miRNA-Guided Imaging and Photodynamic Therapy Treatment of Cancer Cells Using Zn(II)-Protoporphyrin IX-Loaded Metal-Organic Framework Nanoparticles

Portable dual-mode paper chips for highly sensitive and rapid determination of aflatoxin B1 via an aptamer-gated MOFs

Paper chip as a representative microfluidic device has been mushroomed for rapid identification of contaminants in agro-food. However, the sensitivity and accuracy have still been challenged by inevitable background noise or interference in food matrix. Herein, we designed and fabricated a dual-mode paper chip (DPC) by assembling a patterned paper electrode with a platinum nanoparticles-treated colorimetric region through a flow channel. Dual-mode outputs were guided by an aptamer-gated UiO-66-NH2 metal-organic frameworks (MOFs). UiO-66-NH2 loaded with 3, 3', 5, 5'-tetramethylbenzidine (TMB) was controlled by a switch comprised of CdS quantum dots-aptamer. Aflatoxin B1 (AFB1, a kind of carcinogenic mycotoxin) target came and induced TMB release, triggering colorimetric and ECL signals on DPC, ultra-high sensitivity with a detection limit of 7.8 fg/mL was realized. The practicability of the DPC was also confirmed by spiking AFB1 in real corn samples. This portable paper-based device provides an ideal rapid detection platform tailored for diverse food contaminants analysis.

Near-Infrared-II Nanomaterials for Activatable Photodiagnosis and Phototherapy

Near-Infrared-II (NIR-II) spans wavelengths between 1,000 to 1,700 nanometers, featuring deep tissue penetration and reduced tissue scattering and absorption characteristics, providing robust support for cancer treatment and tumor imaging research. This review explores the utilization of activatable NIR-II photodiagnosis and phototherapy based on tumor microenvironments (e. g., reactive oxygen species, pH, glutathione, hypoxia) and external stimulation (e. g., laser, ultrasound, photothermal) for precise tumor treatment and imaging. Special emphasis is placed on the advancements and advantages of activatable NIR-II nanomedicines in novel therapeutic modalities like photodynamic therapy, photothermal therapy, and photoacoustic imaging. This encompasses achieving deep tumor penetration, real-time monitoring of the treatment process, and obtaining high-resolution, high signal-to-noise ratio images even at low material concentrations. Lastly, from a clinical perspective, the challenges faced by activatable NIR-II phototherapy are discussed, alongside potential strategies to overcome these hurdles.

A new strategy based on a cascade amplification strategy biosensor for on-site eDNA detection and outbreak warning of crown-of-thorns starfish

Population outbreaks of the crown-of-thorns starfish (COTS) seriously threaten the sustainability of coral reef ecosystems. However, traditional ecological monitoring techniques cannot provide early warning before the outbreaks, thus preventing timely intervention. Therefore, there is an urgent need for a more accurate and faster technology to predict the outbreaks of COTS. In this work, we developed an electrochemical biosensor based on a programmed catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR) cyclic amplification strategy for sensitive and selective detection of COTS environmental DNA (eDNA) in water bodies. This biosensor exhibited excellent electrochemical characteristics, including a low limit of detection (LOD = 18.4 fM), low limit of quantification (LOQ = 41.1 fM), and wide linear range (50 fM - 10 nM). The biosensing technology successfully allowed the detection of COTS eDNA in the aquarium environment, and the results also demonstrated a significant correlation between eDNA concentration and COTS number (r = 0.990; P < 0.001). The reliability and accuracy of the biosensor results have been further validated through comparison with digital droplet PCR (ddPCR). Moreover, the applicability and accuracy of the biosensor were reconfirmed in field tests at the COTS outbreak site in the South China Sea, which has shown potential application in dynamically monitoring the larvae before the COTS outbreak. Therefore, this efficient electrochemical biosensing technology offers a new solution for on-site monitoring and early warning of the COTS outbreak.

Nucleic acid-responsive smart systems for controlled cargo delivery

Stimulus-responsive delivery systems allow controlled, highly regulated, and efficient delivery of various cargos while minimizing side effects. Owing to the unique properties of nucleic acids, including the ability to adopt complex structures by base pairing, their easy synthesis, high specificity, shape memory, and configurability, they have been employed in autonomous molecular motors, logic circuits, reconfigurable nanoplatforms, and catalytic amplifiers. Moreover, the development of nucleic acid (NA)-responsive intelligent delivery vehicles is a rapidly growing field. These vehicles have attracted much attention in recent years due to their programmable, controllable, and reversible properties. In this work, we review several types of NA-responsive controlled delivery vehicles based on locks and keys, including DNA/RNA-responsive, aptamer-responsive, and CRISPR-responsive, and summarize their advantages and limitations.

