Living Machines: The Potential of ABBMs for Precision Oncology

Corresponding author: Camron Farjami

Palos Verdes Peninsula High School, Rolling Hills Estates, CA 90274 USA. Email: farjamicamron@gmail.com

Authors: Camron Farjami, Aren Dermarderosian (UCLA), Mojtaba Akhtari (Loma Linda University Medical Center)

In the equation for humanity’s continued survival, one variable has consistently galvanized mortality: cancer. Conventional treatments—most prominently chemotherapy—remain blunt instruments, producing severe, body-wide toxic effects and poor delivery accuracy. Targeted therapies have opened a new era, but their reach and cost still leave critical gaps.

This study examines the potential of algae-based biohybrid microbots (ABBMs) as a revolutionary method for cancer treatment. These microrobots, roughly the size of a human hair, blend biological and synthetic components to navigate tumor microenvironments while carrying therapeutic payloads, boosting efficacy and patient quality of life.

The intricacies of ABBMs allow them to traverse volatile tumor microenvironments, reach hypoxic regions, and deliver drugs with reduced harm to healthy cells—cutting side effects and improving outcomes. Preclinical studies in lung metastasis models show reduced tumor growth and improved survival. Incorporating algae lowers manufacturing costs relative to standard chemotherapy, which averages $20,000 per course.

Challenges remain: scalable production, long-term biocompatibility, and immune safety must be validated before clinical deployment. Despite these hurdles, ABBMs hint at a shift toward less invasive, more precise, patient-centric oncology.

Microrobots hold the potential to revolutionize oncology by offering less invasive, more efficacious, more precise, and more patient-centric technologies than have been seen before.

Keywords: microrobots, biohybrids, algae-based drug delivery, precision oncology, tumor microenvironment, targeted therapy

I. Introduction: The Unmet Need in Cancer Therapy

The burden of cancer. Cancer remains a leading cause of death, claiming ~600,000 lives per year in the U.S. Conventional chemotherapy is effective but indiscriminate, damaging healthy tissue and producing toxic side effects that reduce therapy adherence and quality of life.

Limits of existing therapies. Radiation and immunotherapy offer targeted approaches but are costly and often case-specific. Tumor microenvironments (TMEs)—especially hypoxic or non-vascular tumors—impede drug delivery and foster resistance.

Need for better delivery. Systemic delivery floods the body; newer approaches must solve delivery, not just potency. Biohybrid microrobots promise active, precise delivery directly to tumors, transforming inaccessible sites into operable targets.

II. ABBMs: Design, Mechanisms, and Advantages

Defining ABBMs. Comparable in scale to a human hair, ABBMs pair a biological chassis (e.g., Chlorella) with synthetic layers (iron oxide, polymers, chemotherapeutics) and red blood cell membranes for immune evasion and controlled release.

Biological component. Microalgae provide autonomous propulsion via flagella/cilia, adapt to varied environments, and generate oxygen in situ—valuable for hypoxic tumors.

Synthetic component. Magnetic and polymeric layers guide navigation, boost payload capacity, and enable triggered release in response to pH or external fields.

Propulsion variety. Beyond algae, other platforms explore bacteria, sperm-inspired designs, enzyme-powered micromotors, and Mg-based micromotors—each tuned to specific anatomical niches.

III. Advantages Over Traditional Delivery Systems

Targeted delivery. High selectivity minimizes collateral damage to healthy tissue and reduces side effects.

Penetration of challenging TMEs. Active swimming improves drug distribution in hypoxic or dense tissues, such as deep lung regions.

Biocompatibility. Biological cores and RBC coatings reduce immunogenicity and prolong circulation.

Cost potential. Algae-based fabrication and lower side-effect management suggest meaningful cost reductions versus chemotherapy.

IV. Preclinical Efficacy

In melanoma lung metastasis models, algae-based microrobots carrying doxorubicin improved survival and reduced tumor burden compared to passive nanoparticles or free drug. Active propulsion enhanced drug accumulation in deep tissue while enabling lower dosing.

Photosynthetic oxygen generation within hypoxic tumors may further boost oxygen-dependent therapies. Early cargo-delivery studies confirm precise transport of payloads to mammalian cells, underscoring feasibility beyond proof-of-concept.

V. Challenges and Future Outlook

Scalability & cost. Mass-producing complex microrobots with reliable performance remains a hurdle; biomedical cost models are still emerging.

Biocompatibility & safety. Long-term immunogenicity, genotoxicity, and neurotoxicity require rigorous evaluation.

Navigation & control. Magnetic manipulation must balance depth, precision, and heating constraints; swarm coordination and real-time imaging are active research areas.

Drug loading & release. Maximizing payload while preserving motility is nontrivial; coatings can impede propulsion if overbuilt.

Despite these challenges, algae-based biohybrid microrobots point toward a future of active, intelligent drug delivery—targeting tumors with unprecedented precision and potentially redefining oncology care.