Injected liquid turns into a gel to rebuild bones

Injectable hydrogel scaffold undergoes rapid gelation from a soluble liquid at room temperature, left, to form a stable, nonshrinking gel at body temperature, right, after one minute. (Credit: Mikos Laboratory/Rice University)

A material that is liquid at room temperature but that turns into a gel once injected into the body could help repair damaged bones in the skull and face.

The gel conforms to irregular three-dimensional spaces and provides a platform for functional and aesthetic tissue regeneration. It is intended as an alternative to prefabricated implantable scaffolds.

The invention is the subject of a new paper that appeared in the journal Biomacromolecules.


Thermosensitive technologies are not new to the field of tissue engineering and regenerative medicine, says Antonios Mikos, a bioengineer at Rice University who developed the material.

What makes the poly(N-isopropylacrylamide), or PNiPAAm, scaffold promising is that its chemical cross-linking technology allows the researchers to eliminate gel shrinkage without reducing swelling; this improves its stability so that it serves as an effective delivery vehicle for growth factors and stem cell populations.

Once sufficient quality and quantity of bone tissue have regenerated to fill the defected site, the hydrogel scaffold can be turned back into a liquid and released naturally.

The National Institutes of Health, the Baylor College of Medicine Scientific Training Program for Dental Academic Researchers, and the Kirschstein fellowship supported the research.

Source: Rice University