A therapy gaining rapid clinical adoption involves radioembolization with the use of Yttrium-90 (90Y) microspheres. The 20-60 microm-sized microspheres are injected trans-arterially and flow to hepatic tumors given their preferential blood supply from the hepatic artery. Once they lodge in the arterioles, they impart a very intense local radiotherapeutic effect. Given the combined radiation and embolic effect, the imaging findings imparted by this mode of action differ significantly from other treatments. This work represents a comprehensive review of the imaging findings following radioembolization in patients with primary liver tumors. The report discusses imaging response, benign secondary effects, and complications. This should help educate the radiologist on imaging findings that should be expected following radioembolization and therefore aid in the proper image interpretation. Ibrahim, S. M. Nikolaidis, P. Miller, F. H. Lewandowski, R. J. Ryu, R. K. Sato, K. T. Senthilnathan, S. Riaz, A. Kulik, L. Mulcahy, M. F. Omary, R. A. Salem, R. 0 2009-09-06T11:56:49Z 2008-09-09 %0 Journal Article %A Ibrahim, S. M. %A Nikolaidis, P. %A Miller, F. H. %A Lewandowski, R. J. %A Ryu, R. K. %A Sato, K. T. %A Senthilnathan, S. %A Riaz, A. %A Kulik, L. %A Mulcahy, M. F. %A Omary, R. A. %A Salem, R. %D 2009 %T Radiologic findings following Y90 radioembolization for primary liver malignancies. %J Abdom Imaging %V 34 %N 5 %P 566-581 %M 18777189 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18777189 %X A therapy gaining rapid clinical adoption involves radioembolization with the use of Yttrium-90 (90Y) microspheres. The 20-60 microm-sized microspheres are injected trans-arterially and flow to hepatic tumors given their preferential blood supply from the hepatic artery. Once they lodge in the arterioles, they impart a very intense local radiotherapeutic effect. Given the combined radiation and embolic effect, the imaging findings imparted by this mode of action differ significantly from other treatments. This work represents a comprehensive review of the imaging findings following radioembolization in patients with primary liver tumors. The report discusses imaging response, benign secondary effects, and complications. This should help educate the radiologist on imaging findings that should be expected following radioembolization and therefore aid in the proper image interpretation. %+ Department of Radiology, Northwestern Memorial Hospital, Robert H. Lurie Comprehensive Cancer Center, Chicago, IL, USA. Ibrahim, Saad M Nikolaidis, Paul Miller, Frank H Lewandowski, Robert J Ryu, Robert K Sato, Kent T Senthilnathan, Sean Riaz, Ahsun Kulik, Laura Mulcahy, Mary F Omary, Reed A Salem, Riad 4177 false false 5 Abdominal imaging Abdom Imaging 566-581 ppublish Journal Article 18777189 In-Process 2009-09-06T11:56:49Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18777189 34 2009 Graft choice remains an area of contention in anterior cruciate ligament reconstruction. Poorer cosmetic results and anterior knee pain remain a problem in the use of autologous patellar tendon grafts despite excellent clinical results when compared with autologous hamstring tendon grafts. Using a 2-incision technique to harvest the patellar tendon grafts has been shown to decrease the risk of anterior knee pain to a level comparable to hamstring tendon grafts. Proper graft tunnel placement and orientation also remain controversial with several recent researchers arguing the ability to perform an anatomic reconstruction using a conventional endoscopic transtibial technique. We will describe a relatively simple and cosmetically acceptable 2-incision technique for harvesting a bone-tendon-bone graft. In addition, we will describe the bony landmarks that should be used to ensure proper anatomic graft placement and the appropriate angles that need to be used for the tibial tunnel to drill the femoral tunnel in an anatomic position and carry out a successful endoscopic transtibial tunnel anterior cruciate ligament reconstruction. Purnell, M. L. Larson, A. I. 0 2009-11-18T07:17:28Z 2009-11-17 %0 Journal Article %A Purnell, M. L. %A Larson, A. I. %D 2009 %T Mini-incision patellar tendon harvest and anterior cruciate ligament reconstruction using critical bony landmarks. %J Sports Med Arthrosc %V 17 %N 4 %P 234-241 %M 19910781 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19910781 %X Graft choice remains an area of contention in anterior cruciate ligament reconstruction. Poorer cosmetic results and anterior knee pain remain a problem in the use of autologous patellar tendon grafts despite excellent clinical results when compared with autologous hamstring tendon grafts. Using a 2-incision technique to harvest the patellar tendon grafts has been shown to decrease the risk of anterior knee pain to a level comparable to hamstring tendon grafts. Proper graft tunnel placement and orientation also remain controversial with several recent researchers arguing the ability to perform an anatomic reconstruction using a conventional endoscopic transtibial technique. We will describe a relatively simple and cosmetically acceptable 2-incision technique for harvesting a bone-tendon-bone graft. In addition, we will describe the bony landmarks that should be used to ensure proper anatomic graft placement and the appropriate angles that need to be used for the tibial tunnel to drill the femoral tunnel in an anatomic position and carry out a successful endoscopic transtibial tunnel anterior cruciate ligament reconstruction. %+ Orthopaedic Associates of Aspen and Glenwood, 100 E. Main St., Aspen, CO 81611, USA. mark@purnell.com Purnell, Mark L Larson, Andrew I 8605 false false 4 Sports medicine and arthroscopy review Sports Med Arthrosc 234-241 2009-12-01 ppublish Journal Article 19910781 In-Process 2009-11-18T07:17:28Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19910781 17 2009 Cyclocondensations of aromatic diamines with 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium salts afford doubly or quadruply charged, macrocyclic, N,N'-diarylbipyridinium cations. These are tolerant of a wide range of acids, bases, and nucleophiles, although they appear to undergo reversible, one-electron reduction by tertiary amines. Single-crystal X-ray analysis demonstrates the presence of a macrocycle conformation in which the 4,4'-bipyridinium and 4,4'-biphenylenedisulfonyl residues are suitably spaced and aligned for complexation with pi-donor arenes, and NMR studies in solution indeed confirm binding to 1,5-bis[hydroxy(ethoxy)ethoxy]naphthalene. Colquhoun, H. M. Greenland, B. W. Zhu, Z. Shaw, J. S. Cardin, C. J. Burattini, S. Elliott, J. M. Basu, S. Gasa, T. B. Stoddart, J. F. 0 2009-10-30T06:23:27Z 2009-10-29 %0 Journal Article %A Colquhoun, H. M. %A Greenland, B. W. %A Zhu, Z. %A Shaw, J. S. %A Cardin, C. J. %A Burattini, S. %A Elliott, J. M. %A Basu, S. %A Gasa, T. B. %A Stoddart, J. F. %D 2009 %T A general synthesis of macrocyclic pi-electron-acceptor systems. %J Org Lett %V 11 %N 22 %P 5238-5241 %M 19860397 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19860397 %X Cyclocondensations of aromatic diamines with 1,1'-bis(2,4-dinitrophenyl)-4,4'-bipyridinium salts afford doubly or quadruply charged, macrocyclic, N,N'-diarylbipyridinium