Publikationen am Institut für Chemie und Biotechnik

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Köhler, Michael;
Challenges for nanotechnology. - In: Encyclopedia, ISSN 2673-8392, Bd. 1 (2021), 3, S. 618-631

The term "Nanotechnology" describes a large field of scientific and technical activities dealing with objects and technical components with small dimensions. Typically, bodies that are in-at least-two dimensions smaller than 0.1 [my]m are regarded as "nanobjects". By this definition, a lot of advanced materials, as well as the advanced electronic devices, are objects of nanotechnology. In addition, many aspects of molecular biotechnology as well as macromolecular and supermolecular chemistry and nanoparticle techniques are summarized under "nanotechnology". Despite this size-oriented definition, nanotechnology is dealing with physics and chemistry as well as with the realization of technical functions in the area between very small bodies and single particles and molecules. This includes the shift from classical physics into the quantum world of small molecules and low numbers or single elementary particles. Besides the already established fields of nanotechnology, there is a big expectation about technical progress and solution to essential economic, medical, and ecological problems by means of nanotechnology. Nanotechnology can only meet these expectations if fundamental progress behind the recent state of the art can be achieved. Therefore, very important challenges for nanotechnology are discussed here.



https://doi.org/10.3390/encyclopedia1030051
Zhou, Xue-Quan; Mytiliniou, Maria; Hilgendorf, Jonathan; Zeng, Ye; Papadopoulou, Panagiota; Shao, Yang; Dominguez, Maximilian Paradiz; Zhang, Liyan; Hesselberth, Marcel B. S.; Bos, Erik; Siegler, Maxime A.; Buda, Francesco; Brouwer, Albert M.; Kros, Alexander; Koning, Roman I.; Heinrich, Doris; Bonnet, Sylvestre
Intracellular dynamic assembly of deep-red emitting supramolecular nanostructures based on the Pt…Pt metallophilic interaction. - In: Advanced materials, ISSN 1521-4095, Bd. 33 (2021), 37, 2008613, insges. 13 S.

https://doi.org/10.1002/adma.202008613
Zeußel, Lisa; Mai, Patrick; Sharma, Sanjay; Schober, Andreas; Ren, Shizhan; Singh, Sukhdeep
Colorimetric method for instant detection of lysine and arginine using novel Meldrum's acid-furfural conjugate. - In: ChemistrySelect, ISSN 2365-6549, Bd. 6 (2021), 27, S. 6834-6840

In the past few years Meldrum's acid furfural conjugate (MAFC) have been extensively explored as starting material for the synthesis of photo switchable donor acceptor stenhouse adducts (DASA). Hereby, we have explored the interaction of MAFC with various amino acids. To our surprise, nitrogen rich amino acids like lysine and arginine interact spontaneously with MAFC to give colored adduct immediately, whereas other amino acids, including nitrogen rich histidine, didn't show any coloration. Naked eye detection of lysine in benign solvent make this reagent an attractive new entry to the collection of chemosensors for the colorimetric detection of lysine and arginine. Intense coloration corresponds to the absorption at 514 nm under UV-Vis spectrometer. Lowest concentration of 100 m can be detected with UV-Vis spectrometer. NMR titrations reveals that the appearance of color is due to ring opening of a furfural that leads to the formation of conjugated triene species. Compared to previously reported chemosensors for lysine and arginine, MAFC offers advantages including simple synthesis, easy handling, high speed, low cost, good sensitivity/selectivity.



https://doi.org/10.1002/slct.202101140
Cao-Riehmer, Jialan; Chande, Charmi; Kalensee, Franziska; Schüler, Tim; Köhler, Michael
Microfluidically supported characterization of responses of Rhodococcus erythropolis strains isolated from different soils on Cu-, Ni-, and Co-stress. - In: Brazilian journal of microbiology, ISSN 1678-4405, Bd. 52 (2021), 3, S. 1405-1415

We present a new methodological approach for the assessment of the susceptibility of Rhodococcus erythropolis strains from specific sampling sites in response to increasing heavy metal concentration (Cu2+, Ni2+, and Co2+) using the droplet-based microfluid technique. All isolates belong to the species R. erythropolis identified by Sanger sequencing of the 16S rRNA. The tiny step-wise variation of metal concentrations from zero to the lower mM range in 500 nL droplets not only provided accurate data for critical metal ion concentrations but also resulted in a detailed visualization of the concentration-dependent response of bacterial growth and autofluorescence activity. As a result, some of the isolates showed similar characteristics in heavy metal tolerance against Cu2+, Ni2+, and Co2+. However, significantly different heavy metal tolerances were found for other strains. Surprisingly, samples from the surface soil of ancient copper mining areas supplied mostly strains with a moderate sensitivity to Cu2+, Ni2+, and Co2+, but in contrast, a soil sample from an excavation site of a medieval city that had been covered for about eight centuries showed an extremely high tolerance against cobalt ion (up to 36 mM). The differences among the strains not only may be regarded as results of adaptation to the different environmental conditions faced by the strains in nature but also seem to be related to ancient human activities and temporal partial decoupling of soil elements from the surface. This investigation confirmed that microfluidic screening offers empirical characterization of properties from same species which has been isolated from sites known to have different human activities in the past.



