Silica Nanorods Research Articles

Lipid‐Coated Mesoporous Silica Nanoparticles for pH‐Responsive Release and Enhanced Anti‐Proliferative Activity of Piperlongumine Natural Product

AbstractThe incorporation of natural products into a suitable delivery system has the potential to augment their therapeutic effectiveness significantly. In this study, we demonstrate how silicasomes, a lipid‐coated mesoporous silica nanorods, influence the anticancer potency and release behaviour of the natural product. Piperlongumine (Pip), a natural product isolated from long pepper, is loaded into mesoporous silica nanorods (MSNRs) followed by a bilayer coating made of 1,2‐Dimyristoyl‐sn‐glycero‐3‐phosphocholine (DMPC). The size and morphology of Pip‐loaded MSNRs (Pip@MSNRs) and phospholipid‐coated Pip@MSNRs (PL‐Pip@MSNRs) are characterized well using suitable analytical techniques. The release of Pip from Pip@MSNRs attained saturation at 48 h while PL‐Pip@MSNRs exhibited the same only after 100 h in both simulated physiological and endolysosomal acidic environments. Moreover, PL‐Pip@MSNRs displayed a higher percentage of Pip release in an acidic medium than in a physiological medium after 24 h. These results confirm that the DMPC coating could assist the pH‐responsive and sustained release of loaded drug from silica nanorods. Most importantly, PL‐Pip@MSNRs demonstrate a higher potency of cytotoxicity and apoptosis against MCF‐7 (Human Breast Carcinoma) cells than the Pip@MSNRs, emphasizing the significance of DMPC‐coated MSNRs as a suitable nanocarrier for natural product delivery.

Shape Dependent Therapeutic Potential of Nanoparticulate System: Advance Approach for Drug Delivery.

Drug delivery systems rely heavily on nanoparticles because they provide a targeted and monitored release of pharmaceuticals that maximize therapeutic efficacy and minimize side effects. To maximize drug internalization, this review focuses on comprehending the interactions between biological systems and nanoparticles. The way that nanoparticles behave during cellular uptake, distribution, and retention in the body is determined by their shape. Different forms, such as mesoporous silica nanoparticles, micelles, and nanorods, each have special properties that influence how well drugs are delivered to cells and internalized. To achieve the desired particle morphology, shape-controlled nanoparticle synthesis strategies take into account variables like pH, temperatures, and reaction time. Top-down techniques entail dissolving bulk materials to produce nanoparticles, whereas bottom-up techniques enable nanostructures to self-assemble. Comprehending the interactions at the bio-nano interface is essential to surmounting biological barriers and enhancing the therapeutic efficacy of nanotechnology in drug delivery systems. In general, drug internalization and distribution are greatly influenced by the shape of nanoparticles, which presents an opportunity for tailored and efficient treatment plans in a range of medical applications.

Corrosion suppression and strengthening of the Al-10Zn alloy by adding silica nanorods

Aluminum alloys have been widely studied because of their current engineering applications. Due to their high strength and lightweight, cracking can easily initiate on their surface, deteriorating their overall functional and structural properties and causing environmental attacks. The current study highlights the significant influence of incorporating 1 wt% silica nanostructure in aluminum-10 zinc alloys. The characteristics of the composites were examined using Vickers hardness, tensile, and electrochemical testing (OCP, Tafel, and EIS) at various artificial aging temperatures (423, 443, and 463 K). Silica nanorods may achieve ultrafine grains, increase hardness by up to 13.8%, increase σUTS values by up to 79% at 443 K, and improve corrosion rate by up to 89.4%, surpassing Al-10 Zn bulk metallics. We demonstrate that silica nanorods contribute to the creation of a superior nanocomposite that not only limits failure events under loading but also resists corrosion. Our findings suggest that silica nanocomposite can produce unique features for use in a variety of automotive, construction, and aerospace applications. This improvement can be attributed mainly to the large surface area of nano-silica particles, which alters the Al matrix. Microstructural, mechanical, and electrochemical studies revealed that the effects of structure refinement were dependent on nano-silica.

High Specific Surface Area Silica Nanorod Supported Bimetallic NiCu Effectively Catalyzes Levulinic Acid Hydrogenation to γ-Valerolactone

High Specific Surface Area Silica Nanorod Supported Bimetallic NiCu Effectively Catalyzes Levulinic Acid Hydrogenation to γ-Valerolactone

Copper peroxide nanodot-decorated gold nanostar/silica nanorod Janus nanostructure with NIR-II photothermal and acid-triggered hydroxyl radical generation properties for the effective treatment of wound infections.

