Cellular vibro pneumatic compacted corundum. Part 1. Features of the use of vibropressing when obtaining highly phase refractories based on a spherical burning additive

The study of a spherically burning supplement and methods of vibropressing alumina-foam polystyrene mixtures with low molding moisture ensure immediate raw flooring, the mechanization of the main technological converters, the elimination of cropping and grinding products. The peculiarities of the physico-mechanical processes of vibropressing molding masses on the easier-forming polystyrene foam, based on the features of the macro and microstructure of the burning additive are considered. Ill. 1.

Cellular vibro pneumatic compacted corundum. Part 2. Features of physical and mechanical processes of vibration treatment of alumina-foam polystyrene mixtures

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Refractory Metal Coated Alumina Foams as Support Material for Stem Cell and Fibroblasts Cultivation

Ceramics are widely used as implant materials; however, they are brittle and may emit particles when used in these applications. To overcome this disadvantage, alumina foams, which represent a 3D cellular structure comparable to that of human trabecular bone structures, were sputter coated with platinum, tantalum or titanium and modified with fibronectin or collagen type I, components of the extracellular matrix (ECM). To proof the cell material interaction, the unmodified and modified materials were cultured with (a) mesenchymal stem cells being a perfect indicator for biocompatibility and releasing important cytokines of the stem cell niche and (b) with fibroblasts characterized as mediators of inflammation and therefore an important cellular component of the foreign body reaction and inflammation after implantation. To optimize and compare the influence of metal surfaces on cellular behavior, planar glass substrates have been used. Identified biocompatible metal surface of platinum, titanium and tantalum were sputtered on ceramic foams modified with the above-mentioned ECM components to investigate cellular behavior in a 3D environment. The cellular alumina support was characterized with respect to its cellular/porous structure and niche accessibility and coating thickness of the refractory metals; the average cell size was 2.3 mm, the average size of the cell windows was 1.8 mm, and the total foam porosity was 91.4%. The Pt, Ti and Ta coatings were completely dense covering the entire alumina foam surface. The metals titanium and tantalum were colonized very well by the stem cells without a coating of ECM components, whereas the fibroblasts preferred components of the ECM on the alumina foam surface.