Sulfated glycosaminoglycans (GAG) are components of the bone marrow stem cell niche and to a minor extent of mature bone tissue with important functions in regulating stem cell lineage commitment and differentiation. We anticipated that artificial extracellular matrices (aECM) composed of collagen I and synthetically oversulfated GAG derivatives affect preferentially the differentiation of osteoblast-precursor cells and early osteoblasts. A set of gradually sulfated chondroitin sulfate and hyaluronan derivatives was used for the preparation of aECM. All these matrices were analysed with human bone marrow stromal cells to identify the most potent aECM and to determine the influence of the degree and position of sulfate groups and the kind of disaccharide units on the osteogenic differentiation. Oversulfated GAG derivatives with a sulfate group at the C-6 position of the N-acetylglycosamine revealed the most pronounced proosteogenic effect as determined by tissue nonspecific alkaline phosphatase activity and calcium deposition. A subset of the aECM was further analysed with different primary osteoblasts and cell lines reflecting different maturation stages to test whether the effect of sulfated GAG derivatives depends on the maturation status of the cells. It was shown that the proosteogenic effect of aECMwasmost prominent in early osteoblasts. [ABSTRACT FROM AUTHOR]

Sulfated glycosaminoglycans (GAG) are components of the bone marrow stem cell niche and to a minor extent of mature bone tissue with important functions in regulating stem cell lineage commitment and differentiation. We anticipated that artificial extracellular matrices (aECM) composed of collagen I and synthetically oversulfated GAG derivatives affect preferentially the differentiation of osteoblast-precursor cells and early osteoblasts. A set of gradually sulfated chondroitin sulfate and hyaluronan derivatives was used for the preparation of aECM. All these matrices were analysed with human bone marrow stromal cells to identify the most potent aECM and to determine the influence of the degree and position of sulfate groups and the kind of disaccharide units on the osteogenic differentiation. Oversulfated GAG derivatives with a sulfate group at the C-6 position of the N-acetylglycosamine revealed the most pronounced proosteogenic effect as determined by tissue nonspecific alkaline phosphatase activity and calcium deposition. A subset of the aECM was further analysed with different primary osteoblasts and cell lines reflecting different maturation stages to test whether the effect of sulfated GAG derivatives depends on the maturation status of the cells. It was shown that the proosteogenic effect of aECMwasmost prominent in early osteoblasts. [ABSTRACT FROM AUTHOR]

Ziel der vorliegenden Arbeit war es, die methodischen Aspekte bei der Entwicklung mechanischer Simulationen zur Messung der Funktionalitäten von Handballschuhen systematisch zu untersuchen und aus den Ergebnissen allgemeingültige Aussagen zum Abstraktionsgrad abzuleiten. Die Untersuchungen der vier methodischen Aspekte Messgerät, Auswertemodell, Einfluss- und Eingangsgröße haben ergeben, dass insgesamt drei Aspekte einen Einfluss auf den Messwert hatten. Mit Ausnahme der Ergebnisse zum Aspekt Eingangsgröße besaßen die untersuchten methodischen Aspekte jeweils einen Einfluss auf den Messwert. Anhand der Ergebnisse konnte abgeleitet werden, dass der Abstraktionsgrad einen Einfluss auf die Messwerte besitzt. / The aim of the current work was to investigate systematically the methodological aspects used in the development of mechanical simulations, which are capable of measuring the functionalities of handball shoes, and to derive general conclusions about the proper degree of abstraction from the results. The investigations of the four methodological aspects, namely measuring instrument, evaluation model, influence quantity and input quantity, have shown that three aspects had an influence on the measurand. Except for the results on the aspect of input quantity, each of the examined methodological aspects had an influence on the measurand. Based on the results, it could be deduced that the degree of abstraction has an influence on the measurand.