Recently, bacterial infections have become a global crisis, greatly threatening the health of human beings. The development of a non-antibiotic biomaterial is recognized as an alternative way for the effective treatment of bacterial infections. In the present work, a multifunctional copper peroxide (CP) nanodot-decorated gold nanostar (GNS)/silica nanorod (SiNR) Janus nanostructure (GNS@CP/SiNR) with excellent antibacterial activity was reported. Due to the formation of the Janus nanostructure, GNS@CP/SiNR displayed strong plasmonic resonance absorbance in the near infrared (NIR)-II region that enabled the nanosystem to achieve mild photothermal therapy (MPTT). In acidic conditions, CP decorated on GNS@CP/SiNR dissociated rapidly by releasing Cu2+ and H2O2, which subsequently transformed to ˙OH via the Fenton-like reaction for chemodynamic therapy (CDT). As a result, GNS@CP/SiNR could effectively inhibit both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), and eradicate the associated bacterial biofilms by exerting the synergistic MPTT/CDT antibacterial effect. Moreover, GNS@CP/SiNR was also demonstrated to be effective in treating wound infections, as verified on the S. aureus-infected full thickness excision wound rat model. Our mechanism study revealed that the synergistic MPTT/CDT effect of GNS@CP/SiNR firstly caused bacterial membrane damage, followed by boosting intracellular ROS via the severe oxidative stress effect, which subsequently caused the depletion of intracellular GSH and DNA damage, finally leading to the death of bacteria.

Polydiacetylene/lipid-coated red-emissive silica nanorods for the sustained release and ameliorated anticancer efficacy of a Ru(arene) complex bearing piperlongumine natural product.

A suitable drug delivery strategy for metallodrugs is as significant as the strategies adopted for an efficient metallodrug design. In this study, piperlongumine, which is isolated from long pepper, is coordinated with a Ru(II)-p-cymene moiety to obtain an organoruthenated complex containing the natural product (Ru(pip)). The isolated complex shows higher cytotoxicity in MCF-7 breast cancer cells than in THP-1 leukemia and HepG2 liver cancer cells. The IC50 value of the complex in non-cancerous HEK-239 cells is also almost equal to that in MCF-7 cells. Next, with an aim to modulate the antiproliferative activity of Ru(pip) using a drug delivery strategy, the complex is loaded into mesoporous silica nanorods (MSNRs), which have a higher surface area than spherical silica nanoparticles. Furthermore, the outer surface of the loaded nanorods is covered with a polydiacetylene-lipid (PL) hybrid bilayer. Given the unique optical properties of polydiacetylene, the PL coating modifies non-fluorescent MSNRs into red-emissive particles (PL-Ru(pip)@MSNRs), which can be useful for diagnostic applications. The release profile studies reveal that the ene-yne conjugation in the PL coating ensures the sustained release of the complex from nanoparticles in both physiological and simulated cancer cell media. While Ru(pip) exhibits both necrotic and apoptotic modes of cell death, PL-Ru(pip)@MSNRs preferably induce the apoptotic mode of cell death in MCF-7 and THP-1 cells. Also, the nanoformulation exhibits a higher percentage of cell cycle arrest in the G0/G1 phase than Ru(pip), as measured by flow cytometry analysis. In contrast, the in vitro antioxidant potency of the complex is decreased after being loaded into PL-coated silica nanoparticles.

PH-responsive mesoporous silica nanorod for high load and oral delivery of insulin

