Biomimetic Calcium Phosphate Nanoparticles: Biomineralization Models and Precursors for Composite Materials.

The formation of calcium phosphate under the control of water-soluble polymers is important for understanding bone growth in living organisms. These experiments also have spin-offs in the creation of composite materials, including for regenerative medicine applications. The formation of calcium phosphate (hydroxyapatite) from calcium chloride and diammonium phosphate was studied in the presence of polymers containing carboxyl, amine, and imidazole groups.

Uptake and Effects of Nanoplastics on the Dinoflagellate Gymnodinium corollarium.

Plastic nanoparticles (NPs) are the final state of plastic degradation in the environment before they disintegrate into low-molecular-weight organic compounds. Unicellular organisms are highly sensitive to the toxic effects of nanoplastics, because they are often capable of phagotrophy but are unable to consume a foreign material such as synthetic plastic. We studied the effect of polystyrene, poly(vinyl chloride), poly(methyl acrylate), and poly(methyl methacrylate) NPs on the photosynthetic dinoflagellate Gymnodinium corollarium Sundström, Kremp et Daugbjerg.

Acrylamide derivatives: A dynamic nuclear magnetic resonance study.

Substituted acrylamides have found an extensive application in organic and medical chemistry; therefore, it is very important to get insight into their features such as electronic structure, spectral properties, and stereochemical transformations. A correct interpretation of the chemical behavior and biological activity of these heteroatomic systems is impossible without knowledge of the structure of stereodynamic forms and factors determining their relative stability. The structure and peculiarities of stereodynamic behavior of substituted acrylamides and their model compounds were studied by dynamic and multinuclear H, C, and N nuclear magnetic resonance (NMR) spectroscopy in CDCl and DMSO-d solution.

Submicro- and nanoplastics: How much can be expected in water bodies?

Plastic particles smaller than 1 μm are considered to be highly dangerous pollutants due to their ability to penetrate living cells. Model experiments on the toxicity of plastics should be correlated with actual concentrations of plastics in natural water. We simulated the natural destruction of polystyrene, polyvinyl chloride, and poly(methyl methacrylate) in experiments on the abrasion of plastics with small stones.

The Probable Mechanism for Silicon Capture by Diatom Algae: Assimilation of Polycarbonic Acids with Diatoms-Is Endocytosis a Key Stage in Building of Siliceous Frustules?

Many organisms including unicellular (diatoms, radiolaria, and chrysophytes), higher plants (rice and horsetail) and animals (sponges) use silica as a main part of skeletons. The bioavailable form of silicon is silicic acid and the mechanism of silicic acid penetration into living cells is still an enigma. Macropinocytosis was assumed as a key stage of the silicon capture by diatoms but assimilation of monomeric silicic acid by this way requires enormous amounts of water to be passed through the cell.

Design of Oligonucleotide Carriers: Importance of Polyamine Chain Length.

Amine containing polymers are extensively studied as special carriers for short-chain RNA (13⁻25 nucleotides), which are applied as gene silencing agents in gene therapy of various diseases including cancer. Elaboration of the oligonucleotide carriers requires knowledge about peculiarities of the oligonucleotide⁻polymeric amine interaction. The critical length of the interacting chains is an important parameter which allows us to design sophisticated constructions containing oligonucleotide binding segments, solubilizing, protective and aiming parts.

Tagging synthetic polymers with coumarin group for study nucleic acid interaction with gene delivery agents.

Polymeric amines and complex amine containing system are actively studied and applied as gene delivery agents in gene therapy and genetic engineering. Optimizing polymer - nucleic acid ratio is the key stage in elaboration of procedures in this area. Application of fluorescent tagged oligonucleotides is widespread approach which allows to visualize nucleic acid in gel electrophoresis experiments and to find conditions of the full binding of the nucleic acid.

Bioinspired thermo- and pH-responsive polymeric amines: multimolecular aggregates in aqueous media and matrices for silica/polymer nanocomposites.

Polymeric amines have been intensively studied for application in smart systems and as matrices for the design of composite materials, including bioinspired substances. A new thermo- and pH-responsive polymer was obtained by radical polymerization of N-(3-(diethylamino)propyl)-N-methylacrylamide. Upon heating, the polymer precipitated from aqueous solutions above pH 9; the observed cloud point was dependent on the polymer concentration and decreased from 95°C at pH 9 to 40°C at pH 11.