AIM:To investigate the biological features of hepatitis B virus(HBV)-transfected HepG2.2.15 cells. METHODS:The cell ultrastructure,cell cycle and apoptosis,and the abilities of proliferation and invasion of HBV-transf...AIM:To investigate the biological features of hepatitis B virus(HBV)-transfected HepG2.2.15 cells. METHODS:The cell ultrastructure,cell cycle and apoptosis,and the abilities of proliferation and invasion of HBV-transfected HepG2.2.15 and the parent HepG2 cells were examined by electron microscopy,flow cytometry, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and trans-well assay.Oncogenicity of the two cell lines was compared via subcutaneous injection and orthotopic injection or implantation in nude mice,and the pathological analysis of tumor formation was performed.Two cytoskeletal proteins were detected by Western blotting. RESULTS:Compared with HepG2 cells,HepG2.2.15 cells showed organelle degeneration and filopodia disappearance under electron microscope.HepG2.2.15 cells proliferated and migrated slowly in vitro,and hardly formed tumor and lung metastasis in nude mice.Flow cytometry showed that the majority of HepG2.2.15 cells were arrested in G1 phase,and apoptosis was minor in both cell lines.Furthermore,the levels of cytoskeletal proteins F-actin and Ezrin were decreased in HepG2.2.15 cells. CONCLUSION:HepG2.2.15 cells demonstrated a lower proliferation and invasion ability than the HepG2 cells due to HBV transfection.展开更多
Cancer cells differ from normal cells in various parameters, and these differences are caused by genomic mutations and consequential altered gene expression. The genetic and functional heterogeneity of tumor cells is ...Cancer cells differ from normal cells in various parameters, and these differences are caused by genomic mutations and consequential altered gene expression. The genetic and functional heterogeneity of tumor cells is a major challenge in cancer research, detection, and effective treatment. As such, the use of diagnostic methods is important to reveal this heterogeneity at the single-cell level. Droplet microfluidic devices are effective tools that provide exceptional sensitivity for analyzing single cells and molecules. In this review, we highlight two novel methods that employ droplet microfluidics for ultrasensitive detection of nucleic acids and protein markers in cancer cells. We also discuss the future practical applications of these methods.展开更多
Background The induced pluripotent stem cell （iPSC） has shown great potential in cellular therapy of myocardial infarction （MI）, while its application is hampered by the low efficiency of cardiomyocyte differentia...Background The induced pluripotent stem cell （iPSC） has shown great potential in cellular therapy of myocardial infarction （MI）, while its application is hampered by the low efficiency of cardiomyocyte differentiation. The present study was designed to investigate the effects of cardiotrophin-1 （CT-1） on cardiomyocyte differentiation from mouse induced pluripotent stem cells （miPSCs） and the underlying mechanisms involved. Methods The optimal treatment condition for cardiomyocyte differentiation from miPSCs was established with ideal concentration （10 ng/mL） and duration （from day 3 to day 14） of CT-1 administration. Up-regulated expression of cardiac specific genes that accounted for embryonic cardiogenesis was observed by quantitative RT-PCR. Elevated amount of a-myosin heavy chain （ct-MHC） and cardiac troponin I （cTn I） positive cells were detected by immunofluorescence staining and flow cytometry analysis in CT- 1 group. Results Transmission electron microscopic analysis revealed that cells treated with CT- 1 showed better organized sacromeric structure and more mitochondria, which are morphological characteristic of matured cardiomyocytes. Western blot demonstrated that CT-1 promotes cardiomyocyte differentiation from miPSCs partly via JAK2/STAT3/Pim-1 pathway as compared with control group. Conclusions These findings suggested that CT-1 could enhance the cardiomyocyte differentiation as well as the maturation of mouse induced pluripotent stem cell derived cardiomyocytes by regulating JAK2/STAT3/Pim-1 signaling pathway.展开更多
Objective: The aim of this study was to investigate the impact of beta-elemene injection on the growth and beta-tubulin of human hepatocarcinoma HepG2 cells. Methods: Cell proliferation was assessed by MTT assay. Cell...Objective: The aim of this study was to investigate the impact of beta-elemene injection on the growth and beta-tubulin of human hepatocarcinoma HepG2 cells. Methods: Cell proliferation was assessed by MTT assay. Cell cycle distribution was detected by flow cytometry(FCM). The mRNA expression of beta-tubulin was measured by RT-PCR. Western blot analysis was used to determine protein expression of beta-tubulin and the polymerization of beta-tubulin. Results: Beta-elemene injection inhibited HepG2 cells proliferation in a dose- and time-dependent manner; FCM analysis indicated beta-elemene injection induced cell cycle arrested at S phase. RT-PCR and western-blot analysis showed that beta-elemene injection down-regulated beta-tubulin expression at both mRNA and protein levels, presenting a dose-dependent manner. Moreover, beta-elemene injection reduced the polymerization of microtubules in a dose-dependent manner. Conclusion: Beta-elemene injection can inhibit the proliferation of hepatoma HepG2 cells, the mechanism might be partly related to the down-regulation of beta-tubulin and inhibition of microtubular polymerization.展开更多
