Glycosylation on the cell surface contains abundant biological information, and detecting the glycan on cell surfaces can offer critical insight into biology and diseases. Here, a signal amplification strategy for the sensitive detection of glycan expression on the cell surface was proposed. In this approach, glycans on the cell surface were detected with poly(glycidyl methacrylate)-grafted silica nanosphere labeled with quantum dots (QDs) and biotin through the specific affinity reaction of avidin-biotin on the cancer cells. Glycans on the cell surface were first labeled via selective oxidization of sialyl groups into aldehydes by periodate . Aniline-catalyzed hydrazone ligation with biotin hydrazide was then used for the specific recognition to avidin . The nanoprobe was fabricated with “living” SiO 2 nanoparticles with alkyl bromide groups on their surfaces. They were then subsequently grafted with poly(glycidyl methacrylate) (PGMA) brushes via the successive surface-initiated atom transfer radical polymerization . The CdTe QDs and biotin were immobilized through a ring-open reaction with epoxy groups in the PGMA brushes to obtain QDs/biotin-polymer brush-functionalized silica nanosphere (SiO 2 -PGMA-QDs/biotin). Enhanced sensitivity could be achieved by an increase in CdTe QDs loading per assay event, because of the large number of surface functional epoxy groups offered by the PGMA. As a result, fluorescence signal increased versus the unamplified method. This method successfully demonstrates a simple, specific, and potent method to detect glycans on the cell surface.
Graphical This study presents a design strategy, synthesis, and evaluation of balanced COX inhibitors derived from natural anti-inflammatory ascidian metabolites and celecoxib, highlighting their potential therapeutic value in the context of inflammation. The serious adverse effects caused by non-selective and selective cyclooxygenase-2 (COX-2) inhibitors remain significant concerns for current anti-inflammatory drugs. In this study, we present the design and synthesis of a novel series of celecoxib analogs incorporating a hydrazone linker, which were subjected to in silico analysis to compare their binding poses with those of clinically used nonsteroidal anti-inflammatory drugs (NSAIDs) against COX-1 and COX-2. The synthesized analogs were evaluated for their inhibitory activity against both COX enzymes, and compound 6 m , exhibiting potent balanced inhibition, was selected for subsequent in vitro anti-inflammatory assays. Treatment with 6 m effectively suppressed the NF-κB signaling pathway in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophages, resulting in reduced expression of pro-inflammatory factors such as inducible nitric oxide synthase (iNOS), COX-2, tumor necrosis factor- α (TNF-α), interleukin-6 (IL-6), IL-1β, as well as decreased production of prostaglandin E 2 (PGE 2 ), nitric oxide (NO), and reactive oxygen species (ROS). However, 6 m has no effect on the MAPK signaling pathway. Therefore, due to its potent in vitro anti-inflammatory activity coupled with lack of cytotoxicity, 6 m represents a promising candidate for further development as a new lead compound targeting inflammation.
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