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Saftics A, Kurunczi S, Peter B, Szekacs I, Ramsden JJ, Horvath R. Data evaluation for surface-sensitive label-free methods to obtain real-time kinetic and structural information of thin films: A practical review with related software packages. Adv Colloid Interface Sci 2021; 294:102431. [PMID: 34330074 DOI: 10.1016/j.cis.2021.102431] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/16/2021] [Accepted: 04/18/2021] [Indexed: 02/07/2023]
Abstract
Interfacial layers are important in a wide range of applications in biomedicine, biosensing, analytical chemistry and the maritime industries. Given the growing number of applications, analysis of such layers and understanding their behavior is becoming crucial. Label-free surface sensitive methods are excellent for monitoring the formation kinetics, structure and its evolution of thin layers, even at the nanoscale. In this paper, we review existing and commercially available label-free techniques and demonstrate how the experimentally obtained data can be utilized to extract kinetic and structural information during and after formation, and any subsequent adsorption/desorption processes. We outline techniques, some traditional and some novel, based on the principles of optical and mechanical transduction. Our special focus is the current possibilities of combining label-free methods, which is a powerful approach to extend the range of detected and deduced parameters. We summarize the most important theoretical considerations for obtaining reliable information from measurements taking place in liquid environments and, hence, with layers in a hydrated state. A thorough treamtmaent of the various kinetic and structural quantities obtained from evaluation of the raw label-free data are provided. Such quantities include layer thickness, refractive index, optical anisotropy (and molecular orientation derived therefrom), degree of hydration, viscoelasticity, as well as association and dissociation rate constants and occupied area of subsequently adsorbed species. To demonstrate the effect of variations in model conditions on the observed data, simulations of kinetic curves at various model settings are also included. Based on our own extensive experience with optical waveguide lightmode spectroscopy (OWLS) and the quartz crystal microbalance (QCM), we have developed dedicated software packages for data analysis, which are made available to the scientific community alongside this paper.
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Ajdnik U, Zemljič LF, Plohl O, Pérez L, Trček J, Bračič M, Mohan T. Bioactive Functional Nanolayers of Chitosan-Lysine Surfactant with Single- and Mixed-Protein-Repellent and Antibiofilm Properties for Medical Implants. ACS APPLIED MATERIALS & INTERFACES 2021; 13:23352-23368. [PMID: 33998809 PMCID: PMC8289181 DOI: 10.1021/acsami.1c01993] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
Medical implant-associated infections resulting from biofilm formation triggered by unspecific protein adsorption are the prevailing cause of implant failure. However, implant surfaces rendered with multifunctional bioactive nanocoatings offer a promising alternative to prevent the initial attachment of bacteria and effectively interrupt biofilm formation. The need to research and develop novel and stable bioactive nanocoatings for medical implants and a comprehensive understanding of their properties in contact with the complex biological environment are crucial. In this study, we developed an aqueous stable and crosslinker-free polyelectrolyte-surfactant complex (PESC) composed of a renewable cationic polysaccharide, chitosan, a lysine-based anionic surfactant (77KS), and an amphoteric antibiotic, amoxicillin, which is widely used to treat a number of infections caused by bacteria. We successfully introduced the PESC as bioactive functional nanolayers on the "model" and "real" polydimethylsiloxane (PDMS) surfaces under dynamic and ambient conditions. Besides their high stability and improved wettability, these uniformly deposited nanolayers (thickness: 44-61 nm) with mixed charges exhibited strong repulsion toward three model blood proteins (serum albumin, fibrinogen, and γ-globulin) and their competitive interactions in the mixture in real-time, as demonstrated using a quartz crystal microbalance with dissipation (QCM-D). The functional nanolayers with a maximum negative zeta potential (ζ: -19 to -30 mV at pH 7.4), water content (1628-1810 ng cm-2), and hydration (low viscosity and elastic shear modulus) correlated with the mass, conformation, and interaction nature of proteins. In vitro antimicrobial activity testing under dynamic conditions showed that the charged nanolayers actively inhibited the growth of both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria compared to unmodified PDMS. Given the ease of fabrication of multifunctional and charged biobased coatings with simultaneous protein-repellent and antimicrobial activities, the limitations of individual approaches could be overcome leading to a better and advanced design of various medical devices (e.g., catheters, prosthetics, and stents).
