Multifunctional natural polysaccharide peach gum-encapsulated selenium quantum dot nanocrystals monitor and scavenge reactive oxygen species in living cells.

چکیده اصلی

Reactive oxygen species act as essential mediators in physiological processes, yet excess reactive oxygen species cause cellular damage and inflammation. Current strategies for reactive oxygen species monitoring and intervention remain limited in clinical practice. Here, we report selenium quantum dots (SeQDs) coated with peach gum (PG@SeQDs), a fluorescent nanocomposite for simultaneous reactive oxygen species detection and scavenging. SeQDs serve as fluorescent emitters and reactive oxygen species-active centers encapsulated by peach gum as a stabilizing matrix. Transmission electron microscopy and dynamic light scattering show SeQDs ~5 nm (hydrodynamic ~47 nm) and PG@SeQDs ~170 nm (hydrodynamic ~204 nm), with a zeta potential shift from -2.1 to -7.4 mV after peach gum coating, indicating enhanced colloidal stability. PG@SeQDs exhibit excitation-dependent emission, with a maximum intensity near 260 nm. Biocompatibility assays in Schwann cells show markedly higher viability for PG@SeQDs versus SeQDs and minimal hemolysis (0.24-0.32%). Antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl shows concentration-dependent scavenging (56% at 40 μg/mL after 24 hours). In RSC96 cells, PG@SeQDs most effectively suppress hydrogen peroxide-induced reactive oxygen species and demonstrate time-dependent uptake with lysosomal localization and partial mitochondrial association; uptake is enhanced under inflammatory conditions (lipopolysaccharide). Collectively, PG@SeQDs represent a promising theragnostic platform for real-time reactive oxygen species imaging and management of reactive oxygen species-related inflammatory diseases, with potential for spinal cord inflammation.

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