Diabetes is a metabolic disease often characterized by elevated blood sugar levels, which is mainly treated through external injection of insulin. However, long-term insulin injection in patients will produce many adverse side effects such as hypoglycemia, subcutaneous fat atrophy and prolonged absorption, resulting in poor patient compliance. In this work, mesoporous silica (SBA-15) nanorods with large surface area (541.8 m2/g) were prepared via soft-templating method, which retained a large number of ordered mesoporous structures as the drug delivery carrier for insulin. Insulin-loaded mesoporous silica (SBA-15/INS) particle was obtained by solvent adsorption, which was then coated with hydroxypropyl methylcellulose phthalate (HP55) to form pH-sensitive mesoporous silica nanoparticles (HP55@SBA-15/INS). The surface area, structure and morphology of silica particles were addressed by BET, FTIR, XRD, SEM and TEM, indicating that SBA-15/INS and HP55@SBA-15/INS maintained the rod-like and ordered white strips structure similar to SBA-15. Also, insulin was found to be present in the mesoporous silica nanoparticles, with loading capacity and encapsulation efficiency reaching 25.5 % and 80.9 %, respectively. The vitro release results revealed that insulin release in the simulated gastric fluid (SGF, pH = 1.2) was significantly slower than that in the simulated intestinal fluid (SIF, pH = 7.4). Compared with SBA-15/INS, the release percentages in 15 % HP55@SBA-15/INS decreased 30 % in SGF, while it increased approximately 10 % in SIF. Kinetics analysis showed that the release process in HP55@SBA-15/INS was a Fick diffusion in both SGF and SIF and HP55 was degraded in SIF, resulting in accelerated insulin release. The cytotoxicity evaluation results showed that the cell viability of 4T1 after 24 h incubated with SBA-15 and 15 % HP55@SBA-15/INS was both approximately 100 %, demonstrating that the facile manufactured method has great potential to prepare macromolecular drug nanoparticle for oral release.

Development of pedestal-free large mode area fibers withTm3+ doped silica nanostructured core.

We present the pedestal-free thulium doped silica fiber with a large nanostructured core optimized for fiber lasers. The fiber is composed of over 6 thousand thulium doped silica nanorods with a diameter of 71 nm each which form a nanostructured step-index core. We study the influence of non-continuous distribution in nanoscale active areas on gain, beam quality, and fiber laser performance. The proof-of-concept fiber is effectively single mode for wavelength above 1.8 µm. We demonstrate the performance of the fiber in a laser setup pumped at 792 nm. Single mode laser emission with a slope efficiency of 29% at quasi-continuous output power of 4 W with M2 = 1.3 at the emission spectrum 1880-1925 nm is achieved.

Fabrication of mesoporous SiO2/P(VDF-HFP) composite membrane for high-performance lithium-ion batteries

The aim of this work is to improve the characteristics of lithium-ion batteries (LIBs) by designing and applying advanced quasi-solid electrolytes. Mesoporous silica nanorods (m-SiO2) with a high specific surface area (537.8 m2 g−1) were prepared via a sol–gel method, then compounded with poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and Li-salt (in organic solvent) to prepare composite gel electrolyte (m-SiO2/P(VDF-HFP)-GE) membrane. It exhibits strong thermal stability (∼353 °C), wide electrochemical stability window (5.3 V), excellent lithium-ion transfer number (tLi+ = 0.71) and high ionic conductivity (σ = 1.6 × 10−3 S cm−1). Meanwhile, when the m-SiO2/P(VDF-HFP)-GE membrane was assembled with LiFePO4 and Li, a long-cycling stable LIB with high-capacity (137 mA h g−1 at 0.3C) was obtained.

Red Blood Cell Membrane Camouflaged Mesoporous Silica Nanorods as Nanocarriers for Synergistic Chemo-Photothermal Therapy

In recent years, nanoparticles camouflaged by red blood cell membrane (RBCM) have become a potential nano-drug delivery platform due to their good biocompatibility and immune evasion capability. Here, a multifunctional drug nanocarrier based on RBCM camouflaged mesoporous silica nanorods (MSNR) is presented, which can be used in pH and near-infrared (NIR) light triggered synergistic chemo-photothermal killing of cancer cells. To fabricate such a nanocarrier, MSNR and RBCM were prepared by the sol-gel method and modified hypotonic lysis method, respectively. Drugs were loaded into the pores of MSNR. Finally, RBCM was coated on the surface of MSNR by extrusion through a polycarbonate membrane. The advantages of the nanocarrier include: 1) MSNR can induce more cellular uptake than sphere shaped mesoporous silica nanoparticles. 2) The RBCM can reduce drug leakage and prevent clearance of the nanocarriers by macrophages. 3) By simultaneous loading doxorubicin (DOX) and indocyanine green (ICG), pH and NIR triggered synergistic chemo-photothermal therapy can be realized. In the experiment, we studied the drug releasing and cellular uptake of the nanocarriers in a breast cancer cell line (SKBR3 cells), in which a sufficient killing effect was observed. Such a multifunctional drug nanocarrier holds a broad application prospect in cancer treatment.

