3D-Printed PCL/Zn scaffolds for bone regeneration with a dose-dependent effect on osteogenesis and osteoclastogenesis