Fluorescent polymeric nanovehicles for neural stem cell modulation.

Nanomaterials are emerging as strong candidates for applications in drug delivery and offer an alternative platform to modulate the differentiation and activity of neural stem cells. Herein we report the synthesis and characterization of two different classes of polymeric nanoparticles: N-isopropylacrylamide-based thermoresponsive nanogels RM1 and P(TEGA)-b-P(LA) nano-micelles RM2. We covalently linked the nanoparticles with fluorescent tags and demonstrate their ability to be internalized and tracked in neural stem cells from the postnatal subventricular zone, without affecting their proliferation, multipotency and differentiation characteristics up to 150 μg ml.

Epigenetic regulation of survivin by Bmi1 is cell type specific during corticogenesis and in gliomas.

Polycomb group proteins are essential regulators of stem cell function during embryonic development and in adult tissue homeostasis. Bmi1, a key component of the Polycomb Repressive Complex 1, is highly expressed in undifferentiated neural stem cells (NSC) as well as in several human cancers including high-grade gliomas--highly aggressive brain tumors. Using a conditional gene activation approach in mice, we show that overexpression of Bmi1 induces repressive epigenetic regulation of the promoter of Survivin, a well-characterized antiapoptotic protein.

Biogrid--a microfluidic device for large-scale enzyme-free dissociation of stem cell aggregates.

Culturing stem cells as free-floating aggregates in suspension facilitates large-scale production of cells in closed systems, for clinical use. To comply with GMP standards, the use of substances such as proteolytic enzymes should be avoided. Instead of enzymatic dissociation, the growing cell aggregates may be mechanically cut at passage, but available methods are not compatible with large-scale cell production and hence translation into the clinic becomes a severe bottle-neck.

[Tympanosclerosis of the tympanic membrane].

The structure of the tympanosclerotic plaques of the tympanic membrane was examined by using the scanning electron microscope. Studies were carried out on specimens of the tympanosclerotic plaques obtained during surgery in 15 patients for chronic middle ear inflammation. It was found that tympanosclerotic plaques contained fibrous fibers of different densities, distribution and calcification, and without cellular elements.