ABSTRACT
A series of TADF-active compounds: 0D chiral Ln-Ag(I) clusters L-/D-Ln2Ag28-0D (Ln = Eu/Gd) and 2D chiral Ln-Ag(I) cluster-based frameworks L-/D-Ln2Ag28-2D (Ln = Gd) has been synthesized. Atomic-level structural analysis showed that the chiral Ag(I) cluster units {Ag14S12} in L-/D-Ln2Ag28-0D and L-/D-Ln2Ag28-2D exhibited similar configurations, linked by varying numbers of [Ln(H2O)x]3+ (x = 6 for 0D, x = 3 for 2D) to form the final target compounds. Temperature-dependent emission spectra and decay lifetimes measurement demonstrated the presence of TADF in L-Ln2Ag28-0D (Ln = Eu/Gd) and L-Gd2Ag28-2D. Experimentally, the remarkable TADF properties primarily originated from {Ag14S12} moieties in these compounds. Notably, {Ag14S12} in L-Eu2Ag28-0D and L-Gd2Ag28-2D displayed higher promote fluorescence rate and shorter TADF decay times than L-Gd2Ag28-0D. Combined with theoretical calculations, it was determined that the TADF behaviors of {Ag14S12} cluster units were induced by 4f perturbation of Ln3+ ions. Specially, while maintaining ΔE(S1-T1) small enough, it can significantly increase k(S1âS0) and reduce TADF decay time by adjusting the type or number of Ln3+ ions, thus achieving the purpose of improving TADF for cluster-based luminescent materials.
ABSTRACT
Aim To investigate the effect of icariin (ICA) on the proliferation and differentiation of MC3T3-E1 pre-osteoblast cell line. Methods CCK-8 assay was used to detect the proliferation activity of MC3T3-E1 cells. Alizarin red staining (AR-S) assay was used to detect osteoblast differentiation and the formation of calcium nodules. Western blot assay was used to examine the protein expression of osteocalcin, ALP and shh. ALP assay was used to detect its activity. Results The effect of CCK-8 assay showed that ICA (5 ∼ 40 μmol · L-1) significantly promoted MC3T3-E1 cell proliferation compared with control group. The activity and protein expression of ALP and the quantitative analysis of mineralization deposition significantly increased in ICA group compared with control group. The ALP activity, protein expression level of shh and the quantification of alizarin red staining showed a significant decrease in ICA + CYC group compared with ICA group. Conclusions ICA promotes osteoblast proliferation and differentiation through the Hedgehog signaling pathway.
