1
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Montalbo RCK, Tu HL. Micropatterning of functional lipid bilayer assays for quantitative bioanalysis. BIOMICROFLUIDICS 2023; 17:031302. [PMID: 37179590 PMCID: PMC10171888 DOI: 10.1063/5.0145997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023]
Abstract
Interactions of the cell with its environment are mediated by the cell membrane and membrane-localized molecules. Supported lipid bilayers have enabled the recapitulation of the basic properties of cell membranes and have been broadly used to further our understanding of cellular behavior. Coupled with micropatterning techniques, lipid bilayer platforms have allowed for high throughput assays capable of performing quantitative analysis at a high spatiotemporal resolution. Here, an overview of the current methods of the lipid membrane patterning is presented. The fabrication and pattern characteristics are briefly described to present an idea of the quality and notable features of the methods, their utilizations for quantitative bioanalysis, as well as to highlight possible directions for the advanced micropatterning lipid membrane assays.
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2
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Characterization of Protein-Phospholipid/Membrane Interactions Using a "Membrane-on-a-Chip" Microfluidic System. Methods Mol Biol 2021. [PMID: 33481237 DOI: 10.1007/978-1-0716-1142-5_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
It is now clear that organelles of a mammalian cell can be distinguished by phospholipid profiles, both as ratios of common phospholipids and by the absence or presence of certain phospholipids. Organelle-specific phospholipids can be used to provide a specific shape and fluidity to the membrane and/or used to recruit and/or traffic proteins to the appropriate subcellular location and to restrict protein function to this location. Studying the interactions of proteins with specific phospholipids using soluble derivatives in isolation does not always provide useful information because the context in which the headgroups are presented almost always matters. Our laboratory has shown this circumstance to be the case for a viral protein binding to phosphoinositides in solution and in membranes. The system we have developed to study protein-phospholipid interactions in the context of a membrane benefits from the creation of tailored membranes in a channel of a microfluidic device, with a fluorescent lipid in the membrane serving as an indirect reporter of protein binding. This system is amenable to the study of myriad interactions occurring at a membrane surface as long as a net change in surface charge occurs in response to the binding event of interest.
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3
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Hu S, Zhao T, Li H, Cheng D, Sun Z. Effect of tetracaine on dynamic reorganization of lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183351. [PMID: 32416192 DOI: 10.1016/j.bbamem.2020.183351] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 04/18/2020] [Accepted: 05/07/2020] [Indexed: 12/16/2022]
Abstract
To understand the intrinsic influence of a drug on lipid membranes is of critical importance in pharmacological science. Herein, we report fluorescence microscopy analysis of the interaction between the local anesthetic tetracaine (TTC) and planar supported lipid bilayers (SLBs), as model membranes. Our results show that TTC increases lipid chain mobility, destabilizes the SLBs and remarkably induces membrane disruption and solubilization. Upon TTC binding, a local curvature change in the bilayer was observed, which led to the subsequent formation of up to 20-μm-long flexible lipid tubules as well as the formation of micron-size holes. Quantitative analysis revealed that membrane solubilization process can be divided into two distinct different stages as a function of TTC concentration. In the first stage (<800 μM), the bilayer disruption profiles fit well to a Langmuir isotherm, while in the second stage (800 μM-25 mM), TTC solubilizes the membrane in a detergent-like manner. Notably, the onset of membrane solubilization occurred below the critical micelle concentration (cmc) of TTC, indicating a local accumulation of the drug in the membrane. Additionally, cholesterol increases the insertion of TTC into the membrane and thus promotes the solubilization effect of TTC on lipid bilayers. These findings may help to elucidate the possible mechanisms of TTC interaction with lipid membranes, the dose dependent toxicity attributed to local anesthetics, as well as provide valuable information for drug development and modification.
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Affiliation(s)
- Shipeng Hu
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Tao Zhao
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
| | - Hewen Li
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Danling Cheng
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Zhihua Sun
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
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4
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Ravnik M, Everts JC. Topological-Defect-Induced Surface Charge Heterogeneities in Nematic Electrolytes. PHYSICAL REVIEW LETTERS 2020; 125:037801. [PMID: 32745396 DOI: 10.1103/physrevlett.125.037801] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
We show that topological defects in an ion-doped nematic liquid crystal can be used to manipulate the surface charge distribution on chemically homogeneous, charge-regulating external surfaces, using a minimal theoretical model. In particular, the location and type of the defect encodes the precise distribution of surface charges and the effect is enhanced when the liquid crystal is flexoelectric. We demonstrate the principle for patterned surfaces and charged colloidal spheres. More generally, our results indicate an interesting approach to control surface charges on external surfaces without changing the surface chemistry.
