• Medical Nanorobots: A New Era in Targeted Cancer Therapy
  • Navid Mousazadeh,1 Hamidreza Fathi,2,*
    1. Department of Medical Biotechnology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
    2. Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran


  • Introduction: Despite significant breakthroughs in the diagnosis and treatment of malignant diseases, cancer remains a major global health challenge with high morbidity and mortality. As current therapeutic measures are often limited by tumor relapse and metastasis, innovative and effective treatment strategies are urgently needed. Recent and evolving advances in nanotechnology and nanomaterials have introduced novel approaches to cancer diagnosis and therapy. The development of nanorobots, a product of advanced nanotechnology and microfabrication techniques, has revolutionized cancer treatment by enabling precise interventions at the cellular level (1). Nanorobots can convert various energy sources into propulsive forces, enabling autonomous mobility. This holds great promise for precision in tumor diagnosis and therapy by overcoming the challenges posed by Brownian motion and facilitating targeted navigation to specific locations, in contrast to nanoparticle-based drug delivery systems, which depend solely on the enhanced permeability and retention (EPR) effect or active targeting through blood circulation. Because of their strong propulsion capabilities, nanorobots can readily traverse tissues and enhance drug uptake into cells, leading to the enhanced accumulation of therapeutic agents (2-4).Nanorobots designed for medical applications need to adhere to specific size criteria, ranging between 0.5 and 3 µm, with individual components measuring 1 to 100 nm—a range crucial for navigating through capillaries in the human body (5, 6). These nanosized machines can deliver payloads (e.g., drugs, genes, sensing molecules) and perform specific biomedical functions such as diagnosis and therapy, enabling them to target tumor or disease sites. Nanorobots are powered by either active or passive systems, depending on their design and function. Such systems may receive external power sources (e.g., near-infrared (NIR) light, ultrasound, magnetic forces) or utilize biological mediums such as blood flow. A key difference between nanorobots and nanocarriers is the active power system of nanorobots (7).
  • Methods: To prepare this abstract for a poster review, we searched various databases, including Google Scholar and PubMed, using keywords related to micro/nanobots and cancer detection. We selected the most relevant papers for inclusion.
  • Results: In recent years, the practical application of micro- and nanorobots in cancer treatment has advanced from theoretical concepts to real-world implementation, moving from in vitro experiments to in vivo applications. For instance, Andhari et al. engineered a multi-component magnetic nanorobot using multi-walled carbon nanotubes (CNTs) loaded with doxorubicin (DOX) and an anticancer antibody. This self-propelling nanorobot can be driven by an external magnetic field in complex biological fluids, releasing anticancer drug payloads within three-dimensional (3D) spheroidal tumors. This release is triggered by changes in intracellular H₂O₂ levels or local pH in the tumor microenvironment. The nanorobot, chemically conjugated with magnetic Fe₃O₄ nanoparticles, is designed to preferentially release DOX in the intracellular lysosomal compartments of human colorectal carcinoma (HCT116) cells by opening a gate on the Fe₃O₄ surface (8). Similarly, Wang et al. developed a nickel-silver nanoswimmer that can be powered by an external magnetic field, capable of delivering micron-sized particles at speeds exceeding 10 μm/s. Upon reaching the vicinity of human cervical cancer (HeLa) cells, the nanoswimmer released drug-carrying microspheres to kill the cancer cells (9). Felfoul et al. discovered that biohybrid microrobots derived from Magnetococcus marinus strain MC-1 can be effectively maneuvered using an external magnetic field to transport drug-loaded nanoliposomes to hypoxic areas within tumors (10). Garcia et al. demonstrated the use of ultrasound-driven nanowire motors to deliver drugs rapidly to HeLa cancer cells, with 38% of the DOX payload released within 15 minutes of near-infrared (NIR) light irradiation (11). In addition, Deng et al. created NK cell-mimic nanorobots with aggregation-induced emission (AIE) properties by wrapping an NK cell membrane around an AIE-active polymeric nanoendoskeleton, enhancing their ability to target cancer cells (12). Dolev et al. designed a nanorobot capable of detecting circulating cancer cells in the bloodstream and delivering drugs to tumor sites. This nanorobot stored energy in a built-in capacitor, harvesting power from the bloodstream (13). Shi et al. introduced a nanorobot-assisted multifocal cancer detection procedure (MCDP) that employed a niche genetic algorithm (NGA) for accurate cancer detection (14). Song et al. created robust, magnetic tri-bead microrobots that respond to NIR light, releasing drugs when local temperatures reach 50°C. These microrobots showed strong biocompatibility and effectively targeted tumor cells in vitro, demonstrating the potential of nanorobotic chemotherapy-photothermal therapy (15). While these advancements demonstrate the exciting potential of nanorobots in cancer treatment, their clinical implementation faces significant challenges. These include the development of nanoscale components, precise movement control, and ensuring stability in the biological environment. Additionally, the body fluid environment, particularly at low Reynolds numbers, presents further difficulties for nanorobot accuracy and speed. Biological interference from circulating proteins, blood cells, and immune cells can obstruct nanorobot functionality, slowing or even stopping their movements, and potentially leading to their removal from the bloodstream. Addressing these challenges will be critical for the successful use of nanorobots in clinical cancer treatments (16-18).
  • Conclusion: The integration of nanorobots into cancer therapy marks a significant advancement in the field of targeted treatments, offering a promising solution to overcome the limitations of current modalities, such as tumor relapse and metastasis. As evidenced by recent studies, nanorobots have transitioned from theoretical concepts to practical applications, with successful in vitro and in vivo experiments. However, despite their great potential, the clinical application of nanorobots faces several technical challenges. These challenges include the need for precise control over nanorobot movement, the stability of nanoscale components, and the management of biological interferences such as blood proteins and immune responses, which may impede their efficiency. Overall, nanorobots represent a promising frontier in cancer therapy, but further research and development are essential to overcome the technical and biological obstacles that currently limit their widespread use.
  • Keywords: Autonomous mobility, Cancer, Drug delivery, Nanorobots, Targeted cancer therapy