In a pioneering development in cancer nanomedicine, researchers have engineered a multifunctional, near-infrared (NIR)-activated nanomotor capable of selectively homing in on tumors, autonomously navigating cellular barriers, and unleashing an orchestrated on-demand therapeutic assault. This innovative platform, constructed from polydopamine-Fe/BNN6 (PFB) nanoparticles cloaked in cancer cell membranes, signifies a major leap forward in precision oncology by synergizing photothermal therapy, chemodynamic therapy, and nitric oxide (NO)-mediated gas therapy within a single, intelligently designed nanoagent.
The foundation of this technology is a bowl-shaped mesoporous polydopamine nanoparticle matrix, which functions not only as an efficient drug carrier but also as a photothermal transducer and catalytic scaffold. These hollow nanobowls are intricately loaded with iron(II) ions—acting as catalytic centers for Fenton-like reactions—and BNN6, a thermally sensitive NO donor molecule. Following synthesis, the PFB nanoparticles are deliberately cloaked with a fragment of the MCF-7 breast cancer cell membrane, granting the nanomotors an extraordinary ability to evade immune detection and engage in homologous targeting by specifically recognizing and binding to identical cancer cell types.
Upon exposure to an 808-nanometer NIR laser, the platform exhibits remarkable photothermal conversion efficiency. A suspension with a concentration of 100 ppm heats up by nearly 22 degrees Celsius within ten minutes, reaching a terminal temperature of approximately 49 degrees Celsius. This heat is potent enough to induce direct cytotoxicity in targeted tumor cells while simultaneously powering self-thermophoretic propulsion—thereby converting stochastic Brownian movement into directional, enhanced cellular uptake. Experimental measurements have demonstrated that increasing the laser power from 0.5 to 1.5 watts per square centimeter results in a proportional acceleration of nanomotor speed from 3.2 to 8.7 micrometers per second.
This locally generated photothermal energy initiates a tripartite therapeutic cascade within the tumor microenvironment. Firstly, the elevated temperature prompts expedited release of Fe(II) ions from the polydopamine matrix. These iron ions catalyze endogenous hydrogen peroxide decomposition via Fenton-like reactions under acidic tumor conditions, generating highly reactive hydroxyl radicals (·OH)—a cornerstone of chemodynamic therapy. Secondly, thermal energy triggers the controlled decomposition of BNN6, liberating nitric oxide with spatiotemporal precision. The gasotransmitter NO is a well-known cytotoxic agent with potent antitumor effects, yet its clinical application demands stringent control due to rapid degradation and a narrow therapeutic window. Here, NO delivery is restricted strictly to the irradiated tumor locale and laser activation periods, optimizing efficacy while minimizing systemic off-target effects. Thirdly, synergistic cytotoxicity emerges when ·OH radicals react with NO, producing peroxynitrite (ONOO⁻), a highly reactive nitrogen species with even greater tumoricidal capacity than its precursors.
A series of robust in vitro experiments underpinned this mechanistic framework. Extracellular oxidation of the chromogenic substrate TMB in the presence of H₂O₂ and PFB was accompanied by a distinct colorimetric change to blue, unequivocally confirming hydroxyl radical production. The Griess assay quantified dynamic NO release, peaking at 8.8 micromolar following laser irradiation and ceasing immediately upon laser deactivation, epitomizing exquisite temporal control. Peroxynitrite formation was validated via a specific fluorescent probe, with pronounced fluorescence signals only detected in samples exposed to both hydrogen peroxide and NIR light, compellingly evidencing the cascade’s final cytotoxic phase.
Cellular assays using MCF-7 cancer cells revealed that PFB@CM nanomotors alone suppressed cell growth by 36.8% at a dosage of 100 ppm. This inhibition skyrocketed to 87.2% under concurrent NIR laser irradiation, as demonstrated through live/dead staining and CCK-8 viability assays, highlighting the critical role of active photothermal stimulation. Importantly, the homologous targeting hypothesis was corroborated by loading the nanomotors with doxorubicin, an established chemotherapeutic agent. MCF-7 cells exhibited significantly enhanced drug uptake relative to non-cancerous HUVEC endothelial cells, a difference further amplified by laser-driven active propulsion, showcasing the platform’s precision and multifunctionality.