cations. These are tolerant of a wide range of acids, bases, and nucleophiles, although they appear to undergo reversible, one-electron reduction by tertiary amines. Single-crystal X-ray analysis demonstrates the presence of a macrocycle conformation in which the 4,4'-bipyridinium and 4,4'-biphenylenedisulfonyl residues are suitably spaced and aligned for complexation with pi-donor arenes, and NMR studies in solution indeed confirm binding to 1,5-bis[hydroxy(ethoxy)ethoxy]naphthalene. %+ Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AH, UK. h.m.colquhoun@rdg.ac.uk 8542 false false 22 Organic letters Org Lett 5238-5241 2009-11-19 ppublish JOURNAL ARTICLE 19860397 In-Process 2009-11-13T07:20:48Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19860397 11 2009 2-(((3R,4R)-4-(Allyloxy)-1-benzylpyrrolidin-3-yl)methyl)-6-(2,5-dimethyl-1 H-pyrrol-1-yl)-4-methylpyridine (2), a key intermediate for the preparation of novel neuronal nitric oxide synthase (nNOS) inhibitors, is synthesized using diisopropyl (R)-(+)-malate as the starting material. The key steps involve a Frater-Seebach diastereoselective alkylation and a fast intramolecular cyclization. Xue, F. Gu, W. Silverman, R. B. 0 2009-10-30T06:22:46Z 2009-10-29 %0 Journal Article %A Xue, F. %A Gu, W. %A Silverman, R. B. %D 2009 %T Concise route to the chiral pyrrolidine core of selective inhibitors of neuronal nitric oxide. %J Org Lett %V 11 %N 22 %P 5194-5197 %M 19860389 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19860389 %X 2-(((3R,4R)-4-(Allyloxy)-1-benzylpyrrolidin-3-yl)methyl)-6-(2,5-dimethyl-1 H-pyrrol-1-yl)-4-methylpyridine (2), a key intermediate for the preparation of novel neuronal nitric oxide synthase (nNOS) inhibitors, is synthesized using diisopropyl (R)-(+)-malate as the starting material. The key steps involve a Frater-Seebach diastereoselective alkylation and a fast intramolecular cyclization. %+ Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA. 8540 false false 22 Organic letters Org Lett 5194-5197 2009-11-19 ppublish JOURNAL ARTICLE 19860389 In-Process 2009-11-13T07:20:07Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19860389 11 2009 Binary mixtures of C(20)BAS and POPC membranes were studied by solid-state (2)H NMR spectroscopy and small angle x-ray scattering (SAXS) over a wide range of concentrations and at different temperatures. Three specifically deuterated C(20)BAS derivatives--[1',1',20',20'-(2)H(4)]C(20)BAS, [2',2',19',19'-(2)H(4)]C(20)BAS, and [10',11'-(2)H(2)]C(20)BAS--combined with protiated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), as well as membranes containing POPC-d(31) and fully protiated bolalipid, were used in NMR experiments to obtain structural information for the mixtures. The (2)H NMR spectra of [10',11'-(2)H(2)]C(20)BAS/POPC membrane dispersions reveal that the bolalipid is predominantly in the transmembrane conformation at high bolalipid concentrations (100, 90, and 70 mol %). At < or =50 mol % C(20)BAS, smaller quadrupolar couplings appear in the spectra, indicating the presence of U-shaped conformers. The proportion of U-shaped bolalipids increases as the amount of POPC in the membrane increases; however, the transmembrane component remains the dominant bolalipid conformation in the membrane even at 45 degrees C and 10 mol % C(20)BAS, where it accounts for approximately 50% of the bolalipid population. The large fraction of C(20)BAS transmembrane conformers, regardless of the C(20)BAS/POPC ratio, together with the findings from molecular mean-field theory calculations, suggests the coexistence of phase-separated bolalipid-rich domains and POPC-rich domains. A single lamellar repeat distance was observed in SAXS experiments corresponding to the average repeat spacing expected for C(20)BAS- and POPC-rich domains. These observations are consistent with the presence of microphase-separated domains in the mixed membrane samples that arise from POPC-C(20)BAS hydrophobic mismatch. Brownholland, D. P. Longo, G. S. Struts, A. V. Justice, M. J. Szleifer, I. Petrache, H. I. Brown, M. F. Thompson, D. H. 0 2009-11-19T07:24:03Z 2009-11-18 %0 Journal Article %A Brownholland, D. P. %A Longo, G. S. %A Struts, A. V. %A Justice, M. J. %A Szleifer, I. %A Petrache, H. I. %A Brown, M. F. %A Thompson, D. H. %D 2009 %T Phase separation in binary mixtures of bipolar and monopolar lipid dispersions revealed by 2H NMR spectroscopy, small angle x-ray scattering, and molecular theory. %J Biophys J %V 97 %N 10 %P 2700-2709 %M 19917223 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19917223 %X Binary mixtures of C(20)BAS and POPC membranes were studied by solid-state (2)H NMR spectroscopy and small angle x-ray scattering (SAXS) over a wide range of concentrations and at different temperatures. Three specifically deuterated C(20)BAS derivatives--[1',1',20',20'-(2)H(4)]C(20)BAS, [2',2',19',19'-(2)H(4)]C(20)BAS, and [10',11'-(2)H(2)]C(20)BAS--combined with protiated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), as well as membranes containing POPC-d(31) and fully protiated bolalipid, were used in NMR experiments to obtain structural information for the mixtures. The (2)H NMR spectra of [10',11'-(2)H(2)]C(20)BAS/POPC membrane dispersions reveal that the bolalipid is predominantly in the transmembrane conformation at high bolalipid concentrations (100, 90, and 70 mol %). At < or =50 mol % C(20)BAS, smaller quadrupolar couplings appear in the spectra, indicating the presence of U-shaped conformers. The proportion of U-shaped bolalipids increases as the amount of POPC in the membrane increases; however, the transmembrane component remains the dominant bolalipid conformation in the membrane even at 45 degrees C and 10 mol % C(20)BAS, where it accounts for approximately 50% of the bolalipid population. The large fraction of C(20)BAS transmembrane conformers, regardless of the C(20)BAS/POPC ratio, together with the findings from molecular mean-field theory calculations, suggests the coexistence of phase-separated bolalipid-rich domains and POPC-rich domains. A single lamellar repeat distance was observed in SAXS experiments corresponding to the average repeat spacing expected for C(20)BAS- and POPC-rich domains. These observations are consistent with the presence of microphase-separated domains in the mixed membrane samples that arise from POPC-C(20)BAS hydrophobic mismatch. %+ Department of Chemistry, Purdue University, West Lafayette, Indiana, USA. Brownholland, David P Longo, Gabriel S Struts, Andrey V Justice, Matthew J Szleifer, Igal Petrache, Horia I Brown, Michael F Thompson, David H 8609 false false 10 Biophysical journal Biophys J 2700-2709 2009-11-18 ppublish Journal Article 19917223 In-Data-Review 2009-11-19T07:24:03Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19917223 97 2009 Dense, hydrophobic coatings comprising hydrophilic nanoparticles are deposited rapidly from water/toluene emulsions. The process of deposition is driven by a subtle interplay between interfacial phenomena, electrostatic interparticle repulsions, and hydrogen bonding between the NPs and the substrate(s). The packing fractions and the plasmonic properties of the coatings can be controlled by the pH of the aqueous phase. Once formed, the coatings can be further functionalized without