https://doi.org/10.1007/s42770-021-00495-2
Strutynska, Nataliia; Malyshenko, Anna; Tverdokhleb, Nina; Evstigneev, Maxim; Vovchenko, Ludmila; Prylutskyy, Yuriy; Slobodyanik, Nikolai; Ritter, Uwe
Design, characterization and mechanical properties of new Na+, CO32--apatite/alginate/C60 fullerene hybrid biocomposites. - In: Journal of the Korean Ceramic Society, ISSN 2234-0491, Bd. 58 (2021), 4, S. 422-429
Im Titel sind "+" und "2-" hochgestellt, "3" und "60" tiefgestellt

Nanoparticles (20-50 nm) of Na+, CO32--containing calcium phosphate (Na: 1.49 wt% and C: 1.53 wt%) with apatite-type structure were prepared by precipitation method from aqueous solution. According to FTIR spectroscopy data, the partial substitution of phosphate by carbonate (B-type) realized in the apatite-type structure. Obtained Na+, CO32--hydroxyapatite (HAP) was used for the preparation of hybrid biocomposites with Alginate (Alg) with weight ratio HAP: Alg = 1:1 or 2:1 and C60 fullerene (C60; from 0.2 to 4 wt%) and their mechanical properties were determined. It was found, that sample with weight ratio HAP: Alg = 2:1 and containing 4.0 wt% of C60 has the highest Young's modulus 429 MPa comparing with other determined samples. The structure modeling of the investigated system showed that the formation of triple complexes Na+, CO32--HAP-Alg-C60 is stabilized by solvophobic and stacking interactions. The created biocomposites can be used as an effective implant material for bone restoration.



https://doi.org/10.1007/s43207-020-00107-z
Chernykh, Mariia; Zavalny, Dmytro; Sokolova, Viktoriya; Ponomarenko, Stanislav; Prylutska, Svitlana; Kuziv, Yuliia; Chumachenko, Vasyl; Marynin, Andrii; Kutsevol, Nataliya; Epple, Matthias; Ritter, Uwe; Piosik, Jacek; Prylutskyy, Yuriy
A new water-soluble thermosensitive star-like copolymer as a promising carrier of the chemotherapeutic drug doxorubicin. - In: Materials, ISSN 1996-1944, Bd. 14 (2021), 13, 3517, insges. 13 S.

A new water-soluble thermosensitive star-like copolymer, dextran-graft-poly-N-iso-propilacrylamide (D-g-PNIPAM), was created and characterized by various techniques (size-exclusion chromatography, differential scanning calorimetry, Fourier-transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) spectroscopy). The viability of cancer cell lines (human transformed cervix epithelial cells, HeLa) as a model for cancer cells was studied using MTT and Live/Dead assays after incubation with a D-g-PNIPAM copolymer as a carrier for the drug doxorubicin (Dox) as well as a D-g-PNIPAM + Dox mixture as a function of the concentration. FTIR spectroscopy clearly indicated the complex formation of Dox with the D-g-PNIPAM copolymer. The size distribution of particles in Hank’s solution was determined by the DLS technique at different temperatures. The in vitro uptake of the studied D-g-PNIPAM + Dox nanoparticles into cancer cells was demonstrated by confocal laser scanning microscopy. It was found that D-g-PNIPAM + Dox nanoparticles in contrast to Dox alone showed higher toxicity toward cancer cells. All of the aforementioned facts indicate a possibility of further preclinical studies of the water-soluble D-g-PNIPAM particles’ behavior in animal tumor models in vivo as promising carriers of anticancer agents.



https://doi.org/10.3390/ma14133517
Kriničnij, Viktor I.; Yudanova, Evgeniya I.; Denisov, Nikolay N.; Konkin, Aleksei A.; Ritter, Uwe; Bogatyrenko, Victor R.; Konkin, Alexander L.
Light-induced electron paramagnetic resonance study of charge transport in fullerene and nonfullerene PBDB-T-based solar cells. - In: The journal of physical chemistry, ISSN 1932-7455, Bd. 125 (2021), 22, S. 12224-12240

https://doi.org/10.1021/acs.jpcc.1c03427
Kluitmann, Jonas; Zheng, Xuejiao; Köhler, Michael
Tuning the morphology of bimetallic gold-platinum nanorods in a microflow synthesis. - In: Colloids and surfaces, ISSN 1873-4359, Bd. 626 (2021), 127085