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Affiliation(s)
- Miha Ravnik
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
- Department of Condensed Matter Physics, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
| | - Jeffrey C Everts
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
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5
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Erramilli S, Neumann TV, Chester D, Dickey MD, Brown AC, Genzer J. Effect of surface interactions on the settlement of particles on a sinusoidally corrugated substrate. RSC Adv 2020; 10:11348-11356. [PMID: 35495333 PMCID: PMC9050433 DOI: 10.1039/c9ra10297c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 03/06/2020] [Indexed: 12/15/2022] Open
Abstract
Naturally-occurring surface topographies abound in nature and endow diverse properties, i.e., superhydrophobicity, adhesion, anti-fouling, self-cleaning, anti-glare, anti-bacterial, and many others. Researchers have attempted to replicate such topographies to create human-made surfaces with desired functionalities. For example, combining the surface topography with judicial chemical composition could provide an effective, non-toxic solution to combat non-specific biofouling. A systematic look at the effect of geometry, modulus, and chemistry on adhesion is warranted. In this work, we use a model system that comprises silica (SiOx) beads interacting with a substrate made of a commercial polydimethylsiloxane kit (PDMS, Sylgard 184) featuring a sinusoidal topography. To examine the impact of interactions on particle settlement, we functionalize the surfaces of both the PDMS substrate and the SiOx beads with polyacrylic acid (PAA) and polyethyleneimine (PEI), respectively. We also use the PDMS commercial kit coated with liquid glass (LG) to study the effect of the substrate modulus on particle settlement. Substrates with a higher aspect ratio (i.e., amplitude/periodicity) encourage adsorption of particles along the sides of the channel compared with substrates with lower aspect ratio. We employ colloidal probe microscopy to demonstrate the effect of interaction between the substrate and the particle. The interplay among the surface modulus, geometry, and interactions between the surface and the particle governs particle settlement on sinusoidally-corrugated substrates. The interplay among the surface modulus, geometry, and interactions between the surface and the particle governs particle settlement on sinusoidally-corrugated substrates.![]()
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Affiliation(s)
- Shreya Erramilli
- Department of Materials Science & Engineering, North Carolina State University Raleigh NC 27695-7907 USA
| | - Taylor V Neumann
- Department of Chemical & Biomolecular Engineering, North Carolina State University Raleigh NC 27695-7905 USA
| | - Daniel Chester
- Joint Department of Biomedical Engineering, North Carolina State University, University of North Carolina at Chapel Hill Raleigh NC 27695-7115 USA.,Comparative Medicine Institute, North Carolina State University Raleigh NC 27695-7905 USA
| | - Michael D Dickey
- Department of Chemical & Biomolecular Engineering, North Carolina State University Raleigh NC 27695-7905 USA
| | - Ashley C Brown
- Joint Department of Biomedical Engineering, North Carolina State University, University of North Carolina at Chapel Hill Raleigh NC 27695-7115 USA.,Comparative Medicine Institute, North Carolina State University Raleigh NC 27695-7905 USA
| | - Jan Genzer
- Department of Chemical & Biomolecular Engineering, North Carolina State University Raleigh NC 27695-7905 USA
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6
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Sun S, Sendecki AM, Pullanchery S, Huang D, Yang T, Cremer PS. Multistep Interactions between Ibuprofen and Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10782-10792. [PMID: 30148644 DOI: 10.1021/acs.langmuir.8b01878] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ibuprofen (IBU) interacts with phosphatidylcholine membranes in three distinct steps as a function of concentration. In a first step (<10 μM), IBU electrostatically adsorbs to the lipid headgroups and gradually decreases the interfacial potential. This first step helps to facilitate the second step (10-300 μM), in which hydrophobic insertion of the drug occurs. The second step disrupts the packing of the lipid acyl chains and expands the area per lipid. In a final step, above 300 μM IBU, the lipid membrane begins to solubilize, resulting in a detergent-like effect. The results described herein were obtained by a combination of fluorescence binding assays, vibrational sum frequency spectroscopy, and Langmuir monolayer compression experiments. By introducing trimethylammonium-propane, phosphatidylglycerol, and phosphatidylethanolamine lipids as well as cholesterol, we demonstrated that both the chemistry of the lipid headgroups and the packing of lipid acyl chains can substantially influence the interactions between IBU and the membranes. Moreover, different membrane chemistries can alter particular steps in the binding interaction.