a loss of mechanical integrity. Kowalczyk, B. Apodaca, M. M. Soh, S. Grzybowski, B. A. 0 2009-10-28T06:23:05Z 2009-10-27 %0 Journal Article %A Kowalczyk, B. %A Apodaca, M. M. %A Soh, S. %A Grzybowski, B. A. %D 2009 %T Rapid deposition of hydrophobic nanoparticle monolayers onto hydrophilic surfaces from liquid-liquid interfaces. %J Langmuir %V 25 %N 22 %P 12855-12859 %M 19852509 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19852509 %X Dense, hydrophobic coatings comprising hydrophilic nanoparticles are deposited rapidly from water/toluene emulsions. The process of deposition is driven by a subtle interplay between interfacial phenomena, electrostatic interparticle repulsions, and hydrogen bonding between the NPs and the substrate(s). The packing fractions and the plasmonic properties of the coatings can be controlled by the pH of the aqueous phase. Once formed, the coatings can be further functionalized without a loss of mechanical integrity. %+ Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA. 8533 false false 22 Langmuir : the ACS journal of surfaces and colloids Langmuir 12855-12859 2009-11-17 ppublish JOURNAL ARTICLE 19852509 In-Process 2009-11-13T07:20:40Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19852509 25 2009 A series of multithiol-functionalized free-base and Zn-coordinated porphyrazines (pz's) have been prepared and characterized as self-assembled monolayers (SAMs) on Au. The synthetic flexibility of the pz's provides a unique opportunity to tune their electronic and chemical characteristics and to control the distance of the redox-active pz macrocycle from the Au surface. This allows us to study the reduction potentials of these surface-bound pz's as a function of film thickness and molecular charge distribution using angle-resolved X-ray photoelectron spectroscopy and cyclic voltammetry. Upon SAM formation, the reduction potentials of all pz's show a significant positive shift from their formal potentials when free in solution (up to approximately +1 V), with the magnitude of the shift inversely related to the Au-pz distance as determined from the film thickness of the pz SAM (thicknesses ranging from 3.5 to 11.8 A). When the pz lies down on the surface, in a SAM of thickness approximately 3.5 A, the charge distribution within a pz macrocycle also plays a role in determining the potential shift. These observations are consistent with our originally proposed mechanism for potential shifts upon binding to a metal surface based on image charge effects and with the analysis of Liu and Newton (J. Phys. Chem. 1994, 98, 7162). Zong, H. Sun, P. Mirkin, C. A. Barrett, A. G. Hoffman, B. M. 0 2009-10-22T06:20:52Z 2009-10-21 %0 Journal Article %A Zong, H. %A Sun, P. %A Mirkin, C. A. %A Barrett, A. G. %A Hoffman, B. M. %D 2009 %T Varying the electrochemical potential and thickness of porphyrazine SAMs by molecular design. %J J Phys Chem B %V 113 %N 45 %P 14892-14903 %M 19839629 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19839629 %X A series of multithiol-functionalized free-base and Zn-coordinated porphyrazines (pz's) have been prepared and characterized as self-assembled monolayers (SAMs) on Au. The synthetic flexibility of the pz's provides a unique opportunity to tune their electronic and chemical characteristics and to control the distance of the redox-active pz macrocycle from the Au surface. This allows us to study the reduction potentials of these surface-bound pz's as a function of film thickness and molecular charge distribution using angle-resolved X-ray photoelectron spectroscopy and cyclic voltammetry. Upon SAM formation, the reduction potentials of all pz's show a significant positive shift from their formal potentials when free in solution (up to approximately +1 V), with the magnitude of the shift inversely related to the Au-pz distance as determined from the film thickness of the pz SAM (thicknesses ranging from 3.5 to 11.8 A). When the pz lies down on the surface, in a SAM of thickness approximately 3.5 A, the charge distribution within a pz macrocycle also plays a role in determining the potential shift. These observations are consistent with our originally proposed mechanism for potential shifts upon binding to a metal surface based on image charge effects and with the analysis of Liu and Newton (J. Phys. Chem. 1994, 98, 7162). %+ Department of Chemistry and International Institute for Nanotechnology, Northwestern University, Evanston, Illinois 60208, USA. 8505 false false 45 The journal of physical chemistry. B J Phys Chem B 14892-14903 2009-11-12 ppublish JOURNAL ARTICLE 19839629 In-Process 2009-11-07T07:17:13Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19839629 113 2009 Wei, Y. Bishop, K. J. Kim, J. Soh, S. Grzybowski, B. A. 0 2009-11-11T07:22:59Z 2009-11-07 2009-11-10 %0 Journal Article %A Wei, Y. %A Bishop, K. J. %A Kim, J. %A Soh, S. %A Grzybowski, B. A. %D 2009 %T Making Use of Bond Strength and Steric Hindrance in Nanoscale "Synthesis" %J Angew Chem Int Ed Engl %M 19899173 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19899173 %+ Department of Chemistry, Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA) http://dysa.northwestern.edu. 8581 false false Angewandte Chemie (International ed. in English) Angew Chem Int Ed Engl 2009-11-07 aheadofprint JOURNAL ARTICLE 19899173 Publisher 2009-11-11T07:22:59Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19899173 2009 Mechanically interlocked molecular (MIM) switches in the form of bistable [2]rotaxanes and [2]catenanes have proven to be-when incorporated in molecular electronic devices (MEDs) and in nanoelectromechanical systems (NEMS)-a realistic and viable alternative to the silicon chip density challenge. Structural modifications and chemical environment can have a large impact on the relaxation thermodynamics of the molecular motions, such as translation and circumrotation in bistable rotaxanes and catenanes responsible for the operation of devices based on MIMs. The effects of structural modifications on the difference in free energy (DeltaG(o)) for the equilibrium processes in switchable MIMs can be predicted by considering, firstly, the interactions present in their precursor pseudorotaxanes. By employing isothermal titration microcalorimetry (ITC) to investigate the thermodynamic parameters governing pseudorotaxane formation for a series of monosubstituted, acceptor host cyclophanes with various donor guests, in conjunction with X-ray crystallographic data, an obvious link between the noncovalent bonding interactions in pseudorotaxanes and MIMs that survive following the formation of the mechanical bond can be identified. It follows that the changes (DeltaDeltaG(o) values) in the difference of free energy during the formation of different pseudorotaxanes can subsequently be extrapolated to predict DeltaG(o) values for the thermodynamics associated with switching in analogous MIM switches, employing the same donor-acceptor recognition components. In this manner, a systematic and predictive thermodynamic approach to designing and tuning switchable MIMs and MIM-based materials has been established. Additionally, these thermodynamic relationships are reminiscent of the long forgotten concept of the 'parachor' as a molecular descriptor with respect to