Pub Date : 2002-12-01DOI: 10.1109/IEMBS.2002.1106243
J. Neyhart, R.E. Eckert, R. Polikar, S. Mandayam, M. Tseng
The percentage of radiodense tissue in the breast has been shown to be a reliable marker for breast cancer risk. In this paper, we present an image processing technique for estimating radiodense tissue in digitized mammograms. First, the mammogram is segmented into tissue and nontissue regions. This segmentation process involves the generation of a segmentation mask that is developed using a radial basis function neural network. Subsequently, the image is processed for estimating the amount of radiodense tissue. The estimation process involves the generation of a modified Neyman-Pearson threshold to segment the radiodense and radiolucent tissue. Typical research results are presented-these have been independently validated by a radiologist.
{"title":"A modified Neyman-Pearson technique for radiodense tissue estimation in digitized mammograms","authors":"J. Neyhart, R.E. Eckert, R. Polikar, S. Mandayam, M. Tseng","doi":"10.1109/IEMBS.2002.1106243","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1106243","url":null,"abstract":"The percentage of radiodense tissue in the breast has been shown to be a reliable marker for breast cancer risk. In this paper, we present an image processing technique for estimating radiodense tissue in digitized mammograms. First, the mammogram is segmented into tissue and nontissue regions. This segmentation process involves the generation of a segmentation mask that is developed using a radial basis function neural network. Subsequently, the image is processed for estimating the amount of radiodense tissue. The estimation process involves the generation of a modified Neyman-Pearson threshold to segment the radiodense and radiolucent tissue. Typical research results are presented-these have been independently validated by a radiologist.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79751000","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.2002.1137038
C. Chan, D. Hwang, G. Stephanopoulous, G. Stephanopoulous, M. Yarmush
An optimization model based upon multivariate analysis was developed to capture hepatic specific function in relation to the environmental condition and the intracellular metabolic network and the flux information obtained from metabolic flux analysis (MFA). Fisher discriminant analysis (FDA) was applied to maximize the discrimination among groups thus permitting visualization of the sample separation between different conditions. FDA identified factors that contribute greatly to the separation of the groups. Mapping fluxes to a hepatic function permits an examination of the interrelationship of the fluxes and captures the hepatic function in terms of the metabolic profile. Partial least square (PLS) was the mapping technique applied to evaluate the effect of metabolic state on hepatic function, namely, the levels of intracellular triglyceride or urea production. This methodology identified fluxes most relevant to minimizing the accumulation of intracellular triglyceride and maximizing the production of urea, two important hepatic functions. In the study, 75 metabolic fluxes were mapped to measured levels of intracellular triglyceride or urea. Once a mapping model was constructed, analyzing the model parameters permitted the assessment of how the metabolic profile, in turn, pathways collectively regulate and control hepatic function by identifying pathways that are highly correlated with the hepatic function.
{"title":"Application of multivariate analysis for optimizing & predicting hepatic function","authors":"C. Chan, D. Hwang, G. Stephanopoulous, G. Stephanopoulous, M. Yarmush","doi":"10.1109/IEMBS.2002.1137038","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1137038","url":null,"abstract":"An optimization model based upon multivariate analysis was developed to capture hepatic specific function in relation to the environmental condition and the intracellular metabolic network and the flux information obtained from metabolic flux analysis (MFA). Fisher discriminant analysis (FDA) was applied to maximize the discrimination among groups thus permitting visualization of the sample separation between different conditions. FDA identified factors that contribute greatly to the separation of the groups. Mapping fluxes to a hepatic function permits an examination of the interrelationship of the fluxes and captures the hepatic function in terms of the metabolic profile. Partial least square (PLS) was the mapping technique applied to evaluate the effect of metabolic state on hepatic function, namely, the levels of intracellular triglyceride or urea production. This methodology identified fluxes most relevant to minimizing the accumulation of intracellular triglyceride and maximizing the production of urea, two important hepatic functions. In the study, 75 metabolic fluxes were mapped to measured levels of intracellular triglyceride or urea. Once a mapping model was constructed, analyzing the model parameters permitted the assessment of how the metabolic profile, in turn, pathways collectively regulate and control hepatic function by identifying pathways that are highly correlated with the hepatic function.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84499925","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.2002.1053047
T. Hsiai, S. Cho, P. Wong, M. Ing, M. Navab, S. Reddy, L. Demer, C. Ho
Precise characterization of shear stress in the arterial trees is critical to elucidate the effects of spatial versus temporal shear stress gradients on the biological activities of endothelial cells (EC). We developed micro electrical mechanical systems (MEMS) sensors, comparable to the size of EC (2 /spl times/ 80 /spl mu/m), to deliver the spatial and temporal resolution necessary at a frequency response > 100 Hz. We provided the first in vitro evidence of real-time wall shear stress on EC couple with real-time gene expression of monocyte chemoattractant protein (MCP-1).
