ABSTRACT
A study of polyaniline (PANI) doping with various cobalt compounds, that is, cobalt(II) chloride, cobalt(II) acetate, and cobalt(II) salen, is presented. The catalysts were prepared by depositing cobalt compounds onto the polymer surface. PANI powders containing cobalt ions were obtained by one- or two-step method suspending PANI in the following acetonitrile/acetic acid solution or acetonitrile and then acetic acid solution. Moreover different ratios of Co(II) : PANI were studied. Catalysts obtained with both methods and at all ratios were investigated using various techniques including AAS and XPS spectroscopy. The optimum conditions for preparation of PANI/Co catalysts were established. Catalytic activity of polyaniline cobalt(II) supported catalysts was tested in dec-1-ene epoxidation with molecular oxygen at room temperature. The relationship between the amount of cobalt species, measured with both AAS and XPS techniques, and the activity of PANI-Co catalysts has been established.
Subject(s)
Aniline Compounds/chemistry , Cobalt/chemistry , Epoxy Compounds/chemistry , Catalysis , TemperatureABSTRACT
INTRODUCTION: The function of reconstructed bladder depends on the contracting bladder wall. This can be obtained with a proper innervating segment. Polyglycolic acid (PGA) is used as cell vehicle. Chitosan supported the adhesion and differentiation of neurons. The aim of the study was to compare PGA with PGA/chitosan 'sandwich' grafts for bladder regeneration. METHODS: 3T3 fibroblasts were seeded on 6 PGA and on 3 chitosan scaffolds and incubated for 3 days at 37 degrees C in 5% CO(2) before implantation. Three rats underwent bladder reconstruction with PGA cell-seeded grafts and 3 with PGA grafts covered with chitosan cell-seeded grafts ('sandwich' graft). Three rats in the control group were not operated. After 6 months, reconstructed tissue was stained with hematoxylin and eosin. Neurons were identified by synaptophysin and neuron-specific enolase staining. RESULTS: No complications were noticed. PGA/chitosan grafts were evaluated as (+++) and (++), while PGA grafts were evaluated as (++) and (+) with use of synaptophysin antibody. The control group was evaluated as (+). PGA/chitosan grafts were evaluated as (++) and (+), while PGA grafts were evaluated as (++) and (+) in neuron-specific enolase staining. The control group was evaluated as (+). CONCLUSION: Chitosan improved PGA's abilities as a cell matrix and in guiding neurons into the graft.
Subject(s)
Chitosan , Fibroblasts/transplantation , Nerve Regeneration , Neurons/physiology , Polyglycolic Acid , Tissue Engineering , Tissue Scaffolds , Urinary Bladder , 3T3 Cells , Animals , Feasibility Studies , Mice , Neurons/chemistry , Omentum/innervation , Phosphopyruvate Hydratase/analysis , Rats , Synaptophysin/analysis , Urinary Bladder/innervation , Urinary Bladder/surgeryABSTRACT
INTRODUCTION: The aim of this study was to evaluate polyasparagine (PAA), a new, promising scaffold. PAA was compared with alginate, which is used in cell transplantations and may be regarded as a standard. MATERIALS AND METHODS: In vitro cell viability on both scaffolds was assessed. C57B1 mice were injected s. c. alginate or PAA with or without 3T3 cells. After two months specimens from sites of injection were examined and blood samples were taken for enzymatic activity estimation. Cathepsin D activity and alpha1-antitrypsin levels were measured. RESULTS: In vitro cell viability was lowest on PAA and highest in control group. Increase in levels of enzymes measured was observed in response to PAA and alginate and was lower in case of polymer seeded with cells. Increase in alpha1-antitrypsin levels was lower in case of PAA in comparison to alginate. Scaffold degradation in histopathological specimens was visible. CONCLUSION: The results indicate that PAA implants undergo biodegradation and nonspecific inflammatory response is comparable to alginate.
Subject(s)
Cell Culture Techniques/methods , Materials Testing , Peptides , Tissue Scaffolds , 3T3 Cells/metabolism , 3T3 Cells/pathology , Alginates , Animals , Cathepsin D/metabolism , Cell Proliferation , Cell Survival , Cells, Cultured , Glucuronic Acid , Hexuronic Acids , Mice , Mice, Inbred C57BL , Trypsin/metabolismABSTRACT
The oxidation of some arenes with the alkyl side groups by means of hydrogen peroxide is been presented. As the activator of hydrogen peroxide tungstoboric acid was chosen. The catalyst was examined under both homogeneous and heterogeneous conditions. The reactions under conventional conditions were compared with the microwave assisted reactions.
Subject(s)
Borates/pharmacology , Hydrocarbons, Aromatic/chemistry , Hydrogen Peroxide/chemistry , Oxidants/chemistry , Tungsten Compounds/pharmacology , Catalysis , Microwaves , Oxidation-ReductionABSTRACT
Polymer-supported heterogeneous catalysts in a form of complexes of 8-hydroxy- quinoline with cobalt acetate were synthesized. Conjugated polymers - polyaniline (PANI), poly-o-toluidine (POT), poly-o-anisidine (POA) - were used as supports. Oxidation reactions of aliphatic and aromatic hydrocarbons were carried out in the presence of molecular oxygen at atmospheric pressure and epoxides or ketones were obtained as the main products with high selectivity.