Oxidative stress leads to chondrocyte apoptosis and extracellular matrix (ECM) degradation, thus contributing to the pathogenesis of osteoarthritis (OA). Herein, curcumin with remarkable antioxidant and anti-inflammatory activities has been employed as an organic ligand to coordinate ferric ions for enhancing the water-solubility and biocompatibility of natural product curcumin. The obtained iron-curcumin-based coordination nanoparticles (Fe-Cur NPs) exhibit great water-solubility and efficient reactive oxygen/nitrogen species (ROS/RNS) scavenging ability. In vitro chondrocyte evaluation experiments indicated that the intracellular ROS/RNS induced by interleukin 1β (IL-1β) could be efficiently scavenged by these Fe-Cur NPs and oxidative-stress-induced cell death could be preserved as well. In addition, post intra-articular (i.a.) injection into OA rat joints, Fe-Cur NPs could greatly inhibit OA progression via activating the nuclear factor-erythroid 2 related factor-2 (Nrf2) and inhibiting nod-like receptor protein-3 (NLRP3) inflammasome activation in primary rat chondrocytes, as well as decrease the production of matrix degrading proteases and other inflammatory mediators. The efficient antioxidation and anti-inflammation performance of Fe-Cur NPs endow them as a promising nanoplatform for treatment of various inflammatory diseases, and more detailed researches will be conducted in the future.

Drug-eluting stent (DES) is a promising strategy for esophageal cancer. However, full-covered drug-loaded stents cause damage to non-tumor tissue in the esophagus, and the development controlled-release system to prevent non-tumor tissue injure is currently a major challenge. Here, in situ mineralized manganese dioxide coating on Ce6 embedded electrospun fibers covered stent was developed for effective tumor therapy via intraluminal photodynamic therapy (PDT), which could reduce phototoxicity to normal esophageal tissue. Oxidation of manganese ions, which was previously swelled between fibers, was used to accomplish mineralization. After implantation, the manganese dioxide coating in situ reacts with tumor endogenous H⁺ and H₂O₂, which, on the one hand, could effectively alleviate the hypoxic microenvironment which leads to resistance to PDT, and on the other hand, could expose the Ce6-fibers below the coating for intraluminal PDT. In addition, due to the slow degradation of the coating, this stent could own sustained photodynamic performance for up to one month. Notably, the PDT efficiency of the stent was investigated on orthotopic rabbit esophageal cancer models. Overall, this work suggests that in situ mineralized manganese dioxide coated electrospun fibers covered stent may provide a new strategy for advanced esophageal cancer patients as a functional drug delivery platform.

The clinical translation of many inorganic nanomaterials is severely hampered by toxicity issues because of the long-term retention of these nanomaterials in the body. In this study, we developed a bio-clearable theranostic agent based on ultra-small MoS₂ nanodots, which were synthesized by a facile bottom-up approach through one-step solvothermal decomposition of ammonium tetrathiomolybdate. After modification by glutathione (GSH), the obtained MoS₂-GSH nanodots exhibited sub-10-nm hydrodynamic diameters without aggregation in various physiological buffers. Without showing appreciable in vitro toxicity, such MoS₂-GSH nanodots with strong near-infrared (NIR) absorbance could induce remarkable photothermal ablation of cancer cells. Upon intravenous (i.v.) injection, efficient tumor accumulation of MoS₂-GSH nanodots was observed by photoacoustic imaging, and further confirmed by analysis of the biodistribution of Mo. Notably, the MoS₂-GSH nanodots, in contrast to conventional MoS₂ nanoflakes with larger sizes, showed rather efficient body clearance via urine, where the majority of the injected dose was cleared within just seven days. Photothermal ablation of tumors on mice was then realized with the MoS₂-GSH nanodots, achieving excellent therapeutic efficacy. This study presents a new type of ultra-small nanoparticle with efficient tumor homing/treatment abilities, as well as rapid body clearance behavior, making it promising for cancer theranostics without long-term toxicity concerns.