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Transplantation of isolated chondrocytes has long been acknowledged as a potential method for rebuilding small defects in damaged or deformed cartilages. Recent advances in tissue engineering permit us to focus on production of larger amounts of cartilaginous tissue, such as might be needed for reconstructive surgery of the entire auricle. In this report we describe modification of the basic techniques that lead to production of a large amount of elastic cartilage originated from porcine and human isolated chondrocytes. Small fragments of auricular cartilage were harvested from children undergoing ear reconstruction for microtia or extirpation of preauricular tags and from ears of juvenile pigs. Enzymatically isolated elastic chondrocytes were then agitated in suspension to form the chondronlike aggregates, which were further embedded in molded hydrogel constructs made of alginate and type I collagen augmented with κ-elastin. The constructs were then implanted in nude mice and harvested 4 and 12 weeks after heterotransplantation. The resulting neocartilage closely resembled native auricular cartilage at the gross, microscopic, and ultrastructural levels. Immunohistochemistry and electron microscopy additionally confirmed that the newly produced cartilage contained the major components of the elastic cartilage-specific matrix, including collagen type II, proteoglycans, and well-assembled elastic fibers. © 1999 John Wiley & Sons, Inc. J Biomed Mater Res, 44, 280–288, 1999. more...

We report the synthesis of cyclic sulfates by halocyclization. The resulting cyclic sulfate products can be opened selectively with sodium azide to transform them into highly functionalized compounds that contain azide, alcohol, and halide groups. more...

Pertussis toxin stimulates both basal and nicotine-evoked catecholamine secretion from intact bovine adrenal chromaffin cells, as well as Ca2+-evoked release from permeabilized cells. Tetanus toxin inhibits all these effects; it reduces the secretion of intact cells treated with pertussis toxin to the basal level, and decreases by about 50% Ca2+-evoked release from permeabilized cells whether or not previously stimulated by pertussis toxin. more...