Smart drug delivery nanosystem is significant for tumor treatments due to its possibility of temporally, spatially, and dose-controlled release. However, the therapeutic efficacy of drug delivery nanosystem is often compromised in cancer treatment as the enrichment of therapeutic agents in the reticuloendothelial system. Herein, doxorubicin (DOX) loaded biomimetic drug delivery nanosystem with macrophage cell membrane (MCM) camouflaged, MnFe₂O₄-DOX-MCM nanocube (NC), is developed for cancer treatment with tumor targeting, pH-stimuli drug release, and chemo-photothermal therapeutic effects. The nanosystem shows the capability of immune escape and enhanced cellular uptake of cancer cells due to the MCM decoration. Acid-labile bond between the MnFe₂O₄ NCs and DOX remains stable at physiological condition and release drugs immediately in response to the endo-/lysosome pH stimuli. Meanwhile, the photothermal effect of the nanosystem destroys tumor tissue, which further promotes chemotherapeutic efficacy. In vivo results demonstrate the tumor homing ability and produce a notable synergistic therapeutic effect of the NCs. Thus, biomimetic pH-responsive drug delivery nanosystem, MnFe₂O₄-DOX-MCM NCs, is an effective nanoplatform, which might be potential application for cancer synergistic treatment.

Rational design and exploitation of nanomaterials with superior treatment properties for suitable indications is a way out to relieve cost constraint of therapy and solve the unsatisfactory efficacy for cancer patients. In this work, we propose a greatly facile approach to produce heterogeneous Pd-Au nanorods (Pd-Au NRs) that solve the current bottleneck problems of photothermal thermal therapy (PTT) as well as completely eliminate tumors in animal models without toxic side effects. Depositing Pd clusters on both tips of Au NRs offers Pd-Au NRs three novel functions, i.e., the extension of the absorption into NIR-II region, the activation of prodrug of 5-fluorouracil (5-Fu) via the bioorthogonal reaction, and the peroxidase-mimic activity to produce ·OH. The heterogeneous nanorods showed a high and stable photothermal conversion efficiency (52.07%) in a safer NIR-II irradiation region (1,064 nm), which not only eliminate most of tumor cells at only one dose of the irradiation for 5 min but also improve the in situ conversion of 5-fluoro-1-propargyluracil and H₂O₂ into active 5-Fu and ·OH to eradicate residual tumors for inhibiting tumor metastasis. This dual catalytic activity-synergistic mechanism of PTT demonstrates the importance of material design in solving current bottleneck problem of tumor therapy.

The hydrogen evolution reaction (HER) of molybdenum disulfide (MoS₂) is limited in alkaline and acid solution because the active sites are on the finite edge with extended basal plane remaining inert. Herein, we activated the interfacial S sites by coupling with Ru nanoparticles on the inert basal plane of MoS₂ nanosheets. The density functional theory (DFT) calculation and experimental results show that the interfacial S electronic structure was modulated. And the results of ∆G_H* demonstrate that the adsorption of H on the MoS₂ was also optimized. With the advantage of interfacial S sites activation, the Ru-MoS₂ needs only overpotential of 110 and 98 mV to achieve 10 mA·cm^–2 in both 0.5 M H₂SO₄ and 1 M KOH solution, respectively. This strategy paves a new way for activating the basal plane of other transition metal sulfide electrocatalysts for improving the HER performance.

The ordered Pt-based intermetallic nanoparticles (NPs) with small size show superior magnetic or catalytic properties, but the synthesis of these NPs still remains a great challenge due to the requirement of high temperature annealing for the formation of the ordered phase, which usually leads to sintering of the NPs. Here, we report a simple approach to directly synthesize monodisperse ordered L1₀-FePt NPs with average size 10.7 nm without further annealing or doping the third metal atoms, in which hexadecyltrimethylammonium chloride (CTAC) was found to be the key inducing agent for the thermodynamic growth of the Fe and Pt atoms into the ordered intermetallic structure in the synthetic process. In particular, 10.7 nm L1₀-FePt NPs synthesized by the proper amount of CTAC show a coercivity of 3.15 kOe and saturation magnetization of 45 emu/g at room temperature. The current CTAC-assisted synthetic strategy makes it possible to deeply understand the formation of the ordered Pt-based intermetallic NP in solution phase synthesis.

