Cancer Cell Membrane Camouflaged Nanoprobe for Catalytic Ratiometric Photoacoustic Imaging of MicroRNA in Living Mice

Targeted Knockdown of Epithelial Estrogen Receptor α to Mitigate Ferroptosis and Epithelial-Mesenchymal Transition in Eosinophilic Asthma

Estrogen receptor α (ERα) is involved with the hyperresponsiveness and airway remodeling in asthma, but developing therapies targeting ERα remains challenging due to its multifaceted roles in different cell types and the poor efficacy of systemic ERα intervention in asthma. Previously, we uncovered the association of increased ERα expression in airway epithelial cells with poor pulmonary function and epithelial-mesenchymal transition (EMT) in asthma patients. This study further investigated the association of ERα expression with the ferroptosis and EMT levels in a cohort of eosinophilic asthma (EA) patients as well as in an eosinophil-epithelial coculture cell model. By loading small interfering RNA (siRNA) into a mesoporous silica nanoparticle (MSN) and then coating the extracted bronchial epithelial cytomembrane (CM), a bronchial epithelial CM home-targeting nanoplatform (siRNA@MSN@CM) was constructed to selectively decrease the ERα expression in bronchial epithelial cells. The targeting effect of bronchial epithelial cells was confirmed in vitro and in vivo, demonstrating the successful targeted knockdown of ERα expression. Silencing ERα in epithelial cells effectively prevented ferroptosis and EMT induced by coculturing with ferroptotic eosinophils. Targeted intervention of epithelium ERα with intratracheal delivery of siRNA(ERα)@MSN@CM nanoparticle significantly reduced the levels of ferroptosis in bronchial epithelial cells, airway inflammation, and airway remodeling in asthmatic mouse models. This study introduces an innovative nanomaterial for targeted drug delivery to epithelial cells and underscores the potential of targeted knockdown ERα in bronchial epithelial cells as a therapeutic strategy for asthma treatment.

Redox-stimulated catalytic DNA circuit for high-fidelity imaging of microRNA and in situ interpretation of the relevant regulatory pathway

Biomolecules play essential roles in regulating the orderly progression of biochemical reaction networks. DNA-based biocircuits supplement an attractive and ideal approach for the visual imaging of endogenous biomolecules, yet their sensing performance is commonly encumbered by the undesired signal leakage. To solve this issue, here we proposed a glutathione (GSH)-activated DNA circuit for achieving the spatio-selective microRNA imaging through the successive response of a GSH-specific activation procedure and a non-enzymatic catalytic signal amplification procedure. In this design, by incorporating a disulfide bond into the pre-sealed nucleic acid probe, the uncontrolled circuitry leakage could be effectively ameliorated. In target cancer cells with high-abundant GSH and miR-21, endogenous GSH recognized and cleaved the pre-installed disulfide bond within DNA probes, thereby restoring the activity of circuitry components. The miR-21 then catalyzed the specific operation of circuitry for generating an amplified readout signal. We demonstrate that this system not only enables the effective discriminations of various cell types, but also contributes to the exploration of the correlationship between GSH and miR-21. This on-site activated DNA circuit can be extended to the robust analysis and exploration of different biomolecular interactions, offering a reliable reference for the in-depth understanding of biochemical interaction networks.

Entropy driven-based catalytic biosensors for bioanalysis: From construction to application-A review

The rapid advancement of precision medicine and the continuous emergence of novel pathogens have presented new challenges for biosensors, necessitating higher requirements. Target amplification technology serves as the core component in biosensor construction. Enzyme-based amplification methods are often sensitive and selective but involve relatively complex operational steps, whereas enzyme-free amplification methods offer simplicity but frequently fail to meet both sensitivity and selectivity simultaneously. Existing research has confirmed that entropy-driven catalyst (EDC) biosensors not only fulfills the demands for sensitivity and selectivity concurrently but also offers ease of operation and flexibility in construction. In this review, we summarize the key advantages of EDC, explore how to construct DNA nanomachines based on these advantages to achieve intracellular detection and simultaneous detection of multiple targets, as well as point-of-care testing (POCT) to address practical issues in clinical diagnosis and treatment. We also anticipate potential challenges, propose corresponding solutions, and outline future development directions for EDC-based biosensors in practical clinical applications. We firmly believe that EDC sensors will emerge as a crucial branch within the realm of biosensor development.

A switchable magnetic resonance imaging nanoplatform for in situ microRNA imaging

Aberrant microRNA (miRNA) expression is associated with various types of carcinogenesis, making miRNA a promising candidate for diagnostic and therapeutic biomarkers. However, in situ miRNA diagnostics remains a significant challenge owing to the various biological barriers. Herein, we report a novel miRNA imaging probe consisting of PEG-polylysine-PNIPAM polymer matrix-modified small Fe3O4 (PAA-Fe3O4-DNA@PPP) nanoparticles with an improved circulatory half-life, efficient tissue permeability, and enhanced tumor accumulation, for in situ miRNA magnetic resonance imaging (MRI). In this strategy, we employed large size PAA-Fe3O4-DNA@PPP to improve circulatory time and utilized PEG-polylysine-PNIPAM as a GSH-responsive moiety to dissociate PAA-Fe3O4-DNA@PPP and release small size PAA-Fe3O4-DNA for enhanced tumor permeability. Specifically, the target miRNA acts as a cross-linker for PAA-Fe3O4-DNA, forming larger assemblies that not only amplify the MRI signal for detection but also enhance retention for prolonged observation. Both the in vitro and in vivo results validate that the imaging probe exhibits an enhanced MRI signal with 3.69-fold amplification for tumor interior miRNA detection, allowing the dynamic changes in miRNA to be monitored by the probe. Given its long circulation, efficient penetration, and enhanced tumor accumulation, the PAA-Fe3O4-DNA@PPP probe holds great promise for in situ miRNA imaging and spatial genomics analysis in situ.

Mechanisms of extracellular vesicle uptake and implications for the design of cancer therapeutics

The translation of pre-clinical anti-cancer therapies to regulatory approval has been promising, but slower than hoped. While innovative and effective treatments continue to achieve or seek approval, setbacks are often attributed to a lack of efficacy, failure to achieve clinical endpoints, and dose-limiting toxicities. Successful efforts have been characterized by the development of therapeutics designed to specifically deliver optimal and effective dosing to tumour cells while minimizing off-target toxicity. Much effort has been devoted to the rational design and application of synthetic nanoparticles to serve as targeted therapeutic delivery vehicles. Several challenges to the successful application of this modality as delivery vehicles include the induction of a protracted immune response that results in their rapid systemic clearance, manufacturing cost, lack of stability, and their biocompatibility. Extracellular vesicles (EVs) are a heterogeneous class of endogenous biologically produced lipid bilayer nanoparticles that mediate intercellular communication by carrying bioactive macromolecules capable of modifying cellular phenotypes to local and distant cells. By genetic, chemical, or metabolic methods, extracellular vesicles (EVs) can be engineered to display targeting moieties on their surface while transporting specific cargo to modulate pathological processes following uptake by target cell populations. This review will survey the types of EVs, their composition and cargoes, strategies employed to increase their targeting, uptake, and cargo release, and their potential as targeted anti-cancer therapeutic delivery vehicles.

