Upconversion Luminescence-Boosted Escape of DNAzyme from Endosomes for Enhanced Gene-Silencing Efficacy

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.

Modular Weaving DNAzyme in Skeleton of DNA Nanocages for Photoactivatable Catalytic Activity Regulation

DNAzymes exhibit tremendous application potentials in the field of biosensing and gene regulation due to its unique catalytic function. However, spatiotemporally controlled regulation of DNAzyme activity remains a daunting challenge, which may cause nonspecific signal leakage or gene silencing of the catalytic systems. Here, we report a photochemical approach via modular weaving active DNAzyme into the skeleton of tetrahedral DNA nanocages (TDN) for light-triggered on-demand liberation of DNAzyme and thus conditional control of gene regulation activity. We demonstrate that the direct encoding of DNAzyme in TDN could improve the biostability of DNAzyme and ensure the delivery efficiency, comparing with the conventional surface anchoring strategy. Furthermore, the molecular weaving of the DNA nanostructures allows remote control of DNAzyme-mediated gene regulation with high spatiotemporal precision of light. In addition, we demonstrate that the approach is applicable for controlled regulation of the gene editing functions of other functional nucleic acids.

Single Multifunctional Nanocabinets-Based Target-Activated Feedback for Simultaneously Precise Monitoring and Therapy

Stimulus-responsive mode is highly desirable for improving the precise monitoring and physiological efficacy of endogenous biomarkers (EB). However, its integrated application for visual detection and therapy is limited by inappropriate use of responsive triggers and poor delivery of EB signal-transducing agents, which remain challenging in simultaneous monitoring and noninvasive therapy of EB and EB-mediated pathological events. Target microRNA (miRNA) as controllable reaction triggers and DNAzyme as signal-transducing agent are proposed to develop target-stimulated multifunctional nanocabinets (MFNCs) for the visual tracking of both miRNA and miRNA-mediated anticancer events. The MFNCs, equipped with a target-discriminating sequence-incorporated DNAzyme motif, can specifically release therapeutic molecules through target-triggered conformational switches, accompanied by transduction signal output. Target detection and molecule release performance are recorded in parallel via reverse dual-signal feedback at the single-molecule level. In addition, the intrinsic thermal-replenishing of the MFNCs leads to tumor ablation without invasive exogenous aids. The system achieves visual target quantification, anticancer molecule real-time tracking, and tumor suppression in vivo and in vitro. This work proposes a new paradigm for precise visual exploration of EB or EB-mediated bio-events and provides a demonstration of efficacious all-in-one detection and therapy based on the target-triggered multifunctional nanosystem.

Rationally Integrated Precise ER-Targeted and Oxygen-Compensated Photodynamic Immunostimulant for Immunogenicity-Boosted Tumor Therapy

Notwithstanding that immunotherapy has made eminent clinical breakthroughs, activating the immunogenicity and breaking the immunosuppressive tumor microenvironment (ITME) remains tempting yet challenging. Herein, a customized-designed immunostimulant is engineered for attenuating ITME and eliciting an immune response to address this challenge head-on. This immunostimulant is equipped with dual silica layers coated upconversion nanoparticles (UCNPs) as nanocarriers modified with endoplasmic reticulum (ER)-targeted molecular N-p-Tosylglycine, in which the dense silica for chlorin e6 (Ce6) and the glutathione (GSH)-responsive degradable silica for loading resveratrol (RES) - (UCSMRER ). On the one hand, this precise ER-targeted photodynamic therapy (PDT) can generate reactive oxygen species (ROS) in situ under the 980 nm laser irradiation, which not only induced severe cell death directly but also caused intense ER stress-based immunogenic cell death (ICD). On the other hand, tumor hypoxia aggravated by the PDT is alleviated by RES released on-demand, which reduced oxygen consumption by impairing the mitochondrial electron transport chain (ETC). This integrated precise ER-targeted and oxygen-compensated strategy maximized the PDT effect and potentiated ICD-associated immunotherapy, which availed to attenuate ITME, activate tumor immunogenicity, and further magnify the anti-tumor effect. This innovative concept about PDT and immunotherapy sheds light on cancer-related clinical application.

