We present a general strategy to nanoengineer protein‐based colloidal spheres (biomimetic protocells) as versatile delivery carriers with stimuli responsiveness by the electrostatic assembly of binary components (proteins and polypeptides) in association with intermolecular disulfide cross‐linking. The size of the colloidal spheres, ranging from nanoscale to microscale, is readily tuned through parameters like protein and polypeptide concentration, the ratio between both, pH, and so on. Moreover, such colloidal spheres show versatile encapsulation of various guest molecules including small organic molecules and biomacromolecules. The pH and redox dual‐responsiveness facilitates the rapid release of the payload in an acidic and reductant‐enriched ambient such as in lysosomes. Thus, nanoengineering of protein‐based biomimetic protocells opens a new alternative avenue for developing delivery vehicles with multifunctional properties towards a range of therapeutic and diagnostic applications. 相似文献
Understanding and controlling multicomponent co-assembly is of primary importance in different fields, such as materials fabrication, pharmaceutical polymorphism, and supramolecular polymerization, but these aspects have been a long-standing challenge. Herein, we discover that liquid–liquid phase separation (LLPS) into ion-cluster-rich and ion-cluster-poor liquid phases is the first step prior to co-assembly nucleation based on a model system of water-soluble porphyrin and ionic liquids. The LLPS-formed droplets serve as the nucleation precursors, which determine the resulting structures and properties of co-assemblies. Co-assembly polymorphism and tunable supramolecular phase transition behaviors can be achieved by regulating the intermolecular interactions at the LLPS stage. These findings elucidate the key role of LLPS in multicomponent co-assembly evolution and enable it to be an effective strategy to control co-assembly polymorphism as well as supramolecular phase transitions. 相似文献
A kinetic model previously developed to predict the relative intensities of atomic emission lines in laser-induced breakdown
spectroscopy has been extended to include processes related to CN and C2 molecular emissions. Simulations with this model were performed to predict the relative excited-state populations. The results
from the simulations are compared with experimentally determined excited-state populations from 1,064 nm laser irradiation
of organic residues on aluminum foil. The model reasonably predicts the relative intensity of the molecular emissions. Significantly,
the model reproduces the vastly different temporal profiles of the atomic and molecular emissions. The latter are found to
extend to much longer times after the laser pulse, and this appears to be due to the increasing concentration of the molecules
versus time. From the simulations, the important processes affecting the CN and C2 concentrations are identified. 相似文献
We investigate the multifractality of heartbeat dynamics during Chinese CHI meditation in healthy young adults. The results show that the range of multifractal singularity spectrum of heartbeat interval time series during meditation is significantly narrower than those in the pre-meditation state of the same subject, which indicates that during meditation the heartbeat becomes regular and the degree of multifractality decreases. 相似文献
A series of new triorganotin(IV) pyridinecarboxylates with 6-hydroxynicotinic acid (6-OH-3-nicH), 5-hydroxynicotinic acid (5-OH-3-nicH) and 2-hydroxyisonicotinic acid (2-OH-4-isonicH) of the types: [R3Sn (6-OH-3-nic)·L]n (I) (R = Ph, L = Ph·EtOH, 1; R = Bn, L = H2O·EtOH, 2; R = Me, L = 0, 3; R = n-Bu, L = 0, 4), [R3Sn (5-OH-3-nic)]n (II) (R = Ph, 5; R = Bn, 6; R = Me, 7; R = n-Bu, 8), [R3Sn (2-OH-4-isonic·L)]n (III) (R = Bn, 9, L = MeOH; R = Me, L = 0, 10; R = Ph, 11, L = 0.5EtOH) have been synthesized. All the complexes were characterized by elemental analysis, TGA, IR and NMR (1H, 13C, 119Sn) spectroscopy analyses. Among them, except for complexes 5 and 6, all complexes were also characterized by X-ray crystallography diffraction analysis. Crystal structures show that complexes 1-10 adopt 1D infinite chain structures which are generated by the bidentate O, O or N, O and the five-coordinated tin centers. Significant O-H?O, and N-H?O intermolecular hydrogen bonds stabilize these structures. Complex 11 is a 42-membered macrocycle containing six tin atoms, and forms a 2D network by intermolecular N-H?O hydrogen. 相似文献
Ruthenium/reduced graphene oxide nanocomposites (Ru/rGO NCs) were synthesized via an electrostatic self-assembly approach. Polyvinylpyrrolidone (PVP) stabilized and positively charged metallic ruthenium nanoclusters about 1.2 nm were synthesized and uniformly loaded onto negatively charged graphene oxide (GO) sheets via strong electrostatic interactions. The as-prepared Ru/rGO NCs exhibited superior performance in catalytic hydrolysis of sodium borohydride (NaBH4) to generate H2. The hydrogen generation rate was up to 14.87 L H2 min?1 gcat?1 at 318 K with relatively low activation energy of 38.12 kJ mol?1. Kinetics study confirmed that the hydrolysis of NaBH4 was first order with respect to concentration of catalysts. Besides, the conversion of NaBH4 remained at 97% and catalytic activity retained more than 70% after 5 reaction cycles at room temperature. These results suggested that the Ru/rGO NCs have a promising prospect in the field of clean energy.
The compatibility of the solid electrolyte Li1.5Al0.5Ti1.5(PO4)3 (LATP) with the cathode materials LiCoO2, LiMn2O4, LiCoPO4, LiFePO4, and LiMn0.5Fe0.5PO4 was investigated in a co-sintering study. Mixtures of LATP and the different cathode materials were sintered at various temperatures and subsequently analyzed by thermal analysis, X-ray diffraction, and electron microscopy. Oxide cathode materials display a rapid decomposition reaction with the electrolyte material even at temperatures as low as 500 °C, while olivine cathode materials are much more stable. The oxide cathode materials tend to decompose to lithium-free compounds, leaving lithium to form Li3PO4 and other metal phosphates. In contrast, the olivine cathode materials decompose to mixed phosphates, which can, in part, still be electrochemically active. Among the olivine cathode materials, LiFePO4 demonstrated the most promising results. No secondary phases were detected by X-ray diffraction after sintering a LATP/LiFePO4 mixture at temperatures as high as 700 °C. Electron microscopy revealed a small secondary phase probably consisting of Li2FeTi(PO4)3, which is ionically conductive and should be electrochemically active as well. 相似文献