In vivo evaluation of 3D printed polycaprolactone composite scaffold and recombinant human bone morphogenetic protein‐2 for vertical bone augmentation with simultaneous implant placement on rabbit calvaria

Abstract

This study evaluated 3D printed polycaprolactone (PCL) composite scaffold and recombinant human bone morphogenetic protein-2 (rhBMP-2), loaded either onto a PCL composite scaffold or implant surface, for vertical bone augmentation with implant placement. Three-dimensional printed PCL frames were filled with powdered PCL, hydroxyapatite, and β-tricalcium phosphate. RhBMP-2 was loaded to the PCL composite scaffolds and implant surfaces, and rhBMP-2 release was quantified for 21 days. Experimental implants were placed bilaterally on 20 rabbit calvaria, and the PCL composite scaffolds were vertically augmented. The randomly allocated experimental groups were divided by carrier and rhBMP-2 dosage as no rhBMP-2 (control), 5 μg rhBMP-2 loaded to PCL composite (Scaffold/rhBMP-2[5 μg]), 5 μg rhBMP-2 loaded to implant (Implant/rhBMP-2[5 μg]), 30 μg rhBMP-2 loaded to PCL composite (Scaffold/rhBMP-2[30 μg]), and 30 μg rhBMP-2 loaded to implant (Implant/rhBMP-2 [30 μg]). Histologic and histometric analyses were conducted after 8 weeks. In both scaffold-loading and implant-loading, rhBMP-2 released initially rapidly, then slowly and constantly. Released rhBMP-2 totaled 23.02 ± 1.03% and 24.69 ± 1.14% in the scaffold-loaded and implant-loaded groups, respectively. There were no significant differences in histologic bone-implant contact (%). Peri-implant bone density (%) was significantly higher in the Scaffold/rhBMP-2(30 μg) and Implant/rhBMP-2(30 μg) groups. Total bone density (%) was not significantly different between the Scaffold/ rhBMP-2(5 μg), Implant/rhBMP-2(5 μg), and control groups, or between the Scaffold/rhBMP-2(30 μg) and Implant/rhBMP-2(30 μg) groups, but was significantly higher in the Scaffold/rhBMP-2(30 μg) and Implant/rhBMP-2(30 μg) groups than in the controls. Three-dimensional printed PCL composite scaffold with rhBMP-2 produced vertical osteogenesis and osseointegration, regardless of rhBMP-2 loading to the PCL composite scaffold or implant surface.Yun-Young Chang and Sa-Ya Lee contributed equally to this study.

3D printing for bone regeneration: challenges and opportunities for achieving predictability

“…This also included the incorporation of osteogenic cues in the form of either cells 87 or inorganic materials 88 and bone morphogenetic protein 2 (BMP-2). [89][90][91] As expected, the addition of various osteogenic stimuli resulted in enhanced bone formation when compared to the pure polymeric structures. The presence of the scaffold and its inner architecture may also play a role for bone maintenance and dental implant osseointegration.…”

“…Various polymers have been utilized for the manufacturing of 3D‐printing scaffolds for vertical bone augmentation. This also included the incorporation of osteogenic cues in the form of either cells 87 or inorganic materials 88 and bone morphogenetic protein 2 (BMP‐2) 89–91 . As expected, the addition of various osteogenic stimuli resulted in enhanced bone formation when compared to the pure polymeric structures.…”

“…Several studies have utilized the ability of additive manufacturing for fabricating pre-tapered scaffold allowing simultaneous dental implant placement 88,91 (Figure 5C). This approach is promising but has the limitations of placing the dental implant in contact with the polymeric 3D-printed filaments, hence potentially preventing osseointegration as mentioned above.…”