Preparation of superhydrophilic-underwater superoleophobic silica nanorods modified fiber membrane for efficient oil-in-water emulsion separation

Silica nanorods modified fiber membranes were successfully fabricated for the separation of emulsions by filtration deposition method. Compared to the unmodified membranes, the arithmetic mean and root mean square of the membranes were 5.69 μm and 9.71 μm, with an improvement of 39.8% and 46.0%, respectively. Roughness increases improved hydrophilicity and underwater oleophobicity of the membrane. The instantaneous water contact angle (WCA) and underwater oil contact angle (UOCA) reached 0° and 151.92°, showing excellent superhydrophilic and underwater superoleophobic properties. The structural stability of the membranes was demonstrated by testing the mass and microstructural changes after continuous ultrasonic treatment, where the mass loss was only 5.42% and no significant changes in the microstructure were observed. Moreover, following immersion treatment with acid, alkali, and saline solutions, the maximum loss of membrane mass was only 1.20% and it remained underwater oleophobic, displaying excellent chemical stability. The separation efficiency of the silica nanorods modified fiber membrane for oil-in-water emulsions was as high as 96%, and the separation flux was above 1900 L m−2 h−1·bar−1. The separation efficiency of the membranes was consistently maintained above 96% for 5 cycles.

Spatially isolated magnetic-mesoporous units in one anisotropic Janus nanoparticle for rapid and selective extraction of uranium

Iron oxide with superparamagnetic property and mesoporous silica with large surface areas are both important to design multifunctional sorbents, and magnetic-mesoporous nanoparticles of asymmetric morphology may make full use of their advantages. To address this, spatially isolated magnetic-mesoporous units in one anisotropic Janus nanoparticle with abundant amidoxime (AO) groups (AO-Fe3O4@C&mSiO2) was synthesized for rapid and selective extraction of uranium. Chemically and structurally anisotropic AO-Fe3O4@C&mSiO2 was composed of one AO functionalized mesoporous silica nanorods and a carbon coated Fe3O4 nanoparticle, which displayed excellent surface area (139.9 m2 g−1) and saturation magnetization (28.79 emu g−1). Thus, AO-Fe3O4@C&mSiO2 showed fast adsorption kinetics for reaching adsorption equilibrium within 30 min, and then they were able to be collected in 3.0 s under an external magnetic field. The maximum and spontaneous adsorption capacity for uranyl ions was obtained by fitting thermodynamic data through Langmuir model at 298 K was 62.12 mg g−1, and AO-Fe3O4@C&mSiO2 achieved the highest uptake amount and removal rate of almost 100% towards uranium in the presence of competitive ions. Meanwhile, the results from ten regeneration cycles confirmed the high service lifetime of AO-Fe3O4@C&mSiO2. This work not only demonstrates a strategy for preparing multifunctional sorbents with anisotropic structure but also provides a method for selective uranium extraction.

Shape-Controlled synthesis of conjugated microporous polymer nanotubes and their implementation in continuous flow polymerization

Flow reactors have materialized as a reliable and sustainable approach toward polymer production and processing to promote efficient and uniform irradiation pathways. However, the disadvantages of existing homogeneous photocatalysts including noxiousness, restricted photocatalytic activity and stability, and difficult separation and purification, still pose a great challenge to the advancement of this technique. Herein, conjugated microporous polymer nanotubes (hPorBDP NTs) were fabricated through Sonogashira-Hagihara cross-coupling polycondensation with silica nanorods as sacrificial templates, followed by etching of the inner cores. The hPorBDP NTs with a hollow nanostructure and a highly porous texture were demonstrated to facilitate the separation procedure and provide more accessible active sites for photocatalytic reactions. The hPorBDP NTs were employed as heterogeneous catalysts to activate photoinduced electron/energy transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization in batch and in continuous flow system. Screening of the initial monomer concentrations and pump flow rates, high monomer conversions (ɑ > 80%) and narrow dispersities (Đ < 1.15) were achieved in continuous flow system for upscaled production of polymers. Separation and reutilization of the catalyst-bound NTs were realized through facile centrifugation, which resulted in negligible leaching and maintenance of catalytic performance over multiple polymerization cycles. As such, the development of photosynthesis system using hPorBDP NTs as heterogeneous photocatalysts should broaden the application scope of these fascinating catalysts while benefiting synthetic upscaling by continuous flow polymerization.

