A Michael reaction of chitosan was conducted in water containing acetic acid with various acryl reagents. The degree of substitution could be controlled by temperature, reaction time, and the amount of acryl reagents. Although the modified chitosan derivatives with acrylic acid esters showed water-solubility, that with poly(ethylene glycol) acrylate, however, turned to water-insoluble material by lyophilization. Good biodegradation was observed in modified chitosan derivatives by standard activated sludge.
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http://dx.doi.org/10.1021/bm030022o | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
Innovation Center in Salivary Diagnostics and Nanobiotechnology, Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlandia (UFU), Uberlandia, MG, Brazil. Electronic address:
The non-invasive detection of crack/cocaine and other bioactive compounds from its pyrolysis in saliva can provide an alternative for drug analysis in forensic toxicology. Therefore, a highly sensitive, fast, reagent-free, and sustainable approach with a non-invasive specimen is relevant in public health. In this animal model study, we evaluated the effects of exposure to smoke crack cocaine on salivary flow, salivary gland weight, and salivary composition using Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy.
View Article and Find Full Text PDFBraz Dent J
December 2024
Department of Restorative Dentistry. Piracicaba Dental School, University of Campinas, Brazil.
This study investigated the effects of nonthermal atmospheric pressure plasma (NAPP) application and dentin rehydration with water (REHY) on bond strength (BS) of adhesives. Three etch-and-rinse adhesives were tested: Scotchbond Multi-Purpose (SBM / water-based primer + adhesive resin), Gluma Bond Universal (GBU / single-bottle containing acetone as organic solvent) and Prime&Bond Universal (PBU / single-bottle containing propanol as organic solvent). Adhesives were applied: 1- to phosphoric acid-etched dentin (Control), 2- after NAPP application for 45 seconds to etched dentin or 3- after REHY with water (10 seconds) of plasma-treated etched dentin.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Department of Organic and Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1, 02-097 Warsaw, Poland.
Molecularly imprinted polymers (MIPs) are defined as artificial receptors due to their selectivity and specificity. Their advantageous properties compared to biological alternatives have sparked interest among scientists, as detailed in numerous review papers. Currently, there is significant attention on adhering to the principles of green chemistry and environmental protection.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Department of Chemistry, Graduate School of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan.
Covalent adaptable networks (CANs) are polymer networks cross-linked via dynamic covalent bonds that can proceed with bond exchange reactions upon applying external stimuli. In this report, a series of cross-linked polyacrylate films were fabricated by changing the combination of acrylate monomer and the amount of diacrylate cross-linker possessing oxime-urethane bonds as a kind of dynamic covalent bond to evaluate their rheological relaxation properties. Model analysis of the experimental relaxation curves of cross-linked polyacrylate films was conducted by assuming that they consist of two types of relaxation, one of which is related to the oxime-urethane bond exchange reaction, and another of which is associated with the melting of the aggregated cross-linker.
View Article and Find Full Text PDFBiomacromolecules
December 2024
Macromolecular Chemistry and New Polymeric Materials, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 3, 9747AG Groningen, The Netherlands.
The biocompatibility and renewability of starch-based hydrogels have made them popular for applications across various sectors. Their tendency to incur damage after repeated use limits their effectiveness in practical applications. Improving the mechanical properties and self-healing of hydrogels simultaneously remains a challenge.
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