Ultrasmall iron-quercetin metal natural product nanocomplex with antioxidant and macrophage regulation in rheumatoid arthritis

Oxidative stress,due to the disruption of the balance between reactive oxygen species(ROS)generation and the antioxidant defense system,plays an important role in the pathogenesis of rheumatoid arthritis(RA).Excessive ROS leads to the loss of biological molecules and cellular functions,release of many inflammatory mediators,stimulate the polarization of macrophages,and aggravate the inflammatory response,thus promoting osteoclasts and bone damage.Therefore,foreign antioxidants would effectively treat RA.Herein,ultrasmall iron-quercetin natural coordination nanoparticles(Fe-Qur NCNs)with excellent anti-inflammatory and antioxidant properties were constructed to effectively treat RA.Fe-Qur NCNs obtained by simple mixing retain the inherent ability to remove ROS of quercetin and have a better water-solubility and biocompatibility.In vitro experiments showed that Fe-Qur NCNs could effectively remove excess ROS,avoid cell apoptosis,and inhibit the polarization of inflammatory macrophages by reducing the activation of the nuclear factor-κ-gene binding(NF-κB)pathways.In vivo experiments showed that the swollen joints of mice with rheumatoid arthritis treated with Fe-Qur NCNs significantly improved,with Fe-Qur NCNs largely reducing inflammatory cell infiltration,increasing antiinflammatory macrophage phenotypes,and thus inhibiting osteoclasts,which led to bone erosion.This study demonstrated that the new metal-natural coordination nanoparticles could be an effective therapeutic agent for the prevention of RA and other diseases associated with oxidative stress.

The combination of eddy thermal effect of biodegradable magnesium with immune checkpoint blockade shows enhanced efficacy against osteosarcoma

Osteosarcoma(OS)patients have a poor prognosis due to its high degree of heterogeneity and high rate of metastasis.Magnetic hyperthermia therapy(MHT)combined with immunotherapy is an effective strategy to treat solid and metastatic tumors.Here,we combined biodegradable magnesium(Mg)macroscale rods,which acted as an eddy thermo-magnetic agent under a low external alternating magnetic field,and immunotherapy to achieve a radical cure for OS.The eddy thermal effect(ETE)of the Mg rods(MgR)showed outstanding cytotoxic effects and enhanced the maturation of dendritic cells(DCs),and the mild MHT induced the immunogenic cell death(ICD)in the OS cells.Combined with immune checkpoint blockade(ICB)therapy,we obtained an excellent curative effect against OS,and a further evaluation demonstrated that the local MHT induced by the MgR increased T cells infiltration and the polarization of M1 macrophages.Interestingly,the biodegradable MgR also promoted bone osteogenesis.Our work highlighted the uneven ETE mediated by the biodegradable MgR induced a comprehensive immunologic activation in the OS tumor microenvironment(TME),which would inspire the application of MHT for the effective treatment of OS.