MULTIDIMENSIONAL ROUGHNESS CHARACTERIZATION FOR MICROWAVE REMOTE SENSING APPLICATIONS USING A SIMPLE PHOTOGRAMMETRIC ACQUISITION SYSTEM

Soil surface roughness, as investigated in this study, is a critical parameter in microwave remote sensing. As soil surface roughness is treated as a stationary single scale isotropic process in most backscattering models, the overall objective of this study was to better understand the role of soil surface roughness in the context of backscattering. Therefore a simple photogrametric acquisition setup was developed for the characterization of soil surface roughness. In addition several suited SAR images of different sensors (ERS-2 and TerraSAR-X) were acquired to quantify the impact of soil surface roughness on the backscattered signal. Major progress achieved in this work includes the much improved characterization of in-field soil surface roughness. Good progress was also made in the understanding of backscattering from bare surface in the case of directional scattering

Einsatz von demineralisierter humaner Knochenmatrix (DBM) als Trägermaterial im Tissue Engineering von humanen Knorpelgeweben

Demineralisierte Knochenmatrix (DBM) bovinen Ursprungs zeigte in früheren Studien in vitro als auch in vivo viel versprechende Ergebnisse. Seit dem Auftreten der Kreutzfeld-Jakob-Krankheit ist die Anwendung von DBM bovinen Ursprungs kritisch zu sehen. In jüngster Zeit wurde DBM humanen Ursprungs als geeignetes Biomaterial bei der Differenzierung von mesenchymalen Stammzellen in Chondrozyten wiederentdeckt. In dieser Studie sollte DBM als Trägermaterial von Chondrozytenkulturen in vitro getestet werden. Dazu besiedelten wir demineralisierte Spongiosa, welche zur Sterilisation u.a. mit Peressigsäure behandelt wurde, mit humanen Chondrozyten des Nasenseptums in unterschiedlichen Zellkonzentrationen. Es konnten sich allerdings nach Kultivierung keine vitalen Zellen darstellen lassen. In weitergehenden auf Toxizität prüfenden Untersuchungen zeigte sich, dass das Vorhandensein von DBM zum fehlenden Nachweis von vitalen Zellen führte und Zellkulturmedium, welches mit DBM kultiviert wurde in einem anderen Ansatz das Zellwachstum der Chondrozyten hemmte. Eine Freisetzung von H+ -Ionen als Zeichen eines toxischen Effektes von DBM auf die Zellen konnte mittels pH- Metrie ebenso wenig wie ein möglicher Austritt von Peressigsäure aus DBM beobachtet werden. In der Immunhistochemie und im Western Blot wurden die Ansätze auf Kollagen Typ I, II und Kaspase untersucht. Mit den Zytotoxizitäts- und Proliferationsuntersuchungen mittels ELISA testeten wir die Wirkung von DBM auf Chondrozyten in Abhängigkeit von der Konzentration des DBM und der Dauer der Einwirkung von DBM auf die Zellen. Als nächster Schritt ist die Gaschromatografie zur Überprüfung einer eventuellen Freisetzung von Peressigsäure und Chloroform aus dem DBM geplant

Development and phenotypic characterization of a high density in vitro model of auricular chondrocytes with applications in reconstructive plastic surgery

Cultivation of phenotypically stable auricular chondrocytes will have applications in autologous chondrocyte transplantation and reconstructive surgery of cartilage. Chondrocytes grown in monolayer culture rapidly dedifferentiate assuming a fibroblast-like morphology and lose their cartilage-specific pattern of gene expression. Three-dimensional high-density culture models mimic more closely the in vivo conditions of cartilage. Therefore, this study was undertaken to test whether the high-density cultures might serve as a suitable model system to acquire phenotypically and functionally differentiated auricular chondrocytes from porcine cartilage. Freshly isolated porcine auricular chondrocytes were cultured for 7 passages in monolayer culture. From each passage (passage 0 and 1-7) cells were introduced to high-density cultures and examined by transmission electron microscopy. Western blotting was used to analyse the expression of cartilage-specific markers, such as collagen type II and cartilage specific proteoglycan, fibronectin, cell adhesion and signal transduction receptor β1-integrin, matrix metalloproteinases (MMP-9, MMP-13), cyclo-oxygenase (COX)-2 and the apoptosis commitment marker, activated caspase-3. When dedifferentiated auricular chondrocytes from monolayer passages 0-4 were cultured in high-density culture, they recovered their chondrocytic phenotype and formed cartilage nodules surrounded by fibroblast-like cells and synthesised collagen type II, proteoglycans, fibronectin and β1-integrins. However, chondrocytes from monolayer passages 5-7 did not redifferentiate to chondrocytes even when transferred to high-density culture, and did not synthesize a chondrocyte-specific extracellular matrix. Instead, they produced increasing amounts of MMP-9, MMP-13, COX-2, activated caspase-3 and underwent apoptosis. Three-dimensional high-density cultures may therefore be used to obtain sufficient quantities of fully differentiated auricular chondrocytes for autologous chondrocyte transplantation and reconstructive plastic surgery