Objective To determine whether low power density microwave radiation can induce irreversible changes in rabbit lens epithelial cells (LECs) and the mechanisms of the changes.Methods One eye of each rabbit was exposed ...Objective To determine whether low power density microwave radiation can induce irreversible changes in rabbit lens epithelial cells (LECs) and the mechanisms of the changes.Methods One eye of each rabbit was exposed to 5mW/cm2 or 10mW/cm2 power density microwaves for 3 hours, while the contralateral eye served as a control. Annexin Ⅴ-propidium iodide (PI) two-color flow cytometry (FCM) was used to detect the early changes in rabbit lens epithelial cells after radiation. Results Lots of rabbit LECs were in the initial phase of apoptosis in the 5mW/cm2 microwave radiation group. A large number of cells became secondary necrotic cells, and severe damage could be found in the group exposed to 10mW/cm2 microwave radiation. Conclusion Low power densities of microwave radiation (5mW/cm2 and 10mW/cm2) can induce irreversible damage to rabbit LECs. This may be the non-thermal effect of microwave radiation.展开更多
Cell-cell interaction and cell metabolic analysis provide new opportunities for better understanding of critical biochemical processes. Advanced microfluidic technologies enable to create more realistic in vitro micro...Cell-cell interaction and cell metabolic analysis provide new opportunities for better understanding of critical biochemical processes. Advanced microfluidic technologies enable to create more realistic in vitro microenvironment by spatial and temporal control of cell growth and co-culture. In this work, we design a microfluidic device to achieve the co-culture of PC12 cells and 293 cells, and study in vitro cell-cell interaction via cell metabolic analysis by mass spectrometry. The membraneintegrated microfluidic device was firstly used for cell co-culture, and the cellular metabolite was further investigated by mass spectrometer(MS). Our results showed that the differentiation of PC12 cells could be successfully induced by m NGF and also greatly influenced by the microchannel treatment of fetal bovine serum(FBS) solution. The identification of cell morphology, microtubule-associated protein 2(MAP-2) expression and viability of differentiated PC12 cells were conducted before 293 cells being introduced into the top microfluidic channels and stimulated to secrete cell metabolism products. The developed microfluidic device is a potentially useful tool for high throughput of cell-cell interaction study.展开更多
The fabrication of functional microcarriers capable of achieving in vivo-like three-dimensional cell culture is important for many tissue engineering applications. Here,inspired by the structure of Buddha beads, which...The fabrication of functional microcarriers capable of achieving in vivo-like three-dimensional cell culture is important for many tissue engineering applications. Here,inspired by the structure of Buddha beads, which are generally composed of moveable beads strung on a rope, we present novel cell microcarriers with controllable macropores and heterogeneous microstructures by using a capillary array microfluidic technology. Microfibers with a string of moveable and releasable microcarriers could be achieved by an immediate gelation reaction of sodium alginate spinning and subsequent polymerization of cell-dispersed gelatin methacrylate emulsification. The sizes of the microcarriers and their inner macropores could be well tailored by adjusting the flow rates of the microfluidic phases; this was of great importance in guaranteeing a sufficient supply of nutrients during cell culture. In addition, by infusing multiple cell-dispersed pregel solutions into the capillaries, the microcarriers with spatially heterogeneous cell encapsulations for mimicking physiological structures and functions could also be achieved.展开更多