the additivity of physical properties in chemical systems dealing specifically with quantitative structure property-activity relationships (QSPR/QSAR). Olson, M. A. Braunschweig, A. B. Ikeda, T. Fang, L. Trabolsi, A. Slawin, A. M. Khan, S. I. Stoddart, J. F. 0 2009-10-17T06:20:07Z 2009-09-03 2009-10-16 %0 Journal Article %A Olson, M. A. %A Braunschweig, A. B. %A Ikeda, T. %A Fang, L. %A Trabolsi, A. %A Slawin, A. M. %A Khan, S. I. %A Stoddart, J. F. %D 2009 %T Thermodynamic forecasting of mechanically interlocked switches. %J Org Biomol Chem %V 7 %N 21 %P 4391-4405 %M 19830288 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19830288 %X Mechanically interlocked molecular (MIM) switches in the form of bistable [2]rotaxanes and [2]catenanes have proven to be--when incorporated in molecular electronic devices (MEDs) and in nanoelectromechanical systems (NEMS)--a realistic and viable alternative to the silicon chip density challenge. Structural modifications and chemical environment can have a large impact on the relaxation thermodynamics of the molecular motions, such as translation and circumrotation in bistable rotaxanes and catenanes responsible for the operation of devices based on MIMs. The effects of structural modifications on the difference in free energy (DeltaG(o)) for the equilibrium processes in switchable MIMs can be predicted by considering, firstly, the interactions present in their precursor pseudorotaxanes. By employing isothermal titration microcalorimetry (ITC) to investigate the thermodynamic parameters governing pseudorotaxane formation for a series of monosubstituted, acceptor host cyclophanes with various donor guests, in conjunction with X-ray crystallographic data, an obvious link between the noncovalent bonding interactions in pseudorotaxanes and MIMs that survive following the formation of the mechanical bond can be identified. It follows that the changes (DeltaDeltaG(o) values) in the difference of free energy during the formation of different pseudorotaxanes can subsequently be extrapolated to predict DeltaG(o) values for the thermodynamics associated with switching in analogous MIM switches, employing the same donor-acceptor recognition components. In this manner, a systematic and predictive thermodynamic approach to designing and tuning switchable MIMs and MIM-based materials has been established. Additionally, these thermodynamic relationships are reminiscent of the long forgotten concept of the 'parachor' as a molecular descriptor with respect to the additivity of physical properties in chemical systems dealing specifically with quantitative structure property-activity relationships (QSPR/QSAR). %+ Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA. Olson, Mark A Braunschweig, Adam B Ikeda, Taichi Fang, Lei Trabolsi, Ali Slawin, Alexandra M Z Khan, Saeed I Stoddart, J Fraser 8489 false false 21 Organic & biomolecular chemistry Org Biomol Chem 4391-4405 2009-11-07 ppublish Journal Article 19830288 In-Process 2009-10-20T06:21:11Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19830288 7 2009 Chen, H. Pazicni, S. Krett, N. L. Ahn, R. W. Penner-Hahn, J. E. Rosen, S. T. O'Halloran, T. V. 0 2009-11-08T07:20:58Z 2009-11-05 2009-11-07 %0 Journal Article %A Chen, H. %A Pazicni, S. %A Krett, N. L. %A Ahn, R. W. %A Penner-Hahn, J. E. %A Rosen, S. T. %A O'Halloran, T. V. %D 2009 %T Coencapsulation of Arsenic- and Platinum-based Drugs for Targeted Cancer Treatment. %J Angew Chem Int Ed Engl %V 48 %N 49 %P 9295-9299 %M 19894238 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19894238 %+ Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208 (USA), Fax: (+1) 847-491-7713. 8575 false false 49 Angewandte Chemie (International ed. in English) Angew Chem Int Ed Engl 9295-9299 2009-11-05 aheadofprint JOURNAL ARTICLE 19894238 Publisher 2009-11-18T07:16:22Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19894238 48 2009 A method for the oxidative alkylation of ketones through intramolecular allyl-group transfer within preformed allyldimethylsilyl enol ethers is reported. A number of examples are detailed, including a study into the effects of resident sterocenters within cyclic enol ethers. Konkol, L. C. Jones, B. T. Thomson, R. J. 0 2009-11-07T07:17:55Z 2009-11-04 2009-11-06 %0 Journal Article %A Konkol, L. C. %A Jones, B. T. %A Thomson, R. J. %D 2009 %T Oxidative Carbon-Carbon Bond Formation via Allyldimethylsilyl Enol Ethers. %J Org Lett %M 19888716 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19888716 %X A method for the oxidative alkylation of ketones through intramolecular allyl-group transfer within preformed allyldimethylsilyl enol ethers is reported. A number of examples are detailed, including a study into the effects of resident sterocenters within cyclic enol ethers. %+ Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208. 8571 false false Organic letters Org Lett 2009-11-04 aheadofprint JOURNAL ARTICLE 19888716 Publisher 2009-11-07T07:17:55Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19888716 2009 Tissue engineering scaffolds capable of gene delivery can provide a structure that supports tissue formation while also inducing the expression of inductive factors. Sustained release strategies are hypothesized to maintain elevated plasmid concentrations locally that can enhance gene transfer. In this report, we investigate the relationship between plasmid release kinetics and the extent and duration of transgene expression. Scaffolds were fabricated from polymer microspheres modified with cationic polymers (polyethylenimine, poly(l-lysine), poly(allylamine hydrochloride), polydiallyldimethylammonium) or polydopamine (PD), with PD enhancing incorporation and slowing release. In vivo implantation of scaffolds into the peritoneal fat pad had no significant changes in the level and duration of transgene expression between PD and unmodified scaffolds. Control studies with plasmid dried onto scaffolds, which exhibited a rapid release, and scaffolds with extended leaching to reduce initial quantities released had similar levels and duration of expression. Changing the plasmid design, from a cytomegalovirus (CMV) to an ubiquitin C (UbC) promoter substantially altered the duration of expression. These studies suggest that the initial dose released and vector design affect the extent and duration of transgene expression, which may be sustained over several weeks, potentially leading to numerous applications in cell transplantation and regenerative medicine. Aviles, M. O. Lin, C. H. Zelivyanskaya, M. Graham, J. G. Boehler, R. M. Messersmith, P. B. Shea, L. D. 0 2009-11-08T07:21:35Z 2009-11-03 2009-11-07 %0 Journal Article %A Aviles, M. O. %A Lin, C. H. %A Zelivyanskaya, M. %A Graham, J. G. %A Boehler, R. M. %A Messersmith, P. B. %A Shea, L. D. %D 2009 %T The contribution of plasmid design and release to in vivo gene expression following delivery from cationic polymer modified scaffolds. %J Biomaterials %M 19892398 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19892398 %X Tissue engineering scaffolds capable of gene delivery can provide a structure that supports tissue formation while also inducing the expression of inductive factors. Sustained release strategies are hypothesized to maintain elevated plasmid concentrations locally