Pub Date : 2010-12-01DOI: 10.1109/NANOMED.2010.5749839
Jae Hyung Lee, Jae Ah Kim, J. Song
We have developed a high-throughput chip-based assay that uses a photodiode array (PDA) microchip system to explore the inhibitory effects of drug analogs on Xanthine oxidase (XO). Inhibitory effects of dithranol (anthracene derivative), aminoglutethimide (anti-steroid), cyclosporine A (immunosuppressant) and naringenin (flavonoid) on XO were elucidated using the chip-based assay in the presence or absence of a free radical scavenging enzyme (SOD, superoxide dismutase). Drug analogs were assessed for their ability to inhibit XO, which loads to a reduction in the conversion of nitroblue tetrazolium (NBT) to NBT diformazan. The reduction of NBT to NBT formazan in the presence of XO and drug analog can be seen. The PDA microchip system employed in this study consists of an array of red light-emitting diodes (LEDs) focused precisely onto the photodetectors of the PDA chip. The ability of drugs to inhibit XO was assessed based on NBT reduction. Free radicals produced due to the oxidation of xanthine by XO resulted in the reduction of NBT to insoluble NBT formazan. We report a new high-throughput chip-based xanthine assay to explore the XO inhibitory properties of drug analogs, along with their modes of action. The work presented here has important implications with regard to rapid and automated drug discovery screening processes in the pharmaceutical industry.
{"title":"High-throughput screening of xanthine oxidase inhibitory properties of drug analogs using photodiode array microchip","authors":"Jae Hyung Lee, Jae Ah Kim, J. Song","doi":"10.1109/NANOMED.2010.5749839","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749839","url":null,"abstract":"We have developed a high-throughput chip-based assay that uses a photodiode array (PDA) microchip system to explore the inhibitory effects of drug analogs on Xanthine oxidase (XO). Inhibitory effects of dithranol (anthracene derivative), aminoglutethimide (anti-steroid), cyclosporine A (immunosuppressant) and naringenin (flavonoid) on XO were elucidated using the chip-based assay in the presence or absence of a free radical scavenging enzyme (SOD, superoxide dismutase). Drug analogs were assessed for their ability to inhibit XO, which loads to a reduction in the conversion of nitroblue tetrazolium (NBT) to NBT diformazan. The reduction of NBT to NBT formazan in the presence of XO and drug analog can be seen. The PDA microchip system employed in this study consists of an array of red light-emitting diodes (LEDs) focused precisely onto the photodetectors of the PDA chip. The ability of drugs to inhibit XO was assessed based on NBT reduction. Free radicals produced due to the oxidation of xanthine by XO resulted in the reduction of NBT to insoluble NBT formazan. We report a new high-throughput chip-based xanthine assay to explore the XO inhibitory properties of drug analogs, along with their modes of action. The work presented here has important implications with regard to rapid and automated drug discovery screening processes in the pharmaceutical industry.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122994467","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.5749800
Youhua Tan, A. Y. Leung, Kaiqun Wang, T. Fung, Dong Sun
Cell mechanics, in particular mechanical properties, has been suggested as a new biomarker indicative of cell state and phenotype. Acute myeloid leukemia (AML) is characterized by the abnormal increase of myeloblasts in blood and bone marrow. While AML has been extensively studied from the perspectives of biochemical and genetic aspects, little is known about its cellular biophysical properties. In this study, optical tweezer technology was used to examine the micromechanical properties of myeloblasts from bone marrow of AML patients at single cell level. The myeloblasts were separately analyzed according to their expression of CD34+, a marker of primitive hematopoietic cells. To extract the intrinsic properties from the relationship between the stretching force and the induced deformation, a theoretical approach was developed to model the mechanical responses of cells and further characterize their mechanical properties. The preliminary results show that the area compressibility modulus of CD34+ myeloblasts was significantly less than that of CD34− cells, which indicate that micromechanical properties are unique features of myeloblasts and provide us with an insight into the cell mechanics of primitive AML cells.
