Adaptable strategy for reactivation and recycling of spent S-Zorb adsorbents at the laboratory and pilot scale.

The spent S-Zorb adsorbents containing Ni and Zn elements are hazardous wastes. It would generate significant economic and environmental benefits to reactivate and recycle these solid wastes through a reactivation strategy. Furthermore, adaptability investigation of this strategy is also indispensable before its industrial application. Herein, the spent S-Zorb adsorbents (Spent-TJ/MM/QD) from different plants were reactivated at laboratory and pilot scale in 3 m3 reactor via an acid-base coupling reactivation strategy. The spent adsorbents exhibit distinct phase compositions and microstructures of active components. Formation of ZnSi2O4 and ZnS is the primary reason for abandonment of the Spent-TJ (Spent-MM) and Spent-QD, respectively. The nickel species also exhibit different aggregation extent. Fortunately, the inert zinc and nickel species are respectively converted into ZnO and NiO during the reactivation process. Higher surface area (1.7-4.0 times that of the spent adsorbents) and more acid sites are generated over the reactivated adsorbents. Besides, all the reactivated adsorbents possess similar phase compositions and microstructures. Both the adsorbents reactivated at pilot and laboratory scale exhibit comparable desulfurization activity to fresh ones. The sulfur content of the gasoline desulfurized by the reactivated adsorbents is below 10 µg g-1, meeting the Euro V legislations. All the results indicate the excellent adaptability and commercial potential of the reactivation strategy. The possible mechanism for the excellent adaptability of the reactivation method was proposed.

Emerging Porous Two-Dimensional Materials: Current Status, Existing Challenges, and Applications.

Two-Dimensional (2D) materials have attracted immense attention in recent years. These materials have found their applications in various fields, such as catalysis, adsorption, energy storage, and sensing, as they exhibit excellent physical, chemical, electronic, photonic, and biological properties. Recently, researchers have focused on constructing porous structures on 2D materials. Various strategies, such as chemical etching and template-based methods, for the development of surface pores are reported, and the porous 2D materials fabricated over the years are used to develop supercapacitors and energy storage devices. Moreover, the lattice structure of the 2D materials can be modulated during the construction of porous structures to develop 2D materials that can be used in various fields such as lattice defects in 2D nanomaterials for enhancing biomedical performances. This review focuses on the recently developed chemical etching, solvent thermal synthesis, microwave combustion, and template methods that are used to fabricate porous 2D materials. The application prospects of the porous 2D materials are summarized. Finally, the key scientific challenges associated with developing porous 2D materials are presented to provide a platform for developing porous 2D materials.

Functional Nanoparticles with a Reducible Tetrasulfide Motif to Upregulate mRNA Translation and Enhance Transfection in Hard-to-Transfect Cells.

Effective messenger RNA (mRNA) transfection in hard-to-transfect cells delivered by vectors is a long-standing challenge. Now it is hypothesized that the high intracellular glutathione level is associated with suppressed mRNA translation. This theory leads to a new design principle of next-generation mRNA vectors: nanoparticles with glutathione depletion chemistry upregulate mRNA translation and enhance transfection, which is beneficial for mRNA delivery in hard-to-transfect cells in vitro and in vivo.

Dendritic Mesoporous Silica Nanoparticle Adjuvants Modified with Binuclear Aluminum Complex: Coordination Chemistry Dictates Adjuvanticity.

Aluminum-containing adjuvants used in vaccine formulations suffer from low cellular immunity, severe aggregation, and accumulation in the brain. Conventional aluminosilicates widely used in the chemical industry focus mainly on acidic sites for catalytic applications, but they are rarely used as adjuvants. Reported here is an innovative "ligand-assisted steric hindrance" strategy to create a high density of six-coordinate VI Al-OH groups with basicity on dendritic mesoporous silica nanoparticles as new nanoadjuvants. Compared to four-coordinate IV Al-modified counterparts, VI Al-OH-rich aluminosilicate nanoadjuvants enhance cellular delivery of antigens and provoke stronger cellular immunity. Moreover, the aluminum accumulation in the brain is more reduced than that with a commercial adjuvant. These results show that coordination chemistry can be used to control the adjuvanticity, providing new understanding in the development of next-generation vaccine adjuvants.

Openwork@Dendritic Mesoporous Silica Nanoparticles for Lactate Depletion and Tumor Microenvironment Regulation.

The direct depletion of lactate accumulated in the tumor microenvironment holds promise for cancer therapy but remains challenging. Herein, we report a one-pot synthesis of openwork@ dendritic mesoporous silica nanoparticles (ODMSNs) to address this problem. ODMSNs self-assembled through a time-resolved lamellar growth mechanism feature an openworked core and a dendritic shell, both constructed by silica nanosheets of ≈3 nm. With a large pore size, high surface area and pore volume, ODMSNs exhibited a high loading capacity (>0.7 g g-1 ) of lactate oxidase (LOX) and enabled intratumoral lactate depletion by >99.9 %, leading to anti-angiogenesis, down-regulation of vascular endothelial growth factor, and increased tumor hypoxia. The latter event facilitates the activation of a co-delivered prodrug for enhancing anti-tumor and anti-metastasis efficacy. This study provides an innovative nano-delivery system and demonstrates the first example of direct lactate-depletion-enabled chemotherapy.

