Verbundprojekttitel (1.04.2021-28.02.2022): Mikrofluidische Plattform mit Nanosensor-Arrays basierend auf mehreren Nachweisprinzipien für die Multikomponenten-Analyse von Schadstoffen und toxischen Metallionen in Wasser (EMPOLSENS); Teilprojekttitel (1.04.2021-1.03.2022): Design und Herstellung von mikrofluidischen Mehrkanalchips mit integriertem optischen Detektor, sowie die Entwicklung von Modifikationsprotokollen für die Kanälen Funktionalisierung; Verbundprojekttitel (1.09.2022-30.06.2024): Mikrofluidische Plattform mit Nanosensor-Arrays basierend auf mehreren Nachweisprinzipien für die Multikomponenten-Analyse von Schadstoffen in Wasser (EMPOLSENS); Teilprojekttitel (1.09.2022-30.06.2024): Design und Herstellung von mikrofluidischen Mehrkanalchips mit integriertem optischen Detektor, sowie die Entwicklung eines Nachweisassays für ein ausgewähltes Pestizid in Wasser

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Encapsulation of aqueous-core nanocapsules in PLLA multicompartments microparticles

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Schlussbericht zum Vorhaben

Die Acetylierung von Holz mittels Keten ist akademisch nachgewiesen, technisch bislang jedoch nicht umgesetzt. Eine mögliche Ursache ist die hohe Reaktivität von Keten, weshalb es nicht in Flaschen transportiert werden kann (Dimerisierung); unser Ansatz ist daher das Keten in-situ zu erzeugen und unmittelbar für die Modifikation von Holz zu nutzen. Ferner ist die Eindringtiefe des Gases ins Holz gering, laut Rowell (2014) dringt es maximal 3 mm in das Holz ein; unser Ansatz ist daher Furniere bis zu 2 mm und Holzfasern bzw. -späne zu acetylieren. Das Gesamtziel des Vorhabens bestand in der Entwicklung eines Verfahrens zur Acetylierung dünner Furniere und Holzfasern mittels Keten. Die gesamte Entwicklungskette wurde im beantragten Vorhaben erarbeitet: Beginnend bei der Entwicklung der Syntheseanlagen für Keten, über die Verfahrensentwicklung zur Modifikation von Holz mittels Keten, bis hin zur sensorgesteuerten Überwachung der Acetylierungskammern zur Erfüllung der erforderlichen Sicherheitskriterien. Das Arbeiten mit Keten erforderte aufgrund der Toxizität des Gases hohe Sicherheitsanforderungen. Daher stellte die Entwicklung sensorgesteuerter Detektoren zur Gewährleistung der erforderlichen Sicherheitskriterien einen zentralen Aspekt des Vorhabens dar. Am Projektende sollte eine 100-L-Anlage für den Labormaßstab (bis zu 20 kg acetyliertes Holz pro Tag) bereit. Die acetylierten Furniere und Holzfasern sollten zu Sperrholz bzw. MDF weiterverarbeitet. Systematisch wurden verschiedene Parameter variiert, um über den Acetylierungsgrad als Zielgröße die jeweilige Wirkung der Einflussparameter bestimmen zu können. Ein WPG von mindestens 20 % war avisiert, da dies als kritisch für eine Pilzresistenz eingestuft wurde und zudem das Quell- und Schwindverhalten erheblich reduzierte

Labeling of mesenchymal stromal cells with iron oxide-poly(l-lactide) nanoparticles for magnetic resonance imaging: uptake, persistence, effects on cellular function and magnetic resonance imaging properties

