Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1053257
R. Mazhari, E. Marbán, R. Winslow
Regulatory subunit KCNE3 (E3) interacts with KCNQ1 (Q1) in epithelia, regulating its activation kinetics and augmenting current density. Since E3 is expressed weakly in the heart, we hypothesized that ectopic expression of E3 in cardiac myocytes might abbreviate action potential duration by interacting with Q1 and augmenting the delayed rectifier current (I/sub K/). We constructed an adenoviral vector co-expressing GFP and E3, and injected it Into the left ventricular cavity of guinea pigs. After 72 hrs, the electrocardiographic QT interval was reduced by /spl sim/10% compared to baseline. E3-transduced cells had an APD/sub 90/ of 87 /spl plusmn/ 8 vs. 298 /spl plusmn/ 19 ms in control cells, while E-4031-insensitive I/sub K/ and activation kinetics were significantly augmented. Quantitative modeling of a transmural cardiac segment rationalized the degree of QT-interval abbreviation as a consequence of electrotonic interactions in the face of limited transduction efficiency and showed that heterogeneous transduction of E3 may actually potentiate arrhythmias. The results provide proof of the principle that ectopic expression of regulatory subunits can be exploited to enhance repolarization, a principle that may be useful in treating long QT syndrome (but only if fairly homogeneous ventricular expression can be achieved).
{"title":"Regulation of cardiac repolarization by adenoviral gene transfer rationalized by computational modeling","authors":"R. Mazhari, E. Marbán, R. Winslow","doi":"10.1109/IEMBS.2002.1053257","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053257","url":null,"abstract":"Regulatory subunit KCNE3 (E3) interacts with KCNQ1 (Q1) in epithelia, regulating its activation kinetics and augmenting current density. Since E3 is expressed weakly in the heart, we hypothesized that ectopic expression of E3 in cardiac myocytes might abbreviate action potential duration by interacting with Q1 and augmenting the delayed rectifier current (I/sub K/). We constructed an adenoviral vector co-expressing GFP and E3, and injected it Into the left ventricular cavity of guinea pigs. After 72 hrs, the electrocardiographic QT interval was reduced by /spl sim/10% compared to baseline. E3-transduced cells had an APD/sub 90/ of 87 /spl plusmn/ 8 vs. 298 /spl plusmn/ 19 ms in control cells, while E-4031-insensitive I/sub K/ and activation kinetics were significantly augmented. Quantitative modeling of a transmural cardiac segment rationalized the degree of QT-interval abbreviation as a consequence of electrotonic interactions in the face of limited transduction efficiency and showed that heterogeneous transduction of E3 may actually potentiate arrhythmias. The results provide proof of the principle that ectopic expression of regulatory subunits can be exploited to enhance repolarization, a principle that may be useful in treating long QT syndrome (but only if fairly homogeneous ventricular expression can be achieved).","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"23 1","pages":"2233-2234 vol.3"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74596009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1134526
P. Wong, C. H. Kwong, T. Hsiai, C. Ho
This paper reports the study of the trajectory patterns that exist when monocyte and endothelial cells interact within the oscillatory flow known to be present in arterial bifurcations. The rolling and tumbling of monocytes, followed by the tethering and firm attachment to endothelial cells were observed. A cell tracking velocimetry algorithm was developed to characterize the real time cell-cell interactions. The algorithm allows tracking of large amounts of cell trajectories automatically, which is essential for statistical analysis of cell interaction events.
{"title":"Cell tracking velocimetry for monocyte/endothelial cell interactions","authors":"P. Wong, C. H. Kwong, T. Hsiai, C. Ho","doi":"10.1109/IEMBS.2002.1134526","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1134526","url":null,"abstract":"This paper reports the study of the trajectory patterns that exist when monocyte and endothelial cells interact within the oscillatory flow known to be present in arterial bifurcations. The rolling and tumbling of monocytes, followed by the tethering and firm attachment to endothelial cells were observed. A cell tracking velocimetry algorithm was developed to characterize the real time cell-cell interactions. The algorithm allows tracking of large amounts of cell trajectories automatically, which is essential for statistical analysis of cell interaction events.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"13 1","pages":"343-344 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90445794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1053408
A. Adami, K. Yang, X. Song, M. Pavel, D. Dirschl
We describe an approach toward improved classification of fractures in the vicinity of ankle joints using image-specific image enhancement and 3D modeling. The enhancement approach is based on the development of a set of linear features from X-ray images. The 3D models of fractures are used to determine the X-ray image representation from a fractured surface. These models are then used in reverse to find surface parameters that are most consistent with the 2D fracture representations.