{"title":"Bio-MEMS sensors for real-time shear stress on endothelial cell dynamics","authors":"T. Hsiai, S. Cho, P. Wong, M. Ing, M. Navab, S. Reddy, L. Demer, C. Ho","doi":"10.1109/IEMBS.2002.1053047","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053047","url":null,"abstract":"Precise characterization of shear stress in the arterial trees is critical to elucidate the effects of spatial versus temporal shear stress gradients on the biological activities of endothelial cells (EC). We developed micro electrical mechanical systems (MEMS) sensors, comparable to the size of EC (2 /spl times/ 80 /spl mu/m), to deliver the spatial and temporal resolution necessary at a frequency response > 100 Hz. We provided the first in vitro evidence of real-time wall shear stress on EC couple with real-time gene expression of monocyte chemoattractant protein (MCP-1).","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87244906","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.2002.1053128
T. Uchiyama, U. Windhorst, H. Johansson
The purpose of this study was to construct a time domain model of cat medial gastrocnemius muscle with recurrent inhibition by Renshaw cells. The model consists of 300 motoneurons, 300 Renshaw cells and 300 muscle units. The membrane potential was calculated by convoluting EPSP (excitatory postsynaptic potential) caused by the descending command inputs, the AHP (after hyperpolarization) observed after the firing of the motoneurons and the IPSP (inhibitory post-synaptic potential) from Renshaw cells. When the membrane potential reaches the threshold potential, the motoneurons send an excitatory impulse to muscle units and Renshaw cells. The muscle units generate force and the Renshaw cells generate inhibitory burst pulse trains back to the motoneurons. The static firing rate of Renshaw cells of the proposed model was well approximated with the function which was investigated by physiological experiments.
{"title":"Recurrent inhibition model of cat gastrocnemius muscle","authors":"T. Uchiyama, U. Windhorst, H. Johansson","doi":"10.1109/IEMBS.2002.1053128","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053128","url":null,"abstract":"The purpose of this study was to construct a time domain model of cat medial gastrocnemius muscle with recurrent inhibition by Renshaw cells. The model consists of 300 motoneurons, 300 Renshaw cells and 300 muscle units. The membrane potential was calculated by convoluting EPSP (excitatory postsynaptic potential) caused by the descending command inputs, the AHP (after hyperpolarization) observed after the firing of the motoneurons and the IPSP (inhibitory post-synaptic potential) from Renshaw cells. When the membrane potential reaches the threshold potential, the motoneurons send an excitatory impulse to muscle units and Renshaw cells. The muscle units generate force and the Renshaw cells generate inhibitory burst pulse trains back to the motoneurons. The static firing rate of Renshaw cells of the proposed model was well approximated with the function which was investigated by physiological experiments.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84625835","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.2002.1134437
L. Gupta, J. Phegley, D. Molfese
A parameter estimation and classification fusion approach is developed to classify averaged event-related potentials (ERPs) recorded from multiple channels. It is shown that the parameters of the averaged ERP ensemble can be estimated directly from the parameters of the single-trial ensemble. The parameter estimation methods are applied to independently design a Gaussian likelihood ratio classifier for each channel. A fusion rule is formulated to classify an ERP using the classification results from all the channels. Very importantly, it is shown that parametric classifiers can be designed and evaluated without having to collect a prohibitively large number of single-trial ERPs. It is also shown that the performance of a majority rule fusion classifier is consistently superior to the rule that selects a single best channel.
