In their bid to design new bio-materials that promote tissue regeneration, scientists have identified how inflammation, when precisely controlled, is crucial for bone repair.
The findings showed that a new type of ceramic scaffold causes inflammatory cells to behave in a way that is more regenerative than scaffolds that are currently used clinically.
The reason can be attributed to macrophages -- swallowing white blood cells that digest foreign particles, the researchers said.
"We wanted to know why these scaffolds were successful and to understand the contributions of macrophages to that process," said Kara Spiller, Associate Professor Drexel University, in Pennsylvania, the US.
The findings showed that the new ceramic scaffolds caused macrophages to transform into an M2c phenotype, meaning they express genes associated with re-modelling.
This behaviour was not seen in the scaffolds that have been approved to be used in humans.
Further, the study also found that macrophages must be in direct contact with the scaffold in order to regenerate tissue.
"The macrophages degrade the scaffolds and shape them into something new," Spiller said.
Determining why certain scaffolds are successful in re-growing bone will ultimately help biomedical engineers design other types of scaffolds and new drug delivery strategies to promote healing in other areas of the body, the researchers concluded in the paper published in the Journal of the Royal Society Interface.