{"title":"Model-based image processing and analysis for fracture classification","authors":"A. Adami, K. Yang, X. Song, M. Pavel, D. Dirschl","doi":"10.1109/IEMBS.2002.1053408","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053408","url":null,"abstract":"We describe an approach toward improved classification of fractures in the vicinity of ankle joints using image-specific image enhancement and 3D modeling. The enhancement approach is based on the development of a set of linear features from X-ray images. The 3D models of fractures are used to determine the X-ray image representation from a fractured surface. These models are then used in reverse to find surface parameters that are most consistent with the 2D fracture representations.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"460 1","pages":"2525-2526 vol.3"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79828744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1134377
T.D. Coates, S. Wolpert
In this study, a minimally invasive interface to an intact peripheral nerve was developed. The interface was based on a cylindrical cuff installed around the nerve, and fitted with circumferentially dispersed surface electrodes. Differential measurements of bulk potentials were filtered, amplified, and subsequently processed with the objective of identifying unique patterns of electrical activity within the ensheathed nerve bundle. The system was implemented using an in vivo preparation of lateral eye and optic nerve from Limulus polyphemus. Recorded signals were filtered using the discrete wavelet transform and the Daubechies 4 wavelet basis to isolate signal components regarded as significant to the optical pattern. The entropies of the filtered signals were computed and used to build training and testing patterns for a cascade correlation neural network. The values on the eight outputs of the neural network represented the probability of one or more of the eight locations on the lateral eye having been illuminated by the stimulus. From these outputs, an image of the optical stimulus pattern was rendered. In tests, the system displayed an accuracy of 100% in distinguishing stimulus from nonstimulus conditions, and up to 91% in identifying the location(s) illuminated by a given pattern of optical stimulation.
{"title":"Elucidation of simple optic stimuli based on detected nerve activity","authors":"T.D. Coates, S. Wolpert","doi":"10.1109/IEMBS.2002.1134377","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1134377","url":null,"abstract":"In this study, a minimally invasive interface to an intact peripheral nerve was developed. The interface was based on a cylindrical cuff installed around the nerve, and fitted with circumferentially dispersed surface electrodes. Differential measurements of bulk potentials were filtered, amplified, and subsequently processed with the objective of identifying unique patterns of electrical activity within the ensheathed nerve bundle. The system was implemented using an in vivo preparation of lateral eye and optic nerve from Limulus polyphemus. Recorded signals were filtered using the discrete wavelet transform and the Daubechies 4 wavelet basis to isolate signal components regarded as significant to the optical pattern. The entropies of the filtered signals were computed and used to build training and testing patterns for a cascade correlation neural network. The values on the eight outputs of the neural network represented the probability of one or more of the eight locations on the lateral eye having been illuminated by the stimulus. From these outputs, an image of the optical stimulus pattern was rendered. In tests, the system displayed an accuracy of 100% in distinguishing stimulus from nonstimulus conditions, and up to 91% in identifying the location(s) illuminated by a given pattern of optical stimulation.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"7 1","pages":"40-41 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87224087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1136951
J. H. van Zanten, Y. Har-el, J. Hanes
Non-viral vector formation by DNA complexation with cationic condensing agents is a self-assembly process driven primarily by electrostatic interactions and counterion release. DNA complexation kinetics influence three physical parameters that have a direct effect on gene delivery and expression efficiency: DNA complex geometric size, surface charge and density. We demonstrate the utility of time resolved multiangle laser light scattering (TR-MALLS) for probing polyethylenimine (PEI) based polyplex formation kinetics with plasmid DNA. Our studies utilize plasmid DNA coding for VEGF, which may be used to enhance blood vessel in-growth into cell seeded polymeric scaffolds used in tissue engineering applications. We determined PEI/DNA complex size and density in real time and monitored vector stability in various liquid formulations. Parameters such as PEI molecular weight, N/P ratio and solution pH and ionic strength were investigated systematically. The ability to accurately measure polyplex size and density may lead to improvements in the design and control of non-viral gene delivery vectors and facilitate the determination of optimal formulations.