Background aims. Mesenchymal stromal cells (MSC) are the focus of research in regenerative medicine aiming at the regulatory approval of these cells for specific indications. To cope with the regulatory requirements for somatic cell therapy, novel approaches that do not interfere with the natural behavior of the cells are necessary. In this context in vivo magnetic resonance imaging (MRI) of labeled MSC could be an appropriate tool. Cell labeling for MRI with a variety of different iron oxide preparations is frequently published. However, most publications lack a comprehensive assessment of the noninterference of the contrast agent with the functionality of the labeled MSC, which is a prerequisite for the validity of cell-tracking via MRI. Methods.We studied the effects of iron oxide-poly(L-lactide) nanoparticles in MSC with flow cytom-etry, transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), Prussian blue staining, CyQuant® proliferation testing, colony-forming unit-fibroblast (CFU-F) assays, flow chamber adhesion testing, immuno-logic tests and differentiation tests. Furthermore iron-labeled MSC were studied by MRI in agarose phantoms and Wistar rats. Results. It could be demonstrated that MSC show rapid uptake of nanoparticles and long-lasting intracellular persistence in the endosomal compartment. Labeling of the MSC with these particles has no influence on viability, differentiation, clonogenicity, proliferation, adhesion, phenotype and immunosuppressive properties. They show excellent MRI properties in agarose phantoms and after subcutaneous implantation in rats over several weeks. Conclusions. These particles qualify for studying MSC homing and trafficking via MRI

In-vivo time course of organ uptake and blood-brain-barrier permeation of poly(L-lactide) and poly(perfluorodecyl acrylate) nanoparticles with different surface properties in unharmed and brain-traumatized rats

Background: Traumatic brain injury (TBI) has a dramatic impact on mortality and quality of life and the development of effective treatment strategies is of great socio-economic relevance. A growing interest exists in using polymeric nanoparticles (NPs) as carriers across the blood-brain barrier (BBB) for potentially effective drugs in TBI. However, the effect of NP material and type of surfactant on their distribution within organs, the amount of the administrated dose that reaches the brain parenchyma in areas with intact and opened BBB after trauma, and a possible elicited inflammatory response are still to be clarified. Methods: The organ distribution, BBB permeation and eventual inflammatory activation of polysorbate-80 (Tw80) and sodiumdodecylsulfate (SDS) stabilized poly(L-lactide) (PLLA) and poly(perfluorodecyl acrylate) (PFDL) nanoparticles were evaluated in rats after intravenous administration. The NP uptake into the brain was assessed under intact conditions and after controlled cortical impact (CCI). Results: A significantly higher NP uptake at 4 and 24 h after injection was observed in the liver and spleen, followed by the brain and kidney, with minimal concentrations in the lungs and heart for all NPs. A significant increase of NP uptake at 4 and 24 h after CCI was observed within the traumatized hemisphere, especially in the perilesional area, but NPs were still found in areas away from the injury site and the contralateral hemisphere. NPs were internalized in brain capillary endothelial cells, neurons, astrocytes, and microglia. Immunohistochemical staining against GFAP, Iba1, TNFα, and IL1β demonstrated no glial activation or neuroinflammatory changes. Conclusions: Tw80 and SDS coated biodegradable PLLA and non-biodegradable PFDL NPs reach the brain parenchyma with and without compromised BBB by TBI, even though a high amount of NPs are retained in the liver and spleen. No inflammatory reaction is elicited by these NPs within 24 h after injection. Thus, these NPs could be considered as potentially effective carriers or markers of newly developed drugs with low or even no BBB permeation

Synthesis of phosphonate-functionalized polystyrene and poly(methyl methacrylate) particles and their kinetic behavior in miniemulsion polymerization

Phosphonate-functionalized polymer nanoparticles were synthesized by free-radical copolymerization of vinylphosphonic acid (VPA) with styrene or methyl methacrylate (MMA) using the miniemulsion technique. The influence of different parameters such as monomer and surfactant type, amount of vinylphosphonic acid on the average particle size, and size distribution was studied using dynamic light scattering and transmission electron microscopy. Depending on the amount and type of the surfactant used (ionic or non-ionic), phosphonate-functionalized particles in a size range from 102 to 312 nm can be obtained. The density of the phosphonate groups on the particle surface was higher in the case of using MMA as a basis monomer than polystyrene. The kinetic behavior of VPA copolymerization with styrene or MMA using a hydrophobic initiator was investigated by reaction calorimetry. Different kinetic curves were observed for miniemulsion (co)polymerization of styrene- and MMA-based nanoparticles indicating different nucleation mechanisms