High-performance Nd₂Fe₁₄B magnets have been widely required in various fields recently due to the lightweight and miniaturization of devices. In this work, we synthesize Nd₂Fe₁₄B nanostructures with tunable magnetic properties through surfactant-assisted high energy ball milling (SAHEBM) process, achieving prominently enhanced coercivity by forming non-magnetic layers as grain boundary phase. When the reduction annealing process was carried out as pellet with Ca, the coercivity increased from 0.8 kOe to over 3 kOe as Nd₂Fe₁₄B powder, which is proved to be the contribution of the chemical diffusion of Nd elements and the formation of Nd-rich layer as magnetic insulating medium. In addition, two-dimensional graphene oxide (GO) was employed to build extra grain boundary, by which the coercivity of the core@dual-shell structure can achieve up to 8 kOe, tenfold of the original sample. The intrinsic mechanism indicated that the Nd-diffusion induced Nd-rich phase along with the reduced GO in the system could form non-magnetic layer as grain boundary and magnetically isolate the adjacent grains, significantly enhancing the exchange coupling effect. This work markedly opens up an effective approach for the chemical preparation of high-performance Nd₂Fe₁₄B nanostructured magnets, especially after post treatment, and gives an insight on the interactions at nanoscale.

Studies on the influence of one critical parameter (e.g., size), targeting a specific disease, while keeping other factors unchanged, are important for improving understanding and application of the molecular design of biomedical nanomaterials. In this study, we used doxorubicin (Dox)-conjugated gold nanoparticles (GNPs) to investigate the effects of the size of the gold core (10, 20, or 60 nm) on the performance of their conjugates. We found that all three conjugates differed slightly in their physicochemical properties, facilitating a direct and accurate assessment of the size effects of GNP-Dox conjugates on their in vitro and in vivo performance. The cytological properties (the cell penetration rate and efficiency, as well as the cytotoxicity) and antitumor performance (the intratumoral penetration, treatment efficacy, and biodistribution) were highly correlated to the size of the inorganic core. Among all test groups, although the conjugate with a 60-nm gold core had the highest drug loading and release efficiency, the conjugate with a 10-nm gold core displayed the best antitumor efficacy toward the liver cancer models. This was because it showed the deepest tumor permeability and the highest tumor cell-killing ability of Dox transported by the relatively small GNPs. This study provides important evidence for better understanding the effect of size on in vitro and in vivo properties of potential therapeutic nanosystems and their structure design.

Recently, magnetic nanoparticles (NPs) have been extensively used in food industry and biomedical treatments. However, the biocompatibility mechanism on expression proteomics, before consideration of magnetic NPs for clinical application, has not yet been fully elucidated. Therefore, this study was undertaken to identify potential biomarkers of metal ion signaling proteins in human cervical cancer cell line (HeLa) cells. Here, we report the in vitro investigations of the cell cycle response and significant changes in protein abundance of HeLa cells when exposed to self-tailored hydrophilic Fe₂C NPs. The comparative proteomic approach based on ¹⁸O labeling coupled with high performance liquid chromatography/electrospray ionization with ion trap mass analyzer (HPLC/ESI-Orbitrap) was applied, and 394 proteins were identified. There were 46 significantly differentiated proteins based on the specific metal ion signaling response. Among them, 60S ribosomal protein L37a, serine/arginine-rich splicing factor 7, calmodulin, and calumenin were downregulated, whereas transketolase was overexpressed. Functional interaction network of Fe₂C-regulated proteins was successfully created by the STRING algorithm to show the strong interactions between proteins. This work will not only help to understand the molecular mechanism of metal ion signaling proteins that can potentially be used to develop therapeutic protocols for diagnosis of diseases but also give direction for tailoring biocompatible magnetic NPs.