{"title":"Optimization of PEI/VEGF DNA polyplexes for potenital delivery from tissue engineering scaffolds","authors":"J. H. van Zanten, Y. Har-el, J. Hanes","doi":"10.1109/IEMBS.2002.1136951","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1136951","url":null,"abstract":"Non-viral vector formation by DNA complexation with cationic condensing agents is a self-assembly process driven primarily by electrostatic interactions and counterion release. DNA complexation kinetics influence three physical parameters that have a direct effect on gene delivery and expression efficiency: DNA complex geometric size, surface charge and density. We demonstrate the utility of time resolved multiangle laser light scattering (TR-MALLS) for probing polyethylenimine (PEI) based polyplex formation kinetics with plasmid DNA. Our studies utilize plasmid DNA coding for VEGF, which may be used to enhance blood vessel in-growth into cell seeded polymeric scaffolds used in tissue engineering applications. We determined PEI/DNA complex size and density in real time and monitored vector stability in various liquid formulations. Parameters such as PEI molecular weight, N/P ratio and solution pH and ionic strength were investigated systematically. The ability to accurately measure polyplex size and density may lead to improvements in the design and control of non-viral gene delivery vectors and facilitate the determination of optimal formulations.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"39 1","pages":"563-564 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85674599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1053468
G. Birol, A. McKenna, H. Smith, T. Giorgio, S. Brophy
A team of domain experts, learning scientists, learning technologists, assessment experts and students are currently working on developing and refining educational tools for biotechnology as well as for other domains within the "How People Learn" framework in the NSF funded VaNTH ERC in Bioengineering Educational Technologies. Educational modules In biotechnology cover a collection of challenges designed around bioreactors, mass and momentum transfer issues, and microbial kinetics, which are among core biotechnology topics. The activities form the core of the STAR Legacy Cycle method that was adopted as the template for module development. These modules have been tested in classrooms both at Vanderbilt and Northwestern and detailed assessment data have also been collected. The focus of this contribution is on development and implementation of these educational modules at two universities (VU and NJU).
{"title":"Integration of the \"How people learn\" framework into educational module development and implementation in biotechnology","authors":"G. Birol, A. McKenna, H. Smith, T. Giorgio, S. Brophy","doi":"10.1109/IEMBS.2002.1053468","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053468","url":null,"abstract":"A team of domain experts, learning scientists, learning technologists, assessment experts and students are currently working on developing and refining educational tools for biotechnology as well as for other domains within the \"How People Learn\" framework in the NSF funded VaNTH ERC in Bioengineering Educational Technologies. Educational modules In biotechnology cover a collection of challenges designed around bioreactors, mass and momentum transfer issues, and microbial kinetics, which are among core biotechnology topics. The activities form the core of the STAR Legacy Cycle method that was adopted as the template for module development. These modules have been tested in classrooms both at Vanderbilt and Northwestern and detailed assessment data have also been collected. The focus of this contribution is on development and implementation of these educational modules at two universities (VU and NJU).","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"9 1","pages":"2640-2641 vol.3"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86521088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1136852
D. Tang, Chun Yang, S.Q. Liu
Fluid shear stress may play an important role in regulating cell activities and motility of growth factors in artery remodeling, atherosclerosis and re-stenosis process. 3-D computational models based on a multi-cell experimental model are introduced and solved to quantify shear stress distributions on cell surfaces under physiological setting. Combined with experimental data, relationship between fluid shear stress and endothelial cell activities can be established. Cell geometry and membrane mechanical properties affect micro flow environment leading to considerable changes in shear stress distributions and various cell activities such as cell migration and activation of cell migration signaling mechanisms.
