affiliation(s)
- Paraskevi M Kasapidou
- Medway School of Pharmacy, University of Kent, Central Avenue, Chatham, ME4 4TB, UK
- Normandie Univ, UNIROUEN, INSERM U1239, DC2N, 76000 Rouen, France
- Institute for Research and Innovation in Biomedicine (IRIB), 76000 Rouen, France
| | - Emmanuel Laillet de Montullé
- Normandie Univ, UNIROUEN, INSERM U1239, DC2N, 76000 Rouen, France
- Institute for Research and Innovation in Biomedicine (IRIB), 76000 Rouen, France
| | - Kleouforo-Paul Dembélé
- Normandie Univ, UNIROUEN, INSERM U1239, DC2N, 76000 Rouen, France
- Institute for Research and Innovation in Biomedicine (IRIB), 76000 Rouen, France
| | - Alexandre Mutel
- Normandie Univ, UNIROUEN, INSERM U1239, DC2N, 76000 Rouen, France
- Institute for Research and Innovation in Biomedicine (IRIB), 76000 Rouen, France
| | - Laurence Desrues
- Normandie Univ, UNIROUEN, INSERM U1239, DC2N, 76000 Rouen, France
- Institute for Research and Innovation in Biomedicine (IRIB), 76000 Rouen, France
| | - Vladimir Gubala
- Medway School of Pharmacy, University of Kent, Central Avenue, Chatham, ME4 4TB, UK
| | - Hélène Castel
- Normandie Univ, UNIROUEN, INSERM U1239, DC2N, 76000 Rouen, France
- Institute for Research and Innovation in Biomedicine (IRIB), 76000 Rouen, France
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3
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Kah M, Johnston LJ, Kookana RS, Bruce W, Haase A, Ritz V, Dinglasan J, Doak S, Garelick H, Gubala V. Comprehensive framework for human health risk assessment of nanopesticides. Nat Nanotechnol 2021; 16:955-964. [PMID: 34518657 DOI: 10.1038/s41565-021-00964-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Nanopesticides are not only in an advanced state of research and development but have started to appear on the market. Industry and regulatory agencies need a consolidated and comprehensive framework and guidance for human health risk assessments. In this perspective we develop such a comprehensive framework by exploring two case studies from relevant product types: an active ingredient delivered with a nanocarrier system, and a nanoparticle as an active ingredient. For a nanocarrier system, three entities are tracked during the assessment: the nanocarrier-active ingredient complex, the empty nanocarrier remaining after the complete release of the active ingredient, and the released active ingredient. For the nanoparticle of pure active ingredient, only two entities are relevant: the nanoparticle and the released ions. We suggest important adaptations of the existing pesticide framework to determine the relevant nanopesticide entities and their concentrations for toxicity testing. Depending on the nature of the nanopesticides, additional data requirements, such as those pertaining to durability in biological media and potential for crossing biological barriers, have also been identified. Overall, our framework suggests a tiered approach for human health risk assessment, which is applicable for a range of nanopesticide products to support regulators and industry in making informed decisions on nanopesticide submissions. Brief summaries of suitable methods including references to existing standards (if available) have been included together with an analysis of current knowledge gaps. Our study is an important step towards a harmonized approach accepted by regulatory agencies for assessing nanopesticides.
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Affiliation(s)
- Melanie Kah
- School of Environment, The University of Auckland, Auckland, New Zealand.
| | - Linda J Johnston
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario, Canada
| | - Rai S Kookana
- CSIRO, Glen Osmond, South Australia, Australia
- University of Adelaide, Glen Osmond, South Australia, Australia
| | - Wendy Bruce
- Health Evaluation Directorate, Health Canada's Pest Management Regulatory Agency, Ottawa, Ontario, Canada
| | - Andrea Haase
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Vera Ritz
- Department of Pesticides Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | | | - Shareen Doak
- Institute of Life Science, Swansea University Medical School, Swansea, UK
| | - Hemda Garelick
- Department of Natural Science, Faculty of Technology, Middlesex University, London, UK
| | - Vladimir Gubala
- Medway School of Pharmacy, University of Kent, Chatham Maritime, UK
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4
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Sully RE, Moore CJ, Garelick H, Loizidou E, Podoleanu AG, Gubala V. Nanomedicines and microneedles: a guide to their analysis and application. Anal Methods 2021; 13:3326-3347. [PMID: 34313266 DOI: 10.1039/d1ay00954k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The fast-advancing progress in the research of nanomedicine and microneedle applications in the past two decades has suggested that the combination of the two concepts could help to overcome some of the challenges we are facing in healthcare. They include poor patient compliance with medication and the lack of appropriate administration forms that enable the optimal dose to reach the target site. Nanoparticles as drug vesicles can protect their cargo and deliver it to the target site, while evading the body's defence mechanisms. Unfortunately, despite intense research on nanomedicine in the past 20 years, we still haven't answered some crucial questions, e.g. about their colloidal stability in solution and their optimal formulation, which makes the translation of this exciting technology from the lab bench to a viable product difficult. Dissolvable microneedles could be an effective way to maintain and stabilise nano-sized formulations, whilst enhancing the ability of nanoparticles to penetrate the stratum corneum barrier. Both concepts have been individually investigated fairly well and many analytical techniques for tracking the fate of nanomaterials with their precious cargo, both in vitro and in vivo, have been established. Yet, to the best of our knowledge, a comprehensive overview of the analytical tools encompassing the concepts of microneedles and nanoparticles with specific and successful examples is missing. In this review, we have attempted to briefly analyse the challenges associated with nanomedicine itself, but crucially we provide an easy-to-navigate scheme of methods, suitable for characterisation and imaging the physico-chemical properties of the material matrix.