Bifunctional folic acid targeted biopolymer Ag@NMOF nanocomposite [{Zn2 (1,4-bdc) 2 (DABCO)} n] as a novel theranostic agent for molecular imaging of colon cancer by SERS

Without a doubt, cancer and its negative impact on human health have created many hurdles for people across the world since conventional approaches have not offered a reliable ability in the eradication of cancer. As a result, finding novel approaches, like using bimodal nanoparticles as a potential nanocarrier in molecular imaging and cancer therapy, is remarkably required these days. In the present study, ex-situ (Ge) and in-situ (Gi) green synthesized silver (Ag) nanoparticles entrapped in metal-organic framework nanocomposites (NMOF) coated with folic acid (FA) targeted chitosan (CS) was successfully developed as a novel bifunctional nanocarrier for detection and treatment of colon cancer cells. Then nanocarriers, such as NMOF-CS-FA, Ge-Ag@NMOF-CS-FA, Gi-Ag@NMOF-CS-FA, and C-Ag@NMOF-CS-FA, were characterized via FT-IR, DLS, SERS, TEM, and SEM and results have potentially confirmed the quality and quantity of synthesized nanocomposites. The hydrodynamic diameters of NMOF-CS, Ge-Ag@NMOF-CS, Gi-Ag@NMOF-CS, and C-Ag@NMOF-CS specimens were measured at around 99.7 ± 10 nm, 110 ± 10 nm, 118 ± 10 nm, 115 ± 10 nm, respectively. Also, the PDI values less than 0.2 confirm the reliable distribution of these nanocomposites. Afterward, the cell viability assay was conducted on HCT116 and HGF cell lines for evaluating biocompatibility and targeting efficiency of nanocomposites; FA functionalized nanocomposites have intensively indicated better performance in cancer cells targeting and their inhibition, and IC50 was attained for 10 ng/mL of Ge-Ag@NMOF-CS-FA while non-targeted nanocarriers did not have toxicity more than 20 % on HCT116 colon cancer cells. Moreover, according to the results, the cell viability of HGF normal cells was at least 85 % after being exposed to different concentrations of nanocomposites for 24 h. This indicates that the synthesized nanocomposites do not have significant toxic effects on normal cells. The results indicate that this novel nanocomposite has the potential to effectively deliver drugs to cancer cells.

Nanoscale Metal-Organic Frameworks and Nanoscale Coordination Polymers: From Synthesis to Cancer Therapy and Biomedical Imaging

Recently, there has been significant interest in nanoscale metal-organic frameworks (NMOFs) characterized by ordered crystal structures and nanoscale coordination polymers (NCPs) featuring amorphous structures. These structures arise from the coordination interactions between inorganic metal ions or clusters and organic ligands. Their advantages, such as the ability to tailor composition and structure, efficiently encapsulate diverse therapeutic or imaging agents within porous frameworks, inherent biodegradability, and surface functionalization capability, position them as promising carriers in the biomedical fields. This review provides an overview of the synthesis and surface modification strategies employed for NMOFs and NCPs, along with their applications in cancer treatment and biological imaging. Finally, future directions and challenges associated with the utilization of NMOFs and NCPs in cancer treatment and diagnosis are also discussed.

Dual-Signal Amplification Strategy Based on Catalytic Hairpin Assembly and APE1-Assisted Amplification for High-Contrast miRNA Imaging in Living Cells

Early tumor diagnosis is crucial to successful treatment. Earlier studies have shown that microRNA is a biomarker for early tumor diagnosis. The development of highly sensitive miRNA detection methods, especially in living cells, plays an indispensable role for early diagnosis and treatment of tumor. Although the catalytic hairpin assembly (CHA)-based miRNA analysis strategy is commonly used for disease diagnosis, further application of CHA is hindered due to its low amplification efficiency and low tumor recognition contrast. To address these limitations, we propose a dual-signal amplification strategy based on CHA and APE1-assisted amplification, enabling highly sensitive and high-contrast miRNA imaging. The miR-221 was selected as a target model. This dual-signal amplification strategy has exhibited high amplification efficiency, which could analyze miRNA as low as 21 fM. This strategy also exhibited high specificity, which could distinguish target miRNA and nontarget with single-base differences. Moreover, this method showed significant potential for practical application, as it could successfully distinguish the expression difference of miR-221 in the plasma samples of normal people and patients. Most importantly, the expression level of the APE1 enzyme in tumor cells is higher than that in normal cells, allowing this strategy to sensitively and specifically image miRNA within tumor cells. This proposed method has also been successfully used to indicate fluctuations of intracellular miRNA and to distinguish miRNA expression between normal cells and cancer cells with high contrast. We anticipate that this method will provide fresh insights and can be a powerful tool for tumor diagnosis and treatment based on miRNA analysis.