An automated microfluidic system with computer-controlled syringe pumps was applied for screening a three-dimensional concentration space for the formation of binary gold-platinum metal nanorods. Leveraging the micro segmented flow technique, precise residence and reactant addition timings as well as concentration spaces were addressed. The density and thickness of quasi-isotropic platinum shells on gold nanorod cores were tuned from isolated spots to a dense arrangement of high-aspect-ratio columns. The changing optical properties of the particles in the platinum deposition were used for monitoring the reaction progress and the products by the means of a fiber based micro flow-through spectrophotometer allowing to optimize process times. From our data, we propose an electrochemical model, postulating a diode-like effect and limitations for the formation of Pt nuclei on the gold surface and the formation of nano local elements. This point of view is supported by the observed decoration effects of gold facets and to the formation of columnar structures of the platinum shell.



https://doi.org/10.1016/j.colsurfa.2021.127085
Visaveliya, Nikunjkumar R.; Köhler, Michael
Softness meets with brightness: dye-doped multifunctional fluorescent polymer particles via microfluidics for labeling. - In: Advanced optical materials, ISSN 2195-1071, Bd. 9 (2021), 13, 2002219, insges. 22 S.

Fluorogenic labeling strategies have emerged as powerful tools for in vivo and in vitro imaging applications for diagnostic and theranostic purposes. Free organic chromophores (fluorescent dyes) are bright but rapidly degrade. Inorganic nanoparticles (e.g., quantum dots) are photostable but toxic to biological systems. Alternatively, dye-doped polymer particles are promising for labeling and imaging due to their properties that overcome limitations of photodegradation and toxicity. This progress report, therefore, presents various synthesis techniques for the generation of dye-doped fluorescent polymer particles. Polymer particles are relatively soft compared to inorganic nanoparticles and can be synthesized with characteristics like biocompatibility and stimuli responsiveness. Also, their ability of loading fluorophores through various interactions reveals brightness. Here, a multiscale-multicolor library of bright and soft fluorescent polymer particles is generated hierarchically. Various microfluidic supported strategies have been applied where fluorophores can be linked to polymeric networks noncovalently and covalently in the interior, and at the surface of nanoparticles (60-550 nm). Besides, microfluidic strategies for hydrophilic and hydrophobic fluorescent polymer microparticles (20-800 [my]m) have been performed for systematic tuning in size and color combination. Furthermore, soft and bright particulate assemblies are enabled through interfacial interactions at the intermediate scale (600 nm-3 [my]m) between the nanometer and micrometer lengthscale.



https://doi.org/https://doi.org/10.1002/adom.202002219
Liu, Tingxian; Berk, Linda; Wondergem, Joeri A. J.; Tong, Ciqing; Kwakernaak, Markus C.; Braak, Bas; Heinrich, Doris; Water, Bob; Kieltyka, Roxanne E.
Squaramide-based supramolecular materials drive HepG2 spheroid differentiation. - In: Advanced healthcare materials, ISSN 2192-2659, Bd. 10 (2021), 11, 2001903, insges. 10 S.

A major challenge in the use of HepG2 cell culture models for drug toxicity screening is their lack of maturity in 2D culture. 3D culture in Matrigel promotes the formation of spheroids that express liver-relevant markers, yet they still lack various primary hepatocyte functions. Therefore, alternative matrices where chemical composition and materials properties are controlled to steer maturation of HepG2 spheroids remain desired. Herein, a modular approach is taken based on a fully synthetic and minimalistic supramolecular matrix based on squaramide synthons outfitted with a cell-adhesive peptide, RGD for 3D HepG2 spheroid culture. Co-assemblies of RGD-functionalized squaramide-based and native monomers resulted in soft and self-recovering supramolecular hydrogels with a tunable RGD concentration. HepG2 spheroids are self-assembled and grown ( 150 m) within the supramolecular hydrogels with high cell viability and differentiation over 21 days of culture. Importantly, significantly higher mRNA and protein expression levels of phase I and II metabolic enzymes, drug transporters, and liver markers are found for the squaramide hydrogels in comparison to Matrigel. Overall, the fully synthetic squaramide hydrogels are proven to be synthetically accessible and effective for HepG2 differentiation showcasing the potential of this supramolecular matrix to rival and replace naturally-derived materials classically used in high-throughput toxicity screening.



https://doi.org/10.1002/adhm.202001903