{"title":"Parameter estimation and multichannel fusion for classifying averaged ERPs","authors":"L. Gupta, J. Phegley, D. Molfese","doi":"10.1109/IEMBS.2002.1134437","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1134437","url":null,"abstract":"A parameter estimation and classification fusion approach is developed to classify averaged event-related potentials (ERPs) recorded from multiple channels. It is shown that the parameters of the averaged ERP ensemble can be estimated directly from the parameters of the single-trial ensemble. The parameter estimation methods are applied to independently design a Gaussian likelihood ratio classifier for each channel. A fusion rule is formulated to classify an ERP using the classification results from all the channels. Very importantly, it is shown that parametric classifiers can be designed and evaluated without having to collect a prohibitively large number of single-trial ERPs. It is also shown that the performance of a majority rule fusion classifier is consistently superior to the rule that selects a single best channel.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84639335","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.2002.1053460
P. Iaizzo, T. Laske
The Visible Heart/spl trade/ is an isolated working heart model that allows for functional intracardiac imaging. This novel visualization method and the resultant images obtained from large mammalian hearts, including those of humans, are considered of unique educational value. The development of this model and the utilization of the images for educational purposes is the joint mission of the University and Medtronic. To date, the mode of distribution of such materials has been non-profit, but they are considered of significant value to each partner because they improve procedural safety through physician education and they facilitate customer and public relations. Without this cooperative effort, progress on this project would not have proceeded to such an extent or at such a rate.
{"title":"The Visible Heart/spl trade/: the collaborative development and use of this educational tool by the University of Minnesota and Medtronic","authors":"P. Iaizzo, T. Laske","doi":"10.1109/IEMBS.2002.1053460","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1053460","url":null,"abstract":"The Visible Heart/spl trade/ is an isolated working heart model that allows for functional intracardiac imaging. This novel visualization method and the resultant images obtained from large mammalian hearts, including those of humans, are considered of unique educational value. The development of this model and the utilization of the images for educational purposes is the joint mission of the University and Medtronic. To date, the mode of distribution of such materials has been non-profit, but they are considered of significant value to each partner because they improve procedural safety through physician education and they facilitate customer and public relations. Without this cooperative effort, progress on this project would not have proceeded to such an extent or at such a rate.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75336093","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.2002.1137020
K. Schmalenberg, H. Buettner, K. Uhrich
After injury to the peripheral nervous system, axons from regenerating nerve cells must reach their innervation target to restore function. Polymeric substrates are currently being evaluated as nerve guides to enhance recovery after peripheral nerve injury. Degradable organic polymer substrates are highly suitable materials as matrices for tissue engineering because they can be specifically designed to serve as scaffolds then be absorbed by the body leaving only native tissue. Protein patterns on polymeric nerve guides may help maximize functional repair after injury because chemical cues can direct cellular components to their intended targets. Using microcontact printing techniques, protein stripes were patterned onto several different degradable polymeric substrates including poly(caprolactone), poly(caprolactam) and poly(3-hydroxybutyrate). The fluorescently tagged protein micro-patterns were visualized by confocal scanning laser fluorescence microscopy. The micropatterned polymer substrates were evaluated for their ability to direct attachment and alignment of Schwann cells (a cellular component of the peripheral nervous system).