A versatile MOF-derived theranostic for dual-miRNA controlled accurate cancer cell recognition and photodynamic therapy

Precise detection and monitoring of microRNAs (miRNAs) in living tumor cells is significant for the prompt diagnosis of cancer and provides important information for treatment of cancer. A significant challenge is developing methods for imaging different miRNAs simultaneously to further enhance diagnostic and treatment accuracy. In this work, a versatile MOF-derived theranostic system (DAPM) was constructed using photosensitive metal-organic frameworks (PMOF, PM) and a DNA AND logic gate (DA). The DAPM exhibited excellent biostability and enabled sensitive detection of miR-21 and miR-155, achieving a low limit of detection (LOD) for miR-21 (89.10 pM) and miR-155 (54.02 pM). The DAPM probe generated a fluorescence signal in tumor cells where miR-21 and miR-155 co-existed, demonstrating the enhanced ability of tumor cell recognition. Additionally, the DAPM achieved efficient ROS generation and concentration-dependent cytotoxicity under light irradiation, providing effective photodynamic therapy for anti-tumors. The proposed DAPM theranostic system enables accurate cancer diagnosis, and provides spatial and temporal information for PDT.

(Nano)platforms in breast cancer therapy: Drug/gene delivery, advanced nanocarriers and immunotherapy

Breast cancer is the most malignant tumor in women, and there is no absolute cure for it. Although treatment modalities including surgery, chemotherapy, and radiotherapy are utilized for breast cancer, it is still a life-threatening disease for humans. Nanomedicine has provided a new opportunity in breast cancer treatment, which is the focus of the current study. The nanocarriers deliver chemotherapeutic agents and natural products, both of which increase cytotoxicity against breast tumor cells and prevent the development of drug resistance. The efficacy of gene therapy is boosted by nanoparticles and the delivery of CRISPR/Cas9, Noncoding RNAs, and RNAi, promoting their potential for gene expression regulation. The drug and gene codelivery by nanoparticles can exert a synergistic impact on breast tumors and enhance cellular uptake via endocytosis. Nanostructures are able to induce photothermal and photodynamic therapy for breast tumor ablation via cell death induction. The nanoparticles can provide tumor microenvironment remodeling and repolarization of macrophages for antitumor immunity. The stimuli-responsive nanocarriers, including pH-, redox-, and light-sensitive, can mediate targeted suppression of breast tumors. Besides, nanoparticles can provide a diagnosis of breast cancer and detect biomarkers. Various kinds of nanoparticles have been employed for breast cancer therapy, including carbon-, lipid-, polymeric- and metal-based nanostructures, which are different in terms of biocompatibility and delivery efficiency.

Aptamer/Peptide-Functionalized Nanoprobe for Detecting Multiple miRNAs in Circulating Malignant Cells to Study Tumor Heterogeneity

Identification of diverse biomarkers in heterogenic circulating malignant cells (CMCs) such as circulating tumor cells (CTCs) and circulating tumor endothelial cells (CTECs) has crucial significance in tumor diagnosis. However, it remains a substantial challenge to achieve in situ detection of multiple miRNA markers in living cells in blood. Herein, we demonstrate that an aptamer/peptide-functionalized vector can deliver molecular beacons into targeted living CMCs in peripheral blood of patients for in situ detection of multiple cancer biomarkers, including miRNA-21 (miR-21) and miRNA-221 (miR-221). Based on miR-21 and miR-221 levels, heterogenic CMCs are identified for both nondistant metastatic and distant metastatic cancer patients. CMCs from nondistant metastatic and distant metastatic cancer patients exhibit similar miR-21 levels, while the miR-221 level in CMCs of the distant metastatic cancer patient is higher than that of the nondistant metastatic cancer patient. With the capability to realize precise probing of multiple intracellular biomarkers in living CMCs at the single-cell resolution, the nanoprobe can reveal the tumor heterogeneity and provide useful information for diagnosis and prognosis. The nanoprobe we developed would accelerate the progress toward noninvasive precise cancer diagnosis.

