Infiltrated 3D-printed zirconia scaffolds with biodegradable and bioactive polymer blend to improve their osseointegration

Bone defects and skeletal disorders continue to demand advanced biomaterials that combine mechanical strength with enhanced bioactivity and customizability. While yttria-stabilized zirconia (YSZ) offers excellent mechanical properties and biocompatibility, its bioinert nature and processing challenges limit its effectiveness for patient-specific bone implants. This study addresses this gap by developing novel polymer-infiltrated ceramic network (PICN) scaffolds based on 3D-printed porous YSZ fabricated via Direct Ink Writing (DIW). The scaffolds were infiltrated with biodegradable polycaprolactone (PCL)/polyvinyl alcohol (PVA) blends loaded with nanohydroxyapatite (nHA) to impart bioactivity and tunable degradation. Scaffold designs with 40% and 60% infill were evaluated for infiltration efficiency, mechanical performance, degradation behavior, and apatite formation capacity. Results demonstrated high infiltration rates (up to 96% , particularly in 40% infill scaffolds), mechanical integrity comparable to cancellous bone (compressive strength within the range of 2–12 MPa ), and enhanced in vitro apatite formation, especially for scaffolds with an 80:20 PCL/PVA blend containing 15% nHA. The degradation analysis indicated that higher PVA content accelerated resorption, with the 50:50 blend showing faster surface changes, while the 80:20 blend maintained gradual porosity increase aligned with tissue replacement. Overall, this work presents a feasible strategy for fabricating patient-specific ceramic scaffolds with enhanced osseointegration potential, thereby bridging the gap between mechanical stability and biological functionality for future bone and dental implant applications.