Fluorescent nanoparticles using hyaluronic acid-histidine-based manganese dioxide for hydrogen peroxide imaging in inflammatory macrophages

The presence of excessive hydrogen peroxide (H₂O₂) in the body plays a key role in inflammatory diseases. Among the various methods available, fluorescent nanoparticles have been used to detect H₂O₂ in living cells. Herein, the design of CD44-targetable fluorescent nanoparticles is presented for intracellular H₂O₂ imaging in inflammatory macrophages. Accordingly, CD44-targetable hyaluronic acid-histidine (HA–His) conjugates were sequentially reacted with permanganate and fluorescein (FL) to synthesize HA–His/MnO₂/FL nanoparticles. These prepared HA–His/MnO₂/FL nanoparticles exhibited good dispersibility in water and 10% fetal bovine serum solution. Owing to their rapid responsiveness to H₂O₂, the HA–His/MnO₂/FL nanoparticles showed a good linear relationship with H₂O₂ concentration (0–100 μM). Moreover, the CD44-targetable HA–His/MnO₂/FL nanoparticles were readily internalized in lipopolysaccharide-induced inflammatory macrophages, allowing successful imaging of intracellular H₂O₂ in inflammatory macrophages.

The HA-His/MnO₂/FL nanoparticles with H₂O₂ responsiveness were readily internalized into activated macrophages, allowing successful intracellular H₂O₂ imaging in inflammatory macrophages