Self-accelerated DNA walker mediated electrochemical biosensor for rapid and ultrasensitive detection of microRNA

Herein, we developed a novel three-dimensional (3D) self-accelerated DNA walker (SADW) which progressively expedite walking rate by unlocking the more walking arm continuously in walker process to construct electrochemical biosensor for ultrasensitive detection of microRNA. Particularly, we skillfully introduced a target analogue sequence in the double-loop hairpin, which could be released in the walking process of SADW, then rapidly activating more silenced walking strands to achieve the continuous self-acceleration, resulting in the expedited reaction rate. Surprisingly, the average reaction rate of SADW was quite higher than that of traditional 3D self-circulating DNA walkers (DW) under pretty low target miRNA concentration, which is ascribed to the outstanding acceleration process of the SADW, readily conquering the major predicaments of DW in detecting target with traces concentration: slow reaction rate and low sensitivity. This way, the elaborated SADW is favorably applied in the ultrasensitive and rapid detection of miRNA-21 in tumor cancer cell lysates with a detection limit down to 5.81 aM which was far from lower than the detection limit of DW. This approach develops the novel generation of widespread strategy for the applications in clinic diagnose, biosensing assay, and DNA nanobiotechnology.

Photodynamic Therapy for Inflammatory and Cancerous Diseases of the Intestines: Molecular Mechanisms and Prospects for Application

Photodynamic therapy (PDT) is a minimally invasive treatment that effectively targets cancer and inflammatory diseases. It has gained recognition for its efficacy, low toxicity, and potential for repeated use. Colorectal cancer (CRC) and inflammatory bowel diseases (IBD), including Crohn's disease (CD), and ulcerative colitis (UC), impose a significant burden on global intestinal health, with increasing incidence and prevalence rates. PDT shows promise as an emerging approach for gastrointestinal disease treatment, particularly IBD and CRC. Extensive preclinical research has demonstrated the safety and effectiveness of PDT for IBD and CRC, while clinical studies are currently underway. This review provides an overview of the underlying mechanisms responsible for the anti-inflammatory and anti-tumor effects of PDT, offering insights into the clinical application of PDT in IBD and CRC treatment. It is expected that this review will serve as a valuable reference for future research on PDT for CRC and IBD, contributing to advancements in the treatment of inflammatory and cancerous diseases of the intestines.

Nanoporous Crystalline Materials for the Recognition and Applications of Nucleic Acids

Nucleic acid plays a crucial role in countless biological processes. Hence, there is great interest in its detection and analysis in various fields from chemistry, biology, to medicine. Nanoporous crystalline materials exhibit enormous potential as an effective platform for nucleic acid recognition and application. These materials have highly ordered and uniform pore structures, as well as adjustable surface chemistry and pore size, making them good carriers for nucleic acid extraction, detection, and delivery. In this review, the latest developments in nanoporous crystalline materials, including metal organic frameworks (MOFs), covalent organic frameworks (COFs), and supramolecular organic frameworks (SOFs) for nucleic acid recognition and applications are discussed. Different strategies for functionalizing these materials are explored to specifically identify nucleic acid targets. Their applications in selective separation and detection of nucleic acids are highlighted. They can also be used as DNA/RNA sensors, gene delivery agents, host DNAzymes, and in DNA-based computing. Other applications include catalysis, data storage, and biomimetics. The development of novel nanoporous crystalline materials with enhanced biocompatibility has opened up new avenues in the fields of nucleic acid analysis and therapy, paving the way for the development of sensitive, selective, and cost-effective diagnostic and therapeutic tools with widespread applications.

Functional Nucleic Acid Probes Based on Two-Photon for Biosensing

Functional nucleic acid (FNA) probes have been widely used in environmental monitoring, food analysis, clinical diagnosis, and biological imaging because of their easy synthesis, functional modification, flexible design, and stable properties. However, most FNA probes are designed based on one-photon (OP) in the ultraviolet or visible regions, and the effectiveness of these OP-based FNA probes may be hindered by certain factors, such as their potential for photodamage and limited light tissue penetration. Two-photon (TP) is characterized by the nonlinear absorption of two relatively low-energy photons of near-infrared (NIR) light with the resulting emission of high-energy ultraviolet or visible light. TP-based FNA probes have excellent properties, including lower tissue self-absorption and autofluorescence, reduced photodamage and photobleaching, and higher spatial resolution, making them more advantageous than the conventional OP-based FNA probes in biomedical sensing. In this review, we summarize the recent advances of TP-excited and -activated FNA probes and detail their applications in biomolecular detection. In addition, we also share our views on the highlights and limitations of TP-based FNA probes. The ultimate goal is to provide design approaches for the development of high-performance TP-based FNA probes, thereby promoting their biological applications.