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Affiliation(s)
- Rachel E Sully
- Medway School of Pharmacy, Universities of Greenwich and Kent, Anson Building, Central Avenue, Chatham, ME4 4TB, UK.
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5
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Gubala V, Giovannini G, Kunc F, Monopoli MP, Moore CJ. Dye-doped silica nanoparticles: synthesis, surface chemistry and bioapplications. Cancer Nanotechnol 2020. [DOI: 10.1186/s12645-019-0056-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Abstract
Background
Fluorescent silica nanoparticles have been extensively utilised in a broad range of biological applications and are facilitated by their predictable, well-understood, flexible chemistry and apparent biocompatibility. The ability to couple various siloxane precursors with fluorescent dyes and to be subsequently incorporated into silica nanoparticles has made it possible to engineer these fluorophores-doped nanomaterials to specific optical requirements in biological experimentation. Consequently, this class of nanomaterial has been used in applications across immunodiagnostics, drug delivery and human-trial bioimaging in cancer research.
Main body
This review summarises the state-of-the-art of the use of dye-doped silica nanoparticles in bioapplications and firstly accounts for the common nanoparticle synthesis methods, surface modification approaches and different bioconjugation strategies employed to generate biomolecule-coated nanoparticles. The use of dye-doped silica nanoparticles in immunoassays/biosensing, bioimaging and drug delivery is then provided and possible future directions in the field are highlighted. Other non-cancer-related applications involving silica nanoparticles are also briefly discussed. Importantly, the impact of how the protein corona has changed our understanding of NP interactions with biological systems is described, as well as demonstrations of its capacity to be favourably manipulated.
Conclusions
Dye-doped silica nanoparticles have found success in the immunodiagnostics domain and have also shown promise as bioimaging agents in human clinical trials. Their use in cancer delivery has been restricted to murine models, as has been the case for the vast majority of nanomaterials intended for cancer therapy. This is hampered by the need for more human-like disease models and the lack of standardisation towards assessing nanoparticle toxicity. However, developments in the manipulation of the protein corona have improved the understanding of fundamental bio–nano interactions, and will undoubtedly assist in the translation of silica nanoparticles for disease treatment to the clinic.
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Kunc F, Moore CJ, Sully RE, Hall AJ, Gubala V. Polycarboxylated Dextran as a Multivalent Linker: Synthesis and Target Recognition of the Antibody-Nanoparticle Bioconjugates in PBS and Serum. Langmuir 2019; 35:4909-4917. [PMID: 30817890 DOI: 10.1021/acs.langmuir.8b03833] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Nanoparticles (NPs) functionalized with antibodies on their surface are used in a wide range of research applications. However, the bioconjugation chemistry between the antibodies and the surface of nanoparticles can be very challenging, often accompanied by several undesired effects such as nanoparticle aggregation, antibody denaturation, or poor target recognition of the surface-bound antibodies. Here, we report on a synthesis of fluorescent silica nanoparticle-antibody (NP-Ab) conjugates, in which polycarboxylated dextran is used as the multivalent linker. First, we present a synthetic methodology to prepare polycarboxylated dextrans with molecular weights of 6, 40, and 70 kDa. Second, we used water-soluble, polycarboxylated dextrans as a multivalent spacers/linkers to immobilize antibodies onto fluorescent silica nanoparticles. The prepared NP-Ab conjugates were tested in a direct binding assay format in both phosphate-buffered saline buffer and whole serum to investigate the role of the spacer/linker in the capacity of the NP-Ab to specifically recognize their target in "clean" and also in complex media. We have compared the dextran conjugates with two standards: (a) NP-Ab with antibodies attached on the surface of nanoparticles through the classical physical adsorption method and (b) NP-Ab where an established poly(amidoamine) (PAMAM) dendrimer was used as the linker. Our results showed that the polycarboxylated 6 kDa dextran facilitates antibody immobilization efficiency of nearly 92%. This was directly translated into the improved molecular recognition of the NP-Ab, which was measured by a direct binding assay. The signal-to-noise ratio in buffered solution for the 6 kDa dextran NP-Ab conjugates was 81, nearly 3 times higher than that of PAMAM G4.5 conjugates and 9 times higher than the physically adsorbed NP-Ab sample. In whole serum, the effect of 6 kDa dextran was more hindered due to the formation of protein corona but the signal-to-noise ratio was at least double that of the physically adsorbed NP-Ab conjugates.
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Affiliation(s)
- Filip Kunc
- National Research Council Canada , 100 Sussex Drive , Ottawa , Ontario K1N 0R6 , Canada
| | - Colin J Moore
- Italian Institute of Technology , 30 Via Morego , Genoa 16163 , Italy
| | - Rachel E Sully
- Medway School of Pharmacy , Universities of Greenwich and Kent , Anson Building, Central Avenue , Chatham ME4 4TB , U.K
| | - Andrew J Hall
- Medway School of Pharmacy , Universities of Greenwich and Kent , Anson Building, Central Avenue , Chatham ME4 4TB , U.K
| | - Vladimir Gubala
- Medway School of Pharmacy , Universities of Greenwich and Kent , Anson Building, Central Avenue , Chatham ME4 4TB , U.K
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7
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Abstract
The rapid and straightforward detection of bacteria in food and human samples is becoming important, particularly in view of the development of point-of-care devices and lab-on-a-chip tools for prevention and treatment of bacterial infections.
