Deferoxamine (DFO), an iron chelator regarded as a hypoxic analogue, has been reported to be involved in angiogenesis and osteogenic differentiation. In this study, DFO was loaded into nanospheres, Then, DFO-loaded NPs and free DFO were co-encapsulated in nanofibers through coaxial electrospinning and its effects on cell viability, migration, and osteogenic differentiation, and the potential mechanisms were investigated. The results suggested that DFO maintained cell viability and promoted the migration of human mesenchymal stem cells (hMSCs) and MC3T3-E1 cells. ALP activity, calcium deposition, and expression of osteogenesis-related markers, including collagen, osteocalcin, and osteopontin, were all increased with DFO. Moreover, hypoxia-inducible factor-1α, transforming growth factor-β, and Smad2 were upregulated with DFO, which indicated activation of the TGF-β1/Smad2 signalling pathway. This may contribute to osteogenic differentiation of cells.
Jun Zhang,Lei Su,Zhinan Liu,Jincheng Tang,Lichen Zhang,Ziang Li,Dong Zhou,Zhuo Sun,Kun Xi,Peirong Lu,Guohua Deng
Following an ocular chemical injury, the release of neutrophil extracellular traps (NETs) triggers an innate immune cascade fibrotic effect involving macrophages (Mø), which limits corneal repair. However, the interplay and mechanisms between NETs and macrophages, as well as the coordination between the innate immunity and corneal repair, remain challenging issues. Using a co-culture system, we report that chemical stimulation exacerbates the accumulation of reactive oxygen species (ROS) within the polymorphonuclear neutrophils, leading to NET formation and the activation of M2 macrophages, ultimately inducing pathological fibrosis of the ocular surface through the IL-10/STAT3/TGF-β1/Smad2 axis. Inspired by the locally formed acidic microenvironment mediated by innate acute inflammatory stimulation, we further integrate sericin with oxidized chitosan nanoparticles loaded with black phosphorus quantum dots (BPQDs) using Schiff base chemistry to construct a functional pH-responsive hydrogel. Following corneal injury , the hydrogel selectively releases BPQDs in response to the acidic environment, inhibiting the innate immune cascade fibrosis triggered by the PMN-ROS-NETs. Thus, corneal pathological fibrosis is alleviated and reshaping of the ocular surface takes place. These results represent a refinement of the mechanism of inherent immune effector cell interactions, and provide new research ideas for the construction of nano biomaterials that regulate pathological fibrosis.