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Affiliation(s)
- Urban Ajdnik
- Faculty
of Mechanical Engineering, Institute of Engineering Materials and
Design, Laboratory for Characterization and Processing of Polymers, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia
| | - Lidija Fras Zemljič
- Faculty
of Mechanical Engineering, Institute of Engineering Materials and
Design, Laboratory for Characterization and Processing of Polymers, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia
| | - Olivija Plohl
- Faculty
of Mechanical Engineering, Institute of Engineering Materials and
Design, Laboratory for Characterization and Processing of Polymers, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia
| | - Lourdes Pérez
- Department
of Surfactants and Nanobiotechnology, Institute
for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
| | - Janja Trček
- Faculty
of Natural Sciences and Mathematics, Department of Biology, University of Maribor, Koroška cesta 160, 2000 Maribor, Slovenia
| | - Matej Bračič
- Faculty
of Mechanical Engineering, Institute of Engineering Materials and
Design, Laboratory for Characterization and Processing of Polymers, University of Maribor, Smetanova ulica 17, 2000 Maribor, Slovenia
| | - Tamilselvan Mohan
- Institute
for Chemistry and Technology of Biobased Systems (IBioSys), Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
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3
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Optical imaging of single-protein size, charge, mobility, and binding. Nat Commun 2020; 11:4768. [PMID: 32958747 PMCID: PMC7505846 DOI: 10.1038/s41467-020-18547-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/31/2020] [Indexed: 12/28/2022] Open
Abstract
Detection and identification of proteins are typically achieved by analyzing protein size, charge, mobility and binding to antibodies, which are critical for biomedical research and disease diagnosis and treatment. Despite the importance, measuring these quantities with one technology and at the single-molecule level has not been possible. Here we tether a protein to a surface with a flexible polymer, drive it into oscillation with an electric field, and image the oscillation with a near field optical imaging method, from which we determine the size, charge, and mobility of the protein. We also measure antibody binding and conformation changes in the protein. The work demonstrates a capability for comprehensive protein analysis and precision protein biomarker detection at the single molecule level. Protein identification at the single-molecule level is the ultimate goal for biological research and disease diagnosis. Here, the authors identify the size, charge, mobility, and binding of individual protein molecules by measuring the optical and electrical responses of each protein molecule tethered to a surface.
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Noguchi Y, Iwasaki Y, Ueda M, Kakinoki S. Surfaces immobilized with oligo-prolines prevent protein adsorption and cell adhesion. J Mater Chem B 2020; 8:2233-2237. [PMID: 32133474 DOI: 10.1039/d0tb00051e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In this study, oligo-prolines, (Pro)n (n = 6 and 9) inspired by the backbone structure of collagen, were evaluated as a novel non-ionic anti-fouling peptide. Two oligo-prolines with a cysteine residue were synthesized and immobilized on gold substrates via Au-thiol binding. The surfaces immobilized with oligo-prolines, and forming a polyproline-II conformation, indicated hydrophilic properties (water contact angle ≈ 25 degrees). The degree of adsorption of human serum albumin, human fibrinogen, and bovine serum components on these surfaces was quantified using a quartz crystal. The immobilization of oligo-prolines prevented the adsorption of proteins and serum components including small molecules, such as fatty acids. Pro9 specifically indicated good resistance to the adsorption of all components due to the highly-packed Pro9 chains on the surface. The adhesion of fibroblasts was drastically suppressed on the surfaces immobilized with oligo-prolines. Our findings suggest that oligo-proline-immobilized surfaces, specifically Pro9-s, are useful for the development of novel vascular devices that have ultra-low fouling properties.
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Affiliation(s)
- Yuri Noguchi
- Graduate School of Science and Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-0836, Japan
| | - Yasuhiko Iwasaki
- Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-0836, Japan. and Organization for Research and Development of Innovative Science and Technology, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-0836, Japan
| | - Masato Ueda
- Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-0836, Japan. and Organization for Research and Development of Innovative Science and Technology, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-0836, Japan
| | - Sachiro Kakinoki
- Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-0836, Japan. and Organization for Research and Development of Innovative Science and Technology, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-0836, Japan
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5
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Hong N, Qiu X. Structure-Adsorption Behavior-Dispersion Property Relationship of Alkyl Chain Cross-Linked Lignosulfonate with Different Molecular Weights. ACS OMEGA 2020; 5:4836-4843. [PMID: 32201769 PMCID: PMC7081325 DOI: 10.1021/acsomega.9b03535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 02/21/2020] [Indexed: 06/10/2023]
Abstract
The structure-adsorption behavior-dispersion property relationship plays a key role in designing a dispersant or surfactant, such as a coal-water dispersant and a water-reducing agent. In this work, was classified into three fractions with narrow molecular weight distributions via the ultrafiltration method. The adsorption behavior of these three fractions was tested via a quartz crystal microbalance with dissipation monitoring, which showed that the adsorption amounts of the three fractions were far higher than that of sulfomethylated lignin. Fraction-1, with the lowest molecular weight, exhibited the greatest adsorption amount on a Au surface under salt-free conditions. This result illustrates that the alkyl chain is more effective for dispersants with low molecular weight to improve its adsorption amount. Fraction-3, with the highest molecular weight, exhibited the greatest adsorption amount on a Au surface under salt-added conditions. This result further illustrates that both the alkyl chain and salt are positive factors for improving the adsorption amount of dispersants. More importantly, the dispersion stabilization of the TiO2 slurry was significantly improved using the alkAL-S fractions, especially Fraction-3. Based on these results, the alkyl chain cross-linked of lignosulfonate is a promising approach for the industrial applications of lignin as an applicable dispersant.
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Affiliation(s)
- Nanlong Hong
- School
of Chemical Engineering and Energy Technology, Dongguan University of Technology, Dongguan 523808, China
| | - Xueqing Qiu
- School
of Chemistry and Chemical Engineering, South
China University of Technology, Guangzhou 510640, China
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6
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Ma G, Wan Z, Zhu H, Tao N. Roles of entropic and solvent damping forces in the dynamics of polymer tethered nanoparticles and implications for single molecule sensing. Chem Sci 2019; 11:1283-1289. [PMID: 33376589 PMCID: PMC7747464 DOI: 10.1039/c9sc05434k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 12/10/2019] [Indexed: 01/19/2023] Open
Abstract
Tethering a particle to a surface with a single molecule allows detection of the molecule and analysis of molecular conformations and interactions.