Deciphering the multifaceted role of microRNAs in hepatocellular carcinoma: Integrating literature review and bioinformatics analysis for therapeutic insights

Hepatocellular carcinoma (HCC) poses a significant global health challenge, necessitating innovative therapeutic strategies. MicroRNAs (miRNAs) have emerged as pivotal regulators of HCC pathogenesis, influencing key processes such as self-renewal, angiogenesis, glycolysis, autophagy, and metastasis. This article integrates findings from a comprehensive literature review and bioinformatics analysis to elucidate the role of miRNAs in HCC. We discuss how dysregulation of miRNAs can drive HCC initiation, progression, and metastasis by modulating various signaling pathways and target genes. Moreover, leveraging high-throughput technology and bioinformatics tools, we identify key miRNAs involved in multiple cancer hallmarks, offering insights into potential combinatorial therapeutic strategies. Through our analysis considering p-values and signaling pathways associated with key features, we unveil miRNAs with simultaneous roles across critical cancer characteristics, providing a basis for the development of high-performance biomarkers. The microRNAs, miR-34a-5p, miR-373-3p, miR-21-5p, miR-214-5p, miR-195-5p, miR-139-5p were identified to be shared microRNAs in stemness, angiogenesis, glycolysis, autophagy, EMT, and metastasis of HCC. However, challenges such as miRNA stability and delivery hinder the translation of miRNA-based therapeutics into clinical practice. This review underscores the importance of further research to overcome existing barriers and realize the full potential of miRNA-based interventions for HCC management.

Ultrasound-Based Micro-/Nanosystems for Biomedical Applications

Due to the intrinsic non-invasive nature, cost-effectiveness, high safety, and real-time capabilities, besides diagnostic imaging, ultrasound as a typical mechanical wave has been extensively developed as a physical tool for versatile biomedical applications. Especially, the prosperity of nanotechnology and nanomedicine invigorates the landscape of ultrasound-based medicine. The unprecedented surge in research enthusiasm and dedicated efforts have led to a mass of multifunctional micro-/nanosystems being applied in ultrasound biomedicine, facilitating precise diagnosis, effective treatment, and personalized theranostics. The effective deployment of versatile ultrasound-based micro-/nanosystems in biomedical applications is rooted in a profound understanding of the relationship among composition, structure, property, bioactivity, application, and performance. In this comprehensive review, we elaborate on the general principles regarding the design, synthesis, functionalization, and optimization of ultrasound-based micro-/nanosystems for abundant biomedical applications. In particular, recent advancements in ultrasound-based micro-/nanosystems for diagnostic imaging are meticulously summarized. Furthermore, we systematically elucidate state-of-the-art studies concerning recent progress in ultrasound-based micro-/nanosystems for therapeutic applications targeting various pathological abnormalities including cancer, bacterial infection, brain diseases, cardiovascular diseases, and metabolic diseases. Finally, we conclude and provide an outlook on this research field with an in-depth discussion of the challenges faced and future developments for further extensive clinical translation and application.

Development of Polymethine Dyes for NIR-II Fluorescence Imaging and Therapy

Fluorescence imaging in the second near-infrared window (NIR-II) is burgeoning because of its higher imaging fidelity in monitoring physiological and pathological processes than clinical visible/the second near-infrared window fluorescence imaging. Notably, the imaging fidelity is heavily dependent on fluorescence agents. So far, indocyanine green, one of the polymethine dyes, with good biocompatibility and renal clearance is the only dye approved by the Food and Drug Administration, but it shows relatively low NIR-II brightness. Importantly, tremendous efforts are devoted to synthesizing polymethine dyes for imaging preclinically and clinically. They have shown feasibility in the customization of structure and properties to fulfill various needs in imaging and therapy. Herein, a timely update on NIR-II polymethine dyes, with a special focus on molecular design strategies for fluorescent, photoacoustic, and multimodal imaging, is offered. Furthermore, the progress of polymethine dyes in sensing pathological biomarkers and even reporting drug release is illustrated. Moreover, the NIR-II fluorescence imaging-guided therapies with polymethine dyes are summarized regarding chemo-, photothermal, photodynamic, and multimodal approaches. In addition, artificial intelligence is pointed out for its potential to expedite dye development. This comprehensive review will inspire interest among a wide audience and offer a handbook for people with an interest in NIR-II polymethine dyes.

A novel combined therapeutic strategy of Nano-EN-IR@Lip mediated photothermal therapy and stem cell inhibition for gastric cancer

Recurrence and metastasis of gastric cancer is a major therapeutic challenge for treatment. The presence of cancer stem cells (CSCs) is a major obstacle to the success of current cancer therapy, often leading to treatment resistance and tumor recurrence and metastasis. Therefore, it is important to develop effective strategies to eradicate CSCs. In this study, we developed a combined therapeutic strategy of photothermal therapy (PTT) and gastric cancer stem cells (GCSCs) inhibition by successfully synthesizing nanoliposomes loaded with IR780 (photosensitizer) and EN4 (c-Myc inhibitor). The nanocomposites are biocompatible and exhibit superior photoacoustic (PA) imaging properties. Under laser irradiation, IR780-mediated PTT effectively and rapidly killed tumor cells, while EN4 synergistically inhibited the self-renewal and stemness of GCSCs by suppressing the expression and activity of the pluripotent transcription factor c-Myc, preventing the tumor progression of gastric cancer. This Nano-EN-IR@Lip is expected to be a novel clinical nanomedicine for the integration of gastric cancer diagnosis, treatment and prevention.

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.

Recent advances in DNA-based probes for photoacoustic imaging

Photoacoustic imaging(PAI) is a widely developing imaging modality that has seen tremendous evolvement in the last decade. PAI has gained the upper hand in the imaging field as it takes advantage of optical absorption and ultrasound detection that imparts higher resolution, rich contrast and elevated penetration depth. Unlike other imaging techniques, PAI does not use ionising radiation and is a better, cost-effective and healthier alternative to other imaging techniques. It offers greater specificity than conventional ultrasound imaging with the ability to detect haemoglobin, lipids, water and other light-absorbing chromophores. These properties of PAI have led to its extended applications in the biomedical field in the treatment of diseases such as cancer. This paper reviews how DNA probes have been used in PAI, the various techniques by which it has been modified, and their role in the process. We also focus on different nanocomposites containing DNA having PAI and photothermal therapy(PTT) properties for detection, diagnosis and therapy, its constituents and the role of DNA in it.

