A series of more than 20 new amides of oleanolic acid and ursolic acid with selected aromatic amines were synthesized, and the structures of all compounds were analyzed and elucidated. Moreover, the compounds were subjected to the cytotoxicity assays in four cancer cell lines (CCRF-CEM, MCF7, HeLa, and G-361), using normal human fibroblasts (BJ) as reference cells for determining the toxicity of the investigated compounds. The 1,10-phenanthroline derivatives 4a, 4b, 5a, and 5b showed the highest cytotoxicity in all four cancer cell lines, but they were comparably toxic in human fibroblasts. The most promising results were achieved with 14a and 14b showing high cytotoxicity in the cancer cell lines and no toxicity in human fibroblasts. They were subjected to the investigation of the in vitro cell apoptosis, resulting in a confirmation of activation of apoptotic pathways in the CCRF-CEM cell line. The structure-activity relationships were documented by the cytotoxicity of 14a vs. 16a, and of 14b vs 16b, showing reverse effects in CCRF-CEM and MCF7 cancer cell lines. To investigate nanoassembly, initial screening of the target compounds by ultraviolet (UV) spectrometry was performed. Compounds 9b, 13b, 16b, and 17b, soluble both in methanol and in water, were selected for a more detailed investigation by transmission electron microscopy (TEM) microscopy and were found to form spherical nanoassemblies, frequently interconnected in small agglomerates and/or loose networks, while the other target compounds of this series showed no nanoassembling based on the TEM imaging. For each investigated compound, the nanoassemblies formed in methanol were substantially bigger than those formed in water.

• Publication type
• Journal Article MeSH

Fluorine magnetic resonance imaging (19F MRI) is a rapidly evolving research area with a high potential to advance the field of clinical diagnostics. In this review, we provide an overview of the recent progress in the field of fluorinated stimuli-responsive polymers applied as 19F MRI tracers. These polymers respond to internal or external stimuli (e.g., temperature, pH, oxidative stress, and specific molecules) by altering their physicochemical properties, such as self-assembly, drug release, and polymer degradation. Incorporating noninvasive 19F labels enables us to track the biodistribution of such polymers. Furthermore, by triggering polymer transformation, we can induce changes in 19F MRI signals, including attenuation, amplification, and chemical shift changes, to monitor alterations in the environment of the tracer. Ultimately, this review highlights the emerging potential of stimuli-responsive fluoropolymer 19F MRI tracers in the current context of polymer diagnostics research.

• MeSH
• Stimuli Responsive Polymers chemistry   MeSH
• Fluorine chemistry   MeSH
• Hydrogen-Ion Concentration MeSH
• Contrast Media chemistry   MeSH
• Humans MeSH
• Magnetic Resonance Imaging methods   MeSH
• Polymers chemistry   MeSH
• Fluorine-19 Magnetic Resonance Imaging * methods   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Stimuli Responsive Polymers MeSH
• Fluorine MeSH
• Contrast Media MeSH
• Polymers MeSH

19F magnetic resonance (19F MR) tracers stand out for their wide range of applications in experimental and clinical medicine, as they can be precisely located in living tissues with negligible fluorine background. This contribution demonstrates the long-term dissolution of multiresponsive fluorinated implants designed for prolonged release. Implants were detected for 14 (intramuscular injection) and 20 (subcutaneous injection) months by 19F MR at 4.7 T, showing favorable MR relaxation times, biochemical stability, biological compatibility and slow, long-term dissolution. Thus, polymeric implants may become a platform for long-term local theranostics.

• Publication type
• Journal Article MeSH

A new method for the preparation of polyaniline (PANI) films that have a 2D structure and can record high active mass loading (up to 30 mg cm-2) via acid-assisted polymerization in the presence of concentrated formic acid was developed. This new approach represents a simple reaction pathway that proceeds quickly at room temperature in quantitative isolated yield with the absence of any byproducts and leads to the formation of a stable suspension that can be stored for a prolonged time without sedimentation. The observed stability was explained by two factors: (a) the small size of the obtained rod-like particles (50 nm) and (b) the change of the surface of colloidal PANI particles to a positively charged form by protonation with concentrated formic acid. The films cast from the concentrated suspension were composed of amorphous PANI chains assembled into 2D structures with nanofibrillar morphology. Such PANI films demonstrated fast and efficient diffusion of the ions in liquid electrolyte and showed a pair of revisable oxidation and reduction peaks in cyclic voltammetry. Furthermore, owing to the high mass loading, specific morphology, and porosity, the synthesized polyaniline film was impregnated by a single-ion conducting polyelectrolyte-poly(LiMn-r-PEGMm) and characterized as a novel lightweight all-polymeric cathode material for solid-state Li batteries by cyclic voltammetry and electrochemical impedance spectroscopy techniques.

• Keywords
• 2D material, acid-assisted synthesis, all-solid-state L batteries, cathode material, poly(ionic liquid), polyaniline, single-ion conductor,
• Publication type
• Journal Article MeSH