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Affiliation(s)
- Simou Sun
- Department of Chemistry , Penn State University , University Park , State College , Pennsylvania 16802 , United States
| | - Anne M Sendecki
- Department of Chemistry , Penn State University , University Park , State College , Pennsylvania 16802 , United States
| | - Saranya Pullanchery
- Department of Chemistry , Penn State University , University Park , State College , Pennsylvania 16802 , United States
| | - Da Huang
- Department of Chemistry , Penn State University , University Park , State College , Pennsylvania 16802 , United States
| | - Tinglu Yang
- Department of Chemistry , Penn State University , University Park , State College , Pennsylvania 16802 , United States
| | - Paul S Cremer
- Department of Chemistry , Penn State University , University Park , State College , Pennsylvania 16802 , United States
- Department of Biochemistry and Molecular Biology , Penn State University , State College , Pennsylvania 16802 , United States
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7
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Sendecki AM, Poyton MF, Baxter AJ, Yang T, Cremer PS. Supported Lipid Bilayers with Phosphatidylethanolamine as the Major Component. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:13423-13429. [PMID: 29119796 DOI: 10.1021/acs.langmuir.7b02323] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Phosphatidylethanolamine (PE) is notoriously difficult to incorporate into model membrane systems, such as fluid supported lipid bilayers (SLBs), at high concentrations because of its intrinsic negative curvature. Using fluorescence-based techniques, we demonstrate that having fewer sites of unsaturation in the lipid tails leads to high-quality SLBs because these lipids help to minimize the curvature. Moreover, shorter saturated chains can help maintain the membranes in the fluid phase. Using these two guidelines, we find that up to 70 mol % PE can be incorporated into SLBs at room temperature and up to 90 mol % PE can be incorporated at 37 °C. Curiously, conditions under which three-dimensional tubules project outward from the planar surface as well as conditions under which domain formation occurs can be found. We have employed these model membrane systems to explore the ability of Ni2+ to bind to PE. It was found that this transition metal ion binds 1000-fold tighter to PE than to phosphatidylcholine lipids. In the future, this platform could be exploited to monitor the binding of other transition metal ions or the binding of antimicrobial peptides. It could also be employed to explore the physical properties of PE-containing membranes, such as phase domain behavior and intermolecular hydrogen bonding.
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Affiliation(s)
- Anne M Sendecki
- Department of Chemistry and ‡Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Matthew F Poyton
- Department of Chemistry and ‡Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Alexis J Baxter
- Department of Chemistry and ‡Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Tinglu Yang
- Department of Chemistry and ‡Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Paul S Cremer
- Department of Chemistry and ‡Department of Biochemistry and Molecular Biology, Pennsylvania State University , University Park, Pennsylvania 16802, United States
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8
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Mazur F, Bally M, Städler B, Chandrawati R. Liposomes and lipid bilayers in biosensors. Adv Colloid Interface Sci 2017; 249:88-99. [PMID: 28602208 DOI: 10.1016/j.cis.2017.05.020] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/30/2017] [Indexed: 10/19/2022]
Abstract
Biosensors for the rapid, specific, and sensitive detection of analytes play a vital role in healthcare, drug discovery, food safety, and environmental monitoring. Although a number of sensing concepts and devices have been developed, many longstanding challenges to obtain inexpensive, easy-to-use, and reliable sensor platforms remain largely unmet. Nanomaterials offer exciting possibilities for enhancing the assay sensitivity and for lowering the detection limits down to single-molecule resolution. In this review, we present an overview of liposomes and lipid bilayers in biosensing applications. Lipid assemblies in the form of spherical liposomes or two-dimensional planar membranes have been widely used in the design of biosensing assays; in particular, we highlight a number of recent promising developments of biosensors based on liposomes in suspension, liposome arrays, and lipid bilayers arrays. Assay sensitivity and specificity are discussed, advantages and drawbacks are reviewed, and possible further developments are outlined.
