In this article, the properties of thermosensitive chitosan hydrogels (structural and biological) prepared using chitosan chloride and β‐glycerophosphate are presented. The porous structure of the gels was observed with a scanning electron microscopy (SEM). Rheological and other structural and morphological investigations were carried out by infrared spectroscopy and X‐ray photoelectron spectroscopy. Crystallinity of the gel was determined by X‐ray diffraction analysis. Biocompatibility of the chitosan gels was investigated by contact with bone cells (line Saos‐2) for 7 and 21 days. The cells were encapsulated and seeded onto the gel. A live/dead test showed no cytotoxic reaction. The structure of the gels, before and after the cell culture, was tested using SEM (including ESEM), to select the most suitable method of preparation and reliable visualization of the gel with cells. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46459.

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This work addresses the issue of kinetics of diffusion-controlled reactions of small radicals with macromolecules in solution. Attack of pulse-generated hydroxyl radicals on poly(N-vinylpyrrolidone)-PVP-chains of various molecular weight in water was used as the model reaction. Pulse radiolysis with spectrophotometric detection was applied to determine the rate constants by competition kinetics. The rate constant depends both on polymer concentration and on its molecular weight. In dilute solutions, a distinct dependence of the rate constant on the molecular weight is observed. In the studied range of molecular weight, the values of reaction radius, calculated using Smoluchowski equation on the basis of experimental kinetic data, are very close to the radius of gyration of polymer coils. We believe that radius of gyration, as an easily determined parameter, could possibly serve for predicting rate constants of diffusion-controlled reactions of polymers with low-molecular-weight compounds in dilute solutions. With increasing polymer concentration and thus increasing spatial overlap of polymer coils the dependence of the rate constant on the molecular weight fades away, and the rate constant values increase with increasing concentration toward the value determined for low-molecular-weight model of PVP. Most steep increase approximately coincides with the

Nematode Caenorhabditis elegans (C. elegans) was used to investigate the impact of silver nanoparticles (SNP), multiwalled carbon nanotubes (MWCNT), and polyamidoamine dendrimers (PAMAM) used in concentration of 10 particle/mL. Population-based observations and gene expression analysis were employed in this study. SNP and PAMAM caused decrease in the number of live nematodes and their body length, but MWCNT did not affect the population of nematodes. Gene expression analysis revealed significant changes caused by the presence of all studied nanomaterials, and the results strongly suggest a specific metabolic response of the nematode organism to exposure to various nanomaterials. It was shown that C. elegans is a very sensitive organism capable to respond specifically to the exposure to some nanomaterials and therefore could be considered as a possible biosensor for early warning of presence of some nanoparticles.