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Affiliation(s)
- Giorgia Giovannini
- Medway School of Pharmacy
- University of Kent
- Central Avenue
- Chatham Maritime
- Kent
| | - Vladimir Gubala
- Medway School of Pharmacy
- University of Kent
- Central Avenue
- Chatham Maritime
- Kent
| | - Andrew J. Hall
- Medway School of Pharmacy
- University of Kent
- Central Avenue
- Chatham Maritime
- Kent
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8
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Giovannini G, Hall AJ, Gubala V. Coumarin-based, switchable fluorescent substrates for enzymatic bacterial detection. Talanta 2018; 188:448-453. [PMID: 30029400 DOI: 10.1016/j.talanta.2018.06.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/05/2018] [Accepted: 06/06/2018] [Indexed: 01/27/2023]
Abstract
Enzymatically-switchable fluorescent substrates, such as the commercially available 4-methyl umbelliferones (4-MU) are used as standard indicators of enzymatic activity for the detection of various microorganisms and pathogens. However, a major disadvantage of 4-MU is its relatively high pKa leading to only partial dissociation of the fluorescent anion under the conditions where the enzymes are most effective (pH 6-6.5). Here we present a method for new, enzymatically-switchable, fluorescent substrates with improved photo-physico/chemical properties. The lead derivative, 4-AAU, shows excellent solubility in aqueous media (0.81 mg/mL) when compared to 4-MU (0.16 mg/mL), significantly improved quantum yield and wider dynamic range of its fluorescence properties. The corresponding bacterial substrate β-4-AAUG showed superior selectivity in the detection of clinically relevant amounts of E. coli, Enterococcus and K. pneumonia (1 CFU). The fluorescence intensity of β-4-AAUG was almost 5 times higher than that of the standard, the detection was possible in reasonably short time (∼ 2.5 h) and with excellent sensitivity.
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Affiliation(s)
- Giorgia Giovannini
- Istituto Italiano di Tecnologia (IIT), Via Morego 30, Genova 16163, Italy.
| | - Andrew J Hall
- Medway School of Pharmacy, University of Kent, Central Ave, Chatham Maritime, Kent ME4 4TB, United Kingdom.
| | - Vladimir Gubala
- Medway School of Pharmacy, University of Kent, Central Ave, Chatham Maritime, Kent ME4 4TB, United Kingdom.
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9
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Giovaninni G, Moore CJ, Hall AJ, Byrne HJ, Gubala V. pH-Dependent silica nanoparticle dissolution and cargo release. Colloids Surf B Biointerfaces 2018; 169:242-248. [DOI: 10.1016/j.colsurfb.2018.04.064] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/23/2018] [Accepted: 04/29/2018] [Indexed: 12/20/2022]
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10
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Gubala V, Johnston LJ, Krug HF, Moore CJ, Ober CK, Schwenk M, Vert M. Engineered nanomaterials and human health: Part 2. Applications and nanotoxicology (IUPAC Technical Report). PURE APPL CHEM 2018. [DOI: 10.1515/pac-2017-0102] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
AbstractResearch on engineered nanomaterials (ENM) has progressed rapidly from the very early stages of studying their unique, size-dependent physicochemical properties and commercial exploration to the development of products that influence our everyday lives. We have previously reviewed various methods for synthesis, surface functionalization, and analytical characterization of ENM in a publication titled ‘Engineered Nanomaterials: Preparation, Functionalization and Characterization’. In this second, inter-linked document, we first provide an overview of important applications of ENM in products relevant to human healthcare and consumer goods, such as food, textiles, and cosmetics. We then highlight the challenges for the design and development of new ENM for bio-applications, particularly in the rapidly developing nanomedicine sector. The second part of this document is dedicated to nanotoxicology studies of ENM in consumer products. We describe the various biological targets where toxicity may occur, summarize the four nanotoxicology principles, and discuss the need for careful consideration of the biodistribution, degradation, and elimination routes of nanosized materials before they can be safely used. Finally, we review expert opinions on the risk, regulation, and ethical aspects of using engineered nanomaterials in applications that may have direct or indirect impact on human health or our environment.
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11
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Giovannini G, Warncke P, Fischer D, Stranik O, Hall AJ, Gubala V. Improving colloidal stability of silica nanoparticles when stored in responsive gel: application and toxicity study. Nanotoxicology 2018; 12:407-422. [DOI: 10.1080/17435390.2018.1457729] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - Paul Warncke
- Department of Pharmaceutical Technology, Friedrich-Schiller-University Jena, Institute of Pharmacy, Jena, Germany
| | - Dagmar Fischer
- Department of Pharmaceutical Technology, Friedrich-Schiller-University Jena, Institute of Pharmacy, Jena, Germany
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12
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Simon AJ, Walls-Smith LT, Freddi MJ, Fong FY, Gubala V, Plaxco KW. Simultaneous Measurement of the Dissolution Kinetics of Responsive DNA Hydrogels at Multiple Length Scales. ACS Nano 2017; 11:461-468. [PMID: 28006092 DOI: 10.1021/acsnano.6b06414] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [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: 06/06/2023]
Abstract
Recent years have seen increasing study of stimulus-responsive hydrogels constructed from aptamer-connected DNA building blocks. Presumably due to a lack of simple, quantitative tools with which to measure gel responsiveness, however, the literature describing these materials is largely qualitative. In response, we demonstrate here simple, time-resolved, multiscale methods for measuring the response kinetics of these materials. Specifically, by employing trace amounts of fluorophore-quencher labeled cross-linkers and the rheology of entrapped fluorescent particles, we simultaneously measure dissolution at molecular, hundred-nanometer, and hundred-micron length-scales. For our test-bed system, an adenine-responsive hydrogel, we find biphasic response kinetics dependent on both effector concentration and depth within the gel and a dissolution pattern uniform at scales longer than a few times the monomer-monomer distance. Likewise, we find that, in agreement with theoretical predictions, dissolution kinetics over the hundred nanometer length scale exhibit a power-law-like dependence on the fraction of disrupted cross-links before a distinct crossover from solid-like to liquid-like behavior.