{"title":"Characterizing the micromechanical properties of myeloblasts from cancer patients with optical tweezers","authors":"Youhua Tan, A. Y. Leung, Kaiqun Wang, T. Fung, Dong Sun","doi":"10.1109/NANOMED.2010.5749800","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749800","url":null,"abstract":"Cell mechanics, in particular mechanical properties, has been suggested as a new biomarker indicative of cell state and phenotype. Acute myeloid leukemia (AML) is characterized by the abnormal increase of myeloblasts in blood and bone marrow. While AML has been extensively studied from the perspectives of biochemical and genetic aspects, little is known about its cellular biophysical properties. In this study, optical tweezer technology was used to examine the micromechanical properties of myeloblasts from bone marrow of AML patients at single cell level. The myeloblasts were separately analyzed according to their expression of CD34+, a marker of primitive hematopoietic cells. To extract the intrinsic properties from the relationship between the stretching force and the induced deformation, a theoretical approach was developed to model the mechanical responses of cells and further characterize their mechanical properties. The preliminary results show that the area compressibility modulus of CD34+ myeloblasts was significantly less than that of CD34− cells, which indicate that micromechanical properties are unique features of myeloblasts and provide us with an insight into the cell mechanics of primitive AML cells.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122614381","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.5749843
Min Jung Kim, J. Song
SH-03 is a rotenoid-containing deguelin analog. In this study, the anticancer activity and the dynamics of the caspase-mediated apoptotic cascade induced by SH-03 was simultaneously monitored in myeloid leukemia cells using multicolor single cell imaging cytometry as a new drug-screening platform. The constructed single cell imaging cytometer consists of an Ar-ion laser beam, a microscope objective lens, an acousto-optic tunable filter (AOTF), a charged coupled device (CCD) camera, and commercially available image processing software (MetaMorph). PI3K/AKT activation and phosphorylation assays were carried out to clarify the mechanistic details of the SH-03-induced intrinsic apoptotic pathway in HL-60 cells. SH-03 inhibited the PI3K/AKT signal transduction pathway in HL-60 cells. Given the fact that PI3K/AKT signaling pathway plays an important role in the proliferation, the inhibition of phosphorylation of PI3K/AKT by SH-03 can be assumed to trigger apoptosis. SH-03-induced caspase cascade was also investigated. Our results suggest that SH-03 induces apoptosis in HL-60 cells via a caspase-9-mediated intrinsic apoptotic pathway. Cellular imaging cytometry revealed that SH-03 triggers apoptosis via a caspase-mediated intrinsic pathway.
{"title":"Multicolor single cell imaging cytometry: A new drug screening platform for monitoring intracellular caspases as potential therapeutic targets","authors":"Min Jung Kim, J. Song","doi":"10.1109/NANOMED.2010.5749843","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749843","url":null,"abstract":"SH-03 is a rotenoid-containing deguelin analog. In this study, the anticancer activity and the dynamics of the caspase-mediated apoptotic cascade induced by SH-03 was simultaneously monitored in myeloid leukemia cells using multicolor single cell imaging cytometry as a new drug-screening platform. The constructed single cell imaging cytometer consists of an Ar-ion laser beam, a microscope objective lens, an acousto-optic tunable filter (AOTF), a charged coupled device (CCD) camera, and commercially available image processing software (MetaMorph). PI3K/AKT activation and phosphorylation assays were carried out to clarify the mechanistic details of the SH-03-induced intrinsic apoptotic pathway in HL-60 cells. SH-03 inhibited the PI3K/AKT signal transduction pathway in HL-60 cells. Given the fact that PI3K/AKT signaling pathway plays an important role in the proliferation, the inhibition of phosphorylation of PI3K/AKT by SH-03 can be assumed to trigger apoptosis. SH-03-induced caspase cascade was also investigated. Our results suggest that SH-03 induces apoptosis in HL-60 cells via a caspase-9-mediated intrinsic apoptotic pathway. Cellular imaging cytometry revealed that SH-03 triggers apoptosis via a caspase-mediated intrinsic pathway.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"68 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129329754","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.5749809
Richard Landers, P. Wen, S. Pather
This paper is a comprehensive literature review on the Depth of Anaesthesia (DoA) monitoring problem. We first investigate the current clinical practice, then briefly introduce the DoA monitors, finally we analyse and discuss the reliability and accuracy of current DoA assessment practice. In this study we find that most of the responses suppressed by anaestheic agents are not of the central nervous system (CNS) but are responses from the peripheral nervous systems (PNS). The responses generated for drug combinations across the therapeutic ranges show considerable variations in drug concentrations that constitute adequate anaesthesia for a particular stimulus. We propose to capture the decision process of anaesthetist using neural networks as neural networks are good at finding patterns in non linear, non stationary signals.