Development and phenotypic characterization of a high density in vitro model of auricular chondrocytes with applications in reconstructive plastic surgery

Cultivation of phenotypically stable auricular chondrocytes will have applications in autologous chondrocyte transplantation and reconstructive surgery of cartilage. Chondrocytes grown in monolayer culture rapidly dedifferentiate assuming a fibroblast-like morphology and lose their cartilage-specific pattern of gene expression. Three-dimensional high-density culture models mimic more closely the in vivo conditions of cartilage. Therefore, this study was undertaken to test whether the high-density cultures might serve as a suitable model system to acquire phenotypically and functionally differentiated auricular chondrocytes from porcine cartilage. Freshly isolated porcine auricular chondrocytes were cultured for 7 passages in monolayer culture. From each passage (passage 0 and 1-7) cells were introduced to high-density cultures and examined by transmission electron microscopy. Western blotting was used to analyse the expression of cartilage-specific markers, such as collagen type II and cartilage specific proteoglycan, fibronectin, cell adhesion and signal transduction receptor ß1-integrin, matrix metalloproteinases (MMP-9, MMP-13), cyclo-oxygenase (COX)-2 and the apoptosis commitment marker, activated caspase-3. When dedifferentiated auricular chondrocytes from monolayer passages 0-4 were cultured in high-density culture, they recovered their chondrocytic phenotype and formed cartilage nodules surrounded by fibroblast-like cells and synthesised collagen type II, proteoglycans, fibronectin and ß1-integrins. However, chondrocytes from monolayer passages 5-7 did not redifferentiate to chondrocytes even when transferred to high-density culture, and did not synthesize a chondrocyte-specific extracellular matrix. Instead, they produced increasing amounts of MMP-9, MMP-13, COX-2, activated caspase-3 and underwent apoptosis. Three-dimensional high-density cultures may therefore be used to obtain sufficient quantities of fully differentiated auricular chondrocytes for autologous chondrocyte transplantation and reconstructive plastic surgery

Development and phenotypic characterization of a high density in vitro model of auricular chondrocytes with applications in reconstructive plastic surgery.

Cultivation of phenotypically stable auricular chondrocytes will have applications in autologous chondrocyte transplantation and reconstructive surgery of cartilage. Chondrocytes grown in monolayer culture rapidly dedifferentiate assuming a fibroblast-like morphology and lose their cartilage-specific pattern of gene expression. Three-dimensional high-density culture models mimic more closely the in vivo conditions of cartilage. Therefore, this study was undertaken to test whether the high-density cultures might serve as a suitable model system to acquire phenotypically and functionally differentiated auricular chondrocytes from porcine cartilage. Freshly isolated porcine auricular chondrocytes were cultured for 7 passages in monolayer culture. From each passage (passage 0 and 1-7) cells were introduced to high-density cultures and examined by transmission electron microscopy. Western blotting was used to analyse the expression of cartilage-specific markers, such as collagen type II and cartilage specific proteoglycan, fibronectin, cell adhesion and signal transduction receptor beta1-integrin, matrix metalloproteinases (MMP-9, MMP-13), cyclo-oxygenase (COX)-2 and the apoptosis commitment marker, activated caspase-3. When dedifferentiated auricular chondrocytes from monolayer passages 0-4 were cultured in high-density culture, they recovered their chondrocytic phenotype and formed cartilage nodules surrounded by fibroblast-like cells and synthesised collagen type II, proteoglycans, fibronectin and beta1-integrins. However, chondrocytes from monolayer passages 5-7 did not redifferentiate to chondrocytes even when transferred to high-density culture, and did not synthesize a chondrocyte-specific extracellular matrix. Instead, they produced increasing amounts of MMP-9, MMP-13, COX-2, activated caspase-3 and underwent apoptosis. Three-dimensional high-density cultures may therefore be used to obtain sufficient quantities of fully differentiated auricular chondrocytes for autologous chondrocyte transplantation and reconstructive plastic surgery