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Affiliation(s)
| | | | - Matthew J Freddi
- Medway School of Pharmacy, University of Kent , Central Avenue, Chatham Maritime, Chatham, ME4 4TB Kent, U.K
| | | | - Vladimir Gubala
- Medway School of Pharmacy, University of Kent , Central Avenue, Chatham Maritime, Chatham, ME4 4TB Kent, U.K
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13
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Moore CJ, Giovannini G, Kunc F, Hall AJ, Gubala V. ‘Overloading’ fluorescent silica nanoparticles with dyes to improve biosensor performance. J Mater Chem B 2017. [DOI: 10.1039/c7tb01284e] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Using dye-doped silica nanoparticles (DSNP) as reporter probes, we describe a simple method of enhancing fluorescent signal and the extension of the detectable target concentration range in a proof-of-concept ‘dissolution immunoassay’.
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Affiliation(s)
- Colin J. Moore
- Medway School of Pharmacy
- University of Kent
- Chatham Maritime
- Kent
- UK
| | | | - Filip Kunc
- Medway School of Pharmacy
- University of Kent
- Chatham Maritime
- Kent
- UK
| | - Andrew J. Hall
- Medway School of Pharmacy
- University of Kent
- Chatham Maritime
- Kent
- UK
| | - Vladimir Gubala
- Medway School of Pharmacy
- University of Kent
- Chatham Maritime
- Kent
- UK
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14
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Giovannini G, Kunc F, Piras CC, Stranik O, Edwards AA, Hall AJ, Gubala V. Stabilizing silica nanoparticles in hydrogels: impact on storage and polydispersity. RSC Adv 2017. [DOI: 10.1039/c7ra02427d] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [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] Open
Abstract
For successful nanomedicine, it is important that the unique, size-dependent physico-chemical properties of the nanomaterial remain predictably constant during both the storage and the manipulation of the material.
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Affiliation(s)
| | - Filip Kunc
- Medway School of Pharmacy
- University of Kent
- Chatham
- UK
| | | | - Ondrej Stranik
- The Leibniz Institute of Photonic Technology (IPHT)
- 07745 Jena
- Germany
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15
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Moore CJ, Montón H, O'Kennedy R, Williams DE, Nogués C, Crean (née Lynam) C, Gubala V. Controlling colloidal stability of silica nanoparticles during bioconjugation reactions with proteins and improving their longer-term stability, handling and storage. J Mater Chem B 2015; 3:2043-2055. [DOI: 10.1039/c4tb01915f] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Robust protocols for antibody-nanoparticle (Ab-NP) conjugation, and improved method for long-term stability and storage of Ab-NPs using cryoprotectants.
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Affiliation(s)
- C. J. Moore
- Medway School of Pharmacy
- Universities of Kent and Greenwich
- Chatham
- UK
| | - H. Montón
- Departament de Biologia Ceŀlular
- Fisiologia i Immunologia
- Universitat Autònoma de Barcelona
- Bellaterra
- Spain
| | - R. O'Kennedy
- National Centre for Sensor Research
- Biomedical Diagnostics Institute
- Dublin City University
- Dublin 9
- Ireland
| | - D. E. Williams
- National Centre for Sensor Research
- Biomedical Diagnostics Institute
- Dublin City University
- Dublin 9
- Ireland
| | - C. Nogués
- Departament de Biologia Ceŀlular
- Fisiologia i Immunologia
- Universitat Autònoma de Barcelona
- Bellaterra
- Spain
| | | | - V. Gubala
- Medway School of Pharmacy
- Universities of Kent and Greenwich
- Chatham
- UK
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16
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Gubala V, Siegrist J, Monaghan R, O'Reilly B, Gandhiraman RP, Daniels S, Williams DE, Ducrée J. Simple approach to study biomolecule adsorption in polymeric microfluidic channels. Anal Chim Acta 2012; 760:75-82. [PMID: 23265736 DOI: 10.1016/j.aca.2012.11.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 11/13/2012] [Accepted: 11/16/2012] [Indexed: 02/05/2023]
Abstract
Herein a simple analytical method is presented for the characterization of biomolecule adsorption on cyclo olefin polymer (COP, trade name: Zeonor(®)) substrates which are widely used in microfluidic lab-on-a-chip devices. These Zeonor(®) substrates do not possess native functional groups for specific reactions with biomolecules. Therefore, depending on the application, such substrates must be functionalized by surface chemistry methods to either enhance or suppress biomolecular adsorption. This work demonstrates a microfluidic method for evaluating the adsorption of antibodies and oligonucleotides surfaces. The method uses centrifugal microfluidic flow-through chips and can easily be implemented using common equipment such as a spin coater. The working principle is very simple. The user adds 40 L of the solution containing the sample to the starting side of a microfluidic channel, where it is moved through by centrifugal force. Some molecules are adsorbed in the channel. The sample is then collected at the other end in a small reservoir and the biomolecule concentration is measured. As a pilot application, we characterized the adsorption of goat anti-human IgG and a 20-mer DNA on Zeonor(®), and on three types of functionalized Zeonor: 3-aminopropyltriethoxysilane (APTES) modified surface with mainly positive charge, negatively charged surface with immobilized bovine serum albumin (BSA), and neutral, hydrogel-like film with polyethylene glycol (PEG) characteristics. This simple analytical approach adds to the fundamental understanding of the interaction forces in real, microfluidic systems. This method provides a straightforward and rapid way to screen surface compositions and chemistry, and relate these to their effects on the sensitivity and resistance to non-specific binding of bioassays using them. In an additional set of experiments, the surface area of the channels in this universal microfluidic chip was increased by precision milling of microscale trenches. This modified surface was then coated with APTES and tested for its potential to serve as a unique protein dilution feature.