{"title":"Depth of Anaesthesia: Measuring or guessing?","authors":"Richard Landers, P. Wen, S. Pather","doi":"10.1109/NANOMED.2010.5749809","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749809","url":null,"abstract":"This paper is a comprehensive literature review on the Depth of Anaesthesia (DoA) monitoring problem. We first investigate the current clinical practice, then briefly introduce the DoA monitors, finally we analyse and discuss the reliability and accuracy of current DoA assessment practice. In this study we find that most of the responses suppressed by anaestheic agents are not of the central nervous system (CNS) but are responses from the peripheral nervous systems (PNS). The responses generated for drug combinations across the therapeutic ranges show considerable variations in drug concentrations that constitute adequate anaesthesia for a particular stimulus. We propose to capture the decision process of anaesthetist using neural networks as neural networks are good at finding patterns in non linear, non stationary signals.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"33 21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128472025","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.5749806
Man-Wai Louie, Tommy Tsz-Him Fong, K. K. Lo
We present the synthesis and characterization of luminescent biological probes derived from rhenium(I) polypyridine fluorous complexes [Re(Me2 bpy)(CO)3(py-Rf-R)](PF6) (R = NH2 (1), NCS (2), TU-C2H5 (3)). The photophysical properties of these complexes have been studied. The fluorous complex 2 has been used to label glutathione (GSH) and bovine serum albumin (BSA). The photophysical properties of the resultant bioconjugates have been studied. The isolation of the luminescent fluorous rhenium-GSH conjugate from a mixture of twenty amino acids has been demonstrated using fluorous solidphase extraction (FSPE). Additionally, the cytotoxicity of complexes 1 and 3 toward HeLa cells has been examined by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cellular uptake properties of complex 3 have been investigated by laser-scanning confocal microscopy.
{"title":"Luminescent rhenium(I) polypyridine fluorous complexes as new biological probes","authors":"Man-Wai Louie, Tommy Tsz-Him Fong, K. K. Lo","doi":"10.1109/NANOMED.2010.5749806","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749806","url":null,"abstract":"We present the synthesis and characterization of luminescent biological probes derived from rhenium(I) polypyridine fluorous complexes [Re(Me2 bpy)(CO)3(py-Rf-R)](PF6) (R = NH2 (1), NCS (2), TU-C2H5 (3)). The photophysical properties of these complexes have been studied. The fluorous complex 2 has been used to label glutathione (GSH) and bovine serum albumin (BSA). The photophysical properties of the resultant bioconjugates have been studied. The isolation of the luminescent fluorous rhenium-GSH conjugate from a mixture of twenty amino acids has been demonstrated using fluorous solidphase extraction (FSPE). Additionally, the cytotoxicity of complexes 1 and 3 toward HeLa cells has been examined by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cellular uptake properties of complex 3 have been investigated by laser-scanning confocal microscopy.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133931246","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.5749808
Hui-Ting Fu, D. Yao, Hung-Ju Huang, Chin-Jung Li, Hong-Yuan Huang
A novel laminar stream-based microfluidic chip that can serve as the high efficient technique for human sperm motility sorting through the use of flow cytometry was proposed in this study. Recently, the selection of good sperms in semen plays an important role in the reproductive medicine. However, the traditional sorting methods are normally expensive and time consuming. This modified microfluidic chip provided a new selection, which had advantages of low-cost, high-precision, and disposable. This paper was proposed and tested the interactions between laminar flow and sperm activity. Due to the laminar flow in a different direction, the semen samples were loaded into a curve laminar flow through straight-curve stream and it would offer a y component force for dead sperms to be selected. In addition, the semen samples were loaded into a straight laminar flow and the results showed that most of the proportion of motile sperms with lateral activity can swim across the two fluid boundaries to be sorted. From the results of flow cytometry analysis, the injected semen sample from a straight inlet with the counted percentage of living sperms was 92.68% by the observation in outlet reservoir. Therefore, the microfluidic chip with remarkable sperm motility sorting has the potential for reproductive medicine.
