Nano-engineering nanomedicines with customized functions for tumor treatment applications

Nano-engineering with unique "custom function" capability has shown great potential in solving technical difficulties of nanomaterials in tumor treatment. Through tuning the size and surface properties controllablly, nanoparticles can be endoewd with tailored structure, and then the characteristic functions to improve the therapeutic effect of nanomedicines. Based on nano-engineering, many have been carried out to advance nano-engineering nanomedicine. In this review, the main research related to cancer therapy attached to the development of nanoengineering nanomedicines has been presented as follows. Firstly, therapeutic agents that target to tumor area can exert the therapeutic effect effectively. Secondly, drug resistance of tumor cells can be overcome to enhance the efficacy. Thirdly, remodeling the immunosuppressive microenvironment makes the therapeutic agents work with the autoimmune system to eliminate the primary tumor and then prevent tumor recurrence and metastasis. Finally, the development prospects of nano-engineering nanomedicine are also outlined.

Copper nanoparticles embedded in polyaniline derived nitrogen-doped carbon as electrocatalyst for bio-energy generation in microbial fuel cells

Microbial fuel cells (SC-MFCs) have emerged as green energy devices to resolve the growing energy and environmental crisis. However, the technology's application depends on the sluggish oxygen reduction reaction (ORR) kinetics. Among the electrocatalysts explored, transition metal-nitrogen-carbon composites exhibit satisfactory ORR activity. Herein, we investigate the performance of copper-nitrogen-carbon (Cu/NC) electrocatalysts for ORR, highlighting the effect of temperature, role of nitrogen functionalities, and Cu-N_x sites in catalyst performance. Cu/NC-700 demonstrated satisfactory ORR activity with an onset potential of 0.7 V (vs. RHE) and a limiting current density of 3.4 mA cm^-2. Cu/NC-700 modified MFC exhibited a maximum power density of 489.2 mW m^-2, higher than NC-700 (107.3 mW m^-2). These observations could result from synergistic interaction between copper and nitrogen atoms, high density of Cu-N_x sites, and high pyridinic-N content. Moreover, the catalyst exhibited superior stability, implying its use in long-term operations. The electrocatalytic performance of the catalyst suggests that copper-doped carbon catalysts could be potential metal-nitrogen-carbon material for scaled-up MFC applications.

Ultrafine platinum nanoparticles supported on N,S-codoped porous carbon nanofibers as efficient multifunctional materials for noticeable oxygen reduction reaction and water splitting performance

The design of highly active, stable and durable platinum-based electrocatalysts towards the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and hydrogen adsorption has a high and urgent demand in fuel cells, water splitting and hydrogen storage. Herein, ultrafine platinum nanoparticles (Pt NPs) supported on N,S-codoped porous carbon nanofibers (Pt-N,S-pCNFs) hybrids were prepared through the electrospinning method coupled with hydrothermal and carbonation processes. The ultrafine Pt NPs are sufficiently dispersed and loaded on pCNFs and codoped with N and S, which can improve oxygen adsorption, afford more active sites, and greatly enhance electron mobility. The Pt-N,S-pCNFs hybrid achieves excellent activity and stability for ORR with ∼70 mV positive shift of onset potential compared to the commercial Pt/C-20 wt% electrocatalyst. The long-term catalytic durability with 89.5% current retention after a 10 000 s test indicates its remarkable ORR behavior. Pt-N,S-pCNFs also exhibits excellent HER and OER performance, and can be used as an efficient catalyst for water splitting. In addition, Pt-N,S-pCNFs exhibits an excellent hydrogen storage capacity of 0.76 wt% at 20 °C and 10 MPa. This work provides novel design strategies for the development of multifunctional materials as high-performance ORR catalysts, water splitting electrocatalysts and hydrogen storage materials.

An interconnected-graphene enveloped titanium dioxide flower as a robust support for proton exchange membrane fuel cells

A three-dimensional (3D) interconnected-graphene enveloped titanium dioxide flower (TiO2@RGO) as a robust support for the oxygen reduction reaction (ORR) is reported.

Synthesis and Pyrolysis of Fullerenol-stabilized Pt Nanocolloids as a unique Approach to Pt-doped Carbon

An aqueous colloidal dispersion of Pt nanoparticles (NPs) stabilized by fullerenol C₆₀ (OH)₁₂ (Pt:C₆₀ (OH)₁₂ ) was successfully synthesized via liquid-phase chemical reduction. The subsequent pyrolysis of Pt:C₆₀ (OH)₁₂ at different temperatures was conducted to afford Pt-doped carbon with different chemical compositions (Pt:C60ⁿ ). X-ray absorption spectroscopy (XAS) and Infrared (IR) absorption spectroscopy and thermogravimetric measurements revealed that the thus-prepared nanocomposite consists of Pt NPs and high valent Pt-C₆₀ (OH)₁₂ complex. One distinct feature of C₆₀ (OH)₁₂ matrix as catalyst support is the suppression of size growth of Pt NPs during the pyrolysis up to 300 °C. Electrochemical experiments using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were performed to find that Pt:C60³⁰⁰ (pyrolyzed at 300 °C) exhibited higher activity than others, that was attributed to the π-extended feature of the as-obtained carbon.

Ultrafine Pt-Ni nanoparticles in hollow porous carbon spheres for remarkable oxygen reduction reaction catalysis

Ultrafine bimetallic Pt-Ni nanoparticles, which catalyze the oxygen reduction reaction (ORR) efficiently, were successfully prepared in hollow porous carbon spheres (HPCSs) under the assistance of organic molecules. 2,2'-Dipyridylamine (dpa) was found to be most effective in preparing homogeneous small Pt-Ni nanoparticles (2.0 ± 0.4 nm) without the phase separation of Pt and Ni during synthesis, and the assistance of the organic molecules was investigated for the alloy nanoparticle formation. The Pt-Ni nanoparticle/HPCS catalyst synthesized in the presence of dpa exhibited remarkable electrochemical performance in the ORR showing a high mass activity of 3.25 ± 0.14 A mg-1Pt at 0.9 VRHE (13.5-fold higher relative to a commercial Pt/C catalyst), a large electrochemical surface area of 105 ± 8 m2 g-1Pt, and high durability. After 60 000 cycles of accelerated durability testing, the mass activity was still 12.3 times higher than that of the commercial Pt/C catalyst.