Filamentous-Actin-Mimicking Nanoplatform for Enhanced Cytosolic Protein Delivery.

Despite the potential of protein therapeutics, the cytosolic delivery of proteins with high efficiency and bioactivity remains a significant challenge owing to exocytosis and lysosomal degradation after endocytosis. Therefore, it is important to develop a safe and efficient strategy to bypass endocytosis. Inspired by the extraordinary capability of filamentous-actin (F-actin) to promote cell membrane fusion, a cyanine dye assembly-containing nanoplatform mimicking the structure of natural F-actin is developed. The nanoplatform exhibits fast membrane fusion to cell membrane mimics and thus enters live cells through membrane fusion and bypasses endocytosis. Moreover, it is found to efficiently deliver protein cargos into live cells and quickly release them into the cytosol, leading to high protein cargo transfection efficiency and bioactivity. The nanoplatform also results in the superior inhibition of tumor cells when loaded with anti-tumor proteins. These results demonstrate that this fusogenic nanoplatform can be valuable for cytosolic protein delivery and tumor treatment.

Enhanced Formaldehyde Oxidation Performance of the Mesoporous TiO2(B)-Supported Pt Catalyst: The Role of Hydroxyls.

As one of the crystal phases of titania, TiO2(B) was first utilized as a catalyst carrier for the oxidation of formaldehyde (HCHO). The mesoporous TiO2(B) loaded with Pt nanoparticles enhanced the HCHO oxidation reaction whose reaction rate was 4.5-8.4 times those of other crystalline TiO2-supported Pt catalysts. Simultaneously, Pt/TiO2(B) exhibited long-term stable HCHO oxidation performance. The structural characterization results showed that in comparison with Pt/anatase, Pt/TiO2(B) had more abundant hydroxyls, facilitating increasing the content of oxygen species. Studies on the role of hydroxyls in HCHO oxidation of Pt/TiO2(B) illustrated that synergistic involvement of terminally bound hydroxyls and bridging hydroxyls in HCHO oxidation accelerated the transformation from HCHO to formate via dioxymethylene. Moreover, hydroxyls could avoid the accumulation of excessive formate on Pt/TiO2(B) and promote the rapid oxidation of CO. Accordingly, the hydroxyl groups could accelerate each substep of formaldehyde oxidation, which enabled Pt/TiO2(B) to exhibit excellent formaldehyde oxidation performance.

Highly Active Hierarchical Au Nanoparticles/Cellulose@TiO2 Prepared by Surface Charge Assisted Self-Assembly.

The catalyst Au/cellulose@TiO2 with a hierarchical structure was one-pot synthesized by conventional deposition-precipitation urea method. Nanosized TiO2 particles, instead of self-agglomeration, homogeneously dispersed on the microsized microcrystalline cellulose. Simultaneously, gold particles with particle size of about 3.4 nm were mainly well-deposited on TiO2 particles. It was found that the surface charges of TiO2, cellulose and gold species played a key role in assisting in selfassembling them into the hierarchical structure. p-nitrophenol hydrogenation results displayed that the catalytic activity of Au/cellulose@TiO2 was 1.8 times and 10.9 times higher than that of Au/TiO2 and Au/cellulose, respectively. The improvement in catalytic performance of Au/cellulose@TiO2 was closely related to its hierarchical structure that influenced mass transfer of reactants and recycle of catalysts.