{"title":"Laminar stream-based microfluidic chip with high efficiency for human sperm motility sorting","authors":"Hui-Ting Fu, D. Yao, Hung-Ju Huang, Chin-Jung Li, Hong-Yuan Huang","doi":"10.1109/NANOMED.2010.5749808","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749808","url":null,"abstract":"A novel laminar stream-based microfluidic chip that can serve as the high efficient technique for human sperm motility sorting through the use of flow cytometry was proposed in this study. Recently, the selection of good sperms in semen plays an important role in the reproductive medicine. However, the traditional sorting methods are normally expensive and time consuming. This modified microfluidic chip provided a new selection, which had advantages of low-cost, high-precision, and disposable. This paper was proposed and tested the interactions between laminar flow and sperm activity. Due to the laminar flow in a different direction, the semen samples were loaded into a curve laminar flow through straight-curve stream and it would offer a y component force for dead sperms to be selected. In addition, the semen samples were loaded into a straight laminar flow and the results showed that most of the proportion of motile sperms with lateral activity can swim across the two fluid boundaries to be sorted. From the results of flow cytometry analysis, the injected semen sample from a straight inlet with the counted percentage of living sperms was 92.68% by the observation in outlet reservoir. Therefore, the microfluidic chip with remarkable sperm motility sorting has the potential for reproductive medicine.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128240957","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.5749834
Gi-Ja Lee, Ji-Hye Kim, Hun-Kuk Park, K. Jeong, Hyun-jung Kang, T. Lee
Atomic force microscopy (AFM) has become an important device to visualize various cells and biological materials for non-invasive imaging. The major advantage of AFM compared to the conventional optical and electron microscopes is its convenience. Sample preparation for AFM does not need special coating or vacuum as a procedure. AFM can detect samples even under the aqueous condition. Although the AFM is originally used to obtain surface topography of sample, it can measure precisely the interactions between its probe tip and the sample surface from force-distance measurements. Epithelial-to-mesenchymal transformation of tubular cells into myofibroblastic phenotype is an important mediator of renal injury in chronic nephropathy. It is generally known that angiotensin II (Ang II) plays a direct profibrotic role in the kidney, but the mechanism is unclear. In this study, we observed structural and mechanical changes in tubular epithelial cell after Ang II treatment using AFM.
原子力显微镜(Atomic force microscopy, AFM)已成为对各种细胞和生物材料进行无创成像的重要手段。与传统的光学显微镜和电子显微镜相比，AFM的主要优点是方便。AFM的样品制备不需要特殊的涂层或真空作为一个过程。AFM可以在水溶液条件下检测样品。虽然AFM最初是用于获取样品表面形貌，但它可以通过力距测量来精确测量其探针尖端与样品表面之间的相互作用。小管细胞上皮向间质转化为肌成纤维细胞表型是慢性肾病肾损伤的重要中介。众所周知，血管紧张素II (angii)在肾脏中起直接促纤维化作用，但其机制尚不清楚。在这项研究中，我们用AFM观察了Ang II处理后小管上皮细胞的结构和力学变化。
{"title":"Observation of angiotensin II-induced changes in tubular epithelial cells utilizing AFM: Angiotensin II-induced changes in tubular cells","authors":"Gi-Ja Lee, Ji-Hye Kim, Hun-Kuk Park, K. Jeong, Hyun-jung Kang, T. Lee","doi":"10.1109/NANOMED.2010.5749834","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749834","url":null,"abstract":"Atomic force microscopy (AFM) has become an important device to visualize various cells and biological materials for non-invasive imaging. The major advantage of AFM compared to the conventional optical and electron microscopes is its convenience. Sample preparation for AFM does not need special coating or vacuum as a procedure. AFM can detect samples even under the aqueous condition. Although the AFM is originally used to obtain surface topography of sample, it can measure precisely the interactions between its probe tip and the sample surface from force-distance measurements. Epithelial-to-mesenchymal transformation of tubular cells into myofibroblastic phenotype is an important mediator of renal injury in chronic nephropathy. It is generally known that angiotensin II (Ang II) plays a direct profibrotic role in the kidney, but the mechanism is unclear. In this study, we observed structural and mechanical changes in tubular epithelial cell after Ang II treatment using AFM.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134464229","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.5749812
J. Song