Transient Transcription Machineries Modulate Dynamic Functions of G-Quadruplexes: Temporal Regulation of Biocatalytic Circuits, Gene Replication and Transcription

Native G-quadruplex-regulated temporal biocatalytic circuits, gene polymerization, and transcription processes are emulated by biomimetic, synthetically engineered transcription machineries coupled to reconfigurable G-quadruplex nanostructures. These are addressed by the following example: (i) A reaction module demonstrates the fuel-triggered transcription machinery-guided transient synthesis of G-quadruplex nanostructures. (ii) A dynamically triggered and modulated transcription machinery that guides the temporal separation and reassembly of the anti-thrombin G-quadruplex aptamer/thrombin complex is introduced, and the transient thrombin-catalyzed coagulation of fibrinogen is demonstrated. (iii) A dynamically fueled transient transcription machinery for the temporal activation of G-quadruplex-topologically blocked gene polymerization circuits is introduced. (iv) Transcription circuits revealing G-quadruplex-promoted or G-quadruplex-inhibited cascaded transcription machineries are presented. Beyond advancing the rapidly developing field of dynamically modulated G-quadruplex DNA nanostructures, the systems introduce potential therapeutic applications.

Modular DNA Tetrahedron Nanomachine-Guided Dual-Responsive Hybridization Chain Reactions for Discernible Bivariate Assay and Cell Imaging

Engineering of multivariate biosensing and imaging platforms involved in disease plays a vital role in effectively discerning cancer cells from normal cells and facilitating reliable targeted therapy. Multiple biomarkers such as mucin 1 (MUC1) and nucleolin are typically overexpressed in breast cancer cells compared to normal human breast epithelium cells. Motivated by this knowledge, a dual-responsive DNA tetrahedron nanomachine (drDT-NM) is constructed through immobilizing two recognition modules, MUC1 aptamer (MA) and a hairpin H1* encoding nucleolin-specific G-rich AS1411 aptamer, in two separate vertexes of a functional DT architecture tethering two localized pendants (P^M and P^N). When drDT-NM identifiably binds bivariate MUC1 and nucleolin, two independent hybridization chain reactions (HCR^M and HCR^N) as amplification modules are initiated with two sets of four functional hairpin reactants. Among them, one hairpin for HCR^M is dually ended by fluorescein and quencher BHQ1 to sense MUC1. The responsiveness of nucleolin is executed by operating HCR^N utilizing another two hairpins programmed with two pairs of AS1411 splits. In the shared HCR^N duplex products, the parent AS1411 aptamers are cooperatively merged and folded into G-quadruplex concatemers to embed Zn-protoporphyrin IX (ZnPPIX/G4) for fluorescence signaling readout, thereby achieving a highly sensitive intracellular assay and discernible cell imaging. The tandem ZnPPIX/G4 unities also act as imaging agents and therapeutic cargos for efficient photodynamic therapy of cancer cells. Based on drDT-NM to guide bispecific HCR amplifiers for adaptive bivariate detection, we present a paradigm of exquisitely integrating modular DNA nanostructures with nonenzymatic nucleic acid amplification, thus creating a versatile biosensing platform as a promising candidate for accurate assay, discernible cell imaging, and targeted therapy.

DNA-guided self-assembly in living cells

Self-assembly processes exist widely in life systems and play essential roles in maintaining life activities. It is promising to explore the molecular fundamentals and mechanisms of life systems through artificially constructing self-assembly systems in living cells. As an excellent self-assembly construction material, deoxyribonucleic acid (DNA) has been widely used to achieve the precise construction of self-assembly systems in living cells. This review focuses on the recent progress of DNA-guided intracellular self-assembly. First, the methods of intracellular DNA self-assembly based on the conformational transition of DNA are summarized, including complementary base pairing, the formation of G-quadruplex/i-motif, and the specific recognition of DNA aptamer. Next, The applications of DNA-guided intracellular self-assembly on the detection of intracellular biomolecules and the regulation of cell behaviors are introduced, and the molecular design of DNA in the self-assembly systems is discussed in detail. Ultimately, the challenges and opportunities of DNA-guided intracellular self-assembly are commented.

A review of recent developments of metal-organic frameworks as combined biomedical platforms over the past decade

Metal-organic frameworks (MOFs), also called porous coordination polymers, represent a class of crystalline porous materials made up of organic ligands and metal ions/metal clusters. Herein, an overview of the preparation of different metal-organic frameworks and the recent advances in MOF-based stimuli-responsive drug delivery systems (DDSs) with the drug release mechanisms including pH-, temperature-, ion-, magnetic-, pressure-, adenosine-triphosphate (ATP)-, H₂S-, redox-, responsive, and photoresponsive MOF were rarely introduced. The combination therapy containing of two or more treatments can be enhanced treatment effectiveness through overcoming limitations of monotherapy. Photothermal therapy (PTT) combined with chemotherapy (CT), chemotherapy in combination with PTT or other combinations were explained to overcome drug resistance and side effects in normal cells as well as enhancing the therapeutic response. Integrated platforms containing of photothermal/drug-delivering functions with magnetic resonance imaging (MRI) properties exhibited great advantages in cancer therapy.