We developed an integrated microfluidic chip for long-term culture of isolated single cells. This polydimethylsiloxane (PDMS) based device could accurately seed each single cell into different culture chambers, and is...We developed an integrated microfluidic chip for long-term culture of isolated single cells. This polydimethylsiloxane (PDMS) based device could accurately seed each single cell into different culture chambers, and isolate one chamber from each other with monolithically integrated pneumatic valves. We optimized the culture conditions, including the frequency of medium replacement and the introduction of conditioned medium, to keep the single cells alive for 4 days. We cultured a few hundred cells in a separated chamber on the same chip to continuously supply the conditioned medium into the culture chambers for single cells. This approach greatly facilitated the growth of single cells, and created a suitable microenvironment for observing cells' autonomous process in situ without the interference of other adjacent cells. This single cell colony assay is expandable to higher throughput, fitting the needs in the studies of drug screening and stem cell differentiation.展开更多
In this article, a computational model and related methodologies have been tested for simulating the motion of a malaria infected red blood cell （iRBC for short） in Poiseuille flow at low Reynolds numbers. Besides t...In this article, a computational model and related methodologies have been tested for simulating the motion of a malaria infected red blood cell （iRBC for short） in Poiseuille flow at low Reynolds numbers. Besides the deformability of the red blood cell membrane, the migration of a neutrally buoyant particle （used to model the malaria parasite inside the membrane） is another factor to determine the iRBC motion. Typically an iRBC oscillates in a Poiseuille flow due to the competition between these two factors. The interaction of an iRBC and several RBCs in a narrow channel shows that, at lower flow speed, the iRBC can be easily pushed toward the wall and stay there to block the channel. But, at higher flow speed, RBCs and iRBC stay in the central region of the channel since their migrations axe dominated by the motion of the RBC membrane.展开更多
This paper aims to the research of the impact of fluid shear stress on the adhesion between vascular endothelial cells and leukocyte induced by tumor necrosis factor-α(TNF-α) by microfliudic chip technology.Microflu...This paper aims to the research of the impact of fluid shear stress on the adhesion between vascular endothelial cells and leukocyte induced by tumor necrosis factor-α(TNF-α) by microfliudic chip technology.Microfluidic chip was fabricated by soft lithograph; Endothelial microfluidic chip was constructed by optimizing types of the extracellular matrix proteins modified in the microchannel and cell incubation time;human umbilical vein endothelial cells EA.Hy926 lined in the microchannel were exposed to fluid shear stress of 1.68 dynes/cm^2 and 8.4 dynes/cm^2 respectively.Meanwhile,adhesion between EA.Hy926 cells and leukocyte was induced by TNF-αunder a flow condition.EA.Hy926 cell cultured in the static condition was used as control group.The numbers of fluorescently-labeled leukocyte in microchannel were counted to quantize the adhesion level between EA.Hy926 cells and leukocyte; cell immunofluorescence technique was used to detect the intercellular adhesion molecule(ICAM-1) expression.The constructed endothelial microfluidic chip can afford to the fluid shear stress and respond to exogenous stimulus of TNF-α; compared with the adhesion numbers of leukocyte in control group,adhesion between EA.Hy926 cells exposed to low fluid shear stress and leukocyte was reduced under the stimulus of TNF-α at a concentration of 10 ng/ml(P<0.05); leukocyte adhesion with EA.Hy926 cells exposed to high fluid shear stress was reduced significantly than EA.Hy926 cells in control group and EA.1Hy926 cells exposed to low fluid shear stress(P<0.01); the regulation mechanism of fluid shear stress to the adhesion between EA.Hy926 cells and leukocyte induced by TNF-αwas through the way of ICAM-1.The endothelial microfluidic chip fabricated in this paper could be used to study the functions of endothelial cell in vitro and provide a new technical platform for exploring the pathophysiology of the related cardiovascular system diseases under a flow environment.展开更多
The research of the motion and deformation of the RBCs is important to reveal the mechanism of blood diseases. A numerical method has been developed with level set formulation for elastic membrane immersed in incompre...The research of the motion and deformation of the RBCs is important to reveal the mechanism of blood diseases. A numerical method has been developed with level set formulation for elastic membrane immersed in incompressible fluid. The numerical model satisfies mass and energy conservation without the leaking problems in classical Immersed Boundary Method(IBM), at the same time, computing grid we used can be much smaller than the general literatures. The motion and deformation of a red blood cell(including pathological & normal status) in microvascular flow are simulated. It is found that the Reynolds number and membrane's stiffness play an important role in the transmutation and oscillation of the elastic membrane. The normal biconcave shape of the RBC is propitious to create high deformation than other pathological shapes. With reduced viscosity of the interior fluid both the velocity of the blood and the deformability of the cell reduced. With increased viscosity of the plasma both the velocity of the blood and the deformability of the cell reduced. The tank treading of the RBC membrane is observed at low enough viscosity contrast in shear flow. The tank tread fixed inclination angle of the cell depends on the shear ratio and viscosity contrast, which can be compared with the experimental observation well.展开更多
