Scientists from the Institute of Nano Science and Technology (INST), Mohali, an autonomous institute under the Department of Science and Technology (DST), in collaboration with researchers from the Bhabha Atomic Research Centre (BARC), Mumbai, have developed an advanced light-activated multifunctional nanobot that could improve targeted breast cancer therapy.
Breast cancer is a leading cause of cancer-related deaths among women worldwide. Conventional chemotherapy often results in severe side effects, drug resistance and damage to healthy tissues because of non-specific drug distribution, poor tumour penetration, and the lack of active control after drug administration.
Existing nanomedicines primarily rely on passive accumulation within tumours, leading to limited tissue penetration and poor spatial control. Similarly, most light-powered micro- and nanorobots require ultraviolet or visible light, which has restricted tissue penetration and may damage healthy tissues.
In contrast, stimulus-responsive nanorobots—controlled by external cues such as near-infrared (NIR) light or magnetic fields, or internal stimuli such as pH and enzymes—offer precise, targeted therapy with minimal systemic toxicity, making them a promising platform for precision medicine.
To address these challenges, the INST research team, including Dr. Jiban Jyoti Panda, Swapnil Srivastava, Pankaj Kharra and Jyoti Yadav, collaborated with Dr. Santosh K. Gupta and Annu Balhara from BARC, Mumbai, to develop upconversion nanoparticle (UCNP)-based nanobots that convert near-infrared light into heat while exhibiting light-guided movement.
The team functionalized the nanobots with a photosensitizer, enabling the generation of reactive oxygen species (ROS) upon NIR exposure. The nanobots also demonstrated light-guided directional movement, or phototaxis, facilitating localized therapeutic action.
Additionally, the researchers functionalized the nanobots with folic acid, enabling selective recognition and targeting of breast cancer cells that overexpress folate receptors, thereby improving tumour-specific phototherapeutic efficacy.
The study highlights the pioneering contribution of first author Swapnil Srivastava and the scientific leadership of corresponding authors Dr. Jiban Jyoti Panda and Dr. Santosh K. Gupta in advancing UCNP-based nanobot-mediated cancer phototherapy.
When exposed to a 980 nm near-infrared laser, the nanobots’ polydopamine coating generates localized heating, creating a temperature gradient that induces thermally driven motion, causing the nanobots to actively move toward the laser source through phototaxis. Simultaneously, photothermal heating and photodynamic generation of reactive oxygen species work together to destroy cancer cells. These combined effects produced significantly greater tumour inhibition than either treatment modality alone.
Fig: Schematic illustration of the therapeutic mechanism of NIR-responsive UCNP nanobot-mediated phototherapy for breast tumour treatment. The illustration depicts the directional movement (phototaxis) of UCNP nanobots under NIR laser irradiation, enabling localized photothermal and photodynamic therapy.
The researchers demonstrated the therapeutic efficacy of the nanobots in both cellular models and breast tumour-bearing mice.
Published in the journal ACS Applied Materials & Interfaces, the study introduces a fuel-free, NIR-responsive nanobot that combines active light-guided movement under biologically compatible NIR irradiation with folic acid-mediated cancer cell targeting. The system also enables controlled drug delivery regulated by laser intensity, pH, and glutathione concentration within the biological environment.
The researchers believe this unique combination would allow precise, externally controlled and minimally invasive treatment of breast tumours through localized therapeutic action.
