Icariin-releasing 3D printed scaffold for bone regeneration

The polycaprolactone (PCL) and nano-hydroxyapatite (nHAP) composite is an attractive material for bone scaffolds with excellent mechanical properties and osteoinductivity. It also exhibited good biocompatibility as well as controllable biodegradability. We have recently developed a PCL and nHAP composite scaffold, which is embedded with poly (lactic-co-glycolic acid) (PLGA) microspheres (μs). It achieved controlled delivery of bioactive factors. In this study, Icariin (ICA) encapsulated with PLGAμs was embedded in 3D printed PCL/nHAP scaffolds to facilitate in situ bone regeneration. The scaffold exhibited excellent mechanical performance owing to the nHAP. The PCL/nHAP scaffold showed sustainable release of ICA as the PCL degraded. The PCL degradation produced cracks on the surface of the scaffold, and then the PLGAμs was exposed to phosphate buffer solution. The released ICA promoted the osteogenic differentiation of MC3T3-E1. Consistently, in vivo studies showed that the composite scaffolds releasing ICA promoted the healing of calvaria bone. In conclusion, PCL/PLGAμs/nHAP composite scaffold by 3D printing may serve as an efficient material for bone tissue repair and regeneration.