Biostimulating fillers and induction of inflammatory pathways: A preclinical investigation of macrophage response to calcium hydroxylapatite and poly-L lactic acid.

Together, these findings indicate that the CaHA mode of action is a non-inflammatory response while PLLA initiates expression of several cytokines known to play a role in inflammation. Our study supports the concept that these two "biostimulatory" fillers follow distinct pathways and should be considered individually with regard to mechanism of action.