基金Supported by Graduate Innovation Foundation of Harbin Medical University No.HCXB2010010Key Technology Project of Heilongjiang Science and Technology Department,No.ZJY04-0102
文摘AIM:To investigate the biological features of hepatitis B virus(HBV)-transfected HepG2.2.15 cells. METHODS:The cell ultrastructure,cell cycle and apoptosis,and the abilities of proliferation and invasion of HBV-transfected HepG2.2.15 and the parent HepG2 cells were examined by electron microscopy,flow cytometry, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and trans-well assay.Oncogenicity of the two cell lines was compared via subcutaneous injection and orthotopic injection or implantation in nude mice,and the pathological analysis of tumor formation was performed.Two cytoskeletal proteins were detected by Western blotting. RESULTS:Compared with HepG2 cells,HepG2.2.15 cells showed organelle degeneration and filopodia disappearance under electron microscope.HepG2.2.15 cells proliferated and migrated slowly in vitro,and hardly formed tumor and lung metastasis in nude mice.Flow cytometry showed that the majority of HepG2.2.15 cells were arrested in G1 phase,and apoptosis was minor in both cell lines.Furthermore,the levels of cytoskeletal proteins F-actin and Ezrin were decreased in HepG2.2.15 cells. CONCLUSION:HepG2.2.15 cells demonstrated a lower proliferation and invasion ability than the HepG2 cells due to HBV transfection.
基金supported by a grant from the National Institutes of Health (Grant No. NIH/NGRR 1R21RR025371–01 to IS)
文摘Cancer cells differ from normal cells in various parameters, and these differences are caused by genomic mutations and consequential altered gene expression. The genetic and functional heterogeneity of tumor cells is a major challenge in cancer research, detection, and effective treatment. As such, the use of diagnostic methods is important to reveal this heterogeneity at the single-cell level. Droplet microfluidic devices are effective tools that provide exceptional sensitivity for analyzing single cells and molecules. In this review, we highlight two novel methods that employ droplet microfluidics for ultrasensitive detection of nucleic acids and protein markers in cancer cells. We also discuss the future practical applications of these methods.
基金This work was supported by the National Funds for Distinguished Young Scientists of China （No. 81325009） and National Nature Science Foundation of China （No. 81270168, No. 81227901）, （Feng Cao BWS12J037）, Innovation Team granted by Ministry of Education PRC （IRT1053）, National Basic Research Program of China （2012CB518101）. Shaanxi Province Program （2013K12-02-03, 2014KCT-20）. The authors declare no conflict of interest.
文摘Background The induced pluripotent stem cell （iPSC） has shown great potential in cellular therapy of myocardial infarction （MI）, while its application is hampered by the low efficiency of cardiomyocyte differentiation. The present study was designed to investigate the effects of cardiotrophin-1 （CT-1） on cardiomyocyte differentiation from mouse induced pluripotent stem cells （miPSCs） and the underlying mechanisms involved. Methods The optimal treatment condition for cardiomyocyte differentiation from miPSCs was established with ideal concentration （10 ng/mL） and duration （from day 3 to day 14） of CT-1 administration. Up-regulated expression of cardiac specific genes that accounted for embryonic cardiogenesis was observed by quantitative RT-PCR. Elevated amount of a-myosin heavy chain （ct-MHC） and cardiac troponin I （cTn I） positive cells were detected by immunofluorescence staining and flow cytometry analysis in CT- 1 group. Results Transmission electron microscopic analysis revealed that cells treated with CT- 1 showed better organized sacromeric structure and more mitochondria, which are morphological characteristic of matured cardiomyocytes. Western blot demonstrated that CT-1 promotes cardiomyocyte differentiation from miPSCs partly via JAK2/STAT3/Pim-1 pathway as compared with control group. Conclusions These findings suggested that CT-1 could enhance the cardiomyocyte differentiation as well as the maturation of mouse induced pluripotent stem cell derived cardiomyocytes by regulating JAK2/STAT3/Pim-1 signaling pathway.
