The potential of surface glycoengineering for biomaterials and biosensors originates from the importance of carbohydrate-protein interactions in biological systems. The strategy employed here utilises carbene generated by illumination of diazirine to achieve covalent bonding of carbohydrates. Here, we describe the synthesis of an aryl diazirine containing a disaccharide (lactose). Surface analysis techniques [X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectroscopy (ToF-SIMS)] demonstrate its successful surface immobilisation on polystyrene (PS). Results are compared to those previously obtained with an aryl diazirine containing a monosaccharide (galactose). The biological activity of galactose- or lactose-modified PS samples is studied using rat hepatocytes, Allo A lectin and solid-phase semi-synthesis with alpha-2,6-sialyltransferase. Allo A shows some binding to galactose-modified PS but none to lactose-modified surfaces. Similar results are obtained with rat hepatocytes. In contrast, sialylation of lactose-modified PS is achieved but not with galactose-modified surfaces. The different responses indicate that the biological activity depends not only on the carbohydrate per se but also on the structure and length of the spacer.
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http://dx.doi.org/10.1016/s0968-0896(01)00172-9 | DOI Listing |
RSC Adv
January 2025
Environmental Biotechnology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Jawahar Nagar, Kapra Mandal, Medchal District Hyderabad 500078 India
Cow milk is readily adulterated due to its complex properties that can emulsify many adulterants. Among the commonly used adulterants in cow milk are hydrogen peroxide (HP) and nitrite. Commercially available HP is added to extend cow milk's shelf life, while nitrite enters through the tap or pond water added to increase cow milk's volume.
View Article and Find Full Text PDFTalanta
January 2025
Department of Chemical Engineering, Jashore University of Science and Technology, Jashore 7408, Bangladesh.
Due to the larger pore structure, the macroporous material can be used as the immobilized carrier to not only increase the enzyme loading capacity, but also facilitate the transfer of reactants and substrates. Based on this, a three-dimensional ordered macro-microporous ZIF-8 (SOM-ZIF-8) was prepared using three-dimensional ordered stacked polystyrene spheres as the hard template. The morphology and structure of SOM-ZIF-8 were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and so on.
View Article and Find Full Text PDFAnal Methods
January 2025
Environmental Biotechnology Laboratory, Department of Biological Sciences, Birla Institute of Technology and Science - Pilani, Hyderabad Campus, Hyderabad, Telangana 500078, India.
The increasing global population has raised the demand for cow milk, leading to its adulteration with harmful substances, including urea and glucose, that cause damage to humans when consumed regularly. Hence, this study started with predicting urea and glucose toxicity using ProTox-III software, wherein the results revealed that urea belongs to class IV with an LD value of 6350 mg kg and glucose belongs to class VI with an LD value of 23 000 mg kg. Then, a qualitative colorimetric kit and Fourier-transform infrared (FTIR) spectroscopy were used for the preliminary detection of urea and glucose in cow milk.
View Article and Find Full Text PDFSci Total Environ
January 2025
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai 200237, China.
Nanoplastics (NPs) have been found in natural environments. However, the sequestration of NPs and natural organic matter (NOM) coupled with the Fe(III) hydrolysis and subsequent iron oxides transformation remains unclear. Here, we investigated the behaviors of NPs during the dynamic transformation process of iron oxides in the presence of humic acids (HA).
View Article and Find Full Text PDFSmall Methods
December 2024
Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3A 0B8, Canada.
Covalently branched DNA molecules are hybrid structures where a small molecule core is covalently linked to different DNA strands. They merge the programmability of DNA nanotechnology with synthetic molecules' functionality, offering enhanced stability over their non-covalent counterparts like double-crossover tiles. They enable the efficient assembly of stable DNA nanostructures with new geometries and functionalities.
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