One-Step Synthesis of Single-Stranded DNA-Bridged Iron Oxide Supraparticles as MRI Contrast Agents

Development of Aptamer-DNAzyme based metal-nucleic acid frameworks for gastric cancer therapy

The metal-nucleic acid nanocomposites, first termed metal-nucleic acid frameworks (MNFs) in this work, show extraordinary potential as functional nanomaterials. However, thus far, realized MNFs face limitations including harsh synthesis conditions, instability, and non-targeting. Herein, we discover that longer oligonucleotides can enhance the synthesis efficiency and stability of MNFs by increasing oligonucleotide folding and entanglement probabilities during the reaction. Besides, longer oligonucleotides provide upgraded metal ions binding conditions, facilitating MNFs to load macromolecular protein drugs at room temperature. Furthermore, longer oligonucleotides facilitate functional expansion of nucleotide sequences, enabling disease-targeted MNFs. As a proof-of-concept, we build an interferon regulatory factor-1(IRF-1) loaded Ca2+/(aptamer-deoxyribozyme) MNF to target regulate glucose transporter (GLUT-1) expression in human epidermal growth factor receptor-2 (HER-2) positive gastric cancer cells. This MNF nanodevice disrupts GSH/ROS homeostasis, suppresses DNA repair, and augments ROS-mediated DNA damage therapy, with tumor inhibition rate up to 90%. Our work signifies a significant advancement towards an era of universal MNF application.

Recent advances in functional nucleic acid decorated nanomaterials for cancer imaging and therapy

Nanomaterials possess unusual physicochemical properties including unique optical, magnetic, electronic properties, and large surface-to-volume ratio. However, nanomaterials face some challenges when they were applied in the field of biomedicine. For example, some nanomaterials suffer from the limitations such as poor selectivity and biocompatibility, low stability, and solubility. To address the above-mentioned obstacles, functional nucleic acid has been widely served as a powerful and versatile ligand for modifying nanomaterials because of their unique characteristics, such as ease of modification, excellent biocompatibility, high stability, predictable intermolecular interaction and recognition ability. The functionally integrating functional nucleic acid with nanomaterials has produced various kinds of nanocomposites and recent advances in applications of functional nucleic acid decorated nanomaterials for cancer imaging and therapy were summarized in this review. Further, we offer an insight into the future challenges and perspectives of functional nucleic acid decorated nanomaterials.

Developing Prussian blue/wood-derived biochar catalyst for persistent organic pollutant degradation: Preparation, characterization, and mechanism

Biomass-derived biochar shows broad promise for persistent organic pollutants (POPs) degradation and thus establishes a more sustainable homestead. However, effective catalytic performance is still challenging. Herein, an efficient catalyst (Prussian blue decorated wood-derived biochar, PBB) was constructed by introducing Prussian blue (PB) into wood-based biochar to activate peroxymonosulfate (PMS) for removing POPs. After anchoring of PB, the degradation performance of biochar was enhanced (degradation efficiency of methylene blue (MB, 20 mg/L) increased from 52% of biochar to 95% of PBB within 60 min). The PBB presents effective MB degradation performance with a wide pH value (3.0 < pH < 11.0) or co-existing diverse anions (Cl-, NO3-, H2PO4-, and HCO3-). Electron paramagnetic resonance (EPR) analysis as well as electrochemical tests confirmed that the non-radical pathway (1O2) is the key to biochar activation of PMS, but by restricting PB into the biochar, the radical pathway (SO4•- and •OH), the non-radical pathway (1O2), and direct electron transfer can work together to activate PMS. In addition, the degradation efficiency could remain about 80% after five-time cyclic tests. This work elucidates the role of PB nanoparticles in enhancing biochar catalysts, which can inspire the development of a carbon-neutralized, cost-effective, and effective strategy for POPs removal.

Engineered Macrophages Tune Intratumoral Cytokines through Precisely Controlled Self-Pyroptosis to Enhance Bladder Cancer Immunotherapy

Engineered macrophages are a promising tool for drug delivery and immunotherapy in cancer treatment. However, simultaneous targeted enrichment and controllable immunological activation of these macrophages at the tumor site remains challenging. As a solution, macrophages loaded with an advanced nanoparticle encapsulating CpG-conjugated magnetic nanoclusters (MNC) with indocyanine green (ICG) and nigericin (NIG) (MNC-ICG-NIG@SiO2 (MINS)), utilizing Se─Se bond-modified SiO2 , are designed and applied in bladder cancer, which is typically managed surgically, followed by Bacillus Calmette-Guerin (BCG) adjuvant instillation therapy. Upon intravenous administration, BCG-mediated tumor-localized inflammation leads to targeted accumulation of MINS@MΦ. MINS@MΦ accumulates within the tumor tissue and is immunologically activated through laser irradiation, leading to ICG-mediated generation of reactive oxygen species, Se─Se bond cleavage, and subsequent NIG release to induce self-pyroptosis. Consequently, MINS@MΦ releases Fe2+ ions and CpG, thus promoting the M1 polarization of tumor-associated macrophages and secretion of appropriate antitumor cytokines. However, without intervention, MINS@MΦ undergoes apoptosis in the bloodstream after 48 h without eliciting any immune response. Therefore, this innovative approach optimizes and enhances the efficacy of BCG immunotherapy by precisely modulating the cytokines for effective bladder cancer treatment without inducing a systemic inflammatory response.

