Dynamic properties of the alkaline vesicle population at hippocampal synapses.

In compensatory endocytosis, scission of vesicles from the plasma membrane to the cytoplasm is a prerequisite for intravesicular reacidification and accumulation of neurotransmitter molecules. Here, we provide time-resolved measurements of the dynamics of the alkaline vesicle population which appears upon endocytic retrieval. Using fast perfusion pH-cycling in live-cell microscopy, synapto-pHluorin expressing rat hippocampal neurons were electrically stimulated.

Comparative studies on osteogenic potential of micro- and nanofibre scaffolds prepared by electrospinning of poly(ε-caprolactone).

The biocompatibility and osteogenic potential of four fibrous scaffolds prepared by electrospinning of poly(ε-caprolactone) (PCL) was studied with MG-63 osteoblast cells. Two different kinds of scaffolds were obtained by adjustment of spinning conditions, which were characterized as nano- or microfibrous. In addition of one nanofibrous, scaffold was made more hydrophilic by blending PCL with Pluronics F 68.

Key physiological parameters dictate triggering of activity-dependent bulk endocytosis in hippocampal synapses.

To maintain neurotransmission in central neurons, several mechanisms are employed to retrieve synaptically exocytosed membrane. The two major modes of synaptic vesicle (SV) retrieval are clathrin-mediated endocytosis and activity-dependent bulk endocytosis (ADBE). ADBE is the dominant SV retrieval mode during intense stimulation, however the precise physiological conditions that trigger this mode are not resolved.

Systematic heterogeneity of fractional vesicle pool sizes and release rates of hippocampal synapses.

Hippocampal neurons in tissue culture develop functional synapses that exhibit considerable variation in synaptic vesicle content (20-350 vesicles). We examined absolute and fractional parameters of synaptic vesicle exocytosis of individual synapses. Their correlation to vesicle content was determined by activity-dependent discharge of FM-styryl dyes.

Immobilization of Candida antarctica lipase B on Polystyrene Nanoparticles.

Polystyrene (PS) nanoparticles were prepared via a nanoprecipitation process. The influence of the pH of the buffer solution used during the immobilization process on the loading of Candida antarctica lipase B (Cal-B) and on the hydrolytic activity (hydrolysis of p-nitrophenyl acetate) of the immobilized Cal-B was studied. The pH of the buffer solution has no influence on enzyme loading, while immobilized enzyme activity is very dependent on the pH of adsorption.

Batchwise and continuous organophilic nanofiltration of Grubbs-type olefin metathesis catalysts.

A mass-tagged N-mesityl imidazolinium salt with four additional -CH(2)NCy(2) substituents was synthesized, leading to a molecular mass of nearly 1100 g mol(-1) in the corresponding carbene ligand. This mass-tagged ligand was used to generate the respective Grubbs II and Grubbs-Hoveyda type complexes. The catalytic activity of the latter complex was tested in several olefin metathesis reactions and found to be slightly superior to that of the related N-mesityl based complex.