{"title":"Directed attachment of Schwann cells on protein micropatterned degradable polymeric substrates","authors":"K. Schmalenberg, H. Buettner, K. Uhrich","doi":"10.1109/IEMBS.2002.1137020","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1137020","url":null,"abstract":"After injury to the peripheral nervous system, axons from regenerating nerve cells must reach their innervation target to restore function. Polymeric substrates are currently being evaluated as nerve guides to enhance recovery after peripheral nerve injury. Degradable organic polymer substrates are highly suitable materials as matrices for tissue engineering because they can be specifically designed to serve as scaffolds then be absorbed by the body leaving only native tissue. Protein patterns on polymeric nerve guides may help maximize functional repair after injury because chemical cues can direct cellular components to their intended targets. Using microcontact printing techniques, protein stripes were patterned onto several different degradable polymeric substrates including poly(caprolactone), poly(caprolactam) and poly(3-hydroxybutyrate). The fluorescently tagged protein micro-patterns were visualized by confocal scanning laser fluorescence microscopy. The micropatterned polymer substrates were evaluated for their ability to direct attachment and alignment of Schwann cells (a cellular component of the peripheral nervous system).","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75713594","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.2002.1106379
T. Laske, N. Skadsberg, P. Iaizzo
A study was conducted comparing the pacing and sensing performance of an endocardial pacing lead (5076, Medtronic, Inc., Minneapolis, MN) in vivo to an ex vivo isolated heart model designed to work all four chambers under simulated in vivo physiologic conditions. The lead was implanted in vivo using fluoroscopic guidance. Standard stimulation and sensing parameters were recorded. Using standard cardiac surgical techniques, 8 porcine hearts were excised and reperfused in a working heart model retaining their original lead placement. Following stabilization, the electrical measurements were repeated. Ex vivo electrical values were significantly decreased relative to the in vivo measurements: R-wave amplitude by 39%, P-wave amplitude by 39%, slew rate by 62%, and pacing impedance by 34%. Pacing threshold values were similar in vivo and ex vivo. Variations in performance were in part attributed to local tissue deformation in the isolated heart preparation leading to differences in lead slack and orientation. This comparative study substantiated the value of utilizing the isolated heart model to visualize and simultaneously evaluate lead pacing and sensing performance in comparison with in vivo experimental procedures.
{"title":"Comparative in vivo and ex vivo pacing and sensing performance study using isolated four-chamber working swine heart model","authors":"T. Laske, N. Skadsberg, P. Iaizzo","doi":"10.1109/IEMBS.2002.1106379","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1106379","url":null,"abstract":"A study was conducted comparing the pacing and sensing performance of an endocardial pacing lead (5076, Medtronic, Inc., Minneapolis, MN) in vivo to an ex vivo isolated heart model designed to work all four chambers under simulated in vivo physiologic conditions. The lead was implanted in vivo using fluoroscopic guidance. Standard stimulation and sensing parameters were recorded. Using standard cardiac surgical techniques, 8 porcine hearts were excised and reperfused in a working heart model retaining their original lead placement. Following stabilization, the electrical measurements were repeated. Ex vivo electrical values were significantly decreased relative to the in vivo measurements: R-wave amplitude by 39%, P-wave amplitude by 39%, slew rate by 62%, and pacing impedance by 34%. Pacing threshold values were similar in vivo and ex vivo. Variations in performance were in part attributed to local tissue deformation in the isolated heart preparation leading to differences in lead slack and orientation. This comparative study substantiated the value of utilizing the isolated heart model to visualize and simultaneously evaluate lead pacing and sensing performance in comparison with in vivo experimental procedures.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73612374","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.2002.1106470
A. de Jongh, B.S. Sheals, D. K. Chau, B. Hoffmeister, R. Malkin
A previous study has shown that the cross-sectional area of the left ventricular cavity (LV) increases immediately after defibrillation, suggesting that the defibrillation shock may cause relaxation. Since a single area slice may not reflect the entire myocardium, we wanted to test the relaxation hypothesis by evaluating volume. Ten to twenty defibrillation shocks were delivered in each of six dogs. A catheter was placed in the LV to measure intraventricular volume (IVV). Ultrasound images of the LV were recorded simultaneously with IVV. LV cavity area increased 13% (p<0.001) and IVV increased 4% (p<0.001) post-shock. Our results confirm that the heart is relaxing after defibrillation.
