Auflistung nach Autor:in "Palivan, Cornelia"

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Expanding the potential of the solvent-assisted method to create bio-interfaces from amphiphilic block copolymers
(American Chemical Society, 09.06.2021) Di Leone, Stefano; Vallapurackal, Jaicy; Yorulmaz Avsar, Saziye; Kyropolou, Myrto; Ward, Thomas; Palivan, Cornelia; Meier, Wolfgang
Artificial membranes, as materials with biomimetic properties, can be applied in various fields, such as drug screening or bio-sensing. The solvent-assisted method (SA) represents a straightforward method to prepare lipid solid-supported membranes. It overcomes the main limitations of established membrane preparation methods, such as Langmuir–Blodgett (LB) or vesicle fusion. However, it has not yet been applied to create artificial membranes based on amphiphilic block copolymers, despite their enhanced mechanical stability compared to lipid-based membranes and bio-compatible properties. Here, we applied the SA method on different amphiphilic di- and triblock poly(dimethylsiloxane)-block-poly(2-methyl-2-oxazoline) (PDMS-b-PMOXA) copolymers and optimized the conditions to prepare artificial membranes on a solid support. The real-time membrane formation, the morphology, and the mechanical properties have been evaluated by a combination of atomic force microscopy and quartz crystal microbalance. Then, selected biomolecules including complementary DNA strands and an artificial deallylase metalloenzyme (ADAse) were incorporated into these membranes relying on the biotin–streptavidin technology. DNA strands served to establish the capability of these synthetic membranes to interact with biomolecules by preserving their correct conformation. The catalytic activity of the ADAse following its membrane anchoring induced the functionality of the biomimetic platform. Polymer membranes on solid support as prepared by the SA method open new opportunities for the creation of artificial membranes with tailored biomimetic properties and functionality.
01A - Beitrag in wissenschaftlicher Zeitschrift
High-throughput silica nanoparticle detection for quality control of complex early life nutrition food matrices
(American Chemical Society, 2024) Maffeis, Viviana; Otter, Andrea; Düsterloh, André; Kind, Lucy; Palivan, Cornelia; Saxer, Sina
The addition of nanomaterials to improve product properties has become a matter of course for many commodities: e.g., detergents, cosmetics, and food products. While this practice improves product characteristics, the increasing exposure and potential impact of nanomaterials (<100 nm) raise concerns regarding both the human body and the environment. Special attention should be taken for vulnerable individuals such as those who are ill, elder, or newborns. But detecting and quantifying nanoparticles in complex food matrices like early life nutrition (ELN) poses a significant challenge due to the presence of additional particles, emulsion-droplets, or micelles. There is a pressing demand for standardized protocols for nanoparticle quantification and the specification of “nanoparticle-free” formulations. To address this, silica nanoparticles (SiNPs), commonly used as anticaking agents (AA) in processed food, were employed as a model system to establish characterization methods with different levels of accuracy and sensitivity versus speed, sample handling, and automatization. Different acid treatments were applied for sample digestion, followed by size exclusion chromatography. Morphology, size, and number of NPs were measured by transmission electron microscopy, and the amount of Si was determined by microwave plasma atomic emission spectrometry. This successfully enabled distinguishing SiNP content in ELN food formulations with 2–4% AA from AA-free formulations and sorting SiNPs with diameters of 20, 50, and 80 nm. Moreover, the study revealed the significant influence of the ELN matrix on sample preparation, separation, and characterization steps, necessitating method adaptations compared to the reference (SiNP in water). In the future, we expect these methods to be implemented in standard quality control of formulation processes, which demand high-throughput analysis and automated evaluation.
01A - Beitrag in wissenschaftlicher Zeitschrift