DNA-Condensed Plasmonic Supraballs Transparent to Molecules

DNA nanotechnology offers an unrivaled programmability of plasmonic nanoassemblies based on encodable Watson-Crick basepairing. However, it is very challenging to build rigidified three-dimensional supracolloidal assemblies with strong electromagnetic coupling and a self-confined exterior shape. We herein report an alternative strategy based on a DNA condensation reaction to make such structures. Using DNA-grafted gold nanoparticles as building blocks and metal ions with suitable phosphate affinities as abiological DNA-bonding agents, a seedless growth of spheroidal supraparticles is realized via metal-ion-induced DNA condensation. Some governing rules are disclosed in this process, including kinetic and thermodynamic effects stemming from electrostatic and coordinative forces with different interaction ranges. The supraballs are tailorable by adjusting the volumetric ratio between DNA grafts and gold cores and by overgrowing extra gold layers toward tunable plasmon coupling. Various appealing and highly desirable properties are achieved for the resulting metaballs, including (i) chemical reversibility and fixation ability, (ii) stability against denaturant, salt, and molecular adsorbates, (iii) enriched and continuously tunable plasmonic hotspots, (iv) permeability to small guest molecules and antifoulingness against protein contaminates, and (v) Raman-enhancing and photocatalytic activities. Innovative applications are thus foreseeable for this emerging class of meta-assemblies in contrast to what is achieved by DNA-basepaired ones.

Coordination-driven FBXW7 DNAzyme-Fe nanoassembly enables a binary switch of breast cancer cell cycle checkpoint responses for enhanced ferroptosis-radiotherapy

Radiotherapy is a mainstream modality for breast cancer treatment that employs ionizing radiation (IR) to damage tumor cell DNA and elevate ROS stress, which demonstrates multiple clinically-favorable advantages including localized treatment and low invasiveness. However, breast cancer cells may activate the p53-mediated cell cycle regulation in response to radiotherapy to repair IR-induced cellular damage and facilitate post-treatment survival. F-Box and WD Repeat Domain Containing 7 (FBXW7) is a promoter of p53 degradation and critical nexus of cell proliferation and survival events. Herein, we engineered a cooperative radio-ferroptosis-stimulatory nanomedicine through coordination-driven self-assembly between ferroptosis-inducing Fe2+ ions and FBXW7-inhibiting DNAzymes and further modification of tumor-targeting dopamine-modified hyaluronic acid (HA). The nanoassembly could be selectively internalized by breast cancer cells and disintegrated in lysosomes to release the therapeutic payload. DNAzyme readily abolishes FBXW7 expression and stabilizes phosphorylated p53 to cause irreversible G2 phase arrest for amplifying post-IR tumor cell apoptosis. Meanwhile, the p53 stabilization also inhibits the SLC7A11-cystine-GSH axis, which combines with the IR-upregulated ROS levels to amplify Fe2+-mediated ferroptotic damage. The DNAzyme-Fe-HA nanoassembly could thus systematically boost the tumor cell damaging effects of IR, presenting a simple and effective approach to augment the response of breast cancer to radiotherapy. STATEMENT OF SIGNIFICANCE: To overcome the intrinsic radioresistance in breast cancer, we prepared co-assembly of Fe2+ and FBXW7-targeted DNAzymes and modified surface with dopamine conjugated hyaluronic acid (HA), which enabled tumor-specific FBXW7-targeted gene therapy and ferroptosis therapy in IR-treated breast cancers. The nanoassembly could be activated in acidic condition to release the therapeutic contents. Specifically, the DNAzymes could selectively degrade FBXW7 mRNA in breast cancer cells to simultaneously induce accumulation of p53 and retardation of NHEJ repair, eventually inducing irreversible cell cycle arrest to promote apoptosis. The p53 stabilization would also inhibit the SLC7A11/GSH/GPX4 axis to enhance Fe2+ mediated ferroptosis. These merits could act in a cooperative manner to induce pronounced tumor inhibitory effect, offering new approaches for tumor radiosensitization in the clinics.

