Weak acidic stable carbazate modified cellulose membranes target for scavenging carbonylated proteins in hemodialysis

Synthesis and characterization of nucleophilic polysaccharide carbazates

A simple synthesis of amino polysaccharides (PS) could be developed. Phenyl carbonates (PC) of xylan, dextran, and cellulose were easily transferred into PS carbazates by conversion with hydrazine hydrate. The degree of substitution could be adjusted by varying the molar ratio of hydrazine to PS repeating unit, enabling the preparation of both pure PS carbazates and derivatives with bifunctional reactivity containing the reactive PC and the amino group of the carbazate moiety. Further functionalization of the derivatives is feasible with carbonyl compounds like aldehydes at the carbazate groups. The reactivity of carbazate groups is shown by the reaction with 4-fluorobenzaldehyde, resulting in the formation of Schiff base conjugates.

Ozone Exposure Controls Oxidative Stress and the Inflammatory Process of Hepatocytes in Murine Models

(1) Background: Ozone exposure is a promising tool for treating liver damage since it is known to control the release of free radicals and increase the expression of antioxidant enzymes. The objective is to investigate the main intracellular pathways activated after exposure to ozone, considering the dosage of antioxidant enzymes and markers of oxidative stress. (2) Methods: This systematic review was performed based on the PRISMA guidelines and using a structured search in MEDLINE (PubMed), Scopus, and Web of Science. Bias analysis and methodological quality assessments were examined using the SYRCLE Risk of Bias tool. (3) Results: Nineteen studies were selected. The results showed that the exposure to ozone has a protective effect on liver tissue, promoting a decrease in inflammatory markers and a reduction in oxidative stress in liver tissue. In addition, ozone exposure also promoted an increase in antioxidant enzymes. The morphological consequences of controlling these intracellular pathways were reducing the tissue inflammatory process and reducing areas of degeneration and necrosis. (4) Conclusions: Ozone exposure has a beneficial effect on models of liver injury through the decrease in oxidative stress in tissue and inflammatory markers. In addition, it regulates the Nrf2/ARE antioxidant pathway and blocks the NF-κB inflammatory pathway.

High drug loading hydrophobic cross-linked dextran microspheres as novel drug delivery systems for the treatment of osteoarthritis

Drug delivery via intra-articular (IA) injection has proved to be effective in osteoarthritis (OA) therapy, limited by the drug efficiency and short retention time of the drug delivery systems (DDSs). Herein, a series of modified cross-linked dextran (Sephadex, S0) was fabricated by respectively grafting with linear alkyl chains, branched alkyl chains or aromatic chain, and acted as DDSs after ibuprofen (Ibu) loading for OA therapy. This DDSs expressed sustained drug release, excellent anti-inflammatory and chondroprotective effects both in IL-1β induced chondrocytes and OA joints. Specifically, the introduction of a longer hydrophobic chain, particularly an aromatic chain, distinctly improved the hydrophobicity of S0, increased Ibu loading efficiency, and further led to significantly improving OA therapeutic effects. Therefore, hydrophobic microspheres with greatly improved drug loading ratio and prolonged degradation rates show great potential to act as DDSs for OA therapy.

In Situ Reduced Graphene Oxide and Polyvinyl Alcohol Nanocomposites With Enhanced Multiple Properties

The nanocomposites formed by graphene oxide (GO) and carbazate-modified polyvinyl alcohol (PVA-N) were developed to investigate their multiple properties for wide applications. Their physicochemical characterizations confirmed that the in situ reduced GO (rGO) not only decreased the crystallization but also induced the porous structures inside the nanocomposites. Significantly, it revealed that the comprehensive performance of PVA-N2-2%GO consisted of PVA-N2 with the carbazate degree of substitution (DS) of 7% and the weight ratio (wt%) of 2% GO displayed 79% of tensile elongation and tensile strength of 5.96 N/mm² (MPa) by tensile testing, glass transition temperature (Tg) of 60.8°C and decomposition temperature (Td) of 303.5°C by TGA and DSC, surface contact angle at 89.4 ± 2.1°, and electrical conductivity of 9.95 × 10⁻¹¹ S/cm. The abovementioned comprehensive performance was enhanced with the increased amount of in situ rGO, contributed by the high DS of the carbazate group in PVA-N and high amount of GO. The rGO by in situ reduction was the main driving force for enhancing the multiple properties inside the nanocomposites.

Current Probes for Imaging Carbonylation in Cellular Systems and Their Relevance to Progression of Diseases

Oxidative stress resulted from reactive oxygen or nitrogen species in biological systems has a significant role in the diagnosis/progression of several human diseases. Human diseases associated with oxidative stress include Alzheimer's disease, chronic lung disease, chronic renal failure, cancer, diabetes, and fibrosis. In oxidative stress conditions, carbonylation process can be described as one of the most common modifications in biomolecules that takes place in the presence of carbonyl (C = O) groups which are introduced into molecules by direct metal-catalyzed oxidation of certain amino acids or indirectly by reaction with the oxidation of lipids and sugars. At a molecular cellular level, carbonylation can cause some defective biological consequences or chemical transformations in cells. During this process, specifically, carbonylated proteins can be accumulated in cells and trigger to develop some diseases in human body. The role of the accumulation of carbonylated proteins in the progression of several diseases has also been reported in the literature, such as neurodegenerative diseases, diabetes, obesity, aging, and cancer. Early detection of carbonylation process is, therefore, very critical to monitor these diseases at an early stage. Finding a suitable biomarker or probe is very challenging due to the need for multiple criteria: high fluorescence efficiency, stability, toxicity, and permeability. If they are designed with a good strategy, these probes are highly effective in cell biology applications and they can be used as good diagnostic tools for monitoring oxidative stress-induced carbonylation in relevant diseases. This review highlights the design and use of recent fluorescent probes for visualization of carbonylation in cellular systems and the relationship between oxidative stress and carbonyl species for causing long-term disease complications.

Carbazate-modified cross-linked dextran microparticles suppress the progression of osteoarthritis by ROS scavenging

A series of modified polysaccharide microparticles have been fabricated and their potential application for scavenging reactive oxygen species (ROS) and their derivatives to achieve osteoarthritis (OA) treatment has been explored. These microparticles were cross-linked dextran (Sephadex) with different carbazate substitution ratios determined by the TNBS assay and elemental analysis. It has been demonstrated that they could effectively scavenge carbonylated proteins and ROS including hydroxyl radicals (˙OH), superoxide anions (˙O₂^-) and H₂O₂ and their derivatives with high efficiency, improve the viability of H₂O₂-treated chondrocytes by reducing their ROS levels, as well as lower their inflammatory factors. The above ability of antioxidation and inflammation resistance improved with the increase of carbazate substitution ratio. Significantly, this work provided the proof that modified Sephadex successfully alleviated the deterioration of cartilage and the progression of OA in vivo. The proposed microparticles showed a very promising capability for reducing ROS levels and further treating OA.