Tethering a particle to a surface with a single molecule allows detection of the molecule and analysis of molecular conformations and interactions. Understanding the dynamics of the system is critical to all applications. Here we present a plasmonic imaging study of two important forces that govern the dynamics. One is entropic force arising from the conformational change of the molecular tether, and the other is solvent damping on the particle and the molecule. We measure the response of the particle by driving it into oscillation with an alternating electric field. By varying the field frequency, we study the dynamics on different time scales. We also vary the type of the tether molecule (DNA and polyethylene glycol), size of the particle, and viscosity of the solvent, and describe the observations with a model. The study allows us to derive a single parameter to predict the relative importance of the entropic and damping forces. The findings provide insights into single molecule studies using not only tethered particles, but also other approaches, including force spectroscopy using atomic force microscopy and nanopores.
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Affiliation(s)
- Guangzhong Ma
- Biodesign Center for Biosensors and Bioelectronics , Arizona State University , Tempe , Arizona 85287 , USA .
| | - Zijian Wan
- Biodesign Center for Biosensors and Bioelectronics , Arizona State University , Tempe , Arizona 85287 , USA . .,School of Electrical, Computer and Energy Engineering , Arizona State University , Tempe , Arizona 85287 , USA
| | - Hao Zhu
- State Key Laboratory of Analytical Chemistry for Life Science , School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , P. R. China
| | - Nongjian Tao
- Biodesign Center for Biosensors and Bioelectronics , Arizona State University , Tempe , Arizona 85287 , USA . .,School of Electrical, Computer and Energy Engineering , Arizona State University , Tempe , Arizona 85287 , USA
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Mohan T, Čas A, Bračič M, Plohl O, Vesel A, Rupnik M, Zemljič LF, Rebol J. Highly Protein Repellent and Antiadhesive Polysaccharide Biomaterial Coating for Urinary Catheter Applications. ACS Biomater Sci Eng 2019; 5:5825-5832. [DOI: 10.1021/acsbiomaterials.9b01288] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Tamilselvan Mohan
- Laboratory for Characterization and Processing of Polymers (LCPP), Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, Maribor 2000, Slovenia
| | - Alja Čas
- Laboratory for Characterization and Processing of Polymers (LCPP), Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, Maribor 2000, Slovenia
| | - Matej Bračič
- Laboratory for Characterization and Processing of Polymers (LCPP), Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, Maribor 2000, Slovenia
| | - Olivija Plohl
- Laboratory for Characterization and Processing of Polymers (LCPP), Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, Maribor 2000, Slovenia
| | - Alenka Vesel
- Department of Surface Engineering and Optoelectronics, Jožef Stefan Institute, Teslova 30, Ljubljana SI-1000, Slovenia
| | - Maja Rupnik
- Faculty of Medicine, University of Maribor, Taborska ulica 8, Maribor 2000, Slovenia
- National Laboratory for Health, Environment and Food, Prvomajska ulica 1, Maribor 2000, Slovenia
| | - Lidija Fras Zemljič
- Laboratory for Characterization and Processing of Polymers (LCPP), Faculty of Mechanical Engineering, University of Maribor, Smetanova ulica 17, Maribor 2000, Slovenia
| | - Janez Rebol
- Department of Otorhinolaryngology, Cervical and Maxillofacial Surgery, University Medical Centre Maribor, Ljubljanska ulica 5, Maribor 2000, Slovenia
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8
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Lv J, Jin J, Han Y, Jiang W. Effect of end-grafted PEG conformation on the hemocompatibility of poly(styrene-b-(ethylene-co-butylene)-b-styrene). JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2019; 30:1670-1685. [DOI: 10.1080/09205063.2019.1657621] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Jianhua Lv
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, PR China
- University of Science and Technology of China, Hefei, PR China
| | - Jing Jin
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, PR China
| | - Yuanyuan Han
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, PR China
| | - Wei Jiang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, PR China
- University of Science and Technology of China, Hefei, PR China
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9
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Wasilewska M, Adamczyk Z, Sadowska M, Boulmedais F, Cieśla M. Mechanisms of Fibrinogen Adsorption on Silica Sensors at Various pHs: Experiments and Theoretical Modeling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11275-11284. [PMID: 31394033 DOI: 10.1021/acs.langmuir.9b01341] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The adsorption kinetics of human serum fibrinogen at silica substrates was studied using optical waveguide lightmode spectroscopy (OWLS) and quartz crystal microbalance (QCM) techniques. Measurements were performed at pH 3.5, 4, and 7.4 for various ionic strengths. The experimental data were interpreted in terms of a hybrid random sequential adsorption model. This allowed the mass transfer rate coefficient for the OWLS cell and maximum coverages to be determined at various pHs. The appearance of different, pH-dependent mechanisms of fibrinogen adsorption on silica substrates was confirmed. At pH 3.5 the molecules mostly adsorb in the side-on orientation that produces a low maximum coverage of ca. 1 mg m-2. At this pH, the kinetics derived from the OWLS measurements agree with those theoretically predicted using the convective-diffusion theory. In consequence, a comparison of the OWLS and QCM results allows the water factor and the dynamic hydration of fibrinogen molecules to be determined. At pH 7.4, the OWLS method gives inaccurate kinetic data for the low coverage range. However, the maximum coverage that was equal to ca. 4 mg m-2 agrees with the QCM results and with previous literature results. It is postulated that the limited accuracy of the OWLS method for lower coverage stems from a heterogeneous structure of fibrinogen monolayers, which consist of side-on and end-on adsorbed molecules. One can expect that the results acquired in this work allow development of a robust procedure for preparing fibrinogen monolayers of well-controlled coverage and molecule orientation, which can be exploited for efficient immunosensing purposes.