Metal-Organic Frameworks Nanocarriers for Functional Nucleic Acid Delivery in Biomedical Applications

Metal-organic frameworks (MOFs), a distinctive funtionalmaterials which is constructed by various metal ions and organic molecules, have gradually attracted researchers' attention from they were founded. In the last decade, MOFs emerge as a biomedical material with potential applications due to their unique properties. However, the MOFs performed as nanocarriers for functional nucleic acid delivery in biomedical applications rarely summarized. In this review, we introduce recent developments of MOFs for nucleic acid delivery in various biologically relevant applications, with special emphasis on cancer therapy (including siRNA, ASO, DNAzyme, miRNA and CpG oligodeoxynucleotides), bioimaging, biosensors and separation of biomolecules. We expect the accomplishment of this review could benefit certain researchers in biomedical field to develop novel sophisticated nanocarriers for functional nucleic acid delivery based on the promising material of MOFs.

Kinetics-accelerated one-step detection of MicroRNA through spatially localized reactions based on DNA tile self-assembly

The localization of isothermal amplification systems has elicited extensive attention due to the enhanced reaction kinetics when detecting ultra-trace small-molecule nucleic acids. Therefore, the seek for an appropriate localization cargo of spatially confined reactions is urgent. Herein, we have developed a novel approach to localize the catalytic hairpin assembly (CHA) system into the DNA tile self-assembly nanostructure. Thanks to the precise programming and robust probe loading capacity, this strategy achieved a 2.3 × 10⁵-fold higher local reaction concentration than a classical CHA system with enhanced reaction kinetics in theory. From the experimental results, this strategy could reach the reaction plateau faster and get access to a magnified effect of 1.57-6.99 times higher in the linear range of microRNA (miRNA) than the simple CHA system. Meanwhile, this strategy satisfied the demand for the one-step detection of miRNA in cell lysates at room temperature with good sensitivity and specificity. These features indicated its excellent potential for ultra-trace molecule detection in clinical diagnosis and provided new insights into the field of bioassays based on DNA tile self-assembly nanotechnology.

Metal-Organic Framework-Based Colloidal Particle Synthesis, Assembly, and Application

Metal-organic frameworks (MOFs) assembled from metal nodes and organic ligands have received significant attention over the past two decades for their fascinating porous properties and broad applications. Colloidal MOFs (CMOFs) not only inherit the intrinsic properties of MOFs, but can also serve as building blocks for self-assembly to make functional materials. Compared to bulk MOFs, the colloidal size of CMOFs facilitates further manipulation of CMOF particles in a single or collective state in a liquid medium. The resulting crystalline order obtained by self-assembly in position and orientation can effectively improve performance. In this review, we summarize the latest developments of CMOFs in synthesis strategies, self-assembly methods, and related applications. Finally, we discuss future challenges and opportunities of CMOFs in synthesis and assembly, by which we hope that CMOFs can be further developed into new areas for a wider range of applications.

Multifunctional nanoparticle for cancer therapy

Cancer is a complex disease associated with a combination of abnormal physiological process and exhibiting dysfunctions in multiple systems. To provide effective treatment and diagnosis for cancer, current treatment strategies simultaneously focus on various tumor targets. Based on the rapid development of nanotechnology, nanocarriers have been shown to exhibit excellent potential for cancer therapy. Compared with nanoparticles with single functions, multifunctional nanoparticles are believed to be more aggressive and potent in the context of tumor targeting. However, the development of multifunctional nanoparticles is not simply an upgraded version of the original function, but involves a sophisticated system with a proper backbone, optimized modification sites, simple preparation method, and efficient function integration. Despite this, many well-designed multifunctional nanoparticles with promising therapeutic potential have emerged recently. Here, to give a detailed understanding and analyzation of the currently developed multifunctional nanoparticles, their platform structures with organic or inorganic backbones were systemically generalized. We emphasized on the functionalization and modification strategies, which provide additional functions to the nanoparticle. We also discussed the application combination strategies that were involved in the development of nanoformulations with functional crosstalk. This review thus provides an overview of the construction strategies and application advances of multifunctional nanoparticles.