that can enhance gene transfer. In this report, we investigate the relationship between plasmid release kinetics and the extent and duration of transgene expression. Scaffolds were fabricated from polymer microspheres modified with cationic polymers (polyethylenimine, poly(l-lysine), poly(allylamine hydrochloride), polydiallyldimethylammonium) or polydopamine (PD), with PD enhancing incorporation and slowing release. In vivo implantation of scaffolds into the peritoneal fat pad had no significant changes in the level and duration of transgene expression between PD and unmodified scaffolds. Control studies with plasmid dried onto scaffolds, which exhibited a rapid release, and scaffolds with extended leaching to reduce initial quantities released had similar levels and duration of expression. Changing the plasmid design, from a cytomegalovirus (CMV) to an ubiquitin C (UbC) promoter substantially altered the duration of expression. These studies suggest that the initial dose released and vector design affect the extent and duration of transgene expression, which may be sustained over several weeks, potentially leading to numerous applications in cell transplantation and regenerative medicine. %+ Departments of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Rd, Evanston, IL 60208, USA. 8576 false false Biomaterials Biomaterials 2009-11-03 aheadofprint JOURNAL ARTICLE 19892398 Publisher 2009-11-08T07:21:35Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19892398 2009 We report the development of a previously undescribed gold nanoparticle bio-barcode assay probe for the detection of prostate specific antigen (PSA) at 330 fg/mL, automation of the assay, and the results of a clinical pilot study designed to assess the ability of the assay to detect PSA in the serum of 18 men who have undergone radical prostatectomy for prostate cancer. Due to a lack of sensitivity, available PSA immunoassays are often not capable of detecting PSA in the serum of men after radical prostatectomy. This new bio-barcode PSA assay is approximately 300 times more sensitive than commercial immunoassays. Significantly, with the barcode assay, every patient in this cohort had a measurable serum PSA level after radical prostatectomy. Patients were separated into categories based on PSA levels as a function of time. One group of patients showed low levels of PSA with no significant increase with time and did not recur. Others showed, at some point postprostatectomy, rising PSA levels. The majority recurred. Therefore, this new ultrasensitive assay points to significant possible outcomes: (i) The ability to tell patients, who have undetectable PSA levels with conventional assays, but detectable and nonrising levels with the barcode assay, that their cancer will not recur. (ii) The ability to assign recurrence earlier because of the ability to measure increasing levels of PSA before conventional tools can make such assignments. (iii) The ability to use PSA levels that are not detectable with conventional assays to follow the response of patients to adjuvant or salvage therapies. Shad Thaxton, C. Elghanian, R. Thomas, A. D. Stoeva, S. I. Lee, J. S. Smith, N. D. Schaeffer, A. J. Klocker, H. Horninger, W. Bartsch, G. Mirkin, C. A. 0 2009-10-22T06:21:20Z 2009-10-19 2009-10-21 %0 Journal Article %A Thaxton, C. S. %A Elghanian, R. %A Thomas, A. D. %A Stoeva, S. I. %A Lee, J. S. %A Smith, N. D. %A Schaeffer, A. J. %A Klocker, H. %A Horninger, W. %A Bartsch, G. %A Mirkin, C. A. %D 2009 %T Nanoparticle-based bio-barcode assay redefines "undetectable" PSA and biochemical recurrence after radical prostatectomy. %J Proc Natl Acad Sci U S A %V 106 %N 44 %P 18437-18442 %M 19841273 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19841273 %X We report the development of a previously undescribed gold nanoparticle bio-barcode assay probe for the detection of prostate specific antigen (PSA) at 330 fg/mL, automation of the assay, and the results of a clinical pilot study designed to assess the ability of the assay to detect PSA in the serum of 18 men who have undergone radical prostatectomy for prostate cancer. Due to a lack of sensitivity, available PSA immunoassays are often not capable of detecting PSA in the serum of men after radical prostatectomy. This new bio-barcode PSA assay is approximately 300 times more sensitive than commercial immunoassays. Significantly, with the barcode assay, every patient in this cohort had a measurable serum PSA level after radical prostatectomy. Patients were separated into categories based on PSA levels as a function of time. One group of patients showed low levels of PSA with no significant increase with time and did not recur. Others showed, at some point postprostatectomy, rising PSA levels. The majority recurred. Therefore, this new ultrasensitive assay points to significant possible outcomes: (i) The ability to tell patients, who have undetectable PSA levels with conventional assays, but detectable and nonrising levels with the barcode assay, that their cancer will not recur. (ii) The ability to assign recurrence earlier because of the ability to measure increasing levels of PSA before conventional tools can make such assignments. (iii) The ability to use PSA levels that are not detectable with conventional assays to follow the response of patients to adjuvant or salvage therapies. %+ Department of Urology, Northwestern University Feinberg School of Medicine, 303 East Chicago, Chicago, IL 60611, USA. cthaxton003@md.northwestern.edu 8510 false false 44 Proceedings of the National Academy of Sciences of the United States of America Proc Natl Acad Sci U S A 18437-18442 2009-11-03 ppublish JOURNAL ARTICLE 19841273 In-Process 2009-11-06T07:15:55Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19841273 106 2009 A new strut containing an imidazolium tetracarboxylic acid core has been successfully incorporated into a microporous material using paddlewheel-coordinated copper(II) ions as nodes. Sorption studies conducted on this permanently microporous material imply that it can separate carbon dioxide from methane with high selectivity. Lee, J. Y. Roberts, J. M. Farha, O. K. Sarjeant, A. A. Scheidt, K. A. Hupp, J. T. 0 2009-10-11T06:13:41Z 2009-10-10 %0 Journal Article %A Lee, J. Y. %A Roberts, J. M. %A Farha, O. K. %A Sarjeant, A. A. %A Scheidt, K. A. %A Hupp, J. T. %D 2009 %T Synthesis and gas sorption properties of a metal-azolium framework (MAF) material. %J Inorg Chem %V 48 %N 21 %P 9971-9973 %M 19813724 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19813724 %X A new strut containing an imidazolium tetracarboxylic acid core has been successfully incorporated into a microporous material using paddlewheel-coordinated copper(II) ions as nodes. Sorption studies conducted on this permanently microporous material imply that it can separate carbon dioxide from methane with high selectivity. %+ Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA. 8469 false false 21 Inorganic chemistry Inorg Chem 9971-9973 2009-11-02 ppublish JOURNAL ARTICLE 19813724 In-Process 2009-10-29T06:22:35Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19813724 48 2009 PURPOSE: To combine dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging with x-ray fluorescence microscopy (XFM) of mammary