{"title":"Shear stress distributions on the membrane of endothelial cells using 3-D computational modeling with fluid-structure interactions","authors":"D. Tang, Chun Yang, S.Q. Liu","doi":"10.1109/IEMBS.2002.1136852","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1136852","url":null,"abstract":"Fluid shear stress may play an important role in regulating cell activities and motility of growth factors in artery remodeling, atherosclerosis and re-stenosis process. 3-D computational models based on a multi-cell experimental model are introduced and solved to quantify shear stress distributions on cell surfaces under physiological setting. Combined with experimental data, relationship between fluid shear stress and endothelial cell activities can be established. Cell geometry and membrane mechanical properties affect micro flow environment leading to considerable changes in shear stress distributions and various cell activities such as cell migration and activation of cell migration signaling mechanisms.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"95 1","pages":"375-376 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79454922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1137001
J. Abulencia, R. Gaspard, John Quackenbush, K. Konstantopoulos
The behavior of the chondrocytic cell line T/C-28a2 under shear flow was examined using a 32,448 element microarray. A parallel plate flow chamber was used to generate a shear stress level of 20 dyn/cm/sup 2/ for 1.5 or 24 hours (h), after which gene regulation was measured. Microarray analysis revealed differentially regulated genes affecting proliferation/differentiation, extracellular matrix/cytoskeleton, and inflammation at both time points. A ribonuclease protection assay was performed on a subset of genes to confirm the data obtained from the microarray. However, the cyclooxygenase-2 (COX-2) gene, which plays a role in the prostaglandin production in inflamed tissues and the synovium of rheumatoid arthritis (RA) patients, was studied further. Western hybridization revealed that COX-2 protein is present at 24 h, but not at 6 or 12 h. Also, immunofluorescence microscopy shows that COX-2 protein localizes in the cytosol after 24 h of shear, and is not present after 1.5 h. By examining the overall gene expression profiles of chondrocytes under different conditions of dynamic fluid shear, new insights on the pathogenesis of cartilage related diseases such as rheumatoid arthritis might be generated.
{"title":"Microarray analysis of the chondrocytic cell line T/C-28a2 under dynamic fluid shear","authors":"J. Abulencia, R. Gaspard, John Quackenbush, K. Konstantopoulos","doi":"10.1109/IEMBS.2002.1137001","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1137001","url":null,"abstract":"The behavior of the chondrocytic cell line T/C-28a2 under shear flow was examined using a 32,448 element microarray. A parallel plate flow chamber was used to generate a shear stress level of 20 dyn/cm/sup 2/ for 1.5 or 24 hours (h), after which gene regulation was measured. Microarray analysis revealed differentially regulated genes affecting proliferation/differentiation, extracellular matrix/cytoskeleton, and inflammation at both time points. A ribonuclease protection assay was performed on a subset of genes to confirm the data obtained from the microarray. However, the cyclooxygenase-2 (COX-2) gene, which plays a role in the prostaglandin production in inflamed tissues and the synovium of rheumatoid arthritis (RA) patients, was studied further. Western hybridization revealed that COX-2 protein is present at 24 h, but not at 6 or 12 h. Also, immunofluorescence microscopy shows that COX-2 protein localizes in the cytosol after 24 h of shear, and is not present after 1.5 h. By examining the overall gene expression profiles of chondrocytes under different conditions of dynamic fluid shear, new insights on the pathogenesis of cartilage related diseases such as rheumatoid arthritis might be generated.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"26 1","pages":"654-655 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82504288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1136945
Jie Fu, E. Krauland, Y. Har-el, J. Hanes
A new family of biodegradable cationic polyesters consisting of aspartic acid and aliphatic diols of various lengths has been synthesized. Since the polymers formed are strictly alternating, the cationic charge density can be controlled by simply changing the size of the spacer aliphatic monomer. One such polymer, poly(aspartic anhydride-co-ethylene glycol) (PAE), was found to be capable of self-assembly (/spl sim/100 nm) into polymeric micelles and complexation with DNA. Kinetic studies reveal PAE initially complexes DNA into sub-100 nm complexes and subsequently releases it after 3-6 days at room temperature. With the ability to degrade and unpack its genetic material, this new family of biodegradable cationic polymers shows promise as versatile gene carriers for in vitro and in vivo applications.
