The Times - UK (2022-05-27)

14 Friday May 27 2022 | the times

News

Scientists have made “exciting

progress” towards a new gene therapy

that could revolutionise the treatment

of serious brain injuries, strokes and

multiple sclerosis.

The experimental treatment, de-

signed to reduce inflammation of the

brain, has also shown very early signs of

limiting the cognitive decline that

comes with age.

After positive results in mice, a

research team that includes the Babra-

ham Institute in Cambridge hopes to

begin human trials in two years.

Serious brain injuries can result in

inflammation or swelling that persists

for weeks. This can lead to permanent

damage as irreplaceable brain cells are

crushed in the confines of the skull,

which itself leads to fresh inflamma-

tion. The immune system includes a

type of cell — regulatory T cells — that

can play a protective role. These sense

inflammation and produce a cocktail of

compounds to reduce it. However, very

few are found in the brain and after a

serious injury they are typically over-

whelmed.

Professor Adrian Liston, of the

Babraham Institute, said: “We sought

to design a new therapeutic to boost the

population of regulatory T cells in the

brain so that they could manage in-

flammation.”

The researchers found that these

cells are scarce in the brain because of a

limited supply of a protein known as

interleukin 2, or IL2.

Levels of IL2 are much lower in the

brain than the rest of the body, and it

can not move from the body to the

brain because it cannot pass through

the blood-brain barrier — a wall of

specialised cells that prevent a host of

New gene therapy

boost for stroke

and MS patients

substances found in the blood from

crossing into the fluid that surrounds

the brain.

The new therapy involves a harmless

virus being injected into a vein. It does

not cause inflammation but can pass

through the blood-brain barrier. The

virus is modified to contain a new piece

of DNA. It carries this genetic code to

brain cells, which then use it to produce

extra IL2.

In laboratory mice, the number of

regulatory T cells in the brain increased

by as much as ten times. The rodents

suffered less brain damage after an

injury. Mice with a disease similar to

multiple sclerosis, which affects the

brain and spinal cord, also showed

significant improvements.

In mice that had suffered a simulated

stroke, the treatment helped to protect

against secondary strokes. And in a

follow-up study, still undergoing peer

review, the research team has seen

signs that the treatment prevents

cognitive decline in ageing mice.

Professor Matthew Holt of KU

Leuven in Belgium, a co-author of the

study that was published in the journal

Nature Immunology, said: “For years,

the blood-brain barrier has seemed like

an insurmountable hurdle to the effi-

cient delivery of [powerful anti-infla-

mmatory drugs] to the brain. This is no

longer the case.”

Dr Ed Needham, a neurocritical care

consultant at Addenbrooke’s Hospital

in Cambridge, who was not part of the

study, said: “The exciting progress in

this study is that not only can the

treatment successfully reduce the brain

damage caused by inflammation, but it

can do so without affecting the rest of

the body’s immune system, thereby

preserving the natural defences needed

to survive critical illness.”

Rhys Blakely Science Correspondent

T

he inventors

of a flea-sized

robot crab

have

suggested

that future versions

could travel through

the arteries of patients

with heart disease to

clear blockages (Rhys

Blakely writes).

Measuring about

half a millimetre

across, the “crab-bot”

is said to be the

smallest remote-

controlled walking

robot. The scientists

behind it have also

produced millimetre-

sized caterpillars,

crickets and beetles.

They believe that the

technology could be

harnessed to create

micro-robots capable

Tiny robotic crabs

could enter arteries

to clear blockages

of working inside the

human body.

Professor John

Rogers, of

Northwestern

University in Illinois,

said: “You might

imagine micro-robots

... as surgical assistants
to clear clogged
arteries, to stop
internal bleeding or to
eliminate cancerous
tumours — all in
minimally invasive
procedures.”
Before that crab-bots
could be used to

monitor hard-to-reach

places. In a study

published in the

journal Science

Robotics, Rogers and

his colleagues show

how they were able to

attach materials to the

devices, which

changed colour

depending on the

humidity. This suggests

that crab-bots could be

used as “mobile

sensors in the

environment, limited

spaces or biological

systems”, they write.

The robot crabs are

made of silicon

oxide and rubber

and can snap into

a “remembered”

shape when

heated by a laser.

As their joints

expand, or

contract when the

laser is off, they are

able to scuttle

sideways. Their speed

and direction can be

controlled by altering

the frequency and

angle of the laser

flashes.

“Because these

structures are so tiny,

the rate of cooling is

very fast,” Rogers said.

“Reducing the sizes of

these robots allows

them to run faster.”

Last September the

same team presented a

microchip with wings

— about the size of a

grain of sand.

Meanwhile, a team

at the Max Planck

Institute for Intelligent

Systems in Stuttgart

has built a “millirobot”

that is 4mm long and

as flat as a sheet of

paper. Its developers

suggest it could

navigate through the

gut or urinary tract.

The flea-sized “crab-bot”

scuttles across a US

one-cent piece. Lasers

heat its joints, which

expand and contract,

creating movement

The r

mad

ox

an

a

sh

h

A

ex

co

lase

able

sidewa

and dir

control

the freq

Th fl i d “ b b t” l