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Affiliation(s)
- Monika Wasilewska
- Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences , Niezapominajek 8 , 30-239 Kracow , Poland
| | - Zbigniew Adamczyk
- Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences , Niezapominajek 8 , 30-239 Kracow , Poland
| | - Marta Sadowska
- Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences , Niezapominajek 8 , 30-239 Kracow , Poland
| | - Fouzia Boulmedais
- Institut Charles Sadron, Centre National de la Recherche Scientifique, Université de Strasbourg , 23 rue du Loess , 67034 Strasbourg Cedex 2 , France
| | - Michał Cieśla
- Jagiellonian University , Faculty of Physics, Astronomy, and Applied Computer Science , ul. prof. Stanisława Łojasiewicza 11 , 30-348 Kracow , Poland
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10
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Ortiz R, Olsen S, Thormann E. Salt-Induced Control of the Grafting Density in Poly(ethylene glycol) Brush Layers by a Grafting-to Approach. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4455-4464. [PMID: 29583002 DOI: 10.1021/acs.langmuir.8b00030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In this work, a method to obtain control of the grafting density during the formation of polymer brush layers by the grafting-to method of thiolated poly(ethylene glycol) onto gold is presented. The grafting density of the polymer chains was adjusted by adding Na2SO4 in concentrations between 0.2 and 0.9 M to the aqueous polymer solution during the grafting process. The obtained grafting densities ranged from 0.26 to 1.60 chains nm-2, as determined by surface plasmon resonance. The kinetics of the grafting process were studied in situ by a quartz crystal microbalance with dissipation, and a mushroom to brush conformational transition was observed when the polymer was grafted in the presence of Na2SO4. The transition from mushroom to brush was only observed for long periods of grafting, highlighting the importance of time to obtain high grafting densities. Finally, the prepared brush layer with the highest grafting density showed high resistance to the adsorption of bovine serum albumin, while layers with a lower grafting density showed only limited resistance.
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Affiliation(s)
- Roberto Ortiz
- Department of Chemistry , Technical University of Denmark , 2800 Kgs. Lyngby , Denmark
| | | | - Esben Thormann
- Department of Chemistry , Technical University of Denmark , 2800 Kgs. Lyngby , Denmark
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11
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Pomorska A, Adamczyk Z, Nattich-Rak M, Sadowska M. Kinetics of human serum albumin adsorption at silica sensor: Unveiling dynamic hydration function. Colloids Surf B Biointerfaces 2018; 167:377-384. [PMID: 29705664 DOI: 10.1016/j.colsurfb.2018.04.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 02/21/2018] [Accepted: 04/04/2018] [Indexed: 11/18/2022]
Abstract
Adsorption kinetics of human serum albumin (HSA) at a silica substrate was studied using the QCM-D and AFM methods. Measurements were performed at pH 3.5 for various bulk suspension concentrations and ionic strengths. The QCM experimental data were compared with the dry coverage of HSA derived from AFM and from the solution of the mass transfer equation. In this way, the dynamic hydration functions and water factors of HSA monolayers were quantitatively evaluated as a function of dry coverage for various ionic strengths. Using the hydration functions, the HSA adsorption runs derived from QCM-D measurements were converted to the dry coverage vs. the time relationships. In this way, the maximum coverage of irreversibly bound HSA molecules was determined. It was equal to 0.35 and 1.4 mg m-2 for NaCl concentration of 0.001 and 0.15 M, respectively. These results agree with previous experimental data derived by streaming potential measurements for mica and with theoretical modeling. Therefore, the side-on mechanism of HSA adsorption at silica sensor at pH 3.5 was confirmed. Also, a quantitative analysis of the desorption runs allowed one to calculate the binding energy of the reversibly bound HSA fraction. Beside significance to basic science, these results enable to develop a robust technique of preparing HSA monolayers at silica sensor of well-controlled coverage and molecule orientation.