Regulating the surface topography of CpG nanoadjuvants via coordination-driven self-assembly for enhanced tumor immunotherapy

Immunoadjuvants play a key role in enhancing the efficacy of therapeutic tumor vaccines for treating malignant and recurrent cancers. However, due to the bottleneck in the rational design and mechanistic understanding of novel adjuvants, currently available immunoadjuvants in clinical practice are very limited. To boost adjuvant design and development, herein we propose a surface topography regulatory strategy for constructing novel adjuvants with improved adjuvant properties. One of the licensed adjuvants with a well-defined molecular mechanism of immune activation, cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODNs), was used as the material framework. We constructed immunostimulatory CpG nanoparticles (CpG NPs) with different surface topographies by coordination-driven self-assembly between CpG ODNs and ferrous ions. These self-assembled CpG NPs combine the biological and physical activation abilities of innate immunity and can be used as adjuvants of tumor antigens for malignant tumor immunotherapy. The experimental results showed that these CpG NPs could rapidly enter innate immune cells and remold the tumor microenvironment (TME) to enhance anti-tumor immunotherapy via (i) inducing proinflammatory cytokine production; (ii) promoting the transformation of macrophages from immunosuppressed M2 types into immunoactivated M1 types; (iii) amplifying the antigen presentation of mature dendritic cells (DCs), and (iv) activating T cells in tumor sites. Among the prepared nanostructures, pompon-shaped nanoparticles (NPpo) showed the strongest adjuvant properties and anti-tumor immunotherapeutic effect as the adjuvant of ovalbumin in melanoma-bearing mice. Overall, this work provides an effective strategy for designing novel adjuvants for activating the immunosuppressed TME to enable better cancer immunotherapy.

Multifunctional Layered Double Hydroxides for Drug Delivery and Imaging

Two-dimensional nanomaterials, particularly layered double hydroxides (LDHs), have been widely applied in the biomedical field owing to their biocompatibility, biodegradability, controllable drug release/loading ability, and enhanced cellular permeability. Since the first study analyzing intercalative LDHs in 1999, numerous studies have investigated their biomedical applications, including drug delivery and imaging; recent research has focused on the design and development of multifunctional LDHs. This review summarizes the synthetic strategies and in-vivo and in-vitro therapeutic actions and targeting properties of single-function LDH-based nanohybrids and recently reported (from 2019 to 2023) multifunctional systems developed for drug delivery and/or bio-imaging.

Multi-compartment supracapsules made from nano-containers towards programmable release

The assembly of nanomaterials into suprastructures offers the possibility to fabricate larger scale functional materials, whose inner structure strongly influences their functionality for a vast range of applications. In spite of the many current strategies, achieving multi-compartment structures in a targeted and versatile way remains highly challenging. Here, we describe a controllable and straightforward route to create uniform suprastructured materials with a multi-compartmentalized architecture by confining primary nanocapsules into droplets using a cross-junction microfluidic device. Following solvent evaporation from the droplets, the nanocapsules spontaneously assemble into precisely sized multi-compartment particles, which we term supracapsules. Thanks to the process, each spatially separated nanocapsule unit retains its cargo and functionalities within the resulting supracapsules. However, new collective properties emerge, and, particularly, programmable release profiles that are distinct from those of single-compartment capsules. Finally, the suprastructures can be disassembled into single-compartment units by applying ultra-sonication, switching their release to a burst-release mode. These findings open up exciting opportunities to fabricate multi-compartment suprastructures incorporating diverse functionalities for materials with emerging properties.

DNA-Templated ultrasmall bismuth sulfide nanoparticles for photoacoustic imaging of myocardial infarction

Photoacoustic imaging (PAI) has shown great clinical potential in diagnosing various diseases due to its noninvasive, cost-effective, and real-time imaging properties but is limited by the lack of contrast agents with high sensitivity for deep tissue imaging. Here, DNA-templated ultrasmall bismuth sulfide (Bi₂S₃) nanoparticles (NPs) were reported as a photoacoustic (PA) probe for imaging myocardial infarction. We present a simple synthesis strategy of ultrasmall NPs via self-assembly of single-stranded DNA (ssDNA)/metal ion complexes. The in vivo imaging results showed a dramatically enhanced PA signal in the region of myocardial infarction after intravenous injection of DNA-Bi₂S₃ NPs in the myocardial ischaemia/reperfusion (I/R) mouse model. Further near infrared fluorescence imaging indicated that Bi₂S₃ NPs mainly accumulated in the infarcted area, leading to enhancement of PA signals. Moreover, such hybrid NPs possess a well-defined nanostructure, superior photobleaching resistance, excellent water dispersibility and negligible acute toxicity. These results not only demonstrate that ultrasmall DNA-Bi₂S₃ NPs are a potent PA probe for imaging the infarcted region but also provide a new avenue for preparing ultrasmall-sized PA probes by using ssDNA as a template.

Designer Nanomaterials through Programmable Assembly

Nanoparticles have long been recognized for their unique properties, leading to exciting potential applications across optics, electronics, magnetism, and catalysis. These specific functions often require a designed organization of particles, which includes the type of order as well as placement and relative orientation of particles of the same or different kinds. DNA nanotechnology offers the ability to introduce highly addressable bonds, tailor particle interactions, and control the geometry of bindings motifs. Here, we discuss how developments in structural DNA nanotechnology have enabled greater control over 1D, 2D, and 3D particle organizations through programmable assembly. This Review focuses on how the use of DNA binding between nanocomponents and DNA structural motifs has progressively allowed the rational formation of prescribed particle organizations. We offer insight into how DNA-based motifs and elements can be further developed to control particle organizations and how particles and DNA can be integrated into nanoscale building blocks, so-called "material voxels", to realize designer nanomaterials with desired functions.