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9
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Shengjuler D, Sun S, Cremer PS, Cameron CE. PIP-on-a-chip: A Label-free Study of Protein-phosphoinositide Interactions. J Vis Exp 2017:55869. [PMID: 28784961 PMCID: PMC5613778 DOI: 10.3791/55869] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Numerous cellular proteins interact with membrane surfaces to affect essential cellular processes. These interactions can be directed towards a specific lipid component within a membrane, as in the case of phosphoinositides (PIPs), to ensure specific subcellular localization and/or activation. PIPs and cellular PIP-binding domains have been studied extensively to better understand their role in cellular physiology. We applied a pH modulation assay on supported lipid bilayers (SLBs) as a tool to study protein-PIP interactions. In these studies, pH sensitive ortho-Sulforhodamine B conjugated phosphatidylethanolamine is used to detect protein-PIP interactions. Upon binding of a protein to a PIP-containing membrane surface, the interfacial potential is modulated (i.e. change in local pH), shifting the protonation state of the probe. A case study of the successful usage of the pH modulation assay is presented by using phospholipase C delta1 Pleckstrin Homology (PLC-δ1 PH) domain and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) interaction as an example. The apparent dissociation constant (Kd,app) for this interaction was 0.39 ± 0.05 µM, similar to Kd,app values obtained by others. As previously observed, the PLC-δ1 PH domain is PI(4,5)P2 specific, shows weaker binding towards phosphatidylinositol 4-phosphate, and no binding to pure phosphatidylcholine SLBs. The PIP-on-a-chip assay is advantageous over traditional PIP-binding assays, including but not limited to low sample volume and no ligand/receptor labeling requirements, the ability to test high- and low-affinity membrane interactions with both small and large molecules, and improved signal to noise ratio. Accordingly, the usage of the PIP-on-a-chip approach will facilitate the elucidation of mechanisms of a wide range of membrane interactions. Furthermore, this method could potentially be used in identifying therapeutics that modulate protein's capacity to interact with membranes.
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Affiliation(s)
- Djoshkun Shengjuler
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University;
| | - Simou Sun
- Department of Chemistry, The Pennsylvania State University
| | - Paul S Cremer
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University; Department of Chemistry, The Pennsylvania State University;
| | - Craig E Cameron
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University;
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10
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Alsager OA, Kumar S, Hodgkiss JM. Lateral Flow Aptasensor for Small Molecule Targets Exploiting Adsorption and Desorption Interactions on Gold Nanoparticles. Anal Chem 2017; 89:7416-7424. [DOI: 10.1021/acs.analchem.7b00906] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Omar A. Alsager
- King Abdulaziz City for Science and Technology, Riyadh 12371, Saudi Arabia
- School
of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Shalen Kumar
- School
of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- AuramerBio Ltd., Callaghan Innovation Quarter, 69 Seaview Road, Gracefield, Lower Hutt 5010, New Zealand
| | - Justin M. Hodgkiss
- School
of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
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11
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Lowry TW, Hariri H, Prommapan P, Kusi-Appiah A, Vafai N, Bienkiewicz EA, Van Winkle DH, Stagg SM, Lenhert S. Quantification of Protein-Induced Membrane Remodeling Kinetics In Vitro with Lipid Multilayer Gratings. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:506-15. [PMID: 26649649 PMCID: PMC4843995 DOI: 10.1002/smll.201502398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/28/2015] [Indexed: 05/08/2023]
Abstract
The dynamic self-organization of lipids in biological systems is a highly regulated process that enables the compartmentalization of living systems at micro- and nanoscopic scales. Consequently, quantitative methods for assaying the kinetics of supramolecular remodeling such as vesicle formation from planar lipid bilayers or multilayers are needed to understand cellular self-organization. Here, a new nanotechnology-based method for quantitative measurements of lipid-protein interactions is presented and its suitability for quantifying the membrane binding, inflation, and budding activity of the membrane-remodeling protein Sar1 is demonstrated. Lipid multilayer gratings are printed onto surfaces using nanointaglio and exposed to Sar1, resulting in the inflation of lipid multilayers into unilamellar structures, which can be observed in a label-free manner by monitoring the diffracted light. Local variations in lipid multilayer volume on the surface is used to vary substrate availability in a microarray format. A quantitative model is developed that allows quantification of binding affinity (K D ) and kinetics (kon and koff ). Importantly, this assay is uniquely capable of quantifying membrane remodeling. Upon Sar1-induced inflation of single bilayers from surface supported multilayers, the semicylindrical grating lines are observed to remodel into semispherical buds when a critical radius of curvature is reached.
