Systematic Research and Evaluation Models of Nanomotors for Cancer Combined Therapy

Covalent Organic Framework-Based Nanomotor for Multimodal Cancer Photo-Theranostics

Developing efficient integrated diagnosis and treatment agents based on fuel-free self-movement nanomotors remains challenging in antitumor therapy. In this study, a covalent organic framework (COF)-based biomimetic nanomotor composed of polypyrrole (PPy) core, porphyrin-COF shell, and HCT116 cancer cell membrane coating is reported. Under near-infrared (NIR) light irradiation, the obtained mPPy@COF-Por can overcome Brownian motion and achieves directional motion through self-thermophoretic force generated from the PPy core. The HCT116 cancer cell membrane coating enables the nanomotor to selectively recognize the source cell lines and reduces the bio-adhesion of mPPy@COF-Por in a biological medium, endowing with this NIR light-powered nanomotor good mobility. More importantly, such multifunctional integration allows the COF-based nanomotor to be a powerful nanoagent for cancer treatment, and the high infrared thermal imaging/photoacoustic imaging/fluorescence trimodal imaging-guided combined photothermal/photodynamic therapeutic effect on HCT116 tumor cell is successfully achieved. The results offer considerable promise for the development of COF nanomotors with integrated imaging/therapy modalities in biomedical applications.

NIR-II Light Powered Asymmetric Hydrogel Nanomotors for Enhanced Immunochemotherapy

Nanomotors are appealing drug carriers, and the strength of the propelling force is important for their motion capability. Though high motion efficiency has been achieved with 808 nm light driven Janus-structured noble metal nanomotors, the NIR-I light penetration depth and material biocompatibility limit their broad application. Herein, we develop a 1064 nm NIR-II light driven asymmetric hydrogel nanomotor (AHNM) with high motion capability and load it with doxorubicin for enhanced immunochemotherapy. Magnetic field assisted photopolymerization generates an asymmetric distribution of Fe₃ O₄ @Cu₉ S₈ nanoparticles in the AHNM, producing self-thermophoresis as driving force under NIR-II irradiation. The AHNM is also functionalized with dopamine for the capture and retention of tumor-associated antigens to boost immune activation. The as-obtained NIR-II light driven AHNM has a high tumor tissue penetration capability and enhances immunochemotherapy, providing a promising strategy for cancer therapy.

Laminar flow-assisted synthesis of amorphous ZIF-8-based nano-motor with enhanced transmigration for photothermal cancer therapy

Because of their biocompatibility, there are promising applications in various fields for enzyme-powered nano-motors. However, enzymes can undergo denaturation under harsh conditions. Here, we report the flow-assisted synthesis of an enzyme-based amorphous ZIF-8 nano-motor (A-motor; Pdop@urease@aZIF-8) for enhanced movement and protection of polydopamine and enzymes. Multiple laminar flow types with varied input ratios effectively entrapped enzymes into amorphous ZIF-8 shells in a serial flow with a momentary difference. The obtained A-motor exhibited superior enzymatic activity and photothermal ablation properties with excellent durability due to the protection the amorphous shell offers from the external environment. Furthermore, in the bio-mimic 2D membrane model, the enhanced mobility of the A-motor afforded high transmigration (>80%), which had a powerful effect on bladder cancer cell ablation via photothermal therapy. This work envisages that the rapid flow approach will facilitate scalable manufacturing of the nano-motors under low stress to vulnerable biomolecules, which would be extended to nano-biomedical applications in various body environments.

Enzyme-Powered Micro/Nanomotors for Cancer Treatment

The incidence and lethal rate of cancers are rapidly rising recently, however current treatments of cancers, such as surgical resection, radiotherapy, chemotherapy and targeted therapy, usually require long treatment period and have more side effects and high recurrence rate. Enzyme-powered micro/nanomotors (EMNMs), with powerful self-propulsion, enhanced permeability and good biocompatibility, have shown great potential in crossing biological barrier and targeted drug transportation for cancer treatment; moreover, advanced approaches based on EMNMs such as photothermal therapy and starvation therapy have also been widely explored in cancer treatment. Although there are several review works discussing the progress of micro/nanomotors for biomedical applications, there is not one review paper with the focus on the cancer treatment based on EMNMs. Therefore, in this review, we try to concisely and timely summarize the recent progress of cancer treatment based on enzyme-driven micro/nanomotors, such as brain tumors, bladder cancer, breast cancer and others. Finally, the challenges and outlook of cancer therapy based on EMNMs are discussed, hoping to provide fundamental guidance for the future development.

