Resident leptin-receptor-expressing (LepR + ) cells senescence in the aged bone marrow impairs the regenerative capacity of osteo- and other lineages of cells. In this study, a LepR + cell-targeting nitric oxide (NO) nanopump with in vivo self-controlled turn-on ability was constructed to rejuvenate the LepR + cells in the aged bone marrow. The nanopump co-entrapped hydrophobic chemiluminescence substrate and NO donor into the matrix of amphiphilic polymer through a nanoprecipitation process. The chemiluminescence substrate in the NO nanopump automatically reacts with the accumulated H 2 O 2 in the aged bone marrow and then directly transfers the chemical energy to the NO donor to induce in situ NO release. The NO produced in situ within the aged bone marrow triggered the regeneration of the osteoblastic and the other niches in vivo through activating the glycolysis signaling in the senescent LepR + cells. Conclusively, the constructed NO nanopump is a promising tool to counter aging-induced bone marrow disorders.
Junce Wang,Jinfeng Chen,Ningning Liu,Jingjing Lei,Hong-Wen Gao,Fei Yu,Fanghui Pan,Jie Ma
Controlled synthesis and regulation of 2D nanomaterials with sufficient active sites are promising in electrochemical fluorine capture, but simultaneously achieving rapid rates and efficient activity of intercalation materials remains challengs. Herein, an integrated strategy of micro-regulation interlayer space and in situ modification of MXenes is proposed to enhance ion storage kinetics. The wedge-like microstructure of aluminum oxide/incomplete-Ti 3 C 2 T x MXene (Al 2 O 3 /i-Ti 3 C 2 T x ) is constructed by incomplete etching MAX and in situ derivation of A-layer element, in which the sub-nanoscale interlayer space is conducive to the small size ions intercalation, and the formation of “nanopump-like” effect boosted the ions diffusion. As evidenced by simulation calculations, Al 2 O 3 nanoparticles not only shorten the migration distance of electrons/hydrated ions in interlayers but also contribute a lower adsorption energy barrier, bringing excellent capture kinetics and stability. Benefiting from the interfacial conversion-intercalation pseudocapacitance, such electrode is endowed with a high defluoridation capacity (69.9 mg g −1 at 1.6V) and an outstanding instantaneous adsorption rate (9.51 mg g −1 min −1 ), and shows satisfactory stability in more than 200 cycles. The physicochemical coupling strategy opens a novel approach to optimizing the interlayer structure and in situ modification interface of MXene, which also provids a universal idea for efficient capture of varisized ions of intercalation materials.