Nerve Injury may occur using Printable Ink for Nerve Cell Growth

In peripheral nerve regeneration, nerve tissue engineering is an application of tissue engineering, and tissue-engineered nerve grafts are usually composed of a nerve scaffold combined with cellular and/or molecular components, like other tissue-engineered constructs. Working with scientists from India and Bangladesh, a team of researchers from RMIT University in Australia have developed a neuron-growing ink that uses the body's own electrical signals to precisely direct nerve cell growth. In nerve engineering, their work opens a new path.

The research title was "Three-dimensional directional nerve guide conduits fabricated by dopamine-functionalized conductive carbon nanofiber-based nanocomposite ink printing" published in RSC Advance.

In current nerve guides, a possible problem is that they do not transmit electrical nerve impulses, i.e. a synapse, between the distal and proximal end of an injured nerve, the researchers noted. Conductivity is the beneficial property of an ideal nerve guide for peripheral nerve regeneration that is being considered. Most conductive polymers, such as polypyrrole and polyaniline, documented for the manufacture of tissue engineering scaffolds, are non-biodegradable and possess poor mechanical properties and can therefore not be manufactured into 3D structures. A new nanocomposite material consisting of dopamine, carbon nanofibre (CNF) and polycaprolactone ( PCL) has been developed for the manufacture of nerve conduits, promoting the development and migration of neurons towards the targeted end of the injured nerve.

Nerve cells need to be meticulously directed to regrow between the broken ends of a nerve, explained by Shadi Houshyar, PhD of RMIT University, if they only build up anywhere they cause more pain or sensory problems. With our bioconductive ink, the growth of the neuron can be concentrated where we need it. Our research is in the early stages, but we hope to allow damaged nerves to be completely reconnected one day with further progress, to improve the lives of millions of people worldwide.

Peripheral nerve regeneration, unlike other tissues in the body, is sluggish and usually incomplete. The new nerve-regenerating ink blends dopamine with a conductive carbon nanofiber and polymer to restore good to excellent motor or sensory function in less than half of patients undergoing nerve repair after injury.

"The use of conductive materials allows electrons to move freely, stimulates cell formation, and helps attach damaged neural tissue," said Houshyar, a research fellow at the RMIT School of Engineering, a vice-chancellor.

A biocompatible scaffold was also produced by the researchers, so that the ink could be printed on lines and checked with human cells. The researchers observed the printed lines promoting the attachment and migration of neural cells. Cell differentiation was also improved, as the neural cells expanded along the lines, becoming more specialised.

This encourages proper contact with other neurons, which is promising for the development of sensory and motor processing neural circuits, giving hope that the technology could lead to a real recovery of nerve function, Houshyar said.

The researchers look forward to the future and in preclinical animal experiments they test their ink and scaffold.

"Our ultimate aim is a solution to nerve engineering that can guide the growth of the correct nerve cells in the right places," she said.

We are also keen to explore how the possible applications of this technology can be applied to speed up wound healing and enhance patient recovery.