Multifunctional micro/nanomotors as an emerging platform for smart healthcare applications

Self-propelling micro- and nano-motors (MNMs) are emerging as a multifunctional platform for smart healthcare applications such as biosensing, bioimaging, and targeted drug delivery with high tissue penetration, stirring effect, and rapid drug transport. MNMs can be propelled and/or guided by chemical substances or external stimuli including ultrasound, magnetic field, and light. In addition, enzymatically powered MNMs and biohybrid micromotors have been developed using the biological components in the body. In this review, we describe emerging MNMs focusing on their smart propulsion systems, and diagnostic and therapeutic applications. Finally, we highlight several MNMs for in vivo applications and discuss the future perspectives of MNMs on their current limitations and possibilities toward further clinical applications.

Zwitterion-Based Hydrogen Sulfide Nanomotors Induce Multiple Acidosis in Tumor Cells by Destroying Tumor Metabolic Symbiosis

Destruction of tumor metabolism symbiosis is an attractive cancer treatment method which targets tumor cells with little harm to normal cells. Yet, a single intervention strategy and poor penetration of the drug in tumor tissue result in limited effect. Herein, we propose a zero-waste zwitterion-based hydrogen sulfide (H2 S)-driven nanomotor based on the basic principle of reaction in human body. When loaded with monocarboxylic acid transporter inhibitor α-cyano-4-hydroxycinnamic acid (α-CHCA), the nanomotor can move in tumor microenvironment and induce multiple acidosis of tumor cells and inhibit tumor growth through the synergistic effect of motion effect, driving force H2 S and α-CHCA. Given the good biosafety of the substrate and driving gas of this kind of nanomotor, as well as the limited variety of nanomotors currently available to move in the tumor microenvironment, this kind of nanomotor may provide a competitive candidate for the active drug delivery system of cancer treatment.

Biosafety, Functionalities, and Applications of Biomedical Micro/nanomotors

Due to their unique ability to actively move, micro/nanomotors offer the possibility of breaking through the limitations of traditional passive drug delivery systems for the treatment of many diseases, and have attracted the increasing attention of researchers. However, at present, the realization of many advantages of micro/nanomotors in disease treatment in vivo is still in its infancy, because of the complexity and particularity of diseases in different parts of human body. In this Minireview, we first focus on the biosafety and functionality of micro/nanomotors as a biomedical treatment system. Then, we address the treatment difficulties of various diseases in vivo (such as ophthalmic disease, orthopedic disease, gastrointestinal disease, cardiovascular disease, and cancer), and then review the research progress of biomedical micro/nanomotors in the past 20 years, Finally, we propose the challenges in this field and possible future development directions.

Endogenous mRNA Triggered DNA-Au Nanomachine for In Situ Imaging and Targeted Multimodal Synergistic Cancer Therapy

The development of versatile nanotheranostic platforms that integrate both diagnostic and therapeutic functions have always been an intractable challenge in precise cancer treatment. Herein, an aptamer-tethered deoxyribonucleic acids-gold particle (Apt-DNA-Au) nanomachine has been developed for in situ imaging and targeted multimodal synergistic therapy of mammary carcinoma. Upon specifically internalized into MCF-7 cells, the tumor-related TK1 mRNA activates the Apt-DNA-Au nanomachine by DNA strand displacement cascades, resulting in the release of the fluorophore and antisense DNA as well as the aggregation of AuNPs for in situ imaging, suppression of survivin expression and photothermal therapy, respectively. Meanwhile, the controlled released drugs are used for chemotherapy, while under the laser irradiation the loaded photosensitizer produces reactive oxygen species (ROS) for photodynamic therapy. The results confirm that the proposed Apt-DNA-Au nanomachine provides a powerful nanotheranostic platform for in situ imaging-guided combinatorial anticancer therapy.