Mechanism of Iron Oxide-Induced Macrophage Activation: The Impact of Composition and the Underlying Signaling Pathway.

Iron oxide nanoparticles (IONPs) have emerging anticancer applications via polarizing tumor-associated macrophages from tumor-promoting phenotype (M2) to tumor-suppressing phenotype (M1). However, the underlying mechanism and structure-function relationship remain unclear. We report magnetite IONPs are more effective compared to hematite in M1 polarization and tumor suppression. Moreover, magnetite IONPs specifically rely on interferon regulatory factor 5 signaling pathway for M1 polarization and down-regulate M2-assoicated arginase-1. This study provides new understandings and paves the way for designing advanced iron-based anticancer technologies.

Hybrid Nanoreactors: Enabling an Off-the-Shelf Strategy for Concurrently Enhanced Chemo-immunotherapy.

Immunosuppressive tumors generally exhibit poor response to immune checkpoint blockade based cancer immunotherapy. Rationally designed hybrid nanoreactors are now presented that have integrated functions as Fenton catalysts and glutathione depletion agents for amplifying the immunogenic cell death and activating immune cells. A simple physical mixture of nanoreactors and chemodrugs in combination with immune checkpoint blockades show synergistically and concurrently enhanced chemo-immunotherapy efficacy, inhibiting the growth of both treated primary immunosuppressive tumors and untreated distant tumors. The off-the-shelf strategy uses tumor antigens generated in situ and avoids cargo loading, and is thus a substantial advance in personalized nanomedicine for clinical translation.

Plasmid DNA Delivery: Nanotopography Matters.

Plasmid DNA molecules with unique loop structures have widespread bioapplications, in many cases relying heavily on delivery vehicles to introduce them into cells and achieve their functions. Herein, we demonstrate that control over delicate nanotopography of silica nanoparticles as plasmid DNA vectors has significant impact on the transfection efficacy. For silica nanoparticles with rambutan-, raspberry-, and flower-like morphologies composed of spike-, hemisphere-, and bowl-type subunit nanotopographies, respectively, the rambutan-like nanoparticles with spiky surfaces demonstrate the highest plasmid DNA binding capability and transfection efficacy of 88%, higher than those reported for silica-based nanovectors. Moreover, it is shown that the surface spikes of rambutan nanoparticles provide a continuous open space to bind DNA chains via multivalent interactions and protect the gene molecules sheltered in the spiky layer against nuclease degradation, exhibiting no significant transfection decay. This unique protection feature is in great contrast to a commercial transfection agent with similar transfection performance but poor protection capability against enzymatic cleavage. Our study provides new understandings in the rational design of nonviral vectors for efficient gene delivery.

A hierarchical spatial assembly approach of silica-polymer composites leads to versatile silica/carbon nanoparticles.

Assembly of silica and polymer in the absence of surfactant templates is an emerging strategy to construct intricate nanostructures, whereas the underlying mechanism and structural versatility remain largely unexplored. We report a hierarchical spatial assembly strategy of silica-polymer composites to produce silica and carbon nanoparticles with unprecedented structures. The assembly hierarchy involves a higher length scale asymmetric A-B-A core-shell-type spatial assembly in a composite sphere, and a nanoscale assembly in the middle layer B in which the silica/polymer ratio governs the assembled structures of silica nanodomains. Through an in-depth understanding of the hierarchical spatial assembly mechanism, a series of silica and carbon nanoparticles with intriguing and controllable architectures are obtained that cannot be easily achieved via conventional surfactant-templating approaches. This work opens an avenue toward the designed synthesis of nanoparticles with precisely regulated structures.

Subtractive Nanopore Engineered MXene Photonic Nanomedicine with Enhanced Capability of Photothermia and Drug Delivery for Synergistic Treatment of Osteosarcoma.