基金Supported by grants from the National Natural Science Foundation of China(No.81173615)the Scientific Research Foundation for the Returned Overseas Chinese Scholars and State Education Ministrythe Specialized Research Fund for the Doctoral Program of Higher Education(No.20102105120002)
文摘Objective: The aim of this study was to investigate the impact of beta-elemene injection on the growth and beta-tubulin of human hepatocarcinoma HepG2 cells. Methods: Cell proliferation was assessed by MTT assay. Cell cycle distribution was detected by flow cytometry(FCM). The mRNA expression of beta-tubulin was measured by RT-PCR. Western blot analysis was used to determine protein expression of beta-tubulin and the polymerization of beta-tubulin. Results: Beta-elemene injection inhibited HepG2 cells proliferation in a dose- and time-dependent manner; FCM analysis indicated beta-elemene injection induced cell cycle arrested at S phase. RT-PCR and western-blot analysis showed that beta-elemene injection down-regulated beta-tubulin expression at both mRNA and protein levels, presenting a dose-dependent manner. Moreover, beta-elemene injection reduced the polymerization of microtubules in a dose-dependent manner. Conclusion: Beta-elemene injection can inhibit the proliferation of hepatoma HepG2 cells, the mechanism might be partly related to the down-regulation of beta-tubulin and inhibition of microtubular polymerization.
文摘Objective To determine whether low power density microwave radiation can induce irreversible changes in rabbit lens epithelial cells (LECs) and the mechanisms of the changes.Methods One eye of each rabbit was exposed to 5mW/cm2 or 10mW/cm2 power density microwaves for 3 hours, while the contralateral eye served as a control. Annexin Ⅴ-propidium iodide (PI) two-color flow cytometry (FCM) was used to detect the early changes in rabbit lens epithelial cells after radiation. Results Lots of rabbit LECs were in the initial phase of apoptosis in the 5mW/cm2 microwave radiation group. A large number of cells became secondary necrotic cells, and severe damage could be found in the group exposed to 10mW/cm2 microwave radiation. Conclusion Low power densities of microwave radiation (5mW/cm2 and 10mW/cm2) can induce irreversible damage to rabbit LECs. This may be the non-thermal effect of microwave radiation.
基金supported by the National Natural Science Foundation of China(8137337321227006+1 种基金91213305)China Equipment and Education Resources System(CERS-1-75)
文摘Cell-cell interaction and cell metabolic analysis provide new opportunities for better understanding of critical biochemical processes. Advanced microfluidic technologies enable to create more realistic in vitro microenvironment by spatial and temporal control of cell growth and co-culture. In this work, we design a microfluidic device to achieve the co-culture of PC12 cells and 293 cells, and study in vitro cell-cell interaction via cell metabolic analysis by mass spectrometry. The membraneintegrated microfluidic device was firstly used for cell co-culture, and the cellular metabolite was further investigated by mass spectrometer(MS). Our results showed that the differentiation of PC12 cells could be successfully induced by m NGF and also greatly influenced by the microchannel treatment of fetal bovine serum(FBS) solution. The identification of cell morphology, microtubule-associated protein 2(MAP-2) expression and viability of differentiated PC12 cells were conducted before 293 cells being introduced into the top microfluidic channels and stimulated to secrete cell metabolism products. The developed microfluidic device is a potentially useful tool for high throughput of cell-cell interaction study.
基金supported by the National Natural Science Foundation of China(21473029 and 51522302)the NSAF Foundation of China(U1530260)+3 种基金the Natural Science Foundation of Jiangsu(BK20140028)the Program for New Century Excellent Talents in Universitythe Scientific Research Foundation of Southeast Universitythe Scientific Research Foundation of Graduate School of Southeast University
文摘The fabrication of functional microcarriers capable of achieving in vivo-like three-dimensional cell culture is important for many tissue engineering applications. Here,inspired by the structure of Buddha beads, which are generally composed of moveable beads strung on a rope, we present novel cell microcarriers with controllable macropores and heterogeneous microstructures by using a capillary array microfluidic technology. Microfibers with a string of moveable and releasable microcarriers could be achieved by an immediate gelation reaction of sodium alginate spinning and subsequent polymerization of cell-dispersed gelatin methacrylate emulsification. The sizes of the microcarriers and their inner macropores could be well tailored by adjusting the flow rates of the microfluidic phases; this was of great importance in guaranteeing a sufficient supply of nutrients during cell culture. In addition, by infusing multiple cell-dispersed pregel solutions into the capillaries, the microcarriers with spatially heterogeneous cell encapsulations for mimicking physiological structures and functions could also be achieved.
