One is a type of nanoparticle formed of PEG-PLA copolymers, first developed in Langer’s lab decades ago and now commonly used to package and deliver drugs. The MIT approach relies on a combination of two readily available components. “They don’t require any advanced chemical functionalization.” “We’re working with really simple materials,” Tibbitt says. The MIT team wanted to design something simpler. Other researchers have created such gels by engineering proteins that self-assemble into hydrogels, but this approach requires complex biochemical processes. The MIT team set out to create a gel that could survive strong mechanical forces, known as shear forces, and then reform itself.
These gels, used to make soft contact lenses, among other applications, are tough and sturdy, but once they are formed their shape cannot easily be altered. Scientists have previously constructed hydrogels for biomedical uses by forming irreversible chemical linkages between polymers. Other authors are postdoc Matthew Webber, undergraduate Bradley Mattix, and postdoc Omid Veiseh. Koch Institute postdoc Eric Appel is also a lead author of the paper, and the paper’s senior author is Robert Langer, the David H. That allows you to squeeze it through a syringe or a needle and get it into the body without surgery,” says Mark Tibbitt, a postdoc at MIT’s Koch Institute for Integrative Cancer Research and one of the lead authors of a paper describing the gel in Nature Communications on Feb. “Now you have a gel that can change shape when you apply stress to it, and then, importantly, it can re-heal when you relax those forces.
The new gel consists of a mesh network made of two components: nanoparticles made of polymers entwined within strands of another polymer, such as cellulose. Such gels, which can carry one or two drugs at a time, could be useful for treating cancer, macular degeneration, or heart disease, among other diseases, the researchers say. To help overcome that obstacle, MIT chemical engineers have designed a new type of self-healing hydrogel that could be injected through a syringe. However, current versions aren’t always practical because must be implanted surgically. Scientists are interested in using gels to deliver drugs because they can be molded into specific shapes and designed to release their payload over a specified time period.