gland tissue samples from mice to identify the spatial distribution of gadolinium after intravenous injection. MATERIALS AND METHODS: C3(1) Sv-40 large T antigen transgenic mice (n = 23) were studied with institutional animal care and use committee approval. Twelve mice underwent DCE MR imaging after injection of gadodiamide, and gadolinium concentration-time curves were fit to a two-compartment pharmacokinetic model with the following parameters: transfer constant (K(trans)) and volume of extravascular extracellular space per unit volume of tissue (v(e)). Eleven mice received gadodiamide before XFM. These mice were sacrificed 2 minutes after injection, and frozen slices containing ducts distended with murine ductal carcinoma in situ (DCIS) were prepared for XFM. One mouse received saline and served as the control animal. Elemental gadolinium concentrations were measured in and around the ducts with DCIS. Hematoxylin-eosin-stained slices of mammary tissues were obtained after DCE MR imaging and XFM. RESULTS: Ducts containing DCIS were unambiguously identified on MR images. DCE MR imaging revealed gadolinium uptake along the length of ducts with DCIS, with an average K(trans) of 0.21 min(-1) +/- 0.14 (standard deviation) and an average v(e) of 0.40 +/- 0.16. XFM revealed gadolinium uptake inside ducts with DCIS, with an average concentration of 0.475 mmol/L +/- 0.380; the corresponding value for DCE MR imaging was 0.30 mmol/L +/- 0.13. CONCLUSION: These results provide insight into the physiologic basis of contrast enhancement of DCIS lesions on DCE MR images: Gadolinium penetrates and collects inside neoplastic ducts. Jansen, S. A. Paunesku, T. Fan, X. Woloschak, G. E. Vogt, S. Conzen, S. D. Krausz, T. Newstead, G. M. Karczmar, G. S. 0 2009-10-31T06:20:35Z 2009-10-30 %0 Journal Article %A Jansen, S. A. %A Paunesku, T. %A Fan, X. %A Woloschak, G. E. %A Vogt, S. %A Conzen, S. D. %A Krausz, T. %A Newstead, G. M. %A Karczmar, G. S. %D 2009 %T Ductal carcinoma in situ: X-ray fluorescence microscopy and dynamic contrast-enhanced MR imaging reveals gadolinium uptake within neoplastic mammary ducts in a murine model. %J Radiology %V 253 %N 2 %P 399-406 %M 19864527 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19864527 %X PURPOSE: To combine dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging with x-ray fluorescence microscopy (XFM) of mammary gland tissue samples from mice to identify the spatial distribution of gadolinium after intravenous injection. MATERIALS AND METHODS: C3(1) Sv-40 large T antigen transgenic mice (n = 23) were studied with institutional animal care and use committee approval. Twelve mice underwent DCE MR imaging after injection of gadodiamide, and gadolinium concentration-time curves were fit to a two-compartment pharmacokinetic model with the following parameters: transfer constant (K(trans)) and volume of extravascular extracellular space per unit volume of tissue (v(e)). Eleven mice received gadodiamide before XFM. These mice were sacrificed 2 minutes after injection, and frozen slices containing ducts distended with murine ductal carcinoma in situ (DCIS) were prepared for XFM. One mouse received saline and served as the control animal. Elemental gadolinium concentrations were measured in and around the ducts with DCIS. Hematoxylin-eosin-stained slices of mammary tissues were obtained after DCE MR imaging and XFM. RESULTS: Ducts containing DCIS were unambiguously identified on MR images. DCE MR imaging revealed gadolinium uptake along the length of ducts with DCIS, with an average K(trans) of 0.21 min(-1) +/- 0.14 (standard deviation) and an average v(e) of 0.40 +/- 0.16. XFM revealed gadolinium uptake inside ducts with DCIS, with an average concentration of 0.475 mmol/L +/- 0.380; the corresponding value for DCE MR imaging was 0.30 mmol/L +/- 0.13. CONCLUSION: These results provide insight into the physiologic basis of contrast enhancement of DCIS lesions on DCE MR images: Gadolinium penetrates and collects inside neoplastic ducts. %+ Department of Radiology, University of Chicago, Chicago, IL 60637, USA. Jansen, Sanaz A Paunesku, Tatjana Fan, Xiaobing Woloschak, Gayle E Vogt, Stefan Conzen, Suzanne D Krausz, Thomas Newstead, Gillian M Karczmar, Gregory S 8548 false false 2 Radiology Radiology 399-406 2009-11-01 ppublish Journal Article 19864527 In-Process 2009-10-31T06:20:35Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19864527 253 2009 Stimulation of Na(+)/K(+)-ATPase activity in alveolar epithelial cells by cAMP involves its recruitment from intracellular compartments to the plasma membrane. Here, we studied the role of the actin molecular motor myosin-V in this process. We provide evidence that, in alveolar epithelial cells, cAMP promotes Na(+)/K(+)-ATPase recruitment to the plasma membrane by increasing the average speed of Na(+)/K(+)-ATPase-containing vesicles moving to the cell periphery. We found that three isoforms of myosin-V are expressed in alveolar epithelial cells; however, only myosin-Va and Vc colocalized with the Na(+)/K(+)-ATPase in intracellular membrane fractions. Overexpression of dominant-negative myosin-Va or knockdown with specific shRNA increased the average speed and distance traveled by the Na(+)/K(+)-ATPase-containing vesicles, as well as the Na(+)/K(+)-ATPase activity and protein abundance at the plasma membrane to similar levels as those observed with cAMP stimulation. These data show that myosin-Va has a role in restraining Na(+)/K(+)-ATPase-containing vesicles within intracellular pools and that this restrain is released after stimulation by cAMP allowing the recruitment of the Na(+)/K(+)-ATPase to the plasma membrane and thus increased activity. Lecuona, E. Minin, A. Trejo, H. E. Chen, J. Comellas, A. P. Sun, H. Grillo, D. Nekrasova, O. E. Welch, L. C. Szleifer, I. Gelfand, V. I. Sznajder, J. I. 0 2009-10-09T06:13:28Z 2009-10-06 2009-10-08 %0 Journal Article %A Lecuona, E. %A Minin, A. %A Trejo, H. E. %A Chen, J. %A Comellas, A. P. %A Sun, H. %A Grillo, D. %A Nekrasova, O. E. %A Welch, L. C. %A Szleifer, I. %A Gelfand, V. I. %A Sznajder, J. I. %D 2009 %T Myosin-Va restrains the trafficking of Na+/K+-ATPase-containing vesicles in alveolar epithelial cells. %J J Cell Sci %V 122 %N Pt 21 %P 3915-3922 %M 19808891 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19808891 %X Stimulation of Na(+)/K(+)-ATPase activity in alveolar epithelial cells by cAMP involves its recruitment from intracellular compartments to the plasma membrane. Here, we studied the role of the actin molecular motor myosin-V in this process. We provide evidence that, in alveolar epithelial cells, cAMP promotes Na(+)/K(+)-ATPase recruitment to the plasma membrane by increasing the average speed of Na(+)/K(+)-ATPase-containing vesicles moving to the cell periphery. We found that three isoforms of myosin-V are expressed in alveolar epithelial cells; however, only myosin-Va and Vc colocalized with the Na(+)/K(+)-ATPase in intracellular membrane fractions. Overexpression of dominant-negative myosin-Va or knockdown with specific shRNA increased the average speed and distance traveled by the Na(+)/K(+)-ATPase-containing vesicles, as well as the Na(+)/K(+)-ATPase activity and protein abundance at the plasma membrane to similar levels as those observed