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Adrenocortical carcinoma (ACC) is a rare tumor and prognosis is overall poor but heterogeneous. Mitotane (MT) has been used for treatment of ACC for decades, either alone or in combination with cytotoxic chemotherapy. Even at doses up to 6 g per day, more than half of the patients do not achieve targeted plasma concentration (14–20 mg L\(^{-1}\)) even after many months of treatment due to low water solubility, bioavailability, and unfavorable pharmacokinetic profile. Here a novel MT nanoformulation with very high MT concentrations in physiological aqueous media is reported. The MT‐loaded nanoformulations are characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and powder X‐ray diffraction which confirms the amorphous nature of the drug. The polymer itself does not show any cytotoxicity in adrenal and liver cell lines. By using the ACC model cell line NCI‐H295 both in monolayers and tumor cell spheroids, micellar MT is demonstrated to exhibit comparable efficacy to its ethanol solution. It is postulated that this formulation will be suitable for i.v. application and rapid attainment of therapeutic plasma concentrations. In conclusion, the micellar formulation is considered a promising tool to alleviate major drawbacks of current MT treatment while retaining bioactivity toward ACC in vitro.
The detection of toxic gases, such as NH\(_{3}\) and CO, in the environment is of high interest in chemical, electronic, and automotive industry as even small amounts can display a health risk for workers. Sensors for the real‐time monitoring of these gases should be simple, robust, reversible, highly sensitive, inexpensive and show a fast response. The indicator supraparticles presented herein can fulfill all of these requirements. They consist of silica nanoparticles, which are assembled to supraparticles upon spray‐drying. Sensing molecules such as Reichardt's dye and a binuclear rhodium complex are loaded onto the microparticles to target NH\(_{3}\) and CO detection, respectively. The spray‐drying technique affords high flexibility in primary nanoparticle size selection and thus, easy adjustment of the porosity and specific surface area of the obtained micrometer‐sized supraparticles. This ultimately enables the fine‐tuning of the sensor sensitivity and response. For the application of the indicator supraparticles in a gas detection device, they can be immobilized on a coating. Due to their microscale size, they are large enough to poke out of thin coating layers, thus guaranteeing their gas accessibility, while being small enough to be applicable to flexible substrates.
Lifetime techniques are applied to diverse fields of study including materials sciences, semiconductor physics, biology, molecular biophysics and photochemistry.
Here we present DDRS4PALS, a software for the acquisition and simulation of lifetime spectra using the DRS4 evaluation board (Paul Scherrer Institute, Switzerland) for time resolved measurements and digitization of detector output pulses. Artifact afflicted pulses can be corrected or rejected prior to the lifetime calculation to provide the generation of high-quality lifetime spectra, which are crucial for a profound analysis, i.e. the decomposition of the true information. Moreover, the pulses can be streamed on an (external) hard drive during the measurement and subsequently downloaded in the offline mode without being connected to the hardware. This allows the generation of various lifetime spectra at different configurations from one single measurement and, hence, a meaningful comparison in terms of analyzability and quality. Parallel processing and an integrated JavaScript based language provide convenient options to accelerate and automate time consuming processes such as lifetime spectra simulations.
Detaillierte Einblicke in die Struktur von mit Wirkstoffen beladenen Polymermizellen sind rar, aber wichtig um gezielt optimierte Transportsysteme entwickeln zu können. Wir konnten beobachten, dass eine Erhöhung der Curcumin‐Beladung von Triblockcopolymeren auf Basis von Poly(2‐oxazolinen) und Poly(2‐oxazinen) schlechtere Auflösungseigenschaften nach sich zieht. Mitthilfe von Festkörper‐NMR‐Spektroskopie und komplementären Techniken ist es möglich, ein ladungsabhängiges Strukturmodell auf molekularer Ebene zu erstellen, das eine Erklärung für die beobachteten Unterschiede liefert. Dabei belegen die Änderungen der chemischen Verschiebungen und Kreuzsignale in 2D‐NMR‐Experimenten die Beteiligung des hydrophoben Polymerblocks an der Koordination der Curcumin‐Moleküle, während bei höherer Beladung auch eine zunehmende Wechselwirkung mit dem hydrophilen Polymerblock beobachtet wird. Letztere könnte elementar für die Stabilisierung von ultrahochbeladenen Polymermizellen sowie das Design von verbesserten Wirkstofftransportsystemen sein.
Background: Culturing of cells is typically performed on standard tissue culture plates generating growth conditions, which in general do not reflect the native three-dimensional cellular environment. Recent investigations provide insights in parameters, which strongly affect the general cellular behavior triggering essential processes such as cell differentiation. The physical properties of the used material, such as stiffness, roughness, or topology, as well as the chemical composition of the cell-surface interface are shown to play a key role in the initiation of particular cellular responses. Methods: We extended our previous research, which identified thin films of metallo-supramolecular coordination polyelectrolytes (MEPEs) as substrate to trigger the differentiation of muscular precursor cells. Results: Here, we show that the same MEPEs similarly stimulate the osteogenic differentiation of pre-osteoblasts. Remarkably, MEPE modified surfaces also trigger the differentiation of primary bone derived mesenchymal stem cells (BMSCs) towards the osteogenic lineage. Conclusion: This result leads to the conclusion that these surfaces individually support the specification of cell differentiation toward lineages that correspond to the natural commitment of the particular cell types. We, therefore, propose that Fe-MEPEs may be used as scaffold for the treatment of defects at least in muscular or bone tissue.
Positron annihilation lifetime spectroscopy (PALS) provides a powerful technique for non-destructive microstructure investigations in a broad field of material classes such as metals, semiconductors, polymers or porous glasses. Even though this method is well established for more than five decades, no proper standardization for the used setup configuration and subsequent data processing exists. Eventually, this could lead to an insufficiency of data reproducibility and avoidable deviations.
Here we present experimentally obtained and simulated data of positron lifetime spectra at various statistics measured on pure tin (4N-Sn) by using a semi-analog/digital setup, where the digital section consists of the DRS4 evaluation board, “Design and performance of the 6 GHz waveform digitizing chip DRS4” [1]. The analog section consists of nuclear instrument modules (NIM), which externally trigger the DRS4 evaluation board to reduce the digitization and, thus, increase the acquisition efficiency. For the experimentally obtained lifetime spectra, 22Na sealed in Kapton foil served as a positron source, whereas 60Co was used for the acquisition of the prompt spectrum, i.e. the quasi instrument response function. Both types of measurements were carried out under the same conditions.
All necessary data and information regarding the data acquisition and data reduction are provided to allow reproducibility by other research groups.
Polymer micelles are an attractive means to solubilize water insoluble compounds such as drugs. Drug loading, formulations stability and control over drug release are crucial factors for drug‐loaded polymer micelles. The interactions between the polymeric host and the guest molecules are considered critical to control these factors but typically barely understood. Here, we compare two isomeric polymer micelles, one of which enables ultra‐high curcumin loading exceeding 50 wt.%, while the other allows a drug loading of only 25 wt.%. In the low capacity micelles, steady‐state fluorescence revealed a very unusual feature of curcumin fluorescence, a high energy emission at 510 nm. Time‐resolved fluorescence upconversion showed that the fluorescence life time of the corresponding species is too short in the high‐capacity micelles, preventing an observable emission in steady‐state. Therefore, contrary to common perception, stronger interactions between host and guest can be detrimental to the drug loading in polymer micelles.