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Affiliation(s)
- Vladimir Gubala
- Biomedical Diagnostics Institute (BDI), National Centre for Sensor Research (NCSR), Dublin City University, Dublin 9, Ireland.
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Tivnan A, Orr WS, Gubala V, Nooney R, Williams DE, McDonagh C, Prenter S, Harvey H, Domingo-Fernández R, Bray IM, Piskareva O, Ng CY, Lode HN, Davidoff AM, Stallings RL. Inhibition of neuroblastoma tumor growth by targeted delivery of microRNA-34a using anti-disialoganglioside GD2 coated nanoparticles. PLoS One 2012; 7:e38129. [PMID: 22662276 PMCID: PMC3360657 DOI: 10.1371/journal.pone.0038129] [Citation(s) in RCA: 186] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 05/04/2012] [Indexed: 12/25/2022] Open
Abstract
Background Neuroblastoma is one of the most challenging malignancies of childhood, being associated with the highest death rate in paediatric oncology, underlining the need for novel therapeutic approaches. Typically, patients with high risk disease undergo an initial remission in response to treatment, followed by disease recurrence that has become refractory to further treatment. Here, we demonstrate the first silica nanoparticle-based targeted delivery of a tumor suppressive, pro-apoptotic microRNA, miR-34a, to neuroblastoma tumors in a murine orthotopic xenograft model. These tumors express high levels of the cell surface antigen disialoganglioside GD2 (GD2), providing a target for tumor-specific delivery. Principal Findings Nanoparticles encapsulating miR-34a and conjugated to a GD2 antibody facilitated tumor-specific delivery following systemic administration into tumor bearing mice, resulted in significantly decreased tumor growth, increased apoptosis and a reduction in vascularisation. We further demonstrate a novel, multi-step molecular mechanism by which miR-34a leads to increased levels of the tissue inhibitor metallopeptidase 2 precursor (TIMP2) protein, accounting for the highly reduced vascularisation noted in miR-34a-treated tumors. Significance These novel findings highlight the potential of anti-GD2-nanoparticle-mediated targeted delivery of miR-34a for both the treatment of GD2-expressing tumors, and as a basic discovery tool for elucidating biological effects of novel miRNAs on tumor growth.
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Affiliation(s)
- Amanda Tivnan
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
| | - Wayne Shannon Orr
- Department of Surgery, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
- Department of Surgery, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Vladimir Gubala
- Biomedical Diagnostics Institute, Dublin City University, Dublin, Ireland
| | - Robert Nooney
- Biomedical Diagnostics Institute, Dublin City University, Dublin, Ireland
| | - David E. Williams
- Biomedical Diagnostics Institute, Dublin City University, Dublin, Ireland
| | - Colette McDonagh
- Biomedical Diagnostics Institute, Dublin City University, Dublin, Ireland
| | - Suzanne Prenter
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
| | - Harry Harvey
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
| | - Raquel Domingo-Fernández
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
| | - Isabella M. Bray
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
| | - Olga Piskareva
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
| | - Catherine Y. Ng
- Department of Surgery, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Holger N. Lode
- Department of Paediatrics and Paediatric Haematology/Oncology, University of Greifswald, Greifswald, Germany
| | - Andrew M. Davidoff
- Department of Surgery, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
- Department of Surgery, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Raymond L. Stallings
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
- * E-mail:
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18
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Affiliation(s)
- Vladimir Gubala
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Leanne F. Harris
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Antonio J. Ricco
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - Ming X. Tan
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
| | - David E. Williams
- Biomedical Diagnostics Institute, Dublin City University, Dublin 9, Ireland
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19
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Gandhiraman RP, Le NCH, Dixit CK, Volcke C, Doyle C, Gubala V, Uppal S, Monaghan R, James B, O'Kennedy R, Daniels S, Williams DE. Multi-layered plasma-polymerized chips for SPR-based detection. ACS Appl Mater Interfaces 2011; 3:4640-4648. [PMID: 22029622 DOI: 10.1021/am201061k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The surface functionalization of a noble metal is crucial in a surface plasmon resonance-based biomolecular detection system because the interfacial coating must retain the activity of immobilized biomolecules while enhancing the optimal loading. We present here a one-step, room-temperature, high-speed, gas-phase plasma polymerization process for functionalizing gold substrates using siloxane as an adhesion layer and acrylic acid as a functional layer. Siloxane- and thiol-based coatings were compared for their performance as adhesion and the interfacial layer for subsequent functionalization. An in situ sequential deposition of siloxane and acrylic acid resulted in a 7-fold increase in carboxylic functionality surfacial content compared to films deposited with thiol-containing precursors. Grading of the layer composition achieved as a consequence of ion-induced mixing on the surface coating under the application of the plasma is confirmed through secondary ion mass spectroscopic studies. DNA hybridization assays were demonstrated on gold/glass substrates using surface plasmon enhanced ellipsometry and the applicability of this coating for protein immunoassays were demonstrated with plasma functionalized gold/plastic substrates in Biacore 3000 SPR instrument.
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Affiliation(s)
- Ram P Gandhiraman
- Biomedical Diagnostics Institute (BDI), Dublin City University, Glasnevin, Dublin-9, Ireland.
