Asymmetrically coating Pt nanoparticles on magnetic silica nanospheres for target cell capture and therapy

Micro/Nanomotor-Driven Intelligent Targeted Delivery Systems: Dynamics Sources and Frontier Applications

Micro/nanomotors represent a promising class of drug delivery carriers capable of converting surrounding chemical or external energy into mechanical power, enabling autonomous movement. Their distinct autonomous propulsive force distinguishes them from other carriers, offering significant potential for enhancing drug penetration across cellular and tissue barriers. A comprehensive understanding of micro/nanomotor dynamics with various power sources is crucial to facilitate their transition from proof-of-concept to clinical application. In this review, micro/nanomotors are categorized into three classes based on their energy sources: endogenously stimulated, exogenously stimulated, and live cell-driven. The review summarizes the mechanisms governing micro/nanomotor movements under these energy sources and explores factors influencing autonomous motion. Furthermore, it discusses methods for controlling micro/nanomotor movement, encompassing aspects related to their structure, composition, and environmental factors. The remarkable propulsive force exhibited by micro/nanomotors makes them valuable for significant biomedical applications, including tumor therapy, bio-detection, bacterial infection therapy, inflammation therapy, gastrointestinal disease therapy, and environmental remediation. Finally, the review addresses the challenges and prospects for the application of micro/nanomotors. Overall, this review emphasizes the transformative potential of micro/nanomotors in overcoming biological barriers and enhancing therapeutic efficacy, highlighting their promising clinical applications across various biomedical fields.

Magnetite-based Janus nanoparticles, their synthesis and biomedical applications

The advent of Janus nanoparticles has been a great breakthrough in the emerging field of nanomaterials. Janus nanoparticles refer to a single structure with two distinct chemical functions on either side. Owing to their asymmetric structures, they can be utilized in a variety of applications where monomorphic particles are insufficient. In the last decade, a wide variety of materials have been employed to fabricate Janus nanoparticles, and due to the great advantages of magnetite (Iron-oxide) NPs, they have been considered as one of the best candidates. With the main benefit of magnetic controlling, magnetite Janus nanoparticles fulfill great promises, especially in biomedical areas such as bioimaging, cancer therapies, theranostics, and biosensing. The intrinsic characteristics of magnetite Janus nanoparticles (MJNPs) even hold great potential in magnetite Janus forms of micro-/nanomotors. Despite the great interest and potential in magnetic Janus NPs, the need for a comprehensive review on MJNPs with a concentration on magnetite NPs has been overlooked. Herein, we present recent advancements in the magnetite-based Janus nanoparticles in the flourishing field of biomedicine. First, the synthesis and fabrication methods of Janus nanoparticles are discussed. Then we will delve into their intriguing biomedical applications, with a separate section for magnetite Janus micro-/nanomotors in biomedicine. And finally, the challenges and future outlook are provided. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > In Vitro Nanoparticle-Based Sensing.

On Nanomachines and Their Future Perspectives in Biomedicine

Nano/micromotors are a class of active matter that can self-propel converting different types of input energy into kinetic energy. The huge efforts that are made in this field over the last years result in remarkable advances. Specifically, a high number of publications have dealt with biomedical applications that these motors may offer. From the first attempts in 2D cell cultures, the research has evolved to tissue and in vivo experimentation, where motors show promising results. In this Perspective, an overview over the evolution of motors with focus on bio-relevant environments is provided. Then, a discussion on the advances and challenges is presented, and eventually some remarks and perspectives of the field are outlined.

Application of Janus Particles in Point-of-Care Testing

Janus particles (JPs), named after the two-faced Roman god, are asymmetric particles with different chemical properties or polarities. JPs have been widely used in the biomedical field in recent years, including as drug carriers for targeted controlled drug release and as biosensors for biological imaging and biomarker detection, which is crucial in the early detection and treatment of diseases. In this review, we highlight the most recent advancements made with regard to Janus particles in point-of-care testing (POCT). Firstly, we introduce several commonly used methods for preparing Janus particles. Secondly, we present biomarker detection using JPs based on various detection methods to achieve the goal of POCT. Finally, we discuss the challenges and opportunities for developing Janus particles in POCT. This review will facilitate the development of POCT biosensing devices based on the unique properties of Janus particles.

Moisture-resistant and green cyclodextrin metal-organic framework nanozyme based on cross-linkage for visible detection of cellular hydrogen peroxide

A moisture-resistant and green cyclodextrin metal-organic framework (CD-MOF) nanosheet has been prepared via an one-pot antisolvent synthesis procedure. After the treatment of in situ chemical cross-linkage, the two-dimensional (2D) cross-linked CD-MOF exhibited both peroxidase (POD) and oxidase (OXD) enzymatic activities, as well as hydrolytic stability. On the basis of its POD mimics function, the proof-of-concept biosensors were constructed to realize the colorimetric detection for H₂O₂ and glucose, respectively. In vitro cytotoxicity experiments showed that the 2D cross-linked CD-MOF nanozymes still maintained excellent biocompatibility even at a concentration reaching up to several mg/mL. The in situ colorimetric detection of H₂O₂ secreted by HepG2 cells further confirmed its promising biocompatibility, showing its great promises as label-free colorimetric probe in early cancer detection and pathological process monitoring.

A sandwich-type electrochemical immunosensor for CYFRA 21-1 based on probe-confined in PtPd/polydopamine/hollow carbon spheres coupled with dendritic Au@Rh nanocrystals

A signal-on sandwich-like electrochemical immunosensor was built for determination of cytokeratin 19 fragments 21-1 (CYFRA 21-1) in non-small cell lung cancer (NSCLC) by confining electroactive dye (e.g., methylene blue, MB) as a probe for amplifying signals. Specifically, core-shell gold@rhodium dendritic nanocrystals (Au@Rh DNCs) behaved as a substrate for primary antibody and accelerate interfacial electron transfer. Besides, hollow carbon spheres (HCSs) were subsequently modified with polydopamine (PDA) and PtPd nanoparticles for sequential integration of the secondary antibody and confinement of MB as a label, termed as MB/PtPd/PDA/HCSs for clarity. The built sensors showed a broad linear range (100 fg mL^-1 ~ 100 ng mL^-1) for detection of CYFRA 21-1 with an ultra-low detection limit (31.72 fg mL^-1, S/N = 3), coupled with satisfactory performance in human serum samples. This work can be explored for assays of other proteins and provides some constructive insights for early and accurate diagnosis of NSCLC.

Recent Advances in Strategies for Addressing Hypoxia in Tumor Photodynamic Therapy

Photodynamic therapy (PDT) is a treatment modality that uses light to target tumors and minimize damage to normal tissues. It offers advantages including high spatiotemporal selectivity, low side effects, and maximal preservation of tissue functions. However, the PDT efficiency is severely impeded by the hypoxic feature of tumors. Moreover, hypoxia may promote tumor metastasis and tumor resistance to multiple therapies. Therefore, addressing tumor hypoxia to improve PDT efficacy has been the focus of antitumor treatment, and research on this theme is continuously emerging. In this review, we summarize state-of-the-art advances in strategies for overcoming hypoxia in tumor PDTs, categorizing them into oxygen-independent phototherapy, oxygen-economizing PDT, and oxygen-supplementing PDT. Moreover, we highlight strategies possessing intriguing advantages such as exceedingly high PDT efficiency and high novelty, analyze the strengths and shortcomings of different methods, and envision the opportunities and challenges for future research.