Chemists at the Massachusetts Institute of Technology (MIT) have devised a method of synthesising polymers that can break down more readily in the body and the environment.
The chemical reaction, ring-opening metathesis polymerisation (ROMP) has been utilised by scientist to build novel polymers for various uses, such as, nanofabrication, high-performance resins and delivering drugs or imaging agents.
One negative of this synthesising method is that the resulting polymers do not break down in the natural environment or the body. The new research undertaken by the team at MIT has created a method of making these polymers more degradable. The research team added a monomer it the backbone of the polymer. The monomer forms chemical bonds that can be broken down by weak acids, bases and ions such as fluoride.
“We believe that this is the first general way to produce ROMP polymers with facile degradability under biologically relevant conditions,” says Jeremiah Johnson, an associate professor of chemistry at MIT and the senior author of the study. “The nice part is that it works using the standard ROMP workflow; you just need to sprinkle in the new monomer, making it very convenient.”
These building blocks could be incorporated into polymers for a wide variety of uses, which could be used in the medical field as well as in industrial polymers that would benefit from breaking down more rapidly after use.
“It’s a very robust and powerful polymerisation reaction,” Johnson says. “But one of the big downsides is that the backbone of the polymers produced entirely consists of carbon-carbon bonds, and as a result, the polymers are not readily degradable. That’s always been something we’ve kept in the backs of our minds when thinking about making polymers for the biomaterials space.”
“We prefer to continue to use norbornene as the molecule that enables us to polymerise these complex monomers,” Johnson says. “The dream has been to identify another type of monomer and add it as a co-monomer into a polymerisation that already uses norbornene.”