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Affiliation(s)
- Agata Pomorska
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Science, Niezapominajek 8, 30-239 Cracow, Poland
| | - Zbigniew Adamczyk
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Science, Niezapominajek 8, 30-239 Cracow, Poland.
| | - Małgorzata Nattich-Rak
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Science, Niezapominajek 8, 30-239 Cracow, Poland
| | - Marta Sadowska
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Science, Niezapominajek 8, 30-239 Cracow, Poland
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12
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Bernhard C, Roeters SJ, Franz J, Weidner T, Bonn M, Gonella G. Repelling and ordering: the influence of poly(ethylene glycol) on protein adsorption. Phys Chem Chem Phys 2018; 19:28182-28188. [PMID: 29022982 DOI: 10.1039/c7cp05445a] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Development of new materials for drug delivery and biosensing requires the fine-tuning of interfacial properties. We report here the influence of the poly(ethylene glycol) (PEG) grafting density in model phospholipid monolayers on the adsorption behavior of bovine serum albumin and human fibrinogen, not only with respect to the amount of adsorbed protein, but also its orientational ordering on the surface. As expected, with increasing interfacial PEG density, the amount of adsorbed protein decreases up to the point where complete protein repellency is reached. However, at intermediate concentrations, the net orientation of adsorbed fibrinogen is highest. The different proteins respond differently to PEG, not only in the amount of protein adsorbed, but also in the manner that proteins adsorb. The results show that for specific cases, tuning the interfacial PEG concentration allows to guide the protein adsorption configuration, a feature sought after in materials for both biosensing and biomedical applications.
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Affiliation(s)
- Christoph Bernhard
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
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13
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Heinen S, Weinhart M. Poly(glycidyl ether)-Based Monolayers on Gold Surfaces: Control of Grafting Density and Chain Conformation by Grafting Procedure, Surface Anchor, and Molecular Weight. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:2076-2086. [PMID: 28191961 DOI: 10.1021/acs.langmuir.6b03927] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
For a meaningful correlation of surface coatings with their respective biological response reproducible coating procedures, well-defined surface coatings, and thorough surface characterization with respect to layer thickness and grafting density are indispensable. The same applies to polymeric monolayer coatings which are intended to be used for, e.g., fundamental studies on the volume phase transition of surface end-tethered thermoresponsive polymer chains. Planar gold surfaces are frequently used as model substrates, since they allow a variety of straightforward surface characterization methods. Herein we present reproducible grafting-to procedures performed with thermoresponsive poly(glycidyl ether) copolymers composed of glycidyl methyl ether (GME) and ethyl glycidyl ether (EGE). The copolymers feature different molecular weights (2 kDa, 9 kDa, 24 kDa) and are equipped with varying sulfur-containing anchor groups in order to achieve adjustable grafting densities on gold surfaces and hence control the tethered polymers' chain conformation. We determined "wet" and "dry" thicknesses of these coatings by QCM-D and ellipsometry measurements and deduced anchor distances and degrees of chain overlap of the polymer chains assembled on gold. Grafting under cloud point conditions allowed for higher degrees of chain overlap compared to grafting from a good solvent like ethanol, independent of the used sulfur-containing anchor group for polymers with low (2 kDa) and medium (9 kDa) molecular weights. By contrast, the achieved grafting densities and thus chain overlaps of surface-tethered polymers with high (24 kDa) molecular weights were identical for both grafting methods. Monolayers prepared from an ethanolic solution of poly(glycidyl ether)s equipped with sterically demanding disulfide-containing anchors revealed the lowest degrees of chain overlap. The ratio of the radius of gyration to the anchor distance (2 Rg/l) of the latter coating was found to be lower than 1.4, indicating that the assembly was rather in the mushroom-like than in the brush regime. Polymer chains with thiol-containing anchors of different alkyl chain lengths (C11SH vs C4SH) formed assemblies with comparable degrees of chain overlap with 2 Rg/l values above 1.4 and are thus in the brush regime. Molecular weights influenced the achievable degree of chain overlap on the surface. Coatings prepared with the medium molecular weight polymer (9 kDa) resulted in the highest chain packing density. Control of grafting density and thus chain overlap in different regimes (brush vs mushroom) on planar gold substrates are attainable for monolayer coatings with poly(GME-ran-EGE) by adjusting the polymer's molecular weight and anchor group as well as the conditions for the grafting-to procedure.
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Affiliation(s)
- Silke Heinen
- Institute of Chemistry and Biochemistry, Freie Universitaet Berlin , Takustraße 3, 14195 Berlin, Germany
| | - Marie Weinhart
- Institute of Chemistry and Biochemistry, Freie Universitaet Berlin , Takustraße 3, 14195 Berlin, Germany
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14
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Lee KT, Coffey JW, Robinson KJ, Muller DA, Grøndahl L, Kendall MAF, Young PR, Corrie SR. Investigating the Effect of Substrate Materials on Wearable Immunoassay Performance. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:773-782. [PMID: 28006902 DOI: 10.1021/acs.langmuir.6b03933] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Immunoassays are ubiquitous across research and clinical laboratories, yet little attention is paid to the effect of the substrate material on the assay performance characteristics. Given the emerging interest in wearable immunoassay formats, investigations into substrate materials that provide an optimal mix of mechanical and bioanalytical properties are paramount. In the course of our research in developing wearable immunoassays which can penetrate skin to selectively capture disease antigens from the underlying blood vessels, we recently identified significant differences in immunoassay performance between gold and polycarbonate surfaces, even with a consistent surface modification procedure. We observed significant differences in PEG density, antibody immobilization, and nonspecific adsorption between the two substrates. Despite a higher PEG density formed on gold-coated surfaces than on amine-functionalized polycarbonate, the latter revealed a higher immobilized capture antibody density and lower nonspecific adsorption, leading to improved signal-to-noise ratios and assay sensitivities. The major conclusion from this study is that in designing wearable bioassays or biosensors, the design and its effect on the antifouling polymer layer can significantly affect the assay performance in terms of analytical specificity and sensitivity.