Catalysts for oxygen and hydrogen evolution reactions (OER/HER) are at the heart of renewable green energy sources such as water splitting. Although incredible efforts have been made to develop efficient catalysts for OER and HER, great challenges still remain in the development of bifunctional catalysts. Here, we report a novel hybrid of Co₃O₄ embedded in tubular nanostructures of graphitic carbon nitride (GCN) and synthesized through a facile, large-scale chemical method at low temperature. Strong synergistic effects between Co₃O₄ and GCN resulted in excellent performance as a bifunctional catalyst for OER and HER. The high surface area, unique tubular nanostructure, and composition of the hybrid made all redox sites easily available for catalysis and provided faster ionic and electronic conduction. The Co₃O₄@GCN tubular nanostructured (TNS) hybrid exhibited the lowest overpotential (0.12 V) and excellent current density (147 mA/cm²) in OER, better than benchmarks IrO₂ and RuO₂, and with superior durability in alkaline media. Furthermore, the Co₃O₄@GCN TNS hybrid demonstrated excellent performance in HER, with a much lower onset and overpotential, and a stable current density. It is expected that the Co₃O₄@GCN TNS hybrid developed in this study will be an attractive alternative to noble metals catalysts in large scale water splitting and fuel cells.

Being simple, inexpensive, scalable and environmentally friendly, microporous biomass biochars have been attracting enthusiastic attention for application in lithium-sulfur (Li-S) batteries. Herein, porous bamboo biochar is activated via a KOH/annealing process that creates a microporous structure, boosts surface area and enhances electronic conductivity. The treated sample is used to encapsulate sulfur to prepare a microporous bamboo carbon-sulfur (BC-S) nanocomposite for use as the cathode for Li-S batteries for the first time. The BC-S nanocomposite with 50 wt.% sulfur content delivers a high initial capacity of 1, 295 mA·h/g at a low discharge rate of 160 mA/g and high capacity retention of 550 mA·h/g after 150 cycles at a high discharge rate of 800 mA/g with excellent coulombic efficiency (≥95%). This suggests that the BC-S nanocomposite could be a promising cathode material for Li-S batteries.

Multifunctional probes for simultaneous magnetic resonance imaging (MRI) and drug delivery have attracted considerable interest due to their promising potential applications in the early-stage diagnosis and therapy of the diseases. In this study, hollow manganese phosphate nanoparticles (HMP NPs) with an average diameter of 18 nm were synthesized and aminated through silanization, which enabled the covalent conjugation of biocompatible poly(ethylene glycol) (PEG) on their surfaces. The anti-tumor drug doxorubicin (DOX) could be loaded into the hollow cavities. Under physiological conditions (pH 7.4), the NPs showed low MRI T₁ contrast (r₁ = 1.19 L·mmol^-1·s^-1), whereas high T₁ enhancement (r₁ = 5.22 L·mmol^-1·s^-1) was achieved after dissolving them in endosome/lysosome mimetic conditions (pH 5.4). This is due to the fact that the NPs were easily eroded, which resulted in the release of Mn²⁺ at low pH. To use this interesting phenomenon for targeted DOX drug delivery, we conjugated the tumor-targeting ligand folic acid (FA) on HMP NPs and investigated their drug delivery capacity and cytotoxicity to cell lines expressing different amount of folate receptor (FR). KB cells showed more significant cellular uptake than HeLa cells and A549 cells, as confirmed by confocal laser scanning microscopy (CLSM), flow cytometry and cellular T₁-weighted MRI. Furthermore, the drug-loaded HMP NPs exhibited greater cytotoxicity to KB cells. Our results suggest that functionalized HMP NPs can act as an effective multifunctional probe for selective diagnosis with MRI, as well as giving efficient targeted drug delivery.