Baltimore — A liquid material for restoring damaged soft tissue, developed by biomedical engineers at Johns Hopkins University, shows promise in early testing, Medical News Today reports.
A composite of hyaluronic acid (HA) and polyethylene glycol (PEG), a synthetic molecule used as surgical glue, the material is injected under the skin, then “set” with light to form a more solid structure, much like using cold to set gelatin.
The PEG can be "cross-linked" — or made to form sturdy chemical bonds between many individual molecules — using energy from light, which traps the HA molecules, Medical News Today reports. Such cross-linking makes the implant hold its shape and not ooze away from the injection site.
Preliminary testing has been done on both rats and humans. For the former, researchers injected different concentrations of PEG and HA under the skin and into the back muscle of rats, shone an LED light on them to solidify the material, and later monitored them using magnetic resonance imaging (MRI). The implants were examined at 47 and 110 days and removed. Results showed that the implants created from HA and the highest-tested concentration of PEG with HA remained in place and were the same size over time compared with injections of HA only, which shrank.
Investigators then evaluated the safety and persistence of the PEG-HA implants with a 12-week experiment involving three volunteers undergoing abdominoplasty. Patients were injected with about five drops of either PEG-HA or HA alone under the belly skin. None experienced hospitalization, disability or death directly related to the implants, which were about 8 mm long, although patients did say they sensed heat and pain during the gel-setting process. Twelve weeks after implantation, MRI revealed no loss of implant size.
Researchers noted that more testing is needed to evaluate the material’s safety and efficacy in other types of human tissue.