Human Cell “Biobots” Encourage Neuron Regrowth in Lab Dishes

Made from human cells, researchers have created tiny biological robots – called Anthrobots – that can move across surfaces and even encourage regrowth in damaged regions in dishes of lab-grown neurons. The findings of the study, published in Advanced Science, could one day lead to the development of patient-derived therapeutic “biobots.”

The rise of the Anthrobot

Similar multicellular biological robots – known as “Xenobots” – have previously been developed from embryonic cells of the African clawed frog, Xenopus laevis.

Researchers sculpted the embryonic cells into multicellular structures, observing that the resulting Xenobots could navigate passageways, collect material and record information – even replicating themselves for a few cycles and healing after injury.

These frogs are commonly studied in the laboratory, but it wasn’t clear whether their ability to generate biobots stemmed from their amphibian embryo origins, or if it might be possible to generate similar bots from other species.

In the current study, the researchers sought to discover whether biobots could be created from human cells, creating biobots – termed “Anthrobots” – from human lung cells.

“We wanted to show that no, it’s universal, and that we could study the software of life by letting normal adult human cells reboot their multicellularity to see what they would do,” says Dr. Michael Levin, distinguished professor at Tufts University and the senior author of the study, speaking to Technology Networks.

“Our main impetus for making these biobots was to try to find a new model in which we can explore the latent space around a normal genome – what else can cells do in terms of behavior, new morphologies and effects on other cells without editing the genetic material or micromanaging the construction process (i.e., exploiting self-assembly),” Levin continued.

Anthrobot characteristics

The Anthrobots were created from single cells taken from the surface of the trachea – or windpipe – without the need for genetic modification, and they survived for 45–60 days in the laboratory before naturally degrading.

They came in a variety of shapes – some spherical, some elliptical and with different coverages of cilia – and this affected their movement. Tiny hair-like cilia on the cells’ exterior allow them to move around in different patterns.

Spherical bots with full cilia coverage tended to stay put and wiggle, whereas unevenly shaped ones with uneven cilia tended to move in longer paths that were either straight or slightly curved.

Additionally, experiments showed that the Anthrobots’ abilities surpassed that of the Xenobots – they were able to pass over neurons grown on lab dishes, even aiding new neuronal cell growth after artificial “wounds” were created by scratching a gap in the plated cells.

Though the mechanisms underpinning this effect are not yet known, the researchers observed that areas of new growth were covered by a large formation of Anthrobots termed a “superbot.”

Therapeutic potential

“One limitation is that we don’t yet know how exactly they knit the neural wounds together (but we know it’s not a passive process since we tried replacing them with other materials and it doesn’t work),” explains Levin. “We don’t know their ability to sense, their preferences and ability to learn from experience (if any) – we need to do a full behavioral characterization to understand what they already do and how to manipulate that for useful applications.”

If used for therapeutic purposes, Anthrobots could potentially be produced from a patient’s own cells, the researchers say, reducing the risk of being attacked by the immune system. In this way, they could be designed to perform various functions such as healing tissues, delivering drugs or recognizing bacteria.

“In the long term, this is a kind of sandbox platform in which we can learn to crack the morphogenetic code: what are the environments and stimuli that unlock new capabilities in normal genetically unmodified cells? How do we learn to control the collective competencies of cells toward new forms and functions?” says Levin.

Reference: Gumuskaya G, Srivastava P, Cooper BG, et al. Motile living biobots self-construct from adult human somatic progenitor seed cells. Adv. Sci. 2023:2303575. doi: 10.1002/advs.202303575

Dr. Michael Levin was speaking to Dr. Sarah Whelan, Science Writer for Technology Networks.