Because of increase in bacterial resistance to common antibiotics, antibacterial nanometallopharmaceuticals have been drawing increasing interest. Recent literature reports encouraging results about the bactericidal activity of silver nanoparticles of either a simple or composite nature. We, for the first time, demonstrated that silver nanoparticles (AgNP) undergo a shape dependant interaction with bacteria. We also developed highly antibacterial porous carbon matrices supporting nano-silver by simple and cost effective way. The antibacterial mechanism of the developed composite under prolonged incubation conditions was investigated against Escherichia coli. The application of silver in the treatment of burn wounds is of special interest, and has prompted an upsurge in research on the synthesis of antibacterial silver(I) complexes. However, the antibacterial performance of silver ion is correlated to its valence form and it has been found that the high valence silver ion exhibits stronger and more effective antibacterial action than low valence ion. Recently, we reported the synthesis of highly monodispersed nanoparticles of a trivalent silver polydiguanide complex in reverse microemulsion, demonstrating its flexibility for complexation reaction and the fabrication of essentially monodispersed nanoparticles of higher valent metal complex. The synthesized material showed strong antibacterial activity against the tested Gram (+)/(−) and methicillin-resistant Stahylococcus aureus strains. Interaction of polydiguanide ligands with silver at different oxidation states was also investigated. The in vitro pharmacodynamics of these complexes revealed that silver polydiguanide complexes provide faster killing kinetics compared to silver nitrate or polydiguanide ligands.
{"title":"Silver as antibacterial agent: Metal nanoparticles to nanometallopharmaceuticals: (Silver based antibacterial nanometallopharmaceuticals)","authors":"J. Song","doi":"10.1109/NANOMED.2010.5749812","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749812","url":null,"abstract":"Because of increase in bacterial resistance to common antibiotics, antibacterial nanometallopharmaceuticals have been drawing increasing interest. Recent literature reports encouraging results about the bactericidal activity of silver nanoparticles of either a simple or composite nature. We, for the first time, demonstrated that silver nanoparticles (AgNP) undergo a shape dependant interaction with bacteria. We also developed highly antibacterial porous carbon matrices supporting nano-silver by simple and cost effective way. The antibacterial mechanism of the developed composite under prolonged incubation conditions was investigated against Escherichia coli. The application of silver in the treatment of burn wounds is of special interest, and has prompted an upsurge in research on the synthesis of antibacterial silver(I) complexes. However, the antibacterial performance of silver ion is correlated to its valence form and it has been found that the high valence silver ion exhibits stronger and more effective antibacterial action than low valence ion. Recently, we reported the synthesis of highly monodispersed nanoparticles of a trivalent silver polydiguanide complex in reverse microemulsion, demonstrating its flexibility for complexation reaction and the fabrication of essentially monodispersed nanoparticles of higher valent metal complex. The synthesized material showed strong antibacterial activity against the tested Gram (+)/(−) and methicillin-resistant Stahylococcus aureus strains. Interaction of polydiguanide ligands with silver at different oxidation states was also investigated. The in vitro pharmacodynamics of these complexes revealed that silver polydiguanide complexes provide faster killing kinetics compared to silver nitrate or polydiguanide ligands.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122000556","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.5749818
Tianbiao Zhang, Changlin Zhang, Zai-li Dong, Y. Guan
Atomic force microscope (AFM), as its high resolution and precision, was employed to directly probe intermolecular hydrogen bonds between self-assembled purines and pyrimidines. In the experiment, we directly stretch the DNA double strands that are attached to the planar modified glass surfaces and AFM tip respectively. However, distinguishing from previous literatures we focus on the NaCl density and holding time influencing the rupture force of DNA double helix and monitor the probing process under three different densities of sodium chloride (NaCl): 0mM, 50mM, and 100mM. The result shows complementary DNA strands are easier to bond as the density of NaCl increases. At the same time we test the probing process considering three holding durations: 0S, 10S, and 40S. We find the complementary DNA strands bond forming well under the situation of 40S. Then we separately do experiments with three lengths of strands: 10bp, 14bp, 20bp. Using cluster analysis method we find that the clustering center intervals are about 0.21nN, 0.29nN, and 0.39nN, and we can calculate the hydrogen bond of the single G-C is about 20pN.
