Temperature-controlled nanorockets deliver medicine to diseased tissue
Image credit: Nature Chemistry
Temperature-controlled nanorockets are being tested by Dutch researchers to deliver medicine into inflamed and diseased tissue.
The nanorockets studied by a team from the Radbout University in Nijmegen, the Netherlands, self-assemble into functional units and change shape to fit into various spaces in the human body.
“Our biggest challenge is to provide our nanorockets with various functionalities,” said Daniela Wilson, head of Radboud University’s bio-organic chemistry department. “We now demonstrate the first molecularly built brake system, enabling the rockets to start and stop at desired locations.”
The temperature-responsive brakes consist of brushes made of polymers – long chains of responsive units – that grow onto the surface of the nanorockets. These brushes swell or collapse in response to the environmental temperature, thus regulating access to hydrogen peroxide, which fuels the nanorockets.
The brushes immediately collapse at a temperature of 35°C or higher, making the machine stop.
“This all happens without affecting the catalytic activity or the shape of the nanorocket,” explained Wilson. “Therefore, nanorockets equipped with this valve system are able to move with great efficiency in water, even at low concentrations of fuel.”
However, Wilson hopes that in future, the team will be able to control the motion of the nanorockets with light instead of temperature.
“This would allow us to start or stop a nanorocket by shining a laser light on it,” Wilson said.
The researchers are also experimenting with magnetic fields acting as steering wheels for the nanorockets. By growing magnetic metallic nickel in the core of the rockets, a magnetic field can be used to guide and steer the movement of the rockets.
Currently, the rockets are not yet completely biodegradable, which prevents their use in humans.
“Even though our nanorockets are not toxic to living cells, they are not completely biodegradable yet,” Wilson said. “That is one of the prerequisites for their use as medicine carriers in the body.”
The study is published in the latest issue of Nature Chemistry.