Aptamer-Functionalized Ce4+-Ion-Modified C-Dots: Peroxidase Mimicking Aptananozymes for the Oxidation of Dopamine and Cytotoxic Effects toward Cancer Cells

Aptamer-functionalized Ce⁴⁺-ion-modified C-dots act as catalytic hybrid systems, aptananozymes, catalyzing the H₂O₂ oxidation of dopamine. A series of aptananozymes functionalized with different configurations of the dopamine binding aptamer, DBA, are introduced. All aptananozymes reveal substantially enhanced catalytic activities as compared to the separated Ce⁴⁺-ion-modified C-dots and aptamer constituents, and structure-catalytic functions between the structure and binding modes of the aptamers linked to the C-dots are demonstrated. The enhanced catalytic functions of the aptananozymes are attributed to the aptamer-induced concentration of the reaction substrates in spatial proximity to the Ce⁴⁺-ion-modified C-dots catalytic sites. The oxidation processes driven by the Ce⁴⁺-ion-modified C-dots involve the formation of reactive oxygen species (^•OH radicals). Accordingly, Ce⁴⁺-ion-modified C-dots with the AS1411 aptamer or MUC1 aptamer, recognizing specific biomarkers associated with cancer cells, are employed as targeted catalytic agents for chemodynamic treatment of cancer cells. Treatment of MDA-MB-231 breast cancer cells and MCF-10A epithelial breast cells, as control, with the AS1411 aptamer- or MUC1 aptamer-modified Ce⁴⁺-ion-modified C-dots reveals selective cytotoxicity toward the cancer cells. In vivo experiments reveal that the aptamer-functionalized nanoparticles inhibit MDA-MB-231 tumor growth.

Potential Roles of miRNAs in Acute Rejection for Vascularized Composite Allotransplantation

Aim

The development of microsurgery has greatly advanced vascularized composite allotransplantation (VCA). However, like organ transplantation, VCA is also limited by acute rejection, and concerns regarding long-term survival and function of the transplanted graft. Therefore, it is necessary to elucidate the molecular mechanisms underlying acute rejection caused by VCA, in order to improve patient survival.

Methods

Firstly, we used Brown Norway rats and Lewis rats to construct animal model of VCA. Regularly record the appearance changes of all subjects. Specimens were collected for histological examination, microRNAs (miRNAs) sequencing and RT-qPCR verification when acute immune rejection occurred. Then, bioinformatics analysis was employed to predict miRNA related molecules and pathway information. Finally, differentially expressed miRNAs were tested and verified.

Results

MiRNAs are small non coding RNA transcripts that regulate gene expression at the post-transcriptional level. Studies have shown that miRNAs are involved in immune regulation and several miRNAs have been identified that are potential diagnostic and prognostic biomarkers of acute rejection. In this study, we found that the expression levels of rno-miR-21-5p, rno-miR-340-5p, rno-miR-1-3p and rno-miR-195-5p are significantly associated with acute rejection following VCA.

Conclusion

This miRNA signature can potentially an auxiliary diagnostic indicator of rejection, which can help clinicians adjust the immunosuppressive program in time during acute rejection.

Delivery of miRNAs through Metal-Organic Framework Nanoparticles for Assisting Neural Stem Cell Therapy for Ischemic Stroke

Stroke is the most common cause of disability globally. Neural stem cell (NSC) therapy, which can replace lost and damaged neurons, has been proposed as a potential treatment for stroke. The therapeutic efficacy of NSC therapy is hindered by the fact that only a small number of NSCs undergo neuronal differentiation. Neuron-specific miR-124, which promotes the differentiation of NSCs into mature neurons, can be combined with NSC therapy to cure ischemic stroke. However, the instability and poor internalization of miR-124 seriously hamper its broad clinical application. Herein, an innovative strategy involving delivery of miR-124 via a Ca-MOF@miR-124 nanodelivery system, which effectively prevents the degradation of miR-124 by nucleases and promotes the internalization of miR-124 by NSCs, is presented. The effect of accelerated neuronal directed differentiation of NSCs was assessed through in vitro cell experiments, and the clinical application potential of this nanodelivery system for the treatment of ischemic stroke was assessed through in vivo experiments involving the combination of NSC therapy and Ca-MOF@miR-124 nanoparticles. The results indicate that Ca-MOF@miR-124 nanoparticles can promote the differentiation of NSCs into mature neurons with electrophysiological function within 5 days. The differentiation rate of cells treated with Ca-MOF@miR-124 nanoparticles was at least 5 days faster than that of untreated cells. Moreover, Ca-MOF@miR-124 nanoparticles decreased the ischemic area to almost normal levels by day 7. The combination of Ca-MOF@miR-124 nanoparticles and NSC therapy will enhance the treatment of traumatic nerve injury and neurodegenerative diseases.