Two-dimensional (2D) nanomaterials as drug carriers and photosensitizers have emerged as a promising antitumor strategy. However, our understanding of 2D antitumor nanomaterials is limited to intrinsic properties or additive modification of different materials. Subtractive structural engineering of 2D nanomaterials for better antitumor efficacy is largely overlooked. Here, subtractively engineered 2D MXenes with uniformly distributed nanopores are synthesized. The nanoporous defects endowed MXene with enhanced surface plasmon resonance effect for better optical absorbance performance and strong exciton-phonon coupling for higher photothermal conversion efficiency. In addition, porous structure improves the binding ability between drug and unsaturated bonds, thus promoting drug-loading capacity and reducing uncontrolled drug release. Furthermore, the porous structure provides adhesion sites for filopodia, thereby promoting the cellular internalization of the drug. Clinically, osteosarcoma is the most common bone malignancy routinely treated with doxorubicin-based chemotherapy. There have been no significant treatment advances in the past decade. As a proof-of-concept, nanoporous MXene loaded with doxorubicin is developed for treating human osteosarcoma cells. The porous MXene platform results in a higher amount of doxorubicin-loading, faster near-infrared (NIR)-controlled doxorubicin release, higher photothermal efficacy under NIR irradiation, and increased cell adhesion and internalization. This facile method pioneers a new paradigm for enhancing 2D material functions and is attractive for tumor treatment.

Asymmetric Silica Nanoparticles with Tailored Spiky Coverage Derived from Silica-Polymer Cooperative Assembly for Enhanced Hemocompatibility and Gene Delivery.

Asymmetric mesoporous silica nanoparticles (AMSNs) with one side featuring a spiky nanotopography, while the other side is smooth and solid, were synthesized via an ethylenediamine (EDA)-directed silica-polymer cooperative assembly approach. By simply varying the EDA amount (x), AMSNs-x samples with adjustable spiky surface coverage were obtained. It is demonstrated that a spiky coverage higher than 50% improved the hemocompatibility of AMSN-x, possibly due to the reduced contact area of the smooth side exposed to the red blood cell (RBC) membrane. Moreover, AMSNs-175 and AMSNs-200 with high spiky coverage enhanced their plasmid DNA (pDNA) loading and binding capability, as well as cellular uptake into HEK-293T cells, thus resulting in high transfection performance. The good hemocompatibility and high performance in pDNA delivery of AMSNs-x with high spiky coverage allow them to serve as promising nonviral vectors for potential applications in gene therapies and DNA vaccines.

Progress in the therapeutic applications of polymer-decorated black phosphorus and black phosphorus analog nanomaterials in biomedicine.

Wonderful black phosphorus (BP) and some BP analogs (BPAs) have been increasingly studied for their biomedical applications owing to their fascinating properties and biodegradability, but opportunities and challenges have always coexisted in their study. Poor stability upon exposure to the natural environment is the major obstacle hampering their in vivo applications. BP/polymer and BPAs/polymer nanocomposites can not only efficiently prevent their oxidation and aggregation but also exhibit "biological activity" due to synergistic effects. In this review, we briefly describe the synthesis methods and stability strategies of BP/polymer and BPAs/polymer. Then, advances pertaining to their exciting therapeutic applications in various fields are systematically introduced, such as cancer therapy (phototherapy, drug delivery, and synergistic immunotherapy), bone regeneration, and neurogenesis. Some challenges for future clinical trials and possible directions for further study are finally discussed.

Lyophilization enabled disentanglement of polyethylenimine on rambutan-like silica nanoparticles for enhanced plasmid DNA delivery.

Polyethylenimine (PEI) functionalization onto nanoparticles is a widely used strategy for constructing particulate vectors for gene delivery. However, how to control the conformation of PEI chains and the resultant impact on gene transfection efficiency remains largely unexplored. Herein, we report that drying methods dramatically affect the conformation of PEI chains modified on the surface of silica nanoparticles and consequently the plasmid DNA transfection performance. Specifically, lyophilization renders less entangled PEI compared to commonly used vacuum drying as evidenced by an elevated glass transition temperature. The lyophilization induced disentangled conformation is likely associated with the solid-to-gas phase transition drying mechanism, which removes the bound crystal water content and thus reduces hydrogen bonding between amines. Moreover, we find that the stretched PEI chains on the surface of rambutan-like silica nanoparticles promote their binding capacity towards plasmid DNA molecules and thereby enhanced gene delivery and transfection efficiency. Our findings have provided new understanding about amine based polymers modified on nanoparticles, and have significant implications on the design of efficient particulate vectors for gene delivery.

Bottom-up self-assembly of heterotrimeric nanoparticles and their secondary Janus generations.

A bottom-up self-assembly approach is developed for the synthesis of ABC type heterotrimeric nanoparticles, which can be converted into secondary Janus-type silica derivatives. Compared to spherical ones, Janus silica nanoparticles stimulate stronger phagocytosis and transcytosis through intestinal epithelial microfold cells and exhibit higher cargo transport across an in vitro epithelial monolayer model mimicking the human intestinal epithelium.

Core-Shell-structured Dendritic Mesoporous Silica Nanoparticles for Combined Photodynamic Therapy and Antibody Delivery.

Multifunctional core-shell-structured dendritic mesoporous silica nanoparticles with a fullerene-doped silica core, a dendritic silica shell and large pores have been prepared. The combination of photodynamic therapy and antibody therapeutics significantly inhibits the cancer cell growth by effectively reducing the level of anti-apoptotic proteins.