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20
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O'Mahony CC, Gubala V, Gandhiraman RP, Daniels S, Yuk JS, MacCraith BD, Williams DE. Improving the sensitivity of immunoassays with PEG-COOH-like film prepared by plasma-based technique. J Biomed Mater Res A 2011; 100:230-5. [DOI: 10.1002/jbm.a.33268] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 07/09/2011] [Accepted: 07/17/2011] [Indexed: 11/07/2022]
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21
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Le NCH, Gubala V, Gandhiraman RP, Daniels S, Williams DE. Evaluation of different nonspecific binding blocking agents deposited inside poly(methyl methacrylate) microfluidic flow-cells. Langmuir 2011; 27:9043-9051. [PMID: 21648475 DOI: 10.1021/la2011502] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Poly(methyl methacrylate) (PMMA) flow-cells containing microwells were deposited with different nonspecific binding blocking agents, namely, bovine serum albumin (BSA), cationic lipid (DOTAP:DOPE) and diethylene glycol dimethyl ether (DEGDME). Water contact angle (WCA) and atomic force microscope (AFM) measurements were carried out to confirm the successful depositions of BSA, DOTAP, and DEGDME onto the PMMA surfaces. Fluorescent intensity measurements were performed to evaluate the degree of nonspecific adsorption of Cy5-labeled anti-IgG proteins onto plain and oxygen plasma-treated (PT) PMMA flow-cells as well as PMMA flow-cells deposited with different above-mentioned blocking agents. We then employed a label-free detection method called total internal reflection ellipsometry (TIRE) to evaluate the stability of the deposited blocking agents inside the PMMA flow-cells. It was found that, while DOTAP:DOPE was the best agent for blocking the nonspecific adsorption, it could be removed from the PMMA surfaces of the flow-cells upon rinsing with phosphate buffered saline (PBS) and later deposited back onto the Au-coated glass sensing substrate of the TIRE. The removal of the blocking agents from PMMA surfaces and their deposition onto the sensing substrate were further manifested by measuring the kinetics and the amount of adsorbed anti-α-hCG proteins. Overall, the dry DEGDME coating by plasma-enhanced chemical vapor deposition (PECVD) showed very good blocking and excellent stability for subsequent assay inside the microwells. Our results could be useful when one considers what blocking agents should be used for PMMA-based microfluidic immunosensor or biosensor devices by looking at both the blocking efficiency and the stability of the blocking agent.
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Affiliation(s)
- Nam Cao Hoai Le
- Biomedical Diagnostics Institute (BDI), Dublin City University, Dublin, Republic of Ireland.
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22
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Gubala V, Lynam CCN, Nooney R, Hearty S, McDonnell B, Heydon K, O'Kennedy R, MacCraith BD, Williams DE. Kinetics of immunoassays with particles as labels: effect of antibody coupling using dendrimers as linkers. Analyst 2011; 136:2533-41. [PMID: 21541412 DOI: 10.1039/c1an15017k] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In this article, we report on poly(amidoamine) dendrimers (PAMAM) as coupling agents for recombinant single-chain (ScFv) antibodies to nanoparticle (NP) labels, for use in immunoassay. We present a simple theory for the kinetics of particle capture onto a surface by means of an antibody-antigen reaction, in which the important parameter is the fraction of the particle surface that is active for reaction. We describe how increasing the generation number of the linking dendrimers significantly increased the fraction of the NP surface that is active for antigen binding and consequently also increased the assay kinetic rates. Use of dendrimers for conjugation of the NP to the antibody resulted in a significantly higher surface coverage of active antibody, in comparison with mono-valent linker chemistry. As a direct consequence, the increase in effective avidity significantly out-weighed any effect of a decreased diffusion coefficient due to the NP, when compared to that of a molecular dye-labelled antibody. The signal to noise ratio of the G4.5 dendrimer-sensitised nanoparticles out-performed the dye-labelled antibody by approximately four-fold. Particle aggregation experiments with the multi-valent antigen CRP demonstrated reaction-limited aggregation whose rate increased significantly with increasing generation number of the dendrimer linker.
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Affiliation(s)
- Vladimir Gubala
- Biomedical Diagnostics Institute Dublin City University, Glasnevin, Ireland.
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23
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Charlton C, Gubala V, Gandhiraman RP, Wiechecki J, Le NCH, Coyle C, Daniels S, MacCraith BD, Williams DE. TIRF microscopy as a screening method for non-specific binding on surfaces. J Colloid Interface Sci 2011; 354:405-9. [DOI: 10.1016/j.jcis.2010.10.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 10/12/2010] [Accepted: 10/13/2010] [Indexed: 11/29/2022]
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Betancourt JE, Martín-Hidalgo M, Gubala V, Rivera JM. Solvent-induced high fidelity switching between two discrete supramolecules. J Am Chem Soc 2010; 131:3186-8. [PMID: 19216522 DOI: 10.1021/ja809612d] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here we show the reversible high fidelity switching between two discrete self-assembled supramolecules made from a lipophilic 8-phenyl-2'-deoxyguanosine derivative induced by an indirect solvent effect. A hexadecameric supramolecule containing four stacked tetramers is formed in acetonitrile aided by higher potassium concentrations. When the amount of weakly solvated potassium decreases, due the lower activity of potassium iodide in chloroform, an octamer is formed after the dissociation of the two outer tetramers in the hexadecamer. The switching process results from an unprecedented subtle interplay between the activity of potassium iodide and the steric crowding within the self-assembled structure. Besides the possible applications in nanoconstruction, this phenomenon sheds light into the mechanism of formation of self-assembled supramolecules made from guanosine derivatives.