with cAMP stimulation. These data show that myosin-Va has a role in restraining Na(+)/K(+)-ATPase-containing vesicles within intracellular pools and that this restrain is released after stimulation by cAMP allowing the recruitment of the Na(+)/K(+)-ATPase to the plasma membrane and thus increased activity. %+ Division of Pulmonary and Critical Care Medicine, Department of Medicine, Northwestern University, Chicago, IL 60611, USA. e-lecuona@northwestern.edu 8451 false false Pt 21 Journal of cell science J Cell Sci 3915-3922 2009-11-01 ppublish JOURNAL ARTICLE 19808891 In-Process 2009-11-07T07:17:08Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19808891 122 2009 Several prodrug approaches were taken to mask amino groups in two potent and selective neuronal nitric oxide synthase (nNOS) inhibitors containing either a primary or secondary amino group to lower the charge and improve blood-brain barrier (BBB) penetration. The primary amine was masked as an azide and the secondary amine as an amide or carbamate. The azide was not reduced to the amine under a variety of in vitro and ex vivo conditions. Despite the decrease in charge of the amino group as an amide and as carbamates, BBB penetration did not increase. It appears that the uses of azides as prodrugs for primary amines or amides and carbamates as prodrugs for secondary amines are not universally effective for CNS applications. Silverman, R. B. Lawton, G. R. Ranaivo, H. R. Chico, L. K. Seo, J. Watterson, D. M. 0 2009-10-04T06:14:24Z 2009-09-06 2009-10-03 %0 Journal Article %A Silverman, R. B. %A Lawton, G. R. %A Ralay Ranaivo, H. %A Chico, L. K. %A Seo, J. %A Watterson, D. M. %D 2009 %T Effect of potential amine prodrugs of selective neuronal nitric oxide synthase inhibitors on blood-brain barrier penetration. %J Bioorg Med Chem %V 17 %N 21 %P 7593-7605 %M 19796958 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19796958 %X Several prodrug approaches were taken to mask amino groups in two potent and selective neuronal nitric oxide synthase (nNOS) inhibitors containing either a primary or secondary amino group to lower the charge and improve blood-brain barrier (BBB) penetration. The primary amine was masked as an azide and the secondary amine as an amide or carbamate. The azide was not reduced to the amine under a variety of in vitro and ex vivo conditions. Despite the decrease in charge of the amino group as an amide and as carbamates, BBB penetration did not increase. It appears that the uses of azides as prodrugs for primary amines or amides and carbamates as prodrugs for secondary amines are not universally effective for CNS applications. %+ Department of Chemistry, Northwestern University, Evanston, IL 60208-3113, United States. Agman@chem.northwestern.edu 8434 false false 21 Bioorganic & medicinal chemistry Bioorg Med Chem 7593-7605 2009-11-01 ppublish JOURNAL ARTICLE 19796958 In-Process 2009-10-21T06:21:34Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19796958 17 2009 Bridges for treatment of the injured spinal cord must stabilize the injury site to prevent secondary damage and create a permissive environment that promotes regeneration. The host response to the bridge is central to creating a permissive environment, as the cell types that respond to the injury have the potential to secrete both stimulatory and inhibitory factors. We investigated multiple channel bridges for spinal cord regeneration and correlated the bridge structure to cell infiltration and axonal elongation. Poly(lactide-co-glycolide) (PLG) bridges were fabricated by a gas foaming/particulate leaching process. Channels within the bridge had diameters of 150 microm or 250 microm, and the main body of the bridge was highly porous with a controllable pore size. Upon implantation in a rat spinal cord hemisection site, cells infiltrated into the bridge pores and channels, with the pore size influencing the rate of infiltration. The pores had significant cell infiltration, including fibroblasts, macrophages, S-100 positive cells, and endothelial cells. The channels of the bridge were completely infiltrated with cells, which had aligned axially, and consisted primarily of fibroblasts, S-100 positive cells, and endothelial cells. Reactive astrocytes were observed primarily outside of the bridge, and staining for chondroitin sulfate proteoglycans was decreased in the region surrounding the bridge relative to studies without bridges. Neurofilament staining revealed a preferential growth of the neural fibers within the bridge channels relative to the pores. Multiple channel bridges capable of supporting cellular infiltration, creating a permissive environment, and directing the growth of neural fibers have potential for promoting and directing spinal cord regeneration. Yang, Y. De Laporte, L. Zelivyanskaya, M. Whittlesey, K. J. Anderson, A. Cummings, B. J. Shea, L. D. 0 2009-09-06T11:58:03Z 2009-04-23 %0 Journal Article %A Yang, Y. %A Laporte, L. D. %A Zelivyanskaya, M. L. %A Whittlesey, K. J. %A Anderson, A. J. %A Cummings, B. J. %A Shea, L. D. %D 2009 %T Multiple channel bridges for spinal cord injury: cellular characterization of host response. %J Tissue Eng Part A %V 15 %N 11 %P 3283-3295 %M 19382871 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19382871 %X Bridges for treatment of the injured spinal cord must stabilize the injury site to prevent secondary damage and create a permissive environment that promotes regeneration. The host response to the bridge is central to creating a permissive environment, as the cell types that respond to the injury have the potential to secrete both stimulatory and inhibitory factors. We investigated multiple channel bridges for spinal cord regeneration and correlated the bridge structure to cell infiltration and axonal elongation. Poly(lactide-co-glycolide) bridges were fabricated by a gas foaming/particulate leaching process. Channels within the bridge had diameters of 150 or 250 microm, and the main body of the bridge was highly porous with a controllable pore size. Upon implantation in a rat spinal cord hemisection site, cells infiltrated into the bridge pores and channels, with the pore size influencing the rate of infiltration. The pores had significant cell infiltration, including fibroblasts, macrophages, S-100beta-positive cells, and endothelial cells. The channels of the bridge were completely infiltrated with cells, which had aligned axially, and consisted primarily of fibroblasts, S-100beta-positive cells, and endothelial cells. Reactive astrocytes were observed primarily outside of the bridge, and staining for chondroitin sulfate proteoglycans was decreased in the region surrounding the bridge relative to studies without bridges. Neurofilament staining revealed a preferential growth of the neural fibers within the bridge channels relative to the pores. Multiple channel bridges capable of supporting cellular infiltration, creating a permissive environment, and directing the growth of neural fibers have potential for promoting and directing spinal cord regeneration. %+ Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208-3120, USA. 5533 false false 11 Tissue engineering. Part A Tissue Eng Part A 3283-3295 2009-11-01 ppublish JOURNAL ARTICLE 19382871 In-Process 