Metal-phenolic coated rod-like silica nanocarriers with pH responsiveness for pesticide delivery

Entrapping pesticides in carriers would be beneficial to reduce the risk to environmental safety caused by the heavy use of pesticides. In this paper, hollow silica (hSiO2) nanorods were synthesized by sodium carbonate etching silica nanorods. The prepared hSiO2 nanocarriers have an average diameter of 100 nm and 200 nm in length, and possess good biocompatibility. Compared with spherical silica carriers, the LCH of hSiO2 carrier was increased by 35 %. After loading dinotefuran (DNF) pesticide, tannic acid-Cu complexes (TA/Cu) were coated to block the loaded DNF (DNF@hSiO2 @TA/Cu). Compared with free DNF, the half-life of DNF entrapped in hSiO2 carriers was extended by about 10 times under UV irradiation. The DNF@hSiO2 @TA/Cu system displays excellent wettability to cucumber leaves and good inhibitory effect on Penicillium and diamondback moth. The DNF@hSiO2 @TA/Cu system displays pH-responsive release. This work provides an efficient nanoplatform for effective utilization of pesticides.

In Cellulo Bioorthogonal Catalysis by Encapsulated AuPd Nanoalloys: Overcoming Intracellular Deactivation.

Bioorthogonal metallocatalysis has opened up a xenobiotic route to perform nonenzymatic catalytic transformations in living settings. Despite their promising features, most metals are deactivated inside cells by a myriad of reactive biomolecules, including biogenic thiols, thereby limiting the catalytic functioning of these abiotic reagents. Here we report the development of cytocompatible alloyed AuPd nanoparticles with the capacity to elicit bioorthogonal depropargylations with high efficiency in biological media. We also show that the intracellular catalytic performance of these nanoalloys is significantly enhanced by protecting them following two different encapsulation methods. Encapsulation in mesoporous silica nanorods resulted in augmented catalyst reactivity, whereas the use of a biodegradable PLGA matrix increased nanoalloy delivery across the cell membrane. The functional potential of encapsulated AuPd was demonstrated by releasing the potent chemotherapy drug paclitaxel inside cancer cells. Nanoalloy encapsulation provides a novel methodology to develop nanoreactors capable of mediating new-to-life reactions in cells.

Functionalized nanohybrids with rod shape for improved chemo-phototherapeutic effect against cancer by sequentially generating singlet oxygen and carbon dioxide bubbles.

The application of hybrid nanocarriers is expected to play an active role in improving treatment of chemotherapy and phototherapy. Herein, a nanohybrid with a core of mesoporous silica nanorods and shell of folate-functionalized zeolite imidazole framework (ZIF-8/FA) was synthesized via polydopamine (PDA)-mediated integration. A chemotherapeutic drug (DOX), bubble generator (NH4HCO3, ABC), and photosensitive agent (ICG) were simultaneously loaded into the delivery system to construct smart ZIF-8/FA-coated mesoporous silica nanorods (IDa-PRMSs@ZF). We found that ICG endowed the designed delivery system with a moderate photothermal conversion efficiency of 26.06% and the capacity to release 1O2. The produced hyperthermia caused ABC to decompose and further generate carbon dioxide bubbles, thereby facilitating DOX release, sequentially. Importantly, the underlying mechanism was also investigated using mathematical kinetic modeling. The tumor inhibition rate of IDa-PRMSs@ZF under NIR irradiation reached 83.8%. This study provides a promising strategy based on rod-shaped nanohybrids for effective combination antitumor therapy.

Magnetically Driven Muco-Inert Janus Nanovehicles for Enhanced Mucus Penetration and Cellular Uptake.

One of the main challenges of transmucosal drug delivery is that of enabling particles and molecules to move across the mucosal barrier of the mucosal epithelial surface. Inspired by nanovehicles and mucus-penetrating nanoparticles, a magnetically driven, mucus-inert Janus-type nanovehicle (Janus-MMSN-pCB) was fabricated by coating the zwitterionic polymer poly(carboxybetaine methacrylate) (pCB) on the mesoporous silica nanorod, which was grown on one side of superparamagnetic Fe3O4 nanoparticle using the sol-gel method. X-ray diffraction, transmission electron microscopy, vibrating sample magnetometry, and Fourier infrared spectroscopy were used to characterize the structure and morphology of the nanovehicles, proving the success of each synthesis step. The in vitro cell viability assessment of these composites using Calu-3 cell lines indicates that the nanovehicles are biocompatible in nature. Furthermore, the multiparticle tracking, Transwell® system, and cell imaging experimental results demonstrate that both the modification of pCB and the application of a magnetic field effectively accelerated the diffusion of the nanovehicles in the mucus and improved the endocytosis through Calu-3. The favorable cell uptake performance of Janus-MMSN-pCB in mucus systems with/without magnetic driving proves its potential role in the diagnosis, treatment, and imaging of mucosal-related diseases.