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Affiliation(s)
- Troy W. Lowry
- Department of Physics, Florida State University, Tallahassee, FL 32306-4350, USA
| | - Hanaa Hariri
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Plengchart Prommapan
- Department of Physics, Florida State University, Tallahassee, FL 32306-4350, USA
| | - Aubrey Kusi-Appiah
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4370, USA
| | - Nicholas Vafai
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4370, USA
| | - Ewa A. Bienkiewicz
- Department of Biomedical Science, College of Medicine, Florida State University, Tallahassee, FL 32306-4300, USA
| | - David H. Van Winkle
- Department of Physics, Florida State University, Tallahassee, FL 32306-4350, USA
| | - Scott M. Stagg
- Institute of Molecular Biophysics and Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Steven Lenhert
- Department of Biological Science and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4370, USA
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12
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Xu LQ, Pranantyo D, Ng YX, Teo SLM, Neoh KG, Kang ET, Fu GD. Antifouling Coatings of Catecholamine Copolymers on Stainless Steel. Ind Eng Chem Res 2015. [DOI: 10.1021/acs.iecr.5b00171] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Li Qun Xu
- Department of Chemical & Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 117576
| | - Dicky Pranantyo
- Department of Chemical & Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 117576
| | - Ying Xian Ng
- Tropical
Marine Science Institute, National University of Singapore, Kent Ridge, Singapore 119223
| | - Serena Lay-Ming Teo
- Tropical
Marine Science Institute, National University of Singapore, Kent Ridge, Singapore 119223
| | - Koon-Gee Neoh
- Department of Chemical & Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 117576
| | - En-Tang Kang
- Department of Chemical & Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 117576
| | - Guo Dong Fu
- School
of Chemistry and Chemical Engineering, Southeast University, Jiangning District,
Nanjing, Jiangsu Province, P.R. China 211189
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13
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Preparation and Characterization of Ni-Doped Calcium Silicate Hydrate Based on Steel Slag: Adsorption Capacity for Rhodamine B from Aqueous Solution. J CHEM-NY 2015. [DOI: 10.1155/2015/131050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Calcium silicate hydrate based on steel slag (SCSH) and Ni-doped SCSH (NSCSH) were synthesized under specific hydrothermal conditions at saturated vapor pressure and 185°C for 7 hours. The structure and morphology of SCSH and NSCSH were characterized by XRD, SEM, and N2adsorption/desorption. SCSH mainly consisted of amorphous calcium silicate hydrate gel (C-S-H gel) together with some flake-like tobermorite and NSCSH consisted of crystalline tobermorite and xonotlite. The addition of Ni(NO3)2had great influence on microstructure of the composites, and SCSH possesses a mesoporous structure with slit-shaped pores, but NSCSH has narrow distributions of pore size. Furthermore, NSCSH has a higher adsorption capacity for Rhodamine B (RhB) than SCSH with removal percentages of RhB of about 52.4% and 88.2%, respectively. In addition, the effects of NSCSH dosage and pH values on the adsorption of RhB were investigated. Adsorption isotherm parameters are obtained from both Langmuir and Freundlich analysis and showed a better fit to a Langmuir model. All results indicated that NSCSH has a great potential to be a safe, easily-made, and cost-effective material for the control of RhB contamination.
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14
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Decker JT, Sheats JT, Brennan AB. Engineered antifouling microtopographies: surface pattern effects on cell distribution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:15212-8. [PMID: 25420235 DOI: 10.1021/la504215b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Microtopography has been observed to lead to altered attachment behavior for marine fouling organisms; however, quantification of this phenomenon is lacking in the scientific literature. Here, we present quantitative measurement of the disruption of normal attachment behavior of the fouling algae Ulva linza by antifouling microtopographies. The distribution of the diatom Navicula incerta was shown to be unaffected by the presence of topography. The radial distribution function was calculated for both individual zoospores and cells as well as aggregates of zoospores from attachment data for a variety topographic configurations and at a number of different attachment densities. Additionally, the screening distance and maximum values were mapped according to the location of zoospore aggregates within a single unit cell. We found that engineered topographies decreased the distance between spore aggregates compared to that for a smooth control surface; however, the distributions for individual spores were unchanged. We also found that the local attachment site geometry affected the screening distance for aggregates of zoospores, with certain geometries decreasing screening distance and others having no measurable effect. The distribution mapping techniques developed and explored in this article have yielded important insight into the design parameters for antifouling microtopographies that can be implemented in the next generation of antifouling surfaces.
