Analysis and study of novel terpolymers composed of acrylamide, mono-charged and double-charged cationic monomers

The composition of novel terpolymers containing acrylamide (A), acryloyloxyethyltrimethylammonium chloride (Q), and bis-1,3(N,N,N-trimethylammonium)-2-propylmethacrylate dichloride (M) was analyzed combining FTIR and potentiometric titration. Calibration with A–Q and A–M copolymers of known composition was the prerequisite for the quantitative analysis of the terpolymers by FTIR. The analysis revealed deviations from the initial monomer feed composition resulting from different monomer reactivity. The differences became more pronounced when M increased in the feed. This suggests lowest reactivity for M. Lower intrinsic viscosity [η] for higher fraction of M in the feed confirmed the suggestion. The low reactivity results from the electrostatic influence of the two charges of M on the chain propagation, yielding shorter chains for more double-charged M in the monomer feed. For all terpolymers, the counterion activity was lower than theoretically expected and did not correlate with the average charge density. Heterogeneous charge distribution was hypothesized as the reason

Cell Response to the Exposure to Chitosan-TPP//Alginate Nanogels.

Hydrophilic nanocarriers formed by electrostatic interaction of chitosan with oppositely charged macromolecules have a high potential as vectors in biomedical and pharmaceutical applications. However, comprehensive information about the fate of such nanomaterials in biological environment is lacking. We used chitosan from both animal and fungal sources to form well-characterized chitosan-pentasodium triphosphate (TPP)//alginate nanogels suitable for comparative studies. Upon exposure of human colon cancer cells (HT29 and CaCo2), breast cancer cells (MDA-MB-231 and MCF-7), glioblastoma cells (LN229), lung cancer cells (A549), and brain-derived endothelial cells (HCEC) to chitosan-(TPP)//alginate nanogels, cell type-, nanogel dosage-, and exposure time-dependent responses are observed. Comparing chitosan-TPP//alginate nanogels prepared from either animal or fungal source in terms of nanogel formation, cell uptake, reactive oxygen species production, and metabolic cell activity, no significant differences become obvious. The results identify fungal chitosan as an alternative to animal chitosan in particular if biomedical/pharmaceutical applications are intended

Analytical protocols for characterisation of sulphur-free lignin

Interlaboratory tests for chemical characterisation of sulphur-free lignins were performed by five laboratories to develop useful analytical protocols, which are lacking, and identify quality-related properties. Protocols have been established for reproducible determination of the chemical composition and functional groups, such as phenolic hydroxyl and carboxyl groups of alkaline lignins from annual fibre sources. The lignins studied, were precipitated from black liquors of alkaline pulping of annual fibre crops, flax, hemp and straw. The total (Klason and acid soluble) lignin contents of these lignins range between 83 and 97%. Contaminants may be present, such as sugar residues