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

The invention of silica-based bioactive glass in the late 1960s has sparked significant interest in exploring a wide range of silicon-containing biomaterials from the macroscale to the nanoscale. Over the past few decades, these biomaterials have been extensively explored for their potential in diverse biomedical applications, considering their remarkable bioactivity, excellent biocompatibility, facile surface functionalization, controllable synthesis, etc. However, to expedite the clinical translation and the unexpected utilization of silicon-composed nanomedicine and biomaterials, it is highly desirable to achieve a thorough comprehension of their characteristics and biological effects from an overall perspective. In this review, we provide a comprehensive discussion on the state-of-the-art progress of silicon-composed biomaterials, including their classification, characteristics, fabrication methods, and versatile biomedical applications. Additionally, we highlight the multi-dimensional design of both pure and hybrid silicon-composed nanomedicine and biomaterials and their intrinsic biological effects and interactions with biological systems. Their extensive biomedical applications span from drug delivery and bioimaging to therapeutic interventions and regenerative medicine, showcasing the significance of their rational design and fabrication to meet specific requirements and optimize their theranostic performance. Additionally, we offer insights into the future prospects and potential challenges regarding silicon-composed nanomedicine and biomaterials. By shedding light on these exciting research advances, we aspire to foster further progress in the biomedical field and drive the development of innovative silicon-composed nanomedicine and biomaterials with transformative applications in biomedicine.

Cancer Cell Membrane-Based Materials for Biomedical Applications

The nanodelivery system provides a novel direction for disease diagnosis and treatment; however, its delivery effectiveness is restricted by the short biological half-life and inadequate tumor targeting. The immune evasion properties and homologous targeting capabilities of natural cell membranes, particularly those of cancer cell membranes (CCM), have gained significant interest. The integration of CCM and nanoparticles has resulted in the emergence of CCM-based nanoplatforms (CCM-NPs), which have gained significant attention due to their unique properties. CCM-NPs not only prolong the blood circulation time of core nanoparticles, but also direct them for homologous tumor targeting. Herein, the history and development of CCM-NPs as well as how these platforms have been used for biomedical applications are discussed. The application of CCM-NPs for cancer therapy will be described in detail. Translational efforts are currently under way and further research to address key areas of need will ultimately be required to facilitate the successful clinical adoption of CCM-NPs.

Prolonged near-infrared fluorescence imaging of microRNAs and proteases in vivo by aggregation-enhanced emission from DNA-AuNC nanomachines

Developing a comprehensive strategy for imaging various biomarkers (i.e., microRNAs and proteases) in vivo is an exceptionally formidable task. Herein, we have designed a deoxyribonucleic acid-gold nanocluster (DNA-AuNC) nanomachine for detecting tumor-related TK1 mRNA and cathepsin B in living cells and in vivo. The DNA-AuNC nanomachine is constructed using AuNCs and DNA modules that incorporate a three component DNA hybrid (TD) and a single-stranded fuel DNA (FD). Upon being internalized into tumor cells, the TK1 mRNA initiates the DNA-AuNC nanomachine through DNA strand displacement cascades, leading to the amplified self-assembly and the aggregation-enhanced emission of AuNCs for in situ imaging. Furthermore, with the aid of a protease nanomediator consisting of a mediator DNA/peptide complex and AuNCs (DpAuNCs), the DNA-AuNC nanomachine can be triggered by the protease-activated disassembly of the DNA/peptide complex on the nanomediator, resulting in the aggregation of AuNCs for in vivo protease amplified detection. It is worth noting that our study demonstrates the impressive tumor permeability and accumulation capabilities of the DNA-AuNC nanomachines via in situ amplified self-assembly, thereby facilitating prolonged imaging of TK1 mRNA and cathepsin B both in vitro and in vivo. This strategy presents a versatile and biomarker-specific paradigm for disease diagnosis.

Nanotechnology Utilizing Ferroptosis Inducers in Cancer Treatment

Current cancer treatment options have presented numerous challenges in terms of reaching high efficacy. As a result, an immediate step must be taken to create novel therapies that can achieve more than satisfying outcomes in the fight against tumors. Ferroptosis, an emerging form of regulated cell death (RCD) that is reliant on iron and reactive oxygen species, has garnered significant attention in the field of cancer therapy. Ferroptosis has been reported to be induced by a variety of small molecule compounds known as ferroptosis inducers (FINs), as well as several licensed chemotherapy medicines. These compounds' low solubility, systemic toxicity, and limited capacity to target tumors are some of the significant limitations that have hindered their clinical effectiveness. A novel cancer therapy paradigm has been created by the hypothesis that ferroptosis induced by nanoparticles has superior preclinical properties to that induced by small drugs and can overcome apoptosis resistance. Knowing the different ideas behind the preparation of nanomaterials that target ferroptosis can be very helpful in generating new ideas. Simultaneously, more improvement in nanomaterial design is needed to make them appropriate for therapeutic treatment. This paper first discusses the fundamentals of nanomedicine-based ferroptosis to highlight the potential and characteristics of ferroptosis in the context of cancer treatment. The latest study on nanomedicine applications for ferroptosis-based anticancer therapy is then highlighted.

Tumor-derived systems as novel biomedical tools-turning the enemy into an ally

Cancer is a complex illness that presents significant challenges in its understanding and treatment. The classic definition, "a group of diseases characterized by the uncontrolled growth and spread of abnormal cells in the body," fails to convey the intricate interaction between the many entities involved in cancer. Recent advancements in the field of cancer research have shed light on the role played by individual cancer cells and the tumor microenvironment as a whole in tumor development and progression. This breakthrough enables the utilization of the tumor and its components as biological tools, opening new possibilities. This article delves deeply into the concept of "tumor-derived systems", an umbrella term for tools sourced from the tumor that aid in combatting it. It includes cancer cell membrane-coated nanoparticles (for tumor theranostics), extracellular vesicles (for tumor diagnosis/therapy), tumor cell lysates (for cancer vaccine development), and engineered cancer cells/organoids (for cancer research). This review seeks to offer a complete overview of the tumor-derived materials that are utilized in cancer research, as well as their current stages of development and implementation. It is aimed primarily at researchers working at the interface of cancer biology and biomedical engineering, and it provides vital insights into this fast-growing topic.

Low-Background CRISPR/Cas12a Sensors for Versatile Live-Cell Biosensing

The trans-cleavage activity of CRISPR/Cas12a has been widely used in biosensing. However, many CRISPR/Cas12a-based biosensors, especially those that work in "on-off-on" mode, usually suffer from high background and thus impossible intracellular application. Herein, this problem is efficiently overcome by elaborately designing the activator strand (AS) of CRISPR/Cas12a using the "RESET" effect found by our group. The activation ability of the as-designed AS to CRISPR/Cas12a can be easily inhibited, thus assuring a low background for subsequent biosensing applications, which not only benefits the detection sensitivity improvement of CRISPR/Cas12a-based biosensors but also promotes their applications in live cells as well as makes it possible to design high-performance biosensors with greatly improved flexibility, thus achieving the analysis of a wide range of targets. As examples, by using different strategies such as strand displacement, strand cleavage, and aptamer-substrate interaction to reactivate the inhibited enzyme activity, several CRISPR/Cas12a-based biosensing systems are developed for the sensitive and specific detection of different targets, including nucleic acid (miR-21), biological small molecules (ATP), and enzymes (hOGG1), giving the detection limits of 0.96 pM, 8.6 μM, and 8.3 × 10-5 U/mL, respectively. Thanks to the low background, these biosensors are demonstrated to work well for the accurate imaging analysis of different biomolecules in live cells. Moreover, we also demonstrate that these sensing systems can be easily combined with lateral flow assay (LFA), thus holding great potential in point-of-care testing, especially in poorly equipped or nonlaboratory environments.

