Adsorption of plasma proteins to nanomaterial surfaces has a great influence on their bio-functionality. However, there is limited understanding of the relationship between the functional proteins in the protein corona and the biological identity of the materials. Here we show that the in situ generated thrombin in the protein corona of a Ca-zeolite surface displays a calcium-dependent, unusually high (-3,000 NIH U/mg) procoagulant activity, which is even stable against antithrombin deactivation. Removing the encapsulated Ca^2+ in the zeolites leads to deactivation by antithrombin. Our observations suggest that the thrombin activity can be regulated by the inorganic surface and cations. Most importantly, our discovery indicates the link between the biomolecules in the protein corona and the procoagulant activity of the materials, providing a new molecular basis for the procoagulant mechanism for zeolite hemostatics.
Yunlong LiXiaofeng LiaoXiaoxi ZhangGuicen MaShuai ZuoLiping XiaoGalen D. StuckyZhugang WangXian ChenXiaoqiang ShangJie Fan
The solvent‐free oxidation of benzyl alcohol was studied using supported Pd‐Ni bimetallic nanoparticles.Compared with monometallic Pd,the addition of Ni to Pd was found to be effective in suppressing the nondesired product toluene,thereby enhancing the selectivity towards benzaldehyde.This result was attributed to a dual effect of Ni addition:the weakening of dissociative adsorption of benzyl alcohol and the promotion of oxygen species involved in the oxidation pathway.
Jianwei CheMengjia HaoWuzhong YiHisayoshi KobayashiYuheng ZhouLiping XiaoJie Fan
Stabilizing gold nanoparticles(AuNPs) within a desired size range is critical to realize their promising catalytic performance in many important reactions.Herein,we investigate the anti-sintering properties of cubic mesoporous silica(FDU-12) as a function of pore entrance size.Simple adjustments to the type of organic template and reaction temperature enable the successful synthesis of FDU-12 with controllable entrance sizes( 3,3-5 and 7 nm).Excellent anti-sintering properties are observed for FDU-12 with a sub-5-nm entrance size(3-5 nm) over a wide loading concentration(1.0-8.3 wt%) and the AuNPs can be stabilized within a 4.5-5.0-nm range after calcination at 550 ℃in air for 5 h.Smaller entrance size( 3 nm) prevents ingress of 3-nm AuNPs to the mesopores and results in low loading capacity and sintering.Conversely,FDU-12 possessing a larger entrance size(7 nm) shows promising anti-sintering properties at high loading concentrations,although catalytic performance is significantly lost at lower concentrations(e.g.2.1 wt%,14.2 ± 5.5 nm).Different anti-sintering mechanisms are proposed for each of the different FDU-12 entrance sizes.Additionally,catalytic data indicates that the obtained 4.5-nm AuNPs supported on FDU-12 with a sub-5-nm entrance size exhibit excellent mass-specific activity(1544 mmol g_(Au)^(-1) h^(-1)) and selectivity( 99%)at 230 ℃ for the gas-phase selective oxidation of cyclohexanol.