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Affiliation(s)
- Joseph T Decker
- Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611, United States
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15
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Dyett BP, Wu AH, Lamb RN. Mechanical stability of surface architecture--consequences for superhydrophobicity. ACS APPLIED MATERIALS & INTERFACES 2014; 6:18380-18394. [PMID: 25318076 DOI: 10.1021/am505487r] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Wet chemistry methods such as sol-gel provide a facile means of preparing coatings with controlled surface chemistry and architecture. The manipulation of colloidal "building blocks," film constituents, and reaction conditions makes it a promising method for simple, scalable, and routine production of superhydrophobic coatings. Despite all of this, the practical application of superhydrophobic coatings remains limited by low mechanical durability. The translation of chemistry to mechanical strength within superhydrophobic films is severely hindered by the requisite physical structure. More specifically, porosity and the surface architecture of roughness in sol-gel-derived films contribute significantly to poor mechanical properties. These physical effects emphasize that collective structure and chemistry-based strategies are required. This challenge is not unique to superhydrophobics, and there are many principles that can be drawn upon to greatly improve performance. The delicate interplay between chemistry and physical structure has been highlighted through theory and characterization of porous and rough interfaces within and outside the framework of superhydrophobics. Insights can further be drawn from biology. Nature's capacity for self-repair remains extremely challenging to mimic in materials. However, nature does demonstrate strategies for structuring nano- and microbuilding blocks to achieve generally mutually exclusive properties. Difficulties with characterization and example mechanical characterization methods have also been emphasized.
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Affiliation(s)
- Brendan P Dyett
- School of Chemistry, University of Melbourne , Parkville, Victoria, Australia , 3010
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16
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Dyett BP, Wu AH, Lamb RN. Toward superhydrophobic and durable coatings: effect of needle vs crater surface architecture. ACS APPLIED MATERIALS & INTERFACES 2014; 6:9503-9507. [PMID: 24830848 DOI: 10.1021/am501900b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Practical application of sol-gel derived superhydrophobic films is limited by the fragility of "needlelike" surface roughness. An efficient one step procedure is developed to prepare robust thin films with "craterlike" surface roughness from a methyltrimethoxysilane matrix and polymer sphere templates. The films could be readily spray coated to produce roughened surface textures, which are governed by template concentration and geometry. The effect of this on the wettability and robustness of thin films was examined in detail, revealing a rapid trade-off between the two characteristics due to variations in coating porosity.
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Affiliation(s)
- Brendan P Dyett
- School of Chemistry, University of Melbourne , Parkville, Victoria, 3010, Australia
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Halder P, Nasabi M, Jayasuriya N, Shimeta J, Deighton M, Bhattacharya S, Mitchell A, Bhuiyan MA. An assessment of the dynamic stability of microorganisms on patterned surfaces in relation to biofouling control. BIOFOULING 2014; 30:695-707. [PMID: 24814651 DOI: 10.1080/08927014.2014.914177] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Microstructure-based patterned surfaces with antifouling capabilities against a wide range of organisms are yet to be optimised. Several studies have shown that microtopographic features affect the settlement and the early stages of biofilm formation of microorganisms. It is speculated that the fluctuating stress-strain rates developed on patterned surfaces disrupt the stability of microorganisms. This study investigated the dynamic interactions of a motile bacterium (Escherichia coli) with microtopographies in relation to initial settlement. The trajectories of E. coli across a patterned surface of a microwell array within a microchannel-based flow cell system were assessed experimentally with a time-lapse imaging module. The microwell array was composed of 256 circular wells, each with diameter 10 μm, spacing 7 μm and depth 5 μm. The dynamics of E. coli over microwell-based patterned surfaces were compared with those over plain surfaces and an increased velocity of cell bodies was observed in the case of patterned surfaces. The experimental results were further verified and supported by computational fluid dynamic simulations. Finally, it was stated that the nature of solid boundaries and the associated microfluidic conditions play key roles in determining the dynamic stability of motile bacteria in the close vicinity over surfaces.