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Affiliation(s)
| | | | | | | | | | - Mark A F Kendall
- Australian Infectious Diseases Research Centre, St. Lucia, Queensland 4067, Australia
- Faculty of Medicine and Biomedical Sciences, Royal Brisbane and Women's Hospital , Herston, Queensland 4029, Australia
| | - Paul R Young
- Australian Infectious Diseases Research Centre, St. Lucia, Queensland 4067, Australia
| | - Simon R Corrie
- Australian Infectious Diseases Research Centre, St. Lucia, Queensland 4067, Australia
- Department of Chemical Engineering, ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash University , Clayton, Victoria 3800, Australia
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15
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Han Y, Jin J, Cui J, Jiang W. Effect of hydrophilicity of end-grafted polymers on protein adsorption behavior: A Monte Carlo study. Colloids Surf B Biointerfaces 2016; 142:38-45. [DOI: 10.1016/j.colsurfb.2016.01.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/05/2016] [Accepted: 01/30/2016] [Indexed: 01/01/2023]
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16
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Hu Y, Jin J, Liang H, Ji X, Yin J, Jiang W. pH Dependence of Adsorbed Fibrinogen Conformation and Its Effect on Platelet Adhesion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:4086-4094. [PMID: 27035056 DOI: 10.1021/acs.langmuir.5b04238] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Quartz crystal microbalance with dissipation (QCM-D) and dual polarization interferometry (DPI) were used to investigate fibrinogen (Fib) adsorption behavior on different surfaces by changing the pH value. Moreover, integrin adhesion to the adsorbed Fibs was studied using DPI. Qualitative and quantitative studies of platelet adhesion to the adsorbed Fibs were performed using scanning electron microscopy (SEM), confocal laser scanning microscope (CLSM), and released lactate dehydrogenase (LDH) assay. Experimental results indicated that the conformation and orientation of the absorbed Fibs depended on surface property and pH cycling. For the hydrophilic surface, Fibs adsorbed at pH 7.4 and presented a αC-hidden orientation. As a result, no integrin adhesion was observed, and a small number of platelets were adhered because the αC-domains were hidden under the Fib molecule. By changing the rinsing solution pH from 7.4 to 3.2 and then back to 7.4, the adsorbed Fib orientation became αC-exposed via the transformation of Fib conformation during pH cycling. Therefore, integrin adhesion was more likely to occur, and more platelets were adhered and activated. For the hydrophobic surface, the adsorbed Fibs became more spread and stretched due to the strong interaction between the Fibs and surface. αC-exposed orientation remained unchanged when the rinsing solution pH changed from 7.4 to 3.2 and then back to 7.4. Therefore, a large number of integrins and platelets were adhered to the adsorbed Fibs, and almost all of the adhered platelets were activated.
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Affiliation(s)
- Yu Hu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jing Jin
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P. R. China
| | - Haojun Liang
- Department of Polymer Science and Engineering, University of Science and Technology of China , Hefei, Anhui 230026, P. R. China
| | - Xiangling Ji
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P. R. China
| | - Jinghua Yin
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P. R. China
| | - Wei Jiang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P. R. China
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17
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Kubiak K, Adamczyk Z, Cieśla M. Fibrinogen adsorption mechanisms at the gold substrate revealed by QCM-D measurements and RSA modeling. Colloids Surf B Biointerfaces 2015; 139:123-31. [PMID: 26705826 DOI: 10.1016/j.colsurfb.2015.11.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/18/2015] [Accepted: 11/26/2015] [Indexed: 11/15/2022]
Abstract
Adsorption kinetics of fibrinogen at a gold substrate at various pHs was thoroughly studied using the QCM-D method. The experimental were interpreted in terms of theoretical calculations performed according to the random sequential adsorption model (RSA). In this way, the hydration functions and water factors of fibrinogen monolayers were quantitatively evaluated at various pHs. It was revealed that for the lower range of fibrinogen coverage the hydration function were considerably lower than previously obtained for the silica sensor [33]. The lower hydration of fibrinogen monolayers on the gold sensor was attributed to its higher roughness. However, for higher fibrinogen coverage the hydration functions for both sensors became identical exhibiting an universal behavior. By using the hydration functions, the fibrinogen adsorption/desorption runs derived from QCM-D measurements were converted to the Γd vs. the time relationships. This allowed to precisely determine the maximum coverage that varied between 1.6mgm(-2) at pH 3.5 and 4.5mgm(-2) at pH 7.4 (for ionic strength of 0.15M). These results agree with theoretical eRSA modeling and previous experimental data derived by using ellipsometry, OWLS and TIRF. Various fibrinogen adsorption mechanisms were revealed by exploiting the maximum coverage data. These results allow one to develop a method for preparing fibrinogen monolayers of well-controlled coverage and molecule orientation.