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Affiliation(s)
- José E Betancourt
- Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, Rio Piedras, Puerto Rico 00931
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25
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Abstract
We have previously reported that 8-phenyl-2'-deoxyguanosine derivatives (8PhGs) are able to extract metal cations from an aqueous phase into an organic phase. Herein we report on the ability of 8PhGs to transport metal cations across a bulk lipophilic liquid membrane. The experiments were performed using lithium, sodium, potassium, and strontium picrate salts with the parent lipophilic Gi, two isomeric 8PhG derivatives, cis-dicyclohexano-18-crown-6 (CD18C6) and [2•2•2] cryptand as reference compounds. The relative amounts of the picrate salts were measured by UV spectroscopy in both, the source phase and the receiving phase over a period of 24 h. The results show that the transport efficiency of the self-assembled ionophores formed by 8PhGs is either similar or superior to that of CD18C6, and in all but one case higher than the parent compound Gi. The varying efficiencies between the derivatives can be attributed to the stability (kinetic and thermodynamic) and the different molecularities of the supramolecules formed by these 8PhGs. The ease of the synthesis of 8PhGs, their anion independent assembly and the fact that the transport efficiency can be modulated as a function of the structure of the 8PhGs bode well for the use of such compounds in the development of novel antimicrobial agents and cation sensing devices.
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Affiliation(s)
- Mariana Martín-Hidalgo
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, Puerto Rico 00931
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26
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Gandhiraman R, Gubala V, Nam LCH, Volcke C, Doyle C, James B, Daniels S, Williams D. Deposition of chemically reactive and repellent sites on biosensor chips for reduced non-specific binding. Colloids Surf B Biointerfaces 2010; 79:270-5. [DOI: 10.1016/j.colsurfb.2010.04.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Revised: 04/13/2010] [Accepted: 04/14/2010] [Indexed: 10/19/2022]
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27
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Volcke C, Gandhiraman RP, Gubala V, Doyle C, Fonder G, Thiry PA, Cafolla AA, James B, Williams DE. Plasma functionalization of AFM tips for measurement of chemical interactions. J Colloid Interface Sci 2010; 348:322-8. [DOI: 10.1016/j.jcis.2010.04.042] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 04/08/2010] [Accepted: 04/19/2010] [Indexed: 11/16/2022]
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28
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Volcke C, Gandhiraman R, Gubala V, Raj J, Cummins T, Fonder G, Nooney R, Mekhalif Z, Herzog G, Daniels S. Reactive amine surfaces for biosensor applications, prepared by plasma-enhanced chemical vapour modification of polyolefin materials. Biosens Bioelectron 2010; 25:1875-80. [DOI: 10.1016/j.bios.2009.12.034] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 12/08/2009] [Accepted: 12/29/2009] [Indexed: 10/20/2022]
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Gubala V, Le Guevel X, Nooney R, Williams DE, MacCraith B. A comparison of mono and multivalent linkers and their effect on the colloidal stability of nanoparticle and immunoassays performance. Talanta 2010; 81:1833-9. [PMID: 20441982 DOI: 10.1016/j.talanta.2010.03.048] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 03/20/2010] [Accepted: 03/25/2010] [Indexed: 11/24/2022]
Abstract
When designing devices for biomedical diagnostics, increasing the signal to noise ratio is often critical for achieving clinically relevant sensitivity and limits of detection (LOD). In antibody-based assays, the measured signal can be amplified through the replacement of molecular fluorophores with doped nanoparticles (NP). However, the benefits of using NPs can only be realized if the NPs are coated efficiently with detection antibody, have good colloidal stability and the ratio of specific to non-specific binding (NSB) is high enough. The main focus of this paper is on the optimization of the bioconjugation protocol for antibody labeling of NPs leading to improved assay performance. Two types of linkers were used: monovalent linkers (glutaraldehyde; sulfo-SMCC; and sulfo-SIAB), and three generations of dendrimers endowed with multivalent carboxylic functionality. Overall, the NP-IgG conjugates prepared using multivalent linkers showed a significantly lower LOD and higher sensitivity than their homo- or hetero-functional counterparts. The multivalent dendrimers also improved NP stability and reduced aggregation. Moreover, the dendrimers showed a higher reactivity with biological material, a feature that could significantly reduce the cost of high-throughput biodiagnostics tests.
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Affiliation(s)
- Vladimir Gubala
- Biomedical Diagnostics Institute, Dublin City University, Glasnevin, Dublin 9, Ireland.
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30
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Gandhiraman* RP, Volcke C, Gubala V, Doyle C, Basabe-Desmonts L, Dotzler C, Toney MF, Iacono M, Nooney RI, Daniels S, James B, Williams DE. High efficiency amine functionalization of cycloolefin polymer surfaces for biodiagnostics. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b925737c] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Gubala V, Gandhiraman RP, Volcke C, Doyle C, Coyle C, James B, Daniels S, Williams DE. Functionalization of cycloolefin polymer surfaces by plasma-enhanced chemical vapour deposition: comprehensive characterization and analysis of the contact surface and the bulk of aminosiloxane coatings. Analyst 2010; 135:1375-81. [DOI: 10.1039/b924692d] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Rivera-Sánchez MDC, Andújar-de-Sanctis I, García-Arriaga M, Gubala V, Hobley G, Rivera JM. Walking a supramolecular tightrope: a self-assembled dodecamer from an 8-aryl-2'-deoxyguanosine derivative. J Am Chem Soc 2009; 131:10403-5. [PMID: 19722619 PMCID: PMC2717712 DOI: 10.1021/ja9040384] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Controlling the properties of self-assembled supramolecules via intrinsic parameters (i.e., structural information in the subunits) enables the reliable construction of assemblies of well-defined size and composition. Here we show that an optimum balance between repulsive (e.g., steric) and attractive (e.g., pi-pi, dipole-dipole) noncovalent interactions between subunits of a lipophilic 8-(3-pyridyl)-2'-deoxyguanosine derivative enables the high fidelity formation of a stable and discrete self-assembled dodecamer. In contrast, the isosteric 8-phenyl-2'-deoxyguanosine derivative assembles into an octamer because it cannot engage in additional dipole-dipole interactions. Adding dodecamers to a supramolecular construction toolbox, already containing octamers and hexadecamers made from other 8-aryl-2'-deoxyguanosine derivatives, should enable the preparation of a wide variety of self-assembled nanostructures where the size and the number of functional elements can be precisely fine-tuned for specific applications.