Honeycomb-like porous silica nanoparticles for photo and chemo combination therapy

Spherical silica carriers have attracted great interest in drug delivery and tumor therapy, but the preparation of non-spherical mesoporous silica carriers with controlled morphology and pores is still a challenge. Here, honeycomb-like mesoporous silica (HMS) nanorods (NRs) were designed and prepared by etching silica nanorods with phosphate buffer solution (PBS). HMS sample possesses an average diameter of 150 nm and length of 450 nm. Their intricate cavities and high specific surface area (724.2 m2g-1) would provide good prerequisites for drug adsorption and cellular uptake. HMS carriers have an excellent loading capacity of 43% for doxorubicin hydrochloride (DOX). DOX was loaded into the pores of HMS NRs by electrostatic interaction, followed by introducing indocyanine green (ICG) and melting menthol (LM). ICG is used as photosensitizer and LM acts thermal responsive gatekeeper to block the loaded DOX and ICG. Hyaluronic acid (HA) was grafted onto the surface of HMS carriers to achieve targeting effect and responsive drug release under specific environment. The entrapped LM and HA layer could allow the HMS carrier thermal/enzyme/pH responsive release behavior. ICG can produce singlet oxygen and convert light into local heat under laser irradiation. The DOX/ICG-loaded HMS carrier exhibits triple-responsive characters and displays photochemical combination therapy in vitro.

Cell membrane-coated mesoporous silica nanorods overcome sequential drug delivery barriers against colorectal cancer

Local delivery of nanomedicines holds therapeutic promise for colorectal cancer (CRC). However, it presents tremendous challenges due to the existence of multiple physiological barriers, especially intracellular obstacles, including intracellular trafficking, subcellular accumulation, and drug release. Herein, we report a multifunctional nanoparticle (CMSNR) by wrapping the mesoporous silica nanorod with cell membrane derived from CRC cells for improved chemotherapy. Compared with their naked counterparts, the cell membrane endowed CMSNR with homotypic targeting and improved cellular uptake capacities. Due to the rod-like shape, CMSNR achieved superior colorectal mucus permeability, enhanced tumor accumulation, and boosted cellular uptake than their spherical counterparts. Moreover, the internalized CMSNR underwent robust intracellular trafficking and gained augmented motility toward the nucleus, leading to efficient perinuclear accumulation and a subsequent 5.6-fold higher nuclear accumulation of loaded drug than that of nanospheres. In the orthotopic colorectal tumor-bearing nude mice, rectally administrated mefuparib hydrochloride (MPH)-loaded CMSNR traversed the colorectal mucus, penetrated the tumor tissue, and successfully aggregated in the perinuclear region of cancer cells, thus exhibiting significantly improved antitumor outcomes. Our findings highlight the shape-based design of cell membrane-coated nanoparticles that can address sequential drug delivery barriers has a promising future in cancer nanomedicine.

Hierarchically Porous Three-Dimensional (3D) Carbon Nanorod Networks with a High Content of FeNx Sites for Efficient Oxygen Reduction Reaction.

Efficient, durable, and inexpensive electrocatalysts are recommendable for accelerating the kinetics of oxygen reduction reaction and achieving high performance. Herein, with predesigned hierarchically porous silica nanorods as a hard template, hierarchically macro-bimodal meso/microporous 3D carbon interwoven nanorod networks containing a high content of single-atom FeNx species (Fe/RNC) were prepared by melting of precursors and confined pyrolysis within the pores of the hard template. What distinguishes the use of silica nanorods as a hard template is that it not only provides a porous texture for confined pyrolysis of the precursors but also the interwoven texture of the nanorods gives rise to a macroporous mesh-like morphology. Benefiting from the ultrahigh iron content (5.69 wt %) of the FeNx sites, a 3D porous network configuration with high accessibility of active centers, as well as a high specific surface area of 793 m2g-1, the as-prepared Fe/RNC exhibited superior activity and durability for ORR and zinc-air batteries. For comparison, the catalyst Fe/NC-MCM, which was prepared with a similar procedure but with unimodal mesoporous silica MCM-41 nanoparticles as the hard template, possesses a less porous structure and active accessibility and thus exhibits inferior ORR activity. This work provides an effective design/nanoengineering for electrocatalysts in ORR and zinc-air batteries and will inspire more research on accessibility of active sites in non-noble carbon-based electrocatalysts.