{"title":"New degradable cationic polyesters for nonviral gene delivery","authors":"Jie Fu, E. Krauland, Y. Har-el, J. Hanes","doi":"10.1109/IEMBS.2002.1136945","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1136945","url":null,"abstract":"A new family of biodegradable cationic polyesters consisting of aspartic acid and aliphatic diols of various lengths has been synthesized. Since the polymers formed are strictly alternating, the cationic charge density can be controlled by simply changing the size of the spacer aliphatic monomer. One such polymer, poly(aspartic anhydride-co-ethylene glycol) (PAE), was found to be capable of self-assembly (/spl sim/100 nm) into polymeric micelles and complexation with DNA. Kinetic studies reveal PAE initially complexes DNA into sub-100 nm complexes and subsequently releases it after 3-6 days at room temperature. With the ability to degrade and unpack its genetic material, this new family of biodegradable cationic polymers shows promise as versatile gene carriers for in vitro and in vivo applications.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"15 1","pages":"551-552 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81726389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1053050
T. Vu, U. Saifuddin, M. Řezáč, H. Qian, D. R. Pepperberg, T. Desai
Here we report progress toward the development of bioactive surfaces based on GABA, a major neurotransmitter in the nervous system. While immobilization techniques have focused largely on antibodies, enzymes, and receptors, to our knowledge, this is the first report of a prototype neurotransmitter-immobilized surface. Biosurfaces were assembled onto either mica or glass using passive adsorption of avidin and subsequent attachment of a derivatized form of GABA via a biotin-avidin affinity bond. Surface characterization was carried out using atomic force microscopy to visualize surface topology. The data reveal 1) passive adsorption of avidin is uniformly dispersed and cluster densities can be controlled through the concentration of the avidin incubation solution; and 2) GABA tethered via biotin to these avidin surfaces showed a homogenous distribution of the tethered neurotransmitter molecule onto glass and two different population distributions onto mica. Functional assays performed to test the biological activity or the synthesized GABA, direct sandwich ELISA, as well as comparison of AFM images of anti-GABA antibody incubation of these prepared GABA surfaces to control studies using anti-IgG antibody, together support the idea that these synthesized surfaces are biofunctional.
{"title":"Assembly and characterization of biofunctional GABA-immobilized surfaces","authors":"T. Vu, U. Saifuddin, M. Řezáč, H. Qian, D. R. Pepperberg, T. Desai","doi":"10.1109/IEMBS.2002.1053050","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053050","url":null,"abstract":"Here we report progress toward the development of bioactive surfaces based on GABA, a major neurotransmitter in the nervous system. While immobilization techniques have focused largely on antibodies, enzymes, and receptors, to our knowledge, this is the first report of a prototype neurotransmitter-immobilized surface. Biosurfaces were assembled onto either mica or glass using passive adsorption of avidin and subsequent attachment of a derivatized form of GABA via a biotin-avidin affinity bond. Surface characterization was carried out using atomic force microscopy to visualize surface topology. The data reveal 1) passive adsorption of avidin is uniformly dispersed and cluster densities can be controlled through the concentration of the avidin incubation solution; and 2) GABA tethered via biotin to these avidin surfaces showed a homogenous distribution of the tethered neurotransmitter molecule onto glass and two different population distributions onto mica. Functional assays performed to test the biological activity or the synthesized GABA, direct sandwich ELISA, as well as comparison of AFM images of anti-GABA antibody incubation of these prepared GABA surfaces to control studies using anti-IgG antibody, together support the idea that these synthesized surfaces are biofunctional.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":"29 1","pages":"1834-1835 vol.3"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89563264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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