Researchers have developed nanorobots that track down and kill tumour cells by cutting off their blood supply. It’s the first time that a targeted payload mechanism has been demonstrated to work successfully in a live-mammal model, namely in mice with melanoma. The nanorobots are made up of thin sheets of DNA folded into tubes and loaded with thrombin, by a technique known as DNA origami. Thrombin is a protein that promotes coagulation in the blood vessels that feed oxygen and nutrients to the tumour cells, causing the cells to die, in a process known as vascular occlusion.
The nanorobot has a DNA aptamer (essentially a targeting molecule) located on its surface that detects and binds to proteins released explicitly by tumour-associated cells within the host. Once the nanorobot latches on to a tumour cell, it actively uncoils, releasing thrombin – the payload. Injecting the nanorobot into the animal restricts tumour progression within 24 hours. Furthermore, labelling studies using a fluorescent dye have shown that nanorobots are successfully degraded and cleared from all the major organs within 24 hours of injection. Nanorobots appeared safe, with no apparent adverse immunological response in the animal.
DNA nanorobotic systems such as this one may inspire the development of novel cancer therapies, where quick and effective drug delivery to various types of tumours can be made possible. Such design systems may also open avenues to develop intelligent and sustained drug delivery for other challenging diseases.
Nimisha Joshi (Trainee Medical Writer, HealthCare21)
- Li S, et al. Nat Biotechnol. 2018;36(3):258–64. Accessible at: https://www.ncbi.nlm.nih.gov/pubmed/29431737