{"title":"Left ventricular volume changes after defibrillation","authors":"A. de Jongh, B.S. Sheals, D. K. Chau, B. Hoffmeister, R. Malkin","doi":"10.1109/IEMBS.2002.1106470","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1106470","url":null,"abstract":"A previous study has shown that the cross-sectional area of the left ventricular cavity (LV) increases immediately after defibrillation, suggesting that the defibrillation shock may cause relaxation. Since a single area slice may not reflect the entire myocardium, we wanted to test the relaxation hypothesis by evaluating volume. Ten to twenty defibrillation shocks were delivered in each of six dogs. A catheter was placed in the LV to measure intraventricular volume (IVV). Ultrasound images of the LV were recorded simultaneously with IVV. LV cavity area increased 13% (p<0.001) and IVV increased 4% (p<0.001) post-shock. Our results confirm that the heart is relaxing after defibrillation.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73114326","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.2002.1137067
T. Brieva, P. Moghe
The development of cell-based therapies for liver failure relies on the availability of scaffolds that support high levels of cellular function. In this work, we functionalize biomaterial surfaces using a novel cell-based ligand as an alternative to traditional extracellular matrix-derived ligands. Initial studies in a model coculture system indicate that E-cadherin, a key cell-cell adhesion molecule present on hepatocytes, enhances liver-specific function when presented by chaperone cells. We then investigate the behavior of hepatocytes on acellular cadherin-presenting immobilized microparticle-based biomaterials. Biological activity of acellular cadherins is ensured by appending to the extracellular domain of E-cadherin an immunoglobulin Fc region, which induces dimerization and specifically adheres to a Protein A coating on the microbeads. Hepatocellular function was elevated on these surfaces as compared to the control, Fc presenting surfaces. Both surfaces exhibited similar cell adhesion and morphogenesis, suggesting that induction of hepatocyte function by cadherins was due to signaling activities rather than adhesive activities. Overall, we have demonstrated that functionalization of biomaterials with acellular cadherins is a powerful way to induce hepatocyte function.
{"title":"Hepatocellular engineering via acellular cadherin-derived microinterfaces","authors":"T. Brieva, P. Moghe","doi":"10.1109/IEMBS.2002.1137067","DOIUrl":"https://doi.org/10.1109/IEMBS.2002.1137067","url":null,"abstract":"The development of cell-based therapies for liver failure relies on the availability of scaffolds that support high levels of cellular function. In this work, we functionalize biomaterial surfaces using a novel cell-based ligand as an alternative to traditional extracellular matrix-derived ligands. Initial studies in a model coculture system indicate that E-cadherin, a key cell-cell adhesion molecule present on hepatocytes, enhances liver-specific function when presented by chaperone cells. We then investigate the behavior of hepatocytes on acellular cadherin-presenting immobilized microparticle-based biomaterials. Biological activity of acellular cadherins is ensured by appending to the extracellular domain of E-cadherin an immunoglobulin Fc region, which induces dimerization and specifically adheres to a Protein A coating on the microbeads. Hepatocellular function was elevated on these surfaces as compared to the control, Fc presenting surfaces. Both surfaces exhibited similar cell adhesion and morphogenesis, suggesting that induction of hepatocyte function by cadherins was due to signaling activities rather than adhesive activities. Overall, we have demonstrated that functionalization of biomaterials with acellular cadherins is a powerful way to induce hepatocyte function.","PeriodicalId":60385,"journal":{"name":"中国地球物理学会年刊","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77541746","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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