Current research status of tumor cell biomarker detection

With the annual increases in the morbidity and mortality rates of tumors, the use of biomarkers for early diagnosis and real-time monitoring of tumor cells is of great importance. Biomarkers used for tumor cell detection in body fluids include circulating tumor cells, nucleic acids, protein markers, and extracellular vesicles. Among them, circulating tumor cells, circulating tumor DNA, and exosomes have high potential for the prediction, diagnosis, and prognosis of tumor diseases due to the large amount of valuable information on tumor characteristics and evolution; in addition, in situ monitoring of telomerase and miRNA in living cells has been the topic of extensive research to understand tumor development in real time. Various techniques, such as enzyme-linked immunosorbent assays, immunoblotting, and mass spectrometry, have been widely used for the detection of these markers. Among them, the detection of tumor cell markers in body fluids based on electrochemical biosensors and fluorescence signal analysis is highly preferred because of its high sensitivity, rapid detection and portable operation. Herein, we summarize recent research progress in the detection of tumor cell biomarkers in body fluids using electrochemical and fluorescence biosensors, outline the current research status of in situ fluorescence monitoring and the analysis of tumor markers in living cells, and discuss the technical challenges for their practical clinical application to provide a reference for the development of new tumor marker detection methods.

Dual-layer 3D DNA nanostructure: The next generation of ultrafast DNA nanomachine for microRNA sensing and intracellular imaging

The working efficiency of traditional 3D DNA nanomachines is extremely restricted due to the complex DNA components modified on nanoparticles in the same spatial height. Herein, an ultrafast dual-layer 3D DNA nanomachine (UDDNM) based on catalytic hairpin assembly (CHA) was developed by assembling two different lengths of hairpin DNA on the surface of gold nanoparticles, the long hairpin 1 (H1), to capture the trigger, and the short hairpin 2 (H2), as the signal probe, to recycle the trigger. Compared to the traditional single-layer 3D DNA nanomachine, the dual-layer 3D DNA nanostructure greatly enhances the effective collision between trigger and targeted DNA probe, H1, since the H1 located in outer layer would react with the trigger, inhibiting the invalid collision between the trigger and residual DNA component, H2, and remarkably decreasing the steric hindrance associated with the nucleic acids layer around the nanoparticles. Especially, when the distance of two layers was fixed at 3 nm, the corresponding UDDNM could accomplish the overall reaction only in 3 min with a dramatically high initial rate of up to 5.93 × 10-7 M s-1, which was at least 5-fold beyond that of the typical single-layer 3D DNA nanomachines. As a proof of concept, the described UDDNM was successfully applied in ultrasensitive fluorescence detection and sensitive intracellular imaging of miRNA-21. Consequently, our strategy, based on the creation of dual-layer 3D DNA nanostructure, may create a new approach to designing the next generation of DNA nanomachine and has enormous potential for applications in bio-analysis, logic gate operations, and clinical diagnoses.

Cancer Immunotherapy Based on Cell Membrane-Coated Nanocomposites Augmenting cGAS/STING Activation by Efferocytosis Blockade

Innate immunity triggered by the cGAS/STING pathway has the potential to improve cancer immunotherapy. Previously, the authors reported that double-stranded DNA (dsDNA) released by dying tumor cells can trigger the cGAS/STING pathway. However, owing to efferocytosis, dying tumor cells are engulfed and cleared before the damaged dsDNA is released; hence, immunologic tolerance and immune escape occur. Herein, a cancer-cell-membrane biomimetic nanocomposites that exhibit tumor-immunotherapeutic effects are synthesized by augmenting the cGAS/STING pathway and suppressing efferocytosis. Once internalized by cancer cells, a combined chemo/chemodynamic therapy would be triggered, which damages their nuclear and mitochondrial DNA. Furthermore, the releasing Annexin A5 protein could inhibit efferocytosis effect and promote immunostimulatory secondary necrosis by preventing phosphatidylserine exposure, resulting in the burst release of dsDNA. These dsDNA fragments, as molecular patterns to immunogenic damage, escape from the cancer cells, activate the cGAS/STING pathway, enhance cross-presentation inside dendritic cells, and promote M1-polarization of tumor-associated macrophages. In vivo experiments suggest that the proposed nanocomposite could recruit cytotoxic T-cells and facilitate long-term immunological memory. Moreover, when combined with immune-checkpoint blockades, it could augment the immune response. Therefore, this novel biomimetic nanocomposite is a promising strategy for generating adaptive antitumor immune responses.

Oncogene-targeting nanoprobes for early imaging detection of tumor

Malignant tumors have been one of the major reasons for deaths worldwide. Timely and accurate diagnosis as well as effective intervention of tumors play an essential role in the survival of patients. Genomic instability is the important foundation and feature of cancer, hence, in vivo oncogene imaging based on novel probes provides a valuable tool for the diagnosis of cancer at early-stage. However, the in vivo oncogene imaging is confronted with great challenge, due to the extremely low copies of oncogene in tumor cells. By combining with various novel activatable probes, the molecular imaging technologies provide a feasible approach to visualize oncogene in situ, and realize accurate treatment of tumor. This review aims to declare the design of nanoprobes responded to tumor associated DNA or RNA, and summarize their applications in detection and bioimaging for tumors. The significant challenges and prospective of oncogene-targeting nanoprobes towards tumors diagnosis are revealed as well.

Orthometric multicolor encoded hybridization chain reaction amplifiers for multiplexed microRNA profiling in living cells

Multiplexed microRNA (miRNA) profiling of more than four types in living cells is challenging due to fluorescent spectral overlap, representing a significant limitation in studying the complex interactions related to the occurrence and development of diseases. Herein, we report a multiplexed fluorescent imaging strategy based on an orthometric multicolor encoded hybridization chain reaction amplifier named multi-HCR. The targeting miRNA can trigger this multi-HCR strategy due to the specific sequence recognition, and then its self-assembly to amplify the programmability signals. We take the four-colored chain amplifiers, showing that the multi-HCR can form 15 combinations simultaneously. In a living process of hypoxia-induced apoptosis and autophagy under complicated mitochondria and endoplasmic reticulum stress, the multi-HCR demonstrates excellent performance in detecting eight different miRNA changes. The multi-HCR provides a robust strategy for simultaneously profiling multiplexed miRNA biomarkers in studying complicated cellular processes.

