In this work, hyaluronan (HA) was grafted by a novel and an efficient mixed anhydrides methodology with (hetero)-aryl and aliphatic acrylic moieties suitable for cross-linking. A precise control of stoichiometry was achieved. Derivatives with degree of substitution (DS) below 20% did not show self-crosslinking. Due to mild reaction conditions, a negligible degradation of the polysaccharide was obtained. The influence of the feed components on the reaction efficiency and DS were studied up to 200 g/batch. The structure of the modified HA was characterized by Infrared Spectroscopy, Nuclear Magnetic Resonance, SEC-MALS and chromatographic analyses. Enzymatic degradation of derivatives was performed and isolated dimers demonstrated to be non-cytotoxic. The feasibility of the grafted HA for electrospinning with subsequent photo-crosslinking to avoid nanofibers water dissolution was demonstrated. The biocompatibility of the material, its degradation products, and the formation of honeycomb porous structures also proved the potential of the material for future in vivo applications.
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http://dx.doi.org/10.1016/j.carbpol.2015.10.077 | DOI Listing |
Cureus
December 2024
Radiology Department, Hospital Regional Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado Monterrey, Universidad de Monterrey, Monterrey, MEX.
Placenta percreta is a rare form of disorder found in the spectrum of placenta accreta and represents a considerable cause of maternal complications with an increase in mortality. The radiologist's role is essential due to the support of images acquired by magnetic resonance imaging, given their high sensitivity and specificity to predict the degree of placental invasion in substitution or accompaniment of the ultrasound study between 28 and 32 weeks of gestation. We present the case of a 29-year-old patient who was in her third pregnancy with a history of two cesarean sections at the ISSSTE Regional Hospital in Monterrey, Nuevo León.
View Article and Find Full Text PDFJ Mol Model
January 2025
School of Chemical and Environmental Engineering, China University of Mining and Technology-Beijing, Haidian District, Ding No.11 Xueyuan Road, Beijing, 100083, People's Republic of China.
Context: Understanding the structural characteristics of coal at the molecular level is fundamental for its effective utilization. To explore the molecular structure characteristic, the long-flame coal from Daliuta (DLT), coking coal from Yaoqiao (YQ), and anthracite from Taixi (TX) were investigated using various techniques such as elemental analysis, Fourier transform infrared spectroscopy, solid-state C nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy. Based on the structural parameters, the coal molecular model was constructed and optimized.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Institute of Chemistry, Federal University of Uberlândia, Uberlândia 38400-902, Brazil.
Cellulose tosylate (MCC-Tos) is a key derivative for surface modification and a crucial precursor for cellulose compatibilization in click reactions, enabling its functionalization for advanced applications. Replacing tosyl groups with alkyne groups broadens cellulose's potential in biocompatible reactions, such as thiol-yne click chemistry and protein/enzyme immobilization. To achieve this, we optimized the heterogeneous synthesis of MCC-Tos using a Doehlert matrix statistical design, evaluating the influence and interaction of the reaction conditions.
View Article and Find Full Text PDFMater Horiz
January 2025
Department of Material Sciences, Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Ibaraki 305-5358, Japan.
The efficient immobilization of redox mediators remains a major challenge in the design of mediated enzyme electrode platforms. In addition to stability, the ability of the redox-active material to mediate electron transfer from the active-site buried enzymes, such as flavin adenine dinucleotide-dependent glucose dehydrogenase (FADGDH) and lactate oxidase (LOx), is also crucial. Conventional immobilization techniques can be synthetically challenging, and immobilized mediators often exhibit limited durability, particularly in continuous operation.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
State Key Laboratory of Heavy Oil Processing and Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao, Shandong, People's Republic of China. Electronic address:
Combining polymer and surfactant in one agent namely polymeric surfactants with both high viscosity and surface activity has become a viable alternative for the traditional enhanced oil recovery (EOR) processes. With the purpose of developing new polymeric surfactants, the biopolymer flooding agent sphingan WL gum was modified by octenyl succinic anhydride (OSA) through the esterification reaction. The effects of molecular weight (MW) of WL and the OSA: WL ratio on the properties of the products were investigated.
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