2009-11-17T07:21:24Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19382871 15 2009 Dithiocarbamates (dtcs) have been implicated as important gold-binding groups in molecular electronics. Dtcs have two alkane branches connected at a single anchoring point that has a bidentate resonance structure. Forming readily in situ by the combination of secondary amines and CS(2), dtcs adsorb quickly onto gold surfaces. Electroactive self-assembled monolayers (eSAMs) were prepared by the coadsorption of ferrocene dialkyldithiocarbamates (Fc dtcs) with diluent dtcs on gold electrodes. Short and long alkane chains were used (11 and 16 methylene groups, respectively), and a polar ester group was incorporated. Cyclic voltammetry (CV) shows that the electrochemistry is quasi-reversible. At high surface coverage, the peak separations and full widths at half-maximum for Fc dtcs deviate from theoretical values and are analogous to that of ferrocene alkane thiols on gold at high surface coverage. Importantly, these features do not change at low Fc dtc surface coverage as observed for ferrocene alkane thiols. Ferrocene dtcs were used to label monolayer defect sites and to demonstrate the exchange of surface-bound dtcs with solution dtcs. Finally, the rate of electron transfer was analyzed using Tafel plots and ac voltammetric methods. The results for both techniques are consistent with a kinetically disperse population of redox sites. The length of the diluent alkane chain appears to have an effect on the distribution of electron-transfer rates, likely because of the eSAM structure. This work indicates that structurally, Fc dtc eSAMs are fundamentally different from alkane thiol SAMs on gold. Eckermann, A. L. Shaw, J. A. Meade, T. J. 0 2009-11-04T07:18:56Z 2009-10-30 2009-11-03 %0 Journal Article %A Eckermann, A. L. %A Shaw, J. A. %A Meade, T. J. %D 2009 %T Kinetic Dispersion in Redox-Active Dithiocarbamate Monolayers. %J Langmuir %M 19877702 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19877702 %X Dithiocarbamates (dtcs) have been implicated as important gold-binding groups in molecular electronics. Dtcs have two alkane branches connected at a single anchoring point that has a bidentate resonance structure. Forming readily in situ by the combination of secondary amines and CS(2), dtcs adsorb quickly onto gold surfaces. Electroactive self-assembled monolayers (eSAMs) were prepared by the coadsorption of ferrocene dialkyldithiocarbamates (Fc dtcs) with diluent dtcs on gold electrodes. Short and long alkane chains were used (11 and 16 methylene groups, respectively), and a polar ester group was incorporated. Cyclic voltammetry (CV) shows that the electrochemistry is quasi-reversible. At high surface coverage, the peak separations and full widths at half-maximum for Fc dtcs deviate from theoretical values and are analogous to that of ferrocene alkane thiols on gold at high surface coverage. Importantly, these features do not change at low Fc dtc surface coverage as observed for ferrocene alkane thiols. Ferrocene dtcs were used to label monolayer defect sites and to demonstrate the exchange of surface-bound dtcs with solution dtcs. Finally, the rate of electron transfer was analyzed using Tafel plots and ac voltammetric methods. The results for both techniques are consistent with a kinetically disperse population of redox sites. The length of the diluent alkane chain appears to have an effect on the distribution of electron-transfer rates, likely because of the eSAM structure. This work indicates that structurally, Fc dtc eSAMs are fundamentally different from alkane thiol SAMs on gold. %+ Departments of Chemistry, Biochemistry and Molecular and Cell Biology, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208. 8553 false false Langmuir : the ACS journal of surfaces and colloids Langmuir 2009-10-30 aheadofprint JOURNAL ARTICLE 19877702 Publisher 2009-11-04T07:18:56Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19877702 2009 A new category of mechanized nanoparticles, consisting of a hollow mesoporous silica spherical framework controlled by a supramolecular system containing the alpha-cyclodextrin (alpha-CD) ring on a stalk that is tethered to the pore openings on the nanosphere, is synthesized and tested. Construction of the nanovalve relies on the hydrogen-bonding interaction between alpha-CD and the stalk. The stalk is bonded to the nanoparticle chemically and contains an anilino group that is located on the end of the linker molecule that is closest to the pore entrance. When the alpha-CD ring is complexed with the stalk at neutral pH, the bulky cyclic component is located near the pore openings, thereby blocking departure of cargo molecules that were loaded in the nanopores and hollow interior of the particle. Protonation of the nitrogen atoms at lower pH causes the binding affinity to decrease, releasing the alpha-CD and allowing the cargo molecules to escape. The properties of this newly designed pH-responsive nanovalve are compared to those of conventional mesoporous silica nanoparticles. The on-command pH-activated release is measured using luminescence spectroscopy. The effect of different stalk lengths and pH conditions on the release of fluorescent dye cargo molecules is measured. Du, L. Liao, S. Khatib, H. A. Stoddart, J. F. Zink, J. I. 0 2009-10-07T06:13:36Z 2009-10-06 %0 Journal Article %A Du, L. %A Liao, S. %A Khatib, H. A. %A Stoddart, J. F. %A Zink, J. I. %D 2009 %T Controlled-Access Hollow Mechanized Silica Nanocontainers. %J J Am Chem Soc %V 131 %N 42 %P 15136-15142 %M 19799420 %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19799420 %X A new category of mechanized nanoparticles, consisting of a hollow mesoporous silica spherical framework controlled by a supramolecular system containing the alpha-cyclodextrin (alpha-CD) ring on a stalk that is tethered to the pore openings on the nanosphere, is synthesized and tested. Construction of the nanovalve relies on the hydrogen-bonding interaction between alpha-CD and the stalk. The stalk is bonded to the nanoparticle chemically and contains an anilino group that is located on the end of the linker molecule that is closest to the pore entrance. When the alpha-CD ring is complexed with the stalk at neutral pH, the bulky cyclic component is located near the pore openings, thereby blocking departure of cargo molecules that were loaded in the nanopores and hollow interior of the particle. Protonation of the nitrogen atoms at lower pH causes the binding affinity to decrease, releasing the alpha-CD and allowing the cargo molecules to escape. The properties of this newly designed pH-responsive nanovalve are compared to those of conventional mesoporous silica nanoparticles. The on-command pH-activated release is measured using luminescence spectroscopy. The effect of different stalk lengths and pH conditions on the release of fluorescent dye cargo molecules is measured. %+ Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China 510640, and Department of Chemistry, Northwestern University, Evanston, Illinois 60208. 8445 false false 42 Journal of the American Chemical Society J Am Chem Soc 15136-15142 2009-10-28 ppublish JOURNAL ARTICLE 19799420 Publisher 2009-11-19T07:23:59Z http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19799420 131 2009