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Affiliation(s)
- Partha Halder
- a School of Civil, Environmental and Chemical Engineering , RMIT University , Melbourne , Australia
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18
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Nagata Y, Ishizaki I, Waki M, Ide Y, Hossen MA, Ohnishi K, Sanada N, Setou M. Glutaraldehyde fixation method for single-cell lipid analysis by time-of-flight secondary ion-mass spectrometry. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5522] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yasuyuki Nagata
- Department of Cell Biology and Anatomy; Hamamatsu University School of Medicine; 1-20-1, Handayama, Higashi-ku Hamamatsu Shizuoka Japan
- Oncology Center; Hamamatsu University School of Medicine; Japan
| | | | - Michihiko Waki
- Department of Cell Biology and Anatomy; Hamamatsu University School of Medicine; 1-20-1, Handayama, Higashi-ku Hamamatsu Shizuoka Japan
| | - Yoshimi Ide
- Department of Cell Biology and Anatomy; Hamamatsu University School of Medicine; 1-20-1, Handayama, Higashi-ku Hamamatsu Shizuoka Japan
- Department of Surgery I; Hamamatsu University School of Medicine; Japan
| | - Md Amir Hossen
- Department of Cell Biology and Anatomy; Hamamatsu University School of Medicine; 1-20-1, Handayama, Higashi-ku Hamamatsu Shizuoka Japan
| | | | | | - Mitsutoshi Setou
- Department of Cell Biology and Anatomy; Hamamatsu University School of Medicine; 1-20-1, Handayama, Higashi-ku Hamamatsu Shizuoka Japan
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19
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Kouchak M, Handali S. Effects of various penetration enhancers on penetration of aminophylline through shed snake skin. Jundishapur J Nat Pharm Prod 2014; 9:24-9. [PMID: 24644435 PMCID: PMC3957139 DOI: 10.17795/jjnpp-12904] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 10/15/2013] [Accepted: 10/27/2013] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Cellulite is the accumulation of subcutaneous fat and connective tissue in tights and buttocks. Xanthines, such as aminophylline, are used as phosphodiesterase inhibitors, and are also adenosine receptor antagonists. OBJECTIVES The aim of the present study was to characterize in vitro aminophylline transdermal absorption through shed snake skin, and to investigate the absorption enhancing effect of various enhancers. MATERIALS AND METHODS Aminophylline gels were prepared using theophylline and ethylenediamine as raw materials of aminophylline, hydroxypropyl methyl cellulose (HPMC) F4M as gelling agent, and propylene glycol as a co-solvent. Sodium tauroglycocholate (STGC) (100, 200, and 500 μg/mL), lauric acid (1.7 and 15%), and ethanol (60%) were added as enhancers. In vitro percutaneous absorption experiments were performed on snake skin using Franz diffusion cells. Flux (J), permeability coefficient (P), and enhancement factor (EF) for each formulation were calculated. RESULTS The results indicated that all of enhancers significantly enhanced drug permeability. This effect was decreased by increasing the concentration of STGC; in contrast, by increasing the concentration of lauric acid from 1.7 to 15%, EF was enhanced Although ethanol (60%) and STGC (100 μg/mL) showed the highest EFs, the effect of ethanol on drug permeability appeared with a lag time. CONCLUSIONS According to the findings, type and concentration of penetration enhancers can effect on transdermal permeation of drug.
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Affiliation(s)
- Maryam Kouchak
- Department of Pharmaceutics, Faculty of Pharmacy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Nanotechnology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran
| | - Somayeh Handali
- Nanotechnology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran
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20
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Liu C, Huang D, Yang T, Cremer PS. Monitoring phosphatidic acid formation in intact phosphatidylcholine bilayers upon phospholipase D catalysis. Anal Chem 2014; 86:1753-9. [PMID: 24456402 PMCID: PMC3983022 DOI: 10.1021/ac403580r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/15/2014] [Indexed: 12/25/2022]
Abstract
We have monitored the production of the negatively charged lipid, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidic acid acid (POPA), in supported lipid bilayers via the enzymatic hydrolysis of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (PC), a zwitterionic lipid. Experiments were performed with phospholipase D (PLD) in a Ca(2+) dependent fashion. The strategy for doing this involved using membrane-bound streptavidin as a biomarker for the charge on the membrane. The focusing position of streptavidin in electrophoretic-electroosmotic focusing (EEF) experiments was monitored via a fluorescent tag on this protein. The negative charge increased during these experiments due to the formation of POPA lipids. This caused the focusing position of streptavidin to migrate toward the negatively charged electrode. With the use of a calibration curve, the amount of POPA generated during this assay could be read out from the intact membrane, an objective that has been otherwise difficult to achieve because of the lack of unique chromophores on PA lipids. On the basis of these results, other enzymatic reactions involving the change in membrane charge could also be monitored in a similar way. This would include phosphorylation, dephosphorylation, lipid biosynthesis, and additional phospholipase reactions.