基金supported by the National Natural Science Foundation of China (20733001, 20890020, 90913011, 20905004)the Ministry of Science and Technology of China (2011CB809106)+1 种基金the Ministry of Education of Chinathe Fok Ying Tung Education Foundation
文摘We developed an integrated microfluidic chip for long-term culture of isolated single cells. This polydimethylsiloxane (PDMS) based device could accurately seed each single cell into different culture chambers, and isolate one chamber from each other with monolithically integrated pneumatic valves. We optimized the culture conditions, including the frequency of medium replacement and the introduction of conditioned medium, to keep the single cells alive for 4 days. We cultured a few hundred cells in a separated chamber on the same chip to continuously supply the conditioned medium into the culture chambers for single cells. This approach greatly facilitated the growth of single cells, and created a suitable microenvironment for observing cells' autonomous process in situ without the interference of other adjacent cells. This single cell colony assay is expandable to higher throughput, fitting the needs in the studies of drug screening and stem cell differentiation.
基金supported by the National Science Foundation of the United States(Nos.DMS-0914788,DMS-1418308)
文摘In this article, a computational model and related methodologies have been tested for simulating the motion of a malaria infected red blood cell （iRBC for short） in Poiseuille flow at low Reynolds numbers. Besides the deformability of the red blood cell membrane, the migration of a neutrally buoyant particle （used to model the malaria parasite inside the membrane） is another factor to determine the iRBC motion. Typically an iRBC oscillates in a Poiseuille flow due to the competition between these two factors. The interaction of an iRBC and several RBCs in a narrow channel shows that, at lower flow speed, the iRBC can be easily pushed toward the wall and stay there to block the channel. But, at higher flow speed, RBCs and iRBC stay in the central region of the channel since their migrations axe dominated by the motion of the RBC membrane.
文摘This paper aims to the research of the impact of fluid shear stress on the adhesion between vascular endothelial cells and leukocyte induced by tumor necrosis factor-α(TNF-α) by microfliudic chip technology.Microfluidic chip was fabricated by soft lithograph; Endothelial microfluidic chip was constructed by optimizing types of the extracellular matrix proteins modified in the microchannel and cell incubation time;human umbilical vein endothelial cells EA.Hy926 lined in the microchannel were exposed to fluid shear stress of 1.68 dynes/cm^2 and 8.4 dynes/cm^2 respectively.Meanwhile,adhesion between EA.Hy926 cells and leukocyte was induced by TNF-αunder a flow condition.EA.Hy926 cell cultured in the static condition was used as control group.The numbers of fluorescently-labeled leukocyte in microchannel were counted to quantize the adhesion level between EA.Hy926 cells and leukocyte; cell immunofluorescence technique was used to detect the intercellular adhesion molecule(ICAM-1) expression.The constructed endothelial microfluidic chip can afford to the fluid shear stress and respond to exogenous stimulus of TNF-α; compared with the adhesion numbers of leukocyte in control group,adhesion between EA.Hy926 cells exposed to low fluid shear stress and leukocyte was reduced under the stimulus of TNF-α at a concentration of 10 ng/ml(P<0.05); leukocyte adhesion with EA.Hy926 cells exposed to high fluid shear stress was reduced significantly than EA.Hy926 cells in control group and EA.1Hy926 cells exposed to low fluid shear stress(P<0.01); the regulation mechanism of fluid shear stress to the adhesion between EA.Hy926 cells and leukocyte induced by TNF-αwas through the way of ICAM-1.The endothelial microfluidic chip fabricated in this paper could be used to study the functions of endothelial cell in vitro and provide a new technical platform for exploring the pathophysiology of the related cardiovascular system diseases under a flow environment.
基金supported by the National Key Project of Scientific and Technical Supporting Programs of China(Grant No.2014BAI11B06)the National Natural Science Foundation of China(Grant No.11172156)
文摘The research of the motion and deformation of the RBCs is important to reveal the mechanism of blood diseases. A numerical method has been developed with level set formulation for elastic membrane immersed in incompressible fluid. The numerical model satisfies mass and energy conservation without the leaking problems in classical Immersed Boundary Method(IBM), at the same time, computing grid we used can be much smaller than the general literatures. The motion and deformation of a red blood cell(including pathological & normal status) in microvascular flow are simulated. It is found that the Reynolds number and membrane's stiffness play an important role in the transmutation and oscillation of the elastic membrane. The normal biconcave shape of the RBC is propitious to create high deformation than other pathological shapes. With reduced viscosity of the interior fluid both the velocity of the blood and the deformability of the cell reduced. With increased viscosity of the plasma both the velocity of the blood and the deformability of the cell reduced. The tank treading of the RBC membrane is observed at low enough viscosity contrast in shear flow. The tank tread fixed inclination angle of the cell depends on the shear ratio and viscosity contrast, which can be compared with the experimental observation well.