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Volcke C, Gandhiraman RP, Basabe-Desmonts L, Iacono M, Gubala V, Cecchet F, Cafolla AA, Williams DE. Protein pattern transfer for biosensor applications. Biosens Bioelectron 2009; 25:1295-300. [PMID: 19900799 DOI: 10.1016/j.bios.2009.10.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 09/24/2009] [Accepted: 10/13/2009] [Indexed: 10/20/2022]
Abstract
This paper presents a very simple, industrially scalable method for transferring a high-resolution, biologically active protein pattern from one substrate to another. We demonstrate the transfer of a protein pattern formed initially by microcontact printing from a silicon surface (to which this form of printing is applicable) onto a glass or polymer substrate, almost independently of the surface/bulk properties of the second substrate. A very thin, spin-coated layer of a sugar is used to preserve the structure and organization of proteins during the subsequent plasma deposition of a siloxane polymer, after which the protein pattern could simply be peeled off the silicon substrate and glued onto any other desired substrate.
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Affiliation(s)
- C Volcke
- Biomedical Diagnostics Institute (BDI), Dublin City University, Dublin, Ireland.
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Abstract
We describe the synthesis of 8-heteroaromatic-2'-deoxyguanosine analogues using Suzuki-Miyaura or Stille conditions. Unprotected and protected 8-bromo-2'-deoxyguanosine was coupled with commercially available heteroarylboronic acids or the trialkyltin derivatives of 2-pyridylbromides either with or without microwave irradiation in good yields.
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Affiliation(s)
- Gerard Hobley
- Department of Chemistry, College of Natural Sciences, University of Puerto Rico, Río Piedras Campus, San Juan, Puerto Rico, PR-00931
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35
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Gubala V, Rivera-Sánchez MDC, Hobley G, Rivera JM. The impact of 8-aryl-and 8-heteroaryl-2'-deoxyguanosine derivatives on G-quadruplex formation. ACTA ACUST UNITED AC 2008:39-40. [PMID: 18029575 DOI: 10.1093/nass/nrm020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Guanine and G-rich oligonucleotides are known to self-assemble in the presence of a variety of cations to form higher ordered structures known as Gquadruplexes. We have synthesized a library of 8-aryl/heteroaryl-2'-deoxyguanosine derivatives (8ArGs) that are also able to self-assemble into quadruplex structures. We demonstrate that the properties of such quadruplexes can be modulated by the nature of the groups attached to the guanine base. These supramolecules are potentially useful in the development of self-assembled nanodevices.
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Affiliation(s)
- Vladimir Gubala
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, PO Box 23346, San Juan, Puerto Rico, 00931, USA
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Hernández Prada JA, Ferreira AJ, Katovich MJ, Shenoy V, Qi Y, Santos RAS, Castellano RK, Lampkins AJ, Gubala V, Ostrov DA, Raizada MK. Structure-based identification of small-molecule angiotensin-converting enzyme 2 activators as novel antihypertensive agents. Hypertension 2008; 51:1312-7. [PMID: 18391097 DOI: 10.1161/hypertensionaha.107.108944] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Angiotensin-converting enzyme 2 (ACE2) is a key renin-angiotensin system enzyme involved in balancing the adverse effects of angiotensin II on the cardiovascular system, and its overexpression by gene transfer is beneficial in cardiovascular disease. Therefore, our objectives were 2-fold: to identify compounds that enhance ACE2 activity using a novel conformation-based rational drug discovery strategy and to evaluate whether such compounds reverse hypertension-induced pathophysiologies. We used a unique virtual screening approach. In vitro assays revealed 2 compounds (a xanthenone and resorcinolnaphthalein) that enhanced ACE2 activity in a dose-dependent manner. Acute in vivo administration of the xanthenone resulted in a dose-dependent transient and robust decrease in blood pressure (at 10 mg/kg, spontaneously hypertensive rats decreased 71+/-9 mm Hg and Wistar-Kyoto rats decreased 21+/-8 mm Hg; P<0.05). Chronic infusion of the xanthenone (120 microg/day) resulted in a modest decrease in the spontaneously hypertensive rat blood pressure (17 mm Hg; 2-way ANOVA; P<0.05), whereas it had no effect in Wistar-Kyoto rats. Strikingly, the decrease in blood pressure was also associated with improvements in cardiac function and reversal of myocardial, perivascular, and renal fibrosis in the spontaneously hypertensive rats. We conclude that structure-based screening can help identify compounds that activate ACE2, decrease blood pressure, and reverse tissue remodeling. Administration of ACE2 activators may be a valid strategy for antihypertensive therapy.
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Affiliation(s)
- José A Hernández Prada
- McKnight Brain Institute and Department of Physiology, College of Medicine, University of Florida, Gainesville, USA
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Abstract
[structure: see text] The synthesis and self-assembling properties of 8-aryl-2'-deoxyguanosine derivatives are described. Our studies suggest that a properly placed acetyl group can increase the stability and specificity of the resulting G-quadruplex supramolecules by enhancing noncovalent interactions such as hydrogen bonds and pi-stacking.
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Affiliation(s)
- Vladimir Gubala
- Department of Chemistry, University of Puerto Rico, Río Piedras Campus, Río Piedras, Puerto Rico 00931
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