Synthetic Neurons

Synthetic neurons made of hydrogel could one day be used in sophisticated artificial tissues to repair organs such as the heart or the eyes. Hagan Bayley at the University of Oxford and his colleagues devised a synthetic material that can act in a similar way to a human neuron. Made from hydrogel, the artificial neurons are about 0.7 millimetres across ­– about 700 times wider than a human neuron, but similar to giant axons found in squid. They can also be made up to 25 millimetres long, which is similar in length to a human optic nerve running from the eye to the brain.
When a light is shone on the synthetic neuron, it activates proteins that pump hydrogen ions into the cell. These positively charged ions then move through the neuron, carrying an electrical signal. The speed of transmission was too fast to measure with the team’s equipment and is probably faster than the rate in natural neurons, says Bayley. When the positive charge reaches the tip of the neuron, it makes adenosine triphosphate (ATP) – a neurotransmitter chemicalmove from one water droplet to another. In future work, the researchers hope to make the synthetic neuron interact with another via an ATP signal, just as neurons connect with each other at synapses.
The team bundled seven of the neurons together to work in parallel as a synthetic nerve. “This allows us to send multiple signals simultaneously,” says Bayley. “They can all have very different frequencies and so it’s a very versatile signal.” The main purpose is to send different pieces of information down the same pathway, he says.

Artificial nerve cells made from biocompatible materials have been made in a lab for the first time. The innovation may one day be used in synthetic tissues to repair organs such as the heart or the eyes. 

However, the artificial neurons still have a long way to go. Unlike real neurons, there is no mechanism to recycle and create new neurotransmitters in the synthetic system. The neurons therefore only work for a few hours, says Bayley. “The more you do science, the more you find out how clever science is by virtue of evolution.” Alain Nogaret at the University of Bath in the UK says the innovation could play a major role in improving neuro-implants such as artificial retinas by the end of the decade. “The emulation of nervous activity in soft materials is a major step towards non-invasive brain-machine interfaces and solutions addressing neurodegenerative disease.”

Bayley hopes to eventually use these synthetic neurons to deliver different types of drugs simultaneously to treat wounds more quickly and precisely. “Using light, we could maybe release drug molecules in a patterned way,” he says.

How To Use The Body’s Inbuilt Healing System

Imperial researchers have developed a new bioinspired material that interacts with surrounding tissues to promote healing. Materials are widely used to help heal wounds: Collagen sponges help treat burns and pressure sores, and scaffold-like implants are used to repair broken bones. However, the process of tissue repair changes over time, so scientists are looking to biomaterials that interact with tissues as healing takes place.

Now, Dr Ben Almquist and his team at Imperial College London have created a new molecule that could change the way traditional materials work with the body. Known as traction force-activated payloads (TrAPs), their method lets materials talk to the body’s natural repair systems to drive healing.


The researchers say incorporating TrAPs into existing medical materials could revolutionise the way injuries are treated.

Our technology could help launch a new generation of materials that actively work with tissues to drive healing,” said Dr Almquist, from mperial’s Department of Bioengineering.
After an injury, cells ‘crawl’ through the collagen ‘scaffolds’ found in wounds, like spiders navigating webs. As they move, they pull on the scaffold, which activates hidden healing proteins that begin to repair injured tissue. The researchers in the study designed TrAPs as a way to recreate this natural healing method. They folded the DNA segments into three-dimensional shapes known as aptamers that cling tightly to proteins. Then, they attached a customisable ‘handle’ that cells can grab onto on one end, before attaching the opposite end to a scaffold such as collagen.
During laboratory testing of their technique, they found that cells pulled on the TrAPs as they crawled through the collagen scaffolds. The researchers tailor TrAPs to release specific therapeutic proteins based on which cells are present at a given point in time.

This is the first time scientists have activated healing proteins using differing cell types in man-made materials. The technique mimics healing methods found in nature. “Creatures from sea sponges to humans use cell movement to activate healing. Our approach mimics this by using the different cell varieties in wounds to drive healing,” explains Dr Almquist.”

This approach is adaptable to different cell types, so could be used in a variety of injuries such as fractured bones, scar tissue after heart attacks, and damaged nerves. New techniques are also desperately needed for patients whose wounds won’t heal despite current interventions, like diabetic foot ulcers, which are the leading cause of non-traumatic lower leg amputationsTrAPs are relatively straightforward to create and are fully man-made, meaning they are easily recreated in different labs and can be scaled up to industrial quantities.

TrAPs could harness the body’s natural healing powers to repair bone

TrAPs provide a flexible method of actively communicating with wounds, as well as key instructions when and where they are needed. This intelligent healing is useful during every phase of the healing process, has the potential to increase the body’s chance to recover, and has far-reaching uses on many different types of wounds. This technology could serve as a conductor of wound repair, orchestrating different cells over time to work together to heal damaged tissues,” said Dr Almquist.

The findings are published in Advanced Materials.