Hypoxic preconditioning of human mesenchymal stem cells overcomes hypoxia-induced inhibition of osteogenic differentiation.

Osteogenic differentiation of human mesenchymal stem cells (hMSCs) into osteoblasts is a prerequisite for subsequent bone formation. Numerous studies have explored osteogenic differentiation under standard tissue culture conditions, which usually employ 21% of oxygen. However, bone precursor cells such as hMSCs reside in stem cell niches of low-oxygen atmospheres.

Quality of alcohol-based hand disinfectants and their regulatory status. Development and marketing authorisation.

A 2005 survey showed that there are at least four legal product classifications for hand disinfectants in the European Union: medicinal products, biocidal products, cosmetics and medical devices. An internationally harmonized classification does not exist. The regulatory status of those products is defined at national level.

Hypoxia in static and dynamic 3D culture systems for tissue engineering of bone.

Tissue engineering of sizeable cell-scaffold constructs is limited by gradients in tissue quality from the periphery toward the center. Because homogenous delivery of oxygen to three-dimensional (3D) cell cultures remains an unsolved challenge, we hypothesized that uneven oxygen supply may impede uniform cellular growth on scaffolds. In this study we challenged static and dynamic 3D culture systems designed for bone tissue engineering applications with a well-growing subclone of MC3T3-E1 preosteoblasts and continuously measured the oxygen concentrations in the center of cell-seeded scaffolds and in the surrounding medium.