Switchable and dynamic G-quadruplexes and their applications

G-Quadruplexes attract growing interest as functional constituents in biology, chemistry, nanotechnology, and material science. In particular, the reversible dynamic reconfiguration of G-quadruplexes provides versatile means to switch DNA nanostructures, reversibly control catalytic functions of DNA assemblies, and switch material properties and functions. The present review article discusses the switchable dynamic reconfiguration of G-quadruplexes as central functional and structural motifs that enable diverse applications in DNA nanotechnology and material science. The dynamic reconfiguration of G-quadruplexes has a major impact on the development of DNA switches and DNA machines. The integration of G-quadruplexes with enzymes yields supramolecular assemblies exhibiting switchable catalytic functions guided by dynamic G-quadruplex topologies. In addition, G-quadruplexes act as important building blocks to operate constitutional dynamic networks and transient dissipative networks mimicking complex biological dynamic circuitries. Furthermore, the integration of G-quadruplexes with DNA nanostructures, such as origami tiles, introduces dynamic and mechanical features into these static frameworks. Beyond the dynamic operation of G-quadruplex structures in solution, the assembly of G-quadruplexes on bulk surfaces such as electrodes or nanoparticles provides versatile means to engineer diverse electrochemical and photoelectrochemical devices and to switch the dynamic aggregation/deaggregation of nanoparticles, leading to nanoparticle assemblies that reveal switchable optical properties. Finally, the functionalization of hydrogels, hydrogel microcapsules, or nanoparticle carriers, such as SiO₂ nanoparticles or metal-organic framework nanoparticles, yields stimuli-responsive materials exhibiting shape-memory, self-healing, and controlled drug release properties. Indeed, G-quadruplex-modified nanomaterials find growing interest in the area of nanomedicine. Beyond the impressive G-quadruplex-based scientific advances achieved to date, exciting future developments are still anticipated. The review addresses these goals by identifying the potential opportunities and challenges ahead of the field in the coming years.

Recent Advances on the Metal-Organic Frameworks-Based Biosensing Methods for Cancer Biomarkers Detection

Sensitive and selective detection of cancer biomarkers is crucial for early diagnosis and treatment of cancer, one of the most dangerous diseases in the world. Metal-organic frameworks (MOFs), a class of hybrid porous materials fabricated through the assembly of metal ions/clusters and organic ligands, have attracted increasing attention in the sensing of cancer biomarkers, due to the advantages of adjustable size, high porosity, large surface area and ease of modification. MOFs have been utilized to not only fabricate active sensing interfaces but also arouse a variety of measurable signals. Several representative analytical technologies have been applied in MOF-based biosensing strategies to ensure high detection sensitivity toward cancer biomarkers, such as fluorescence, electrochemistry, electrochemiluminescence, photochemistry and colorimetric methods. In this review, we summarized recent advances on MOFs-based biosensing strategies for the detection of cancer biomarkers in recent three years based on the categories of metal nodes, and aimed to provide valuable references for the development of innovative biosensing platform for the purpose of clinical diagnosis.

Where Is Nano Today and Where Is It Headed? A Review of Nanomedicine and the Dilemma of Nanotoxicology

Worldwide nanotechnology development and application have fueled many scientific advances, but technophilic expectations and technophobic demands must be counterbalanced in parallel. Some of the burning issues today are the following: (1) Where is nano today? (2) How good are the communication and investment networks between academia/research and governments? (3) Is there any spotlight application for nanotechnology? Nanomedicine is a particular arm of nanotechnology within the healthcare landscape, focused on diagnosis, treatment, and monitoring of emerging (such as coronavirus disease 2019, COVID-19) and contemporary (including diabetes, cardiovascular diseases, neurodegenerative disorders, and cancer) diseases. However, it may only represent the bright side of the coin. In fact, in the recent past, the concept of nanotoxicology has emerged to address the dark shadows of nanomedicine. The nanomedicine field requires more nanotoxicological studies to identify undesirable effects and guarantee safety. Here, we provide an overall perspective on nanomedicine and nanotoxicology as central pieces of the giant puzzle of nanotechnology. First, the impact of nanotechnology on education and research is highlighted, followed by market trends and scientific output tendencies. In the next section, the nanomedicine and nanotoxicology dilemma is addressed through the interplay of in silico, in vitro, and in vivo models with the support of omics and microfluidic approaches. Lastly, a reflection on the regulatory issues and clinical trials is provided. Finally, some conclusions and future perspectives are proposed for a clearer and safer translation of nanomedicines from the bench to the bedside.