RNA Nanomedicine: Delivery Strategies and Applications

Delivery of RNA using nanomaterials has emerged as a new modality to expand therapeutic applications in biomedical research. However, the delivery of RNA presents unique challenges due to its susceptibility to degradation and the requirement for efficient intracellular delivery. The integration of nanotechnologies with RNA delivery has addressed many of these challenges. In this review, we discuss different strategies employed in the design and development of nanomaterials for RNA delivery. We also highlight recent advances in the pharmaceutical applications of RNA delivered via nanomaterials. Various nanomaterials, such as lipids, polymers, peptides, nucleic acids, and inorganic nanomaterials, have been utilized for delivering functional RNAs, including messenger RNA (mRNA), small interfering RNA, single guide RNA, and microRNA. Furthermore, the utilization of nanomaterials has expanded the applications of functional RNA as active pharmaceutical ingredients. For instance, the delivery of antigen-encoding mRNA using nanomaterials enables the transient expression of vaccine antigens, leading to immunogenicity and prevention against infectious diseases. Additionally, nanomaterial-mediated RNA delivery has been investigated for engineering cells to express exogenous functional proteins. Nanomaterials have also been employed for co-delivering single guide RNA and mRNA to facilitate gene editing of genetic diseases. Apart from the progress made in RNA medicine, we discuss the current challenges and future directions in this field.

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.

A "Chase and Block" Strategy for Enhanced Cancer Therapy with Hypoxia-Promoted Photodynamic Therapy and Autophagy Inhibition Based on Upconversion Nanocomposites

The combination of hypoxia-promoted photodynamic therapy (PDT) and autophagy modulation has shown strong potential in the treatment of hypoxic tumors. Here, a novel design is put forward for synergistic PDT and autophagy inhibition to amplify the effect of cancer therapy by a "chase and block" strategy. Specifically, the organic photosensitive molecule (denoted FL) is encapsulated in a hydrophobic layer between multi-band emitted upconversion nanoparticles (UCNPs) and the amphiphilic polymer DSPE-PEG-COOH, allowing FL to fully exploit the luminescence spectrum of UCNPs under near-infrared (NIR) light irradiation. The FL is specifically activated by nitroreductase in the tumor microenvironment (TME), enabling hypoxia-promoted PDT and thus performing a "chase" strategy for cancer therapy. Additionally, the nanosystem is combined with an autophagy-inhibiting melittin pro-peptide (denoted as MEL), which could be triggered by the highly expressed legumain in tumor cells to inhibit the autophagy procedure by disrupting the lysosomal membrane, thus "blocking" the cancer cells from rescuing themselves and amplifying the killing effect of PDT. Both FL and MEL can be specifically activated by TME and the upconversion luminescence imaging of UCNPs offers a tracer function for the treatment. Therefore, UCNPs@FL-MEL might be an important reference for the design and development of future nanotherapeutic agents.

Sodium Alginate-Doping Cationic Nanoparticle As Dual Gene Delivery System for Genetically Bimodal Therapy

Photodynamic therapy occupies an important position in cancer therapy because of its minimal invasiveness and high spatiotemporal precision, and photodynamic/gene combined therapy is a promising strategy for additive therapeutic effects. However, the asynchronism and heterogeneity between traditional chemical photosensitizers and nucleic acid would restrict the feasibility of this strategy. KillerRed protein, as an endogenous photosensitizer, could be directly expressed and take effect in situ by transfecting KillerRed reporter genes into cells. Herein, a simple and easily prepared sodium alginate (SA)-doping cationic nanoparticle SA@GP/DNA was developed for dual gene delivery. The nanoparticles could be formed through electrostatic interaction among sodium alginate, polycation, and plasmid DNA. The title complex SA@GP/DNA showed good biocompatibility and gene transfection efficiency. Mechanism studies revealed that SA doping could facilitate the cellular uptake and DNA release. Furthermore, SA@GP/DNA was applied to the codelivery of p53 and KillerRed reporter genes for the synergistic effect combining p53-mediated apoptosis therapy and KillerRed-mediated photodynamic therapy. The ROS generation, tumor cell growth inhibition, and apoptosis assays proved that the dual-gene transfection could mediate the better effect compared with single therapy. This rationally designed dual gene codelivery nanoparticle provides an effective and promising platform for genetically bimodal therapy.