Translational potential was further explored in vivo using MCF-7 tumor-bearing nude mouse models. Animals were stratified into six treatment cohorts, with the PFB@CM + NIR group receiving two NIR laser sessions (each 10 minutes long) at 6 and 24 hours post-intravenous administration. Thermal imaging confirmed tumor site temperatures reaching 50.7 degrees Celsius, sufficient to induce both thermal ablation and trigger NO release. After two weeks, this group displayed a dramatic reduction in tumor burden, with final tumor volumes contracting to 20.6 cubic millimeters and weights plummeting to 11.4 milligrams—translating to impressive diminutions of 98.0% and 97.6%, respectively, relative to untreated controls. Histopathological evaluations using H&E, TUNEL, and Ki-67 staining further substantiated widespread apoptotic induction and attenuation of tumor cell proliferation, affirming the triple-therapy regimen’s profound therapeutic synergy.
Equally critical for clinical translation, the therapy demonstrated an excellent safety profile. No significant body weight loss or pathological abnormalities occurred across treatment groups. Histological examination of vital organs including heart, liver, spleen, lungs, and kidneys revealed preserved tissue architecture, underscoring the nanomotor’s biocompatibility and absence of systemic toxicity—an essential consideration for future human applications.
Despite this platform’s transformative potential, the researchers acknowledge inherent limitations and areas for further innovation. The penetration depth of conventional 808-nanometer lasers is limited to approximately 1 to 2 centimeters, constraining efficacy to superficially located tumors. To circumvent this, ongoing studies are investigating alternative excitation modalities including NIR-II window lasers and magnetothermal strategies to achieve deeper tissue penetration. Additionally, precise modulation of the NO to reactive oxygen species (ROS) ratio remains a crucial challenge; subtherapeutic NO concentrations can paradoxically promote tumor growth, necessitating meticulous dosing optimization within the cascade chemistry framework.
Overall, this study crystallizes a visionary “all-in-one” nanoplatform integrating active motility, immune-evasive homologous targeting, and multimodal therapeutic functionalities. By harmonizing photothermal heating, chemodynamic catalysis, and gas therapy within a biologically inspired camouflaged nanomotor, the researchers have established a new paradigm for ultra-precise and potent cancer treatment. The design principles demonstrated here hold broad applicability for diverse tumor types and therapeutic payloads, heralding a new era of dynamic, targeted, and controllable nanomedicines poised to revolutionize future oncological care.
Subject of Research: Development of a NIR-activated biomimetic nanomotor integrating photothermal, chemodynamic, and nitric oxide-based synergistic tumor therapy.
Article Title: NIR-Propelled Biomimetic Nanomotors for Photothermal/Chemodynamic/NO Synergistic Tumor Therapy
News Publication Date: April 24, 2026
Web References: DOI: 10.34133/cbsystems.0495
References: Research supported by the National Natural Science Foundation of China (Nos. 62373182 and 52502339), National Key Technologies R&D Program of China (Grant No. 2023YFC2415900), Shenzhen Science and Technology Program (Grant No. JCYJ20241202125417024), and Guangdong Basic and Applied Basic Research Foundation (Grant No. 2024A1515011915).
Image Credits: Credit: Chengzhi Hu, Shenzhen Key Laboratory of Biomimetic Robotics and Intelligent Systems, Department of Mechanical and Energy Engineering, Southern University of Science and Technology.
Keywords
Nanomotors, Polydopamine, Near-Infrared Therapy, Photothermal Therapy, Chemodynamic Therapy, Nitric Oxide Release, Cancer Cell Membrane Cloaking, Homologous Targeting, Fenton Reaction, Reactive Oxygen Species, Peroxynitrite, Breast Cancer, MCF-7, Multimodal Therapy, Biocompatibility, Tumor Targeting