原子力显微镜(Atomic force microscope, AFM)以其高分辨率和高精度，直接探测自组装嘌呤和嘧啶之间的分子间氢键。在实验中，我们直接拉伸了分别附着在平面修饰玻璃表面和AFM尖端的DNA双链。然而，与以往文献不同的是，我们重点研究了NaCl浓度和保持时间对DNA双螺旋破裂力的影响，并监测了0mM、50mM和100mM三种不同NaCl浓度下DNA双螺旋破裂力的探测过程。结果表明，随着NaCl浓度的增加，互补DNA链更容易结合。同时，我们测试了探测过程，考虑了三个保持持续时间:0S、10S和40S。我们发现，在40S的情况下，互补DNA链形成良好。然后分别用10bp、14bp、20bp三种长度的链进行实验。利用聚类分析方法，我们发现聚类中心间隔约为0.21nN, 0.29nN和0.39nN，我们可以计算出单个G-C的氢键约为20pN。
{"title":"Measurement of interchain binding affinity of nucleic acid duplex using atomic force microscopy","authors":"Tianbiao Zhang, Changlin Zhang, Zai-li Dong, Y. Guan","doi":"10.1109/NANOMED.2010.5749818","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.5749818","url":null,"abstract":"Atomic force microscope (AFM), as its high resolution and precision, was employed to directly probe intermolecular hydrogen bonds between self-assembled purines and pyrimidines. In the experiment, we directly stretch the DNA double strands that are attached to the planar modified glass surfaces and AFM tip respectively. However, distinguishing from previous literatures we focus on the NaCl density and holding time influencing the rupture force of DNA double helix and monitor the probing process under three different densities of sodium chloride (NaCl): 0mM, 50mM, and 100mM. The result shows complementary DNA strands are easier to bond as the density of NaCl increases. At the same time we test the probing process considering three holding durations: 0S, 10S, and 40S. We find the complementary DNA strands bond forming well under the situation of 40S. Then we separately do experiments with three lengths of strands: 10bp, 14bp, 20bp. Using cluster analysis method we find that the clustering center intervals are about 0.21nN, 0.29nN, and 0.39nN, and we can calculate the hydrogen bond of the single G-C is about 20pN.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126954074","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 : 2010-12-01DOI: 10.1109/NANOMED.2010.6107964
Zhe Cao, R. Zhu, R. Que
We present a portable, low cost, sensitive respiration monitoring system based on a micro hot-film flow sensor. The sensitive component of the flow sensor is a patterned thin-film with nanometer thickness fabricated on a flexible polyimide substrate by incorporating printed circuit technique with micromachining technique. The respiratory flow measurement is under a constanttemperature mode, and the measured signals are sampled and processed using SCM and transferred to PC through USB data communication. Virtual instruments technology is applied to achieve the real-time display of respiratory flow waveform and related respiratory parameters on PC. Finally, the system is experimentally calibrated, static and dynamic characteristics of the system are acquired and the effectiveness of the system is verified.
{"title":"Low-cost portable respiration monitor based on micro hot-film flow sensor","authors":"Zhe Cao, R. Zhu, R. Que","doi":"10.1109/NANOMED.2010.6107964","DOIUrl":"https://doi.org/10.1109/NANOMED.2010.6107964","url":null,"abstract":"We present a portable, low cost, sensitive respiration monitoring system based on a micro hot-film flow sensor. The sensitive component of the flow sensor is a patterned thin-film with nanometer thickness fabricated on a flexible polyimide substrate by incorporating printed circuit technique with micromachining technique. The respiratory flow measurement is under a constanttemperature mode, and the measured signals are sampled and processed using SCM and transferred to PC through USB data communication. Virtual instruments technology is applied to achieve the real-time display of respiratory flow waveform and related respiratory parameters on PC. Finally, the system is experimentally calibrated, static and dynamic characteristics of the system are acquired and the effectiveness of the system is verified.","PeriodicalId":446237,"journal":{"name":"2010 IEEE International Conference on Nano/Molecular Medicine and Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129852651","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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