CRISPR gene editing is a technique famous for its potential to edit the genomes of living organisms, including humans. Using the technique, it may be possible to reverse congenital conditions, kill off viruses, and do things previously only imagined. But now it has been employed to do something else entirely, and that is to give materials the ability to change their properties when specific DNA sequences are nearby.
The MIT and Harvard team behind the new research developed a variety of devices based on the new technology, including gels that release drugs, an electronic circuit that reacts to DNA cues, and a microfluidic device with a DNA sensor that activates a valve to open and close. They envision a whole set of new smart materials that can interact with the human body in a very precise way to perform diagnostics, deliver therapies, and do things that are currently impossible.
CRISPR lets scientists cut DNA in specific locations using proteins called Cas enzymes. In the new research, the scientists were able to use single-stranded DNA as a control mechanism or a structural component, giving smart biological functionality to whatever material it is in.
A polyethylene glycol gel containing DNA bound to encapsulated drug was developed. When a specific DNA sequence in the environment is detected, a Cas12a protein is then activated to cut the DNA within the gel and release the drug it holds onto. The team also created an acrylamide gel with the DNA making up much of the structure of the gel itself, so when it is broken up by the Cas12a protein, the whole gel comes apart and releases the drugs inside, which is useful for administering larger doses.
To further advance the technique, the team created an electronic circuit with another gel that is conductive when the DNA strands within it are intact. However, when the right DNA sequence appears in the sample that flows over the electronic component, the DNA strands in the gel are broken by Cas12a, opening the circuit.
Of course scientists will now be able to build all kinds of CRISPR-based devices and materials. For example, the MIT and Harvard team that developed this technology is already working on how to use it to deliver engineered bacteria to treat gastrointestinal conditions.
Image: MIT engineers created a DNA-acrylamide gel that can be degraded by DNA-editing enzymes. At right, the gel is broken down after two hours of exposure to a DNA “trigger sequence.” At left, the gel is exposed to DNA that doesn’t contain the trigger sequence, so it remains intact. Image courtesy of the researchers
Study in journal Science: Programmable CRISPR-responsive smart materials