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Affiliation(s)
- Katarzyna Kubiak
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Cracow, Poland
| | - Zbigniew Adamczyk
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Cracow, Poland.
| | - Michał Cieśla
- M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Cracow, Poland
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18
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Kubiak K, Adamczyk Z, Wasilewska M. Mechanisms of fibrinogen adsorption at the silica substrate determined by QCM-D measurements. J Colloid Interface Sci 2015. [DOI: 10.1016/j.jcis.2015.07.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Jin J, Han Y, Zhang C, Liu J, Jiang W, Yin J, Liang H. Effect of grafted PEG chain conformation on albumin and lysozyme adsorption: A combined study using QCM-D and DPI. Colloids Surf B Biointerfaces 2015; 136:838-44. [PMID: 26546889 DOI: 10.1016/j.colsurfb.2015.10.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/20/2015] [Accepted: 10/19/2015] [Indexed: 12/23/2022]
Abstract
In this study, elucidation of protein adsorption mechanism is performed using dual polarization interferometry (DPI) and quartz crystal microbalance with dissipation (QCM-D) to study adsorption behaviors of bovine serum albumin (BSA) and lysozyme (LYZ) on poly (ethylene glycol) (PEG) layers. From the analysis of DPI, PEG2000 and PEG5000 show tight and loose mushroom conformations, respectively. Small amount of LYZ could displace the interfacial water surrounding the tight mushroomed PEG2000 chains by hydrogen bond attraction, leading to protein adsorption. The loose mushroomed PEG5000 chains exhibit a more flexible conformation and high elastic repulsion energy that could prevent protein adsorption of all BSA and most of LYZ. From the analysis of QCM, PEG2000 and PEG5000 show tight and extended brush conformations. The LYZ adsorbed mass has critical regions of PEG2000 (0.19 chain/nm(2)) and PEG5000 (0.16 chain/nm(2)) graft density. When graft density of PEG is higher than the critical region (brush conformations), the attraction of hydrogen bonds between PEG and LYZ is the dominant factor. When graft density of PEG is lower than the critical region (mushroom conformations), elastic repulsion between PEG and proteins is driven by the high conformation entropy of PEG chains, which is the dominant force of steric repulsion in PEG-protein systems. Therefore, the adsorption of BSA is suppressed by the high elastic repulsion energy of PEG chains, whereas the adsorption of LYZ is balanced by the interactions between the repulsion of entropy elasticity and the attraction of hydrogen bonds.
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Affiliation(s)
- Jing Jin
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China
| | - Yuanyuan Han
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China
| | - Chang Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China
| | - Jingchuan Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China
| | - Wei Jiang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
| | - Jinghua Yin
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
| | - Haojun Liang
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, PR China
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20
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Construction of P-glycoprotein incorporated tethered lipid bilayer membranes. Biochem Biophys Rep 2015; 2:115-122. [PMID: 29124152 PMCID: PMC5668657 DOI: 10.1016/j.bbrep.2015.05.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/25/2015] [Accepted: 05/29/2015] [Indexed: 11/26/2022] Open
Abstract
To investigate drug–membrane protein interactions, an artificial tethered lipid bilayer system was constructed for the functional integration of membrane proteins with large extra-membrane domains such as multi-drug resistance protein 1 (MDR1). In this study, a modified lipid (i.e., 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino (polyethylene glycol)-2000] (DSPE-PEG)) was utilized as a spacer molecule to elevate lipid membrane from the sensor surface and generate a reservoir underneath. Concentration of DSPE-PEG molecule significantly affected the liposome binding/spreading and lipid bilayer formation, and 0.03 mg/mL of DSPE-PEG provided optimum conditions for membrane protein integration. Further, the incorporation of MDR1 increased the local rigidity on the platform. Antibody binding studies showed the functional integration of MDR1 protein into lipid bilayer platform. The platform allowed to follow MDR!-statin-based drug interactions in vitro. Each binding event and lipid bilayer formation was monitored in real-time using Surface Plasmon Resonance and Quartz Crystal Microbalance–Dissipation systems, and Atomic Force Microscopy was used for visualization experiments. An artificial lipid bilayer system for large integral membrane proteins. Multi-drug resistance protein embedded in lipid bilayers was used as a model system. Interaction between pravastatin and a membrane protein was examined in vitro system. Characterization by surface sensitive methods such as SPR, QCM, liqAFM.
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21
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Petrone L, Aldred N, Emami K, Enander K, Ederth T, Clare AS. Chemistry-specific surface adsorption of the barnacle settlement-inducing protein complex. Interface Focus 2015; 5:20140047. [PMID: 25657832 DOI: 10.1098/rsfs.2014.0047] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Gregarious settlement in barnacle larvae (cyprids) is induced by a contact pheromone, the settlement-inducing protein complex (SIPC). The SIPC has been identified both in the cuticle of adult barnacles and in the temporary adhesive secretion (footprint) of cyprids. Besides acting as a settlement inducer, the presence of the SIPC in footprints points to its additional involvement in the adhesion process. SIPC adsorption behaviour was therefore investigated on a series of self-assembled monolayers (SAMs) by surface plasmon resonance at the pH of seawater (8.3). Fibrinogen and α2-macroglobulin (A2M) (blood complement protease inhibitors with which the SIPC shares 29% sequence homology) were used in the adsorption experiments as positive and negative standards, respectively. The mass uptake of the SIPC was comparable to that of fibrinogen, with adsorption observed even on the protein-resistant oligo(ethylene glycol) surface. Notably, on the positively charged SAM the SIPC showed a kinetic overshoot, indicating a metastable configuration causing the amount of adsorbed protein to temporarily exceed its equilibrium value. A2M adsorption was low or negligible on all SAMs tested, except for the positively charged surface, indicating that A2M adsorption is mainly driven by electrostatics. Evaluation of SIPC non-specific adsorption kinetics revealed that it adsorbed irreversibly and non-cooperatively on all surfaces tested.