A Smart Nano-Theranostic Platform Based on Dual-microRNAs Guided Self-Feedback Tetrahedral Entropy-Driven DNA Circuit

MicroRNAs (miRNAs) can act as oncogenes or tumor suppressors, capable of up or down-regulating gene expression during tumorigenesis; they are diagnostic biomarkers or therapeutic targets for tumors. To detect low abundance of intracellular oncogenic miRNAs (onco-miRNAs) and realize synergistic gene therapy of onco-miRNAs and tumor suppressors, a smart nano-theranostic platform based on dual-miRNAs guided self-feedback tetrahedral entropy-driven DNA circuit is created. The platform as a delivery vehicle is a DNA tetrahedral framework, in which the entropy-driven DNA circuit achieves a dual-miRNAs guided self-feedback, between an in situ amplification of the onco-miRNAs and activation of suppressor miRNAs release. To test this platform, dual-miRNAs are selected, miRNA-155, an up-regulated miRNA, as cancer indicators, and miRNA-122, a down-regulated miRNA as therapy targets in hepatocellular carcinoma, respectively. Through the circuit, the platform to detect onco-miRNAs at femtomolar level as well as visualized miRNAs inside cells, fixed tissues, and mice is programmed. Furthermore, triggered by miRNA-155, preloaded miRNA-122 is amplified via the self-feedback and released into target cells; the sudden increase of miRNA-122 and simultaneous decrease of miRNA-155 synergistically served as therapeutic drugs for gene regulation with enhanced antitumor efficacy and superior biosafety. It is envisioned that this nano-theranostic platform will initiate an essential step toward tumor theranostics in personalized/precise medicine.

Tumor microenvironment targeting system for glioma treatment via fusion cell membrane coating nanotechnology

The tumor microenvironment (TME), comprising cancer cells and stroma, plays a significant role in determining clinical outcomes, which makes targeting cancer cells in the TME an important area of research. One way in which cancer cells in the TME can be specifically targeted is by coating drug-encapsulated nanoparticles (NPs) with homotypic cancer cell membranes. However, incomplete targeting is inevitable for biomimetic nanoformulations coated with only cancer cell membranes because of the inherent heterogeneity of the TME. After observing the structural connection between glioma-associated stromal cells (GASCs) and glioma cells from a clinic, we designed a novel drug delivery system that targets the TME by coating polylactic-co-glycolic acid (PLGA) NPs with GASC-glioma cell fusion cell (SG cell) membranes. The resulting SGNPs inherited membrane proteins from both the glioma membrane and GASC membrane, significantly enhancing the tumor targeting efficiency compared to nanoformulations coated with cancer cell membranes alone. We further demonstrated that encapsulation of temozolomide (TMZ) improved the therapeutic efficacy of TMZ in both heterotopic and orthotopic glioma mouse models. Owing to its significant efficacy, our TME-targeting nanoplatform has potential for clinical applications in the treatment of various cancers.

Clustered Cobalt Nanodots Initiate Ferroptosis by Upregulating Heme Oxygenase 1 for Radiotherapy Sensitization

High cobalt (Co) levels in tumors are associated with good clinical prognosis. An anticancer regimen that increases intratumoral Co through targeted nanomaterial delivery is proposed in this study. Bovine serum albumin and cobalt dichloride are applied to prepare cobaltous oxide nanodots using a facile biomineralization strategy. After iRGD peptide conjugation, the nanodots are loaded into dendritic mesoporous silica nanoparticles, generating a biocompatible product iCoDMSN. This nanocomposite accumulates in tumors after intravenous injection by deep tissue penetration and can be used for photoacoustic imaging. Proteomics research and molecular biology experiments reveal that iCoDMSN is a potent ferroptosis inducer in cancer cells. Mechanistically, iCoDMSNs upregulate heme oxygenase 1 (HMOX1), which increases transferrin receptors and reduces solute carrier family 40 member 1 (SLC40A1), resulting in Fe²⁺ accumulation and ferroptosis initiation. Furthermore, upregulated nuclear factor erythroid 2-related factor 2 (NRF2), arising from the reduction in Kelch-like ECH-associated protein 1 (KEAP1) expression, is responsible for HMOX1 enhancement after iCoDMSN treatment. Owing to intensified ferroptosis, iCoDMSN acts as an efficient radiotherapy enhancer to eliminate cancer cells in vitro and in vivo. This study demonstrates a versatile Co-based nanomaterial that primes ferroptosis by expanding the labile iron pool in cancer cells, providing a promising tumor radiotherapy sensitizer.

Nanoscale coordination polymers enabling antioxidants inhibition for enhanced chemodynamic therapy

Reactive oxygen species (ROS) generation to induce cell death is an effective strategy for cancer therapy. In particular, chemodynamic therapy (CDT), using Fenton-type reactions to generate highly cytotoxic hydroxyl radical (•OH), is a promising treatment modality. However, the therapeutic efficacy of ROS-based cancer treatment is still limited by some critical challenges, such as overexpression of enzymatic and non-enzymatic antioxidants by tumor cells, as well as the low tumor targeting efficiency of therapeutic agents. To address those problems, biomimetic CuZn protoporphyrin IX nanoscale coordination polymers have been developed, which significantly amplify oxidative stress against tumors by simultaneously inhibiting enzymatic and non-enzymatic antioxidants and initiating the CDT. In this design, cancer cell membrane camouflaged nanoparticle exhibits an excellent homotypic targeting effect. After being endocytosed into tumor cells, the nanoparticles induce depletion of the main non-enzymatic antioxidant glutathione (GSH) by undergoing a redox reaction with GSH. Afterward, the redox reaction generated cuprous ion (Cu⁺) works as a CDT agent for •OH generation. Furthermore, the released Zn protoporphyrin IX strongly inhibits the activity of the typical enzymatic antioxidant heme oxygenase-1. This tetra-modal synergistic strategy endows the biomimetic nanoparticles with great capability for anticancer therapy, which has been demonstrated in both in vitro and in vivo studies.

Spherical Nucleic Acid Probe Based on 2'-Fluorinated DNA Functionalization for High-Fidelity Intracellular Sensing

Traditional spherical nucleic acids (SNAs) based on gold nanoparticles (AuNPs) assembled through Au-S covalent bonds are widely used in DNA-programmable assembly, biosensing, imaging, and therapeutics. However, biological thiols and other chemical substances can break the Au-S bonds and cause response distortion during the application process, specifically in cell environments. Herein, we report a new type of SNAs based on 2'-fluorinated DNA-functionalized AuNPs with excellent colloidal stability under high salt conditions (up to 1 M NaCl) and over a broad pH range (1-14), as well as resistance to biothiols. The fluorinated spherical nucleic acid probe (Au/FDNA probe) could detect targeted cancer cells with high fidelity. Compared to the traditional thiolated DNA-functionalized AuNP probe (Au-SDNA probe), the Au/FDNA probe exhibited a higher sensitivity to the target and a lower signal-to-background ratio. Furthermore, the Au/FDNA probe could discriminate target cancer cells in a mixed culture system. Using the proposed FDNA functionalization method, previously developed SNAs based on AuNPs could be directly adapted, which might open a new avenue for the design and application of SNAs.