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Affiliation(s)
- Chunming Liu
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Da Huang
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Tinglu Yang
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
| | - Paul S. Cremer
- Department
of Chemistry, Texas A&M University, 3255 TAMU, College Station, TX 77843, United States
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21
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Velický M, Tam KY, Dryfe RA. Mechanism of ion transfer in supported liquid membrane systems: electrochemical control over membrane distribution. Anal Chem 2014; 86:435-42. [PMID: 24299270 PMCID: PMC3917230 DOI: 10.1021/ac402328w] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 12/03/2013] [Indexed: 11/29/2022]
Abstract
A polarization study carried out on a thin supported liquid membrane separating two aqueous compartments is presented. Transfer of both the ionized and uncharged form of an organic tracer dye, rhodamine B ([9-(2-carboxyphenyl)-6-diethylamino-3-xanthenylidene]-diethylammonium chloride), across supported liquid membranes composed of one of 1-octanol (octan-1-ol), 1,9-decadiene (deca-1,9-diene), 1,2-dichlorobenzene, or nitrophenyl octyl ether (1-(2-nitrophenoxy)octane) was studied using cyclic voltammetry and UV-vis absorption spectrophotometry. Concentration analysis indicates that the high membrane concentration of rhodamine B determines the ionic transfer observed via voltammetry, which is consistent with the low aqueous ionic concentration and large membrane/aqueous distribution of the molecule. The observed double-transfer voltammogram, although it has been largely neglected in previous literature, is a logical consequence of the presence of two liquid-liquid interfaces and is rationalized in terms of ion transfer across the two interfaces on either side of the membrane and supported by voltammograms obtained for a series of ions of varied lipophilicity. The bipolar nature of the voltammetric response offers an effective way of mass transport control via changing polarity of the applied voltage and finds immediate use in extraction, purification, and separation applications.
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Affiliation(s)
- Matěj Velický
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United
Kingdom
| | - Kin Y. Tam
- Faculty
of Health Science, University of Macau, Macau, China
| | - Robert A.W. Dryfe
- School
of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United
Kingdom
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22
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Huang D, Zhao T, Xu W, Yang T, Cremer PS. Sensing small molecule interactions with lipid membranes by local pH modulation. Anal Chem 2013; 85:10240-8. [PMID: 24152205 DOI: 10.1021/ac401955t] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Herein, we utilized a label-free sensing platform based on pH modulation to detect the interactions between tetracaine, a positively charged small molecule used as a local anesthetic, and planar supported lipid bilayers (SLBs). The SLBs were patterned inside a flow cell, allowing for various concentrations of tetracaine to be introduced over the surface in a buffer solution. Studies with membranes containing POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) yielded an equilibrium dissociation constant value of Kd = 180 ± 47 μm for this small molecule-membrane interaction. Adding cholesterol to the SLBs decreased the affinity between tetracaine and the bilayers, while this interaction tightened when POPE (1-hexadecanoyl-2-(9-Z-octadecenoyl)-sn-glycero-3-phosphoethanolamine) was added. Studies were also conducted with three negatively charged membrane lipids, POPG (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt)), POPS (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (sodium salt)), and ganglioside GM1. All three measurements gave rise to a similar tightening of the apparent Kd value compared with pure POPC membranes. The lack of chemical specificity with the identity of the negatively charged lipid indicated that the tightening was largely electrostatic. Through a direct comparison with ITC measurements, it was found that the pH modulation sensor platform offers a facile, inexpensive, highly sensitive, and rapid method for the detection of interactions between putative drug candidates and lipid bilayers. As such, this technique may potentially be exploited as a screen for drug development and analysis.
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Affiliation(s)
- Da Huang
- Department of Chemistry and §Department of Biochemistry and Molecular Biology, Penn State University , University Park, PA 16802
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23
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Decker JT, Magin CM, Long CJ, Finlay JA, Callow ME, Callow JA, Brennan AB. Engineered antifouling microtopographies: an energetic model that predicts cell attachment. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:13023-13030. [PMID: 24044383 DOI: 10.1021/la402952u] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have developed a model for the prediction of cell attachment to engineered microtopographies based on two previous models: the attachment point theory and the engineered roughness index (ERI) model. The new surface energetic attachment (SEA) model is based on both the properties of the cell-material interface and the size and configuration of the topography relative to the organism. We have used Monte Carlo simulation to examine the SEA model's ability to predict relative attachment of the green alga Ulva linza to different locations within a unit cell. We have also compared the predicted relative attachment for Ulva linza, the diatom Navicula incerta, the marine bacterium Cobetia marina, and the barnacle cyprid Balanus amphitrite to a wide variety of microtopographies. We demonstrate good correlation between the experimental results and the model results for all tested experimental data and thus show the SEA model may be used as a powerful indicator of the efficacy for antifouling topographies.
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Affiliation(s)
- Joseph T Decker
- Department of Materials Science and Engineering, University of Florida , Gainesville, Florida 32611-6400, United States
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