3D printing with riboflavin creates polymer medical implants

Researchers have discovered that riboflavin (vitamin B2) can be incorporated into 3D printing processes to create medical implants out of non-toxic polymers.

‘This opens the door to a much wider range of biocompatible implant materials, which can be used to develop customised implant designs using 3D printing technology,’ said Dr Roger Narayan, senior author of a paper describing the work and a professor in the joint biomedical engineering department at North Carolina State University (NCSU) and the University of North Carolina at Chapel Hill.

The researchers focused on a 3D printing technique called two-photon polymerisation, because it can be used to create small objects with detailed features, such as scaffolds for tissue engineering, microneedles or other implantable drug-delivery devices.

Two-photon polymerisation is a 3D printing technique for making small-scale solid structures from many types of photoreactive liquid precursors.

The liquid precursors contain chemicals that react to light, turning the liquid into a solid polymer. By exposing the liquid precursor to targeted amounts of light, the technique allows users to ‘print’ 3D objects.

According to NCSU, two-photon polymerisation has its drawbacks. Most chemicals mixed into the precursors to make them photoreactive are also toxic, which could be problematic if the structures are used in a medical implant or are in direct contact with the body.

The researchers have now determined that riboflavin can be mixed with a precursor material to make it photoreactive.

The paper, Two-photon polymerisation of polyethylene glycol diacrylate scaffolds with riboflavin and triethanolamine used as a water-soluble photoiniator, is published online in Regenerative Medicine.

The work, supported by the US National Science Foundation, involved researchers from Germany’s Laser Zentrum Hannover.