Engineered biomimetic nanoreactor for synergistic photodynamic-chemotherapy against hypoxic tumor

Photodynamic therapy (PDT) can produce a large amount of reactive oxygen species (ROS) in the radiation field to kill tumor cells. However, the sustainable anti-tumor efficacy of PDT is limited due to the hypoxic microenvironment of tumor. In this study, classic PDT agent indocyanine green (ICG) and hypoxia-activated chemotherapeutic drug tirapazamine (TPZ) were loaded on mesoporous polydopamine (PDA) to construct PDA@ICG-TPZ nanoparticles (PIT). Then, PIT was camouflaged with cyclic arginine-glycine-aspartate (cRGD) modified tumor cell membranes to obtain the engineered membrane-coated nanoreactor (cRGD-mPIT). The nanoreactor cRGD-mPIT could achieve the dual-targeting ability via tumor cell membrane mediated homologous targeting and cRGD mediated active targeting. With the enhanced tumor-targeting and penetrating delivery system, PIT could efficiently accumulate in hypoxic tumor cells and the loaded drugs were quickly released in response to near-infrared (NIR) laser. The nanoreactor might produce cytotoxic ROS under NIR and further enhance hypoxia within tumor to activate TPZ, which efficiently inhibited hypoxic tumor by synergistic photodynamic-chemotherapy. Mechanically, hypoxia-inhibitory factor-1α (HIF-1α) was down-regulated by the synergistic therapy. Accordingly, the cRGD-mPIT nanoreactor with sustainable and cascade anti-tumor effects and satisfied biosafety might be a promising strategy in hypoxic tumor therapy.

Robust Dual Enzyme Cascade-Catalytic Cholesterol Depletion for Reverse Tumor Multidrug Resistance

Although combination drugs and P-glycoprotein inhibitors are the main methods to solve multidrug resistance, these methods ignore the pathological structure of drug-resistant cells and extremely limit curative effect. Herein, a new paradigm of reversing multidrug resistance with abnormal expression of cholesterol as the target is proposed, which uses the cascade catalysis of "natural enzyme" cholesterol oxidase (COD) and "nanoenzyme" Cu²⁺ -modified zirconium-based metal-organic framework (ZrMOF(Cu)) to convert cholesterol into the highly cytotoxic hydroxyl radicals. The doxorubicin (DOX)-loaded nanoparticles (DOX@COD-MOF) can significantly reduce the cholesterol content of cancer cells via COD, which decrease the rigidity of drug resistant cancer cell membranes and restore the sensitivity of multidrug-resistant cells to DOX. Afterward, DOX@COD-MOF is encapsulated by cancer cell membranes (CCM) to construct a bionic "dual enzyme catalytic cascade nanoreactor" (DOX@COD-MOF@CCM). Such a rational design presents a preferential accumulation tendency to tumor sites due to the homologous targeting mechanism of CCM, and affords 94.4% in tumor growth suppression without systemic toxicity in vivo. This work aims to achieve the therapeutic purpose of high efficiency and low toxicity. It has the characteristics of "converting enemy into friend, " and opens up a promising way for effectively reversing multidrug resistance of tumors.

Biomedical Photoacoustic Imaging for Molecular Detection and Disease Diagnosis: "Always-On" and "Turn-On" Probes

Photoacoustic (PA) imaging is a nonionizing, noninvasive imaging technique that combines optical and ultrasonic imaging modalities to provide images with excellent contrast, spatial resolution, and penetration depth. Exogenous PA contrast agents are created to increase the sensitivity and specificity of PA imaging and to offer diagnostic information for illnesses. The existing PA contrast agents are categorized into two groups in this review: "always-on" and "turn-on," based on their ability to be triggered by target molecules. The present state of these probes, their merits and limitations, and their future development, is explored.

Recent Advances in Near-Infrared-II Fluorescence Imaging for Deep-Tissue Molecular Analysis and Cancer Diagnosis

Fluorescence imaging with high sensitivity and minimal invasiveness has received tremendous attention, which can accomplish visualized monitoring and evaluation of cancer progression. Compared with the conventional first near-infrared (NIR-I) optical window (650-950 nm), fluorescence imaging in the second NIR optical window (NIR-II, 950-1700 nm) exhibits deeper tissue penetration capability and higher temporal-spatial resolution with lower background interference for achieving deep-tissue in vivo imaging and real-time monitoring of cancer development. Encouraged by the significant preponderances, a variety of multifunctional NIR-II fluorophores have been designed and fabricated for sensitively imaging biomarkers in vivo and visualizing the treatment procedure of cancers. In this review, the differences between NIR-I and NIR-II fluorescence imaging are briefly introduced, especially the advantages of NIR-II fluorescence imaging for the real-time visualization of tumors in vivo and cancer diagnosis. An important focus is to summarize the NIR-II fluorescence imaging for deep-tissue biomarker analysis in vivo and tumor tissue visualization, and a brief introduction of NIR-II fluorescence imaging-guided cancer therapy is also presented. Finally, the significant challenges and reasonable prospects of NIR-II fluorescence imaging for cancer diagnosis in clinical applications are outlined.

Mitochondria MicroRNA Spatial Imaging via pH-Responsive Exonuclease-Assisted AIE Nanoreporter

Mitochondrial microRNAs (mitomiRs) critically orchestrate mitochondrial functions. Spatial imaging of mitomiRs is essential to understand its clinical value in diagnosis and prognosis. However, the direct monitoring of mitomiRs in living cells remains a key challenge. Herein, we report an AIE nanoreporter strategy for mitomiRs imaging in living cells through pH-controlled exonuclease (Exo)-assisted target cycle signal amplification. The AIE-labeled DNA detection probes are conjugated on Exo III encapsulated polymeric nanoparticles (NPs) via consecutive adenines (polyA). The amplified sensing functions are off during the cytoplasm delivery process, and it can be spatially switched from off to on when in the alkaline mitochondria (about pH 8) after triphenylphosphonium (TPP)-mediated mitochondrial targeting. Where the NPs degraded to release Exo III and cancer-specific mitomiRs hybridize with AIE-labeled DNA detection probes to expose the cleavage site of released Exo III, enabling spatially restricted mitomiRs imaging. The mitomiRs expression fluctuation was also realized. This study contributes to a facile strategy that could easily extend to a broad application for the understanding of mitomiRs-related pathological processes.