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Affiliation(s)
- Luigi Petrone
- Division of Molecular Physics, Department of Physics, Chemistry and Biology (IFM) , Linköping University , 58183 Linköping , Sweden
| | - Nick Aldred
- School of Marine Science and Technology , Newcastle University , Newcastle NE1 7RU , UK
| | - Kaveh Emami
- School of Marine Science and Technology , Newcastle University , Newcastle NE1 7RU , UK
| | - Karin Enander
- Division of Molecular Physics, Department of Physics, Chemistry and Biology (IFM) , Linköping University , 58183 Linköping , Sweden
| | - Thomas Ederth
- Division of Molecular Physics, Department of Physics, Chemistry and Biology (IFM) , Linköping University , 58183 Linköping , Sweden
| | - Anthony S Clare
- School of Marine Science and Technology , Newcastle University , Newcastle NE1 7RU , UK
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22
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Xi M, Zhang B. Interaction of Plasma Proteins with Tri-quaternary Ammonium Salt Cationic Surfactant Studied by QCM-D. CHINESE J CHEM 2015. [DOI: 10.1002/cjoc.201400690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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23
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Fukada K, Taniguchi T, Shiratori S. Viscoelastic and durability analysis of nanostructured composite layers of polyelectrolyte and nanoparticles. RSC Adv 2015. [DOI: 10.1039/c5ra07066j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We have evaluated the abrasion and bending durabilities of stacked polymer/nanoparticle layer-by-layer films.
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Affiliation(s)
- Kenta Fukada
- School of Integrated Design Engineering
- Center for Science and Technology for Designing Functions
- Graduate School of Science and Technology
- Keio University
- Yokohama
| | - Taihei Taniguchi
- School of Integrated Design Engineering
- Center for Science and Technology for Designing Functions
- Graduate School of Science and Technology
- Keio University
- Yokohama
| | - Seimei Shiratori
- School of Integrated Design Engineering
- Center for Science and Technology for Designing Functions
- Graduate School of Science and Technology
- Keio University
- Yokohama
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24
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High-Resolution Imaging of Polyethylene Glycol Coated Dendrimers via Combined Atomic Force and Scanning Tunneling Microscopy. JOURNAL OF DRUG DELIVERY 2015; 2015:535683. [PMID: 25685559 PMCID: PMC4313004 DOI: 10.1155/2015/535683] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 12/11/2014] [Indexed: 12/18/2022]
Abstract
Dendrimers have shown great promise as drug delivery vehicles in recent years because they can be synthesized with designed size and functionalities for optimal transportation, targeting, and biocompatibility. One of the most well-known termini used for biocompatibility is polyethylene glycol (PEG), whose performance is affected by its actual conformation. However, the conformation of individual PEG bound to soft materials such as dendrimers has not been directly observed. Using atomic force microscopy (AFM) and scanning tunneling microscopy (STM), this work characterizes the structure adopted by PEGylated dendrimers with the highest resolution reported to date. AFM imaging enables visualization of the individual dendrimers, as well as the differentiation and characterization of the dendrimer core and PEG shell. STM provides direct imaging of the PEG extensions with high-resolution. Collectively, this investigation provides important insight into the structure of coated dendrimers, which is crucial for the design and development of better drug delivery vehicles.
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25
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Escorihuela J, González-Martínez MÁ, López-Paz JL, Puchades R, Maquieira Á, Gimenez-Romero D. Dual-Polarization Interferometry: A Novel Technique To Light up the Nanomolecular World. Chem Rev 2014; 115:265-94. [DOI: 10.1021/cr5002063] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jorge Escorihuela
- Department
of Chemistry, Institute of Molecular Recognition and Technological
Development, Universitat Politècnica de València, Camino
de Vera s/n, 46022 València, Spain
| | - Miguel Ángel González-Martínez
- Department
of Chemistry, Institute of Molecular Recognition and Technological
Development, Universitat Politècnica de València, Camino
de Vera s/n, 46022 València, Spain
| | - José Luis López-Paz
- Department
of Chemistry, Institute of Molecular Recognition and Technological
Development, Universitat Politècnica de València, Camino
de Vera s/n, 46022 València, Spain
| | - Rosa Puchades
- Department
of Chemistry, Institute of Molecular Recognition and Technological
Development, Universitat Politècnica de València, Camino
de Vera s/n, 46022 València, Spain
| | - Ángel Maquieira
- Department
of Chemistry, Institute of Molecular Recognition and Technological
Development, Universitat Politècnica de València, Camino
de Vera s/n, 46022 València, Spain
| | - David Gimenez-Romero
- Physical
Chemistry Department, Faculty of Chemistry, Universitat de València, Avenida Dr. Moliner 50, 46100 Burjassot, València, Spain
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