voltage-calcium-dual-channel-optical-mapping-cultured-hl-1-atrial

Voltage and Calcium Dual Channel Optical Mapping of Cultured HL-1 Atrial Myocyte Monolayer

Optical mapping has proven to be a valuable technique to detect cardiac electrical activity on both intact ex vivo hearts and in cultured myocyte ...

Loyola University Chicago

Endothelialization and antithrombogenicity are two key issues in stent implantation. The layer-by-layer (LbL) deposition of anticoagulant heparin and cell compatible collagen was explored to develop a multilayered coating with synergic property of antithrombogenicity and fast endothelialization. The quartz crystal microbalance with dissipation (QCM-D), UV spectrometer, spectroscopic ellipsometry, scanning electron microscopy, and confocal laser scanning microscopy investigations indicate that the LbL technique, which based on molecular assembly, provides an easy way to develop a smooth, homogenous, and stable coating onto stents. In vitro blood clotting time tests and the platelet adhesion tests show that the multilayer-modified stents present good hemocompatibility. In vitro endothelial cell (EC) culture results show that the multilayer-modified surfaces accelerate the adhesion and proliferation of ECs. These results illustrate that a stent surface coating with properties of antithrombogenicity and EC preference was obtained via heparin/collagen multilayer modification. This surface coating may have great potential in facilitating in situ endothelialization of blood contacting materials.

Heparin/collagen multilayer as a thromboresistant and endothelial favorable coating for intravascular stent.

A series of α-glutamic acid scaffold based 4-(benzamido)-4-(1,3,4-oxadiazol-2-yl) butanoic acids were designed and synthesized as new ADAMTS inhibitors. The compounds dose-dependently inhibited the enzymatic activities of ADAMTS-4 and ADAMTS-5. One of the most active compound 2h potently inhibited ADAMTS-4 and ADAMTS-5 with IC(50) values of 1.2 and 0.8 μM, respectively. These inhibitors may serve as new lead compounds for further development of therapeutics to treat osteoarthritis.

Structure-activity study on a series of α-glutamic acid scaffold based compounds as new ADAMTS inhibitors.

A simple and efficient approach for the synthesis of [1,2,3]triazolo[1,5-a]quinoxalin-4(5H)-ones is described. The methodology is based on a tandem reaction of 1-(2-haloaryl)propiolamides with sodium azide through a [3 + 2] azide-alkyne cycloaddition and intramolecular Ullmann-type C-N coupling process.

Synthesis of [1,2,3]triazolo[1,5-a]quinoxalin-4(5H)-ones through copper-catalyzed tandem reactions of N-(2-haloaryl)propiolamides with sodium azide.

A novel copper-catalyzed tandem reaction was developed by utilizing two famous copper-catalyzed reactions, CuAAC and Ullmann coupling. The trapping of the C-Cu intermediate produced in CuAAC led to further formation of an aryl C-C bond through intramolecular Ullmann C-C coupling.

A CuAAC/Ullmann C-C coupling tandem reaction: copper-catalyzed reactions of organic azides with N-(2-iodoaryl)propiolamides or 2-iodo-N-(prop-2-ynyl)benzenamines.

c-Jun N-terminal kinase (JNK) activation is implicated in cardiovascular diseases and ageing, which are linked to enhanced propensity to atrial fibrillation (AF). However, the contribution of JNK to AF remains unknown. Thus, we assessed the role of JNK in remodelling of gap junction connexin43 (Cx43) and development of AF.

c-Jun N-terminal kinase activation contributes to reduced connexin43 and development of atrial arrhythmias.

An enantioselective intramolecular O-arylation was achieved through desymmetrization with Pd-catalyzed coupling reactions. The intramolecular asymmetric aryl C-O coupling reactions of 2-(2-haloaryl)propane-1,3-diols led to the enantioselective formation of chiral (3,4-dihydro-2H-chromen-3-yl)methanols in good yields and high enantiomeric selectivity.

Pd-catalyzed desymmetric intramolecular O-arylation reaction: enantioselective synthesis of (3,4-dihydro-2H-chromen-3-yl)methanols.

Gap junctions (GJs) are the principal membrane structures that conduct electrical impulses between cardiac myocytes while interstitial collagen (IC) can physically separate adjacent myocytes and limit cell-cell communication. Emerging evidence suggests that both GJ and interstitial structural remodeling are linked to cardiac arrhythmia development. However, automated quantitative identification of GJ distribution and IC deposition from microscopic histological images has proven to be challenging. Such quantification is required to improve the understanding of functional consequences of GJ and structural remodeling in cardiac electrophysiology studies.

Novel methods of automated quantification of gap junction distribution and interstitial collagen quantity from animal and human atrial tissue sections.

Free-standing poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) membranes with polydopamine (PDA) coating were prepared based on the combination of electrospinning and self-polymerization of dopamine. This is a facile, mild, controllable, and low-energy consumption process without any rigorous restriction to reactive conditions. Benefiting from the high specific surface area of electrospun membranes and the abundant "adhesive" functional groups of polydopamine, the as-prepared membranes exhibit efficient adsorption performance towards methyl blue with the adsorption capacity reaching up to 1147.6 mg g(-1). Moreover, compared to other nanoparticle adsorbents, the as-prepared self-standing membrane is highly flexible, easy to operate and retrieve, and most importantly, easy to elute, and regenerate, which enable its potential applications in wastewater treatment.

Polydopamine-coated electrospun poly(vinyl alcohol)/poly(acrylic acid) membranes as efficient dye adsorbent with good recyclability.

To improve the radical-trapping capacity of the natural antioxidants, alkylthio-, alkylseleno-, and alkyltelluro groups were introduced into all vacant aromatic positions in β-, γ- and δ-tocopherol. Reaction of the tocopherols with electrophilic chalcogen reagents generated by persulfate oxidation of dialkyl dichalcogenides provided convenient but low-yielding access to many sulfur and selenium derivatives, but failed in the case of tellurium. An approach based on lithiation of the appropriate bromo-tocopherol, insertion of chalcogen into the carbon-lithium bond, air-oxidation to a dichalcogenide, and final borohydride reduction/alkylation turned out to be generally applicable to the synthesis of all chalcogen derivatives. Whereas alkylthio- and alkylseleno analogues were generally poorer quenchers of lipid peroxyl radicals than the corresponding parents, all tellurium compounds showed a substantially improved radical-trapping activity. Introduction of alkyltelluro groups into the tocopherol scaffold also caused a dramatic increase in the regenerability of the antioxidant. In a two-phase lipid peroxidation system containing N-acetylcysteine as a water-soluble co-antioxidant the inhibition time was up to six-fold higher than that recorded for the natural antioxidants.

Jiajie Yan

Department of Cell and Molecular Physiology

Loyola University Chicago

Voltage and Calcium Dual Channel Optical Mapping of Cultured HL-1 Atrial Myocyte Monolayer