Anti-EpCAM Functionalized I-131 Radiolabeled Biomimetic Nanocarrier Sodium/Iodide-Symporter-Mediated Breast-Cancer Treatment

Currently, breast-cancer treatment has a number of adverse side effects and is associated with poor rates of progression-free survival. Therefore, a radiolabeled anti-EpCAM targeted biomimetic coated nanocarrier (EINP) was developed in this study to overcome some of the treatment challenges. The double emulsion method synthesized the poly(lactic-co-glycolic acid) (PLGA) nanoparticle with Na131I entrapped in the core. The PLGA nanoparticle was coated in human red blood cell membranes and labeled with epithelial cell adhesion molecule (EpCAM) antibody to enable it to target EpCAM overexpression by breast-cancer cells. Characterization determined the EINP size as 295 nm, zeta potential as −35.9 mV, and polydispersity as 0.297. EINP radiochemical purity was >95%. Results determined the EINP efficacy against EpCAM positive MCF-7 breast cancer at 24, 48, and 72 h were 69.11%, 77.84%, and 74.6%, respectively, demonstrating that the EINPs achieved greater cytotoxic efficacy supported by NIS-mediated Na131I uptake than the non-targeted 131INPs and Na131I. In comparison, fibroblast (EpCAM negative) treated with EINPs had significantly lower cytotoxicity than Na131I and 131INPs (p < 0.05). Flow cytometry fluorescence imaging visually signified delivery by EINPs specifically to breast-cancer cells as a result of anti-EpCAM targeting. Additionally, the EINP had a favorable safety profile, as determined by hemolysis.

Light-Controlled Recruitable Hybridization Chain Reaction on Exosome Vehicles for Highly Sensitive MicroRNA Imaging in Living Cells

Sensitive imaging of intracellular microRNA (miRNA) in living cells is of great significance. Isothermal hybridization chain reaction (HCR)-based methods, although have been widely used to monitor intracellular low-abundance miRNA, are still subjected to the challenges of limited signal amplification efficiency and compromised imaging resolution. In this work, we design a light-controlled recruitable HCR (LCR-HCR) strategy that enables us to well overcome these limitations. Exosomes as delivery and recruitment vehicles are modified with three cholesterol-modified hairpins (H₁, H₂, and H₃), in which H₁ is for anchoring target miRNA and H₂ and H₃ with photocleavable linkers (PC-linkers) are designed for spatiotemporal HCR. By controllably releasing probes with high local concentrations to efficiently trigger HCR and further recruiting the generated double-stranded DNA (dsDNA) polymers instead of dispersion in the cytoplasm, the LCR-HCR method can significantly improve the imaging contrast by confining all of the reactants on exosome vehicles. For a proof-of-concept demonstration, the miR-21 was analyzed by LCR-HCR with a limit of detection (LOD) down to 3.3 pM (corresponding to 165 amol per 50 μL) in vitro and four times higher response than traditional HCR in vivo. In general, the LCR-HCR method provides a powerful tool for sensitive miRNA imaging in living cells and cancer diagnosis.

Spatially Resolved, Error-Robust Multiplexed MicroRNA Profiling in Single Living Cells

Simultaneous imaging of multiple microRNAs (miRNAs) in individual living cells is challenging due to the lack of spectrally distinct encoded fluorophores and non-cytotoxic methods. We describe a multiplexed error-robust combinatorial fluorescent label-encoding method, termed fluorophores encoded error-corrected labels (FluoELs), enabling multiplexed miRNA imaging in living cells with error-correcting capability. The FluoELs comprise proportional dual fluorophores for encoding and a constant quantitative single fluorophore for error-corrected quantification. Both are embedded in 260 nm core-shell silica nanoparticles modified with molecular beacon detection probes. The FluoELs are low cytotoxic and could accurately quantify and spatially resolve nine breast-cancer-related miRNAs and evaluate their coordination. The FluoELs enabled a single-cell analysis platform to evaluate miRNA expression profiles and the molecular mechanisms underlying miRNA-associated diseases.

Optical Imaging of Epigenetic Modifications in Cancer: A Systematic Review

Increasing evidence has demonstrated that abnormal epigenetic modifications are strongly related to cancer initiation. Thus, sensitive and specific detection of epigenetic modifications could markedly improve biological investigations and cancer precision medicine. A rapid development of molecular imaging approaches for the diagnosis and prognosis of cancer has been observed during the past few years. Various biomarkers unique to epigenetic modifications and targeted imaging probes have been characterized and used to discriminate cancer from healthy tissues, as well as evaluate therapeutic responses. In this study, we summarize the latest studies associated with optical molecular imaging of epigenetic modification targets, such as those involving DNA methylation, histone modification, noncoding RNA regulation, and chromosome remodeling, and further review their clinical application on cancer diagnosis and treatment. Lastly, we further propose the future directions for precision imaging of epigenetic modification in cancer. Supported by promising clinical and preclinical studies associated with optical molecular imaging technology and epigenetic drugs, the central role of epigenetics in cancer should be increasingly recognized and accepted.

Theophylline-encapsulated Nile Tilapia fish scale-based collagen nanoparticles effectively target the lungs of male Sprague-Dawley rats

Nile Tilapia fish scale collagen has high biodegradability, excellent biocompatibility, and low antigenicity. We assessed both the encapsulation efficiency of theophylline into Nile Tilapia fish scale-based collagen nanoparticles and their stability as a pulmonary drug delivery system in male Sprague-Dawley rats. The present study has demonstrated the successful encapsulation of theophylline into the synthesised nanoparticles as shown by spectrophotometric analysis, light microscope, scanning electron microscope, transmission electron microscope, and dynamic light scattering. The antibacterial activity of the nanoparticles improves with increasing their concentrations. Intratracheal treatment of rats using theophylline-encapsulated nanoparticles reduced the levels of creatinine, alanine transaminase, and aspartate transaminase, compared to the control group. Nevertheless, nanoparticles combined with theophylline exhibited no effects on cholesterol and triglycerides levels. Histopathological examination revealed typical uniform and diffuse thickening of the alveolar walls with capillary oedema in treated rats. We concluded that the synthesised collagen nanoparticles appropriately target the lungs of male Sprague-Dawley rats when delivered via a nebuliser, showing good tolerability to lung cells. However, dose ratio of collagen nanoparticles to theophylline needs further evaluation. The nanoprecipitation method may be optimised to involve poorly water-soluble inhaled drugs, and avoid the drawbacks of traditional drug delivery.

A Novel Ratiometric Electrochemical Biosensor Using Only One Signal Tag for Highly Reliable and Ultrasensitive Detection of miRNA-21

Herein, a novel ratiometric electrochemical biosensor with methylene blue (MB) as the only one signal tag was proposed for highly reliable and ultrasensitive detection of microRNA-21 (miRNA-21) under the assistance of an intelligent target-induced dual signal amplification (T-DSA). First, a small amount of target miRNA-21 could produce abundant mimic targets DNA S1 and Zn²⁺ through target-induced recycle and acid dissolution, respectively. Then, S1 triggered rolling circle amplification (RCA) to generate functional DNA nanospheres (DSP) encoded by DNAzyme and substrate sequence for loading numerous signal tag MB with a remarkable electrochemical signal (signal on), and the Zn²⁺ cofactor mediated the nonviolent DNAzyme-catalyzed cleavage of DSP to sharply release MB with obviously reduced electrochemical responses (signal off). Impressively, our strategy could controllably load and release the only signal tag MB through the well-designed DSP to effectively avoid the false positive responses caused by the non-ideal upright state of DNA probes connected to electrodes in traditional distance-dependent signal adjustment ratiometric strategies with two different signal tags. Meanwhile, with the aid of innovative T-DSA recycle and RCA-produced functional DSP, the detection sensitivity of this sensing platform was significantly improved. As a result, the proposed biosensor successfully realized highly reliable and ultrasensitive detection of miRNA-21 with a detection limit down to 26.7 aM, which shows exceptional promise in biological analysis and medical diagnosis.

Nanoarchitectured prototypes of mesoporous silica nanoparticles for innovative biomedical applications

Despite exceptional morphological and physicochemical attributes, mesoporous silica nanoparticles (MSNs) are often employed as carriers or vectors. Moreover, these conventional MSNs often suffer from various limitations in biomedicine, such as reduced drug encapsulation efficacy, deprived compatibility, and poor degradability, resulting in poor therapeutic outcomes. To address these limitations, several modifications have been corroborated to fabricating hierarchically-engineered MSNs in terms of tuning the pore sizes, modifying the surfaces, and engineering of siliceous networks. Interestingly, the further advancements of engineered MSNs lead to the generation of highly complex and nature-mimicking structures, such as Janus-type, multi-podal, and flower-like architectures, as well as streamlined tadpole-like nanomotors. In this review, we present explicit discussions relevant to these advanced hierarchical architectures in different fields of biomedicine, including drug delivery, bioimaging, tissue engineering, and miscellaneous applications, such as photoluminescence, artificial enzymes, peptide enrichment, DNA detection, and biosensing, among others. Initially, we give a brief overview of diverse, innovative stimuli-responsive (pH, light, ultrasound, and thermos)- and targeted drug delivery strategies, along with discussions on recent advancements in cancer immune therapy and applicability of advanced MSNs in other ailments related to cardiac, vascular, and nervous systems, as well as diabetes. Then, we provide initiatives taken so far in clinical translation of various silica-based materials and their scope towards clinical translation. Finally, we summarize the review with interesting perspectives on lessons learned in exploring the biomedical applications of advanced MSNs and further requirements to be explored.

Engineered G-Quadruplex-Embedded Self-Quenching Probes Regulate Single Probe-Based Multiplex Isothermal Amplification to Light Road Lamp Probes for Sensitized Determination of microRNAs

Design of oligonucleotide probe-based isothermal amplification with the ability to identify miRNA biomarkers is crucial for molecular diagnostics. In this work, we engineered a miRNA-21-responsive G-quadruplex-embedded self-quenching probe (GE-SQP) that can regulate single probe-based multiplex amplifications. The free GE-SQP is tightly locked in a quenching state with no active G-quadruplexes. Introduction of target miRNA to hybridize with GE-SQP would induce a multiplex isothermal amplification to significantly build a lot of one-bulb-contained road lamp probe (OC-RLP) and two-bulb-contained road lamp probe (TC-RLP) using G-quadruplex as the lamp bulb. When lightened by thioflavin T (ThT), beams of fluorescence were emitted to show the presented miRNA-21. Specially, the whole amplification is only a one probe-involved one-step reaction without any wasted species. The mix-to-detection and all-in amplification behavior allows the sensing system a maximally maintained operation simplicity and high assay performance. In such a way, the detection range of miRNA-21 is from 1 fM to 1 nM with a limit of detection of 0.86 fM. The practicability was demonstrated by determining miRNA-21 from serum samples with acceptable results. We expect that this method can open a new avenue for exploring advanced biosensors with improved analytical performances.

Chemical Design of Activatable Photoacoustic Probes for Precise Biomedical Applications

Photoacoustic (PA) imaging technology, a three-dimensional hybrid imaging modality that integrates the advantage of optical and acoustic imaging, has great application prospects in molecular imaging due to its high imaging depth and resolution. To endow PA imaging with the ability for real-time molecular visualization and precise biomedical diagnosis, numerous activatable molecular PA probes which can specifically alter their PA intensities upon reacting with the targets or biological events of interest have been developed. This review highlights the recent developments of activatable PA probes for precise biomedical applications including molecular detection of the biotargets and imaging of the biological events. First, the generation mechanism of PA signals will be given, followed by a brief introduction to contrast agents used for PA probe design. Then we will particularly summarize the general design principles for the alteration of PA signals and activatable strategies for developing precise PA probes. Furthermore, we will give a detailed discussion of activatable PA probes in molecular detection and biomedical imaging applications in living systems. At last, the current challenges and outlooks of future PA probes will be discussed. We hope that this review will stimulate new ideas to explore the potentials of activatable PA probes for precise biomedical applications in the future.

Shedding Light on DNA-Based Nanoprobes for Live-Cell MicroRNA Imaging

DNA-based nanoprobes integrated with various imaging signals have been employed for fabricating versatile biosensor platforms for the study of intracellular biological process and biomarker detection. The nanoprobes developments also provide opportunities for endogenous microRNA (miRNA) in situ analysis. In this review, the authors are primarily interested in various DNA-based nanoprobes for miRNA biosensors and declare strategies to reveal how to customize the desired nanoplatforms. Initially, various delivery vehicles for nanoprobe architectures transmembrane transport are delineated, and their biosecurity and ability for resisting the complex cellular environment are evaluated. Then, the novel strategies for designing DNA sequences as target miRNA specific recognition and signal amplification modules for miRNA detection are presented. Afterward, recent advances in imaging technologies to accurately respond and produce significant signal output are summarized. Finally, the challenges and future directions in the field are discussed.

Cell membrane camouflaged biomimetic nanoparticles: Focusing on tumor theranostics

Nanoparticles (NPs) modified by cell membranes represent an emerging biomimetic platform that can mimic the innate biological functions resulting from the various cell membranes in biological systems. researchers focus on constructing the cell membrane camouflaged NPs using a wide variety of cells, such as red blood cell membranes (RBC), macrophages and cancer cells. Cell membrane camouflaged NPs (CMNPs) inherit the composition of cell membranes, including specific receptors, antigens, proteins, for target delivering to the tumor, escaping immune from clearance, and prolonging the blood circulation time, etc. Combining cell membrane-derived biological functions and the NP cores acted cargo carriers to encapsulate the imaging agents, CMNPs are widely developed to apply in tumor imaging techniques, including computed tomography (CT), magnetic resonance imaging (MRI), fluorescence imaging (FL) and photoacoustic imaging (PA). Herein, in this review, we systematically summarize the superior functions of various CMNPs in tumor imaging, especially highlighting the advanced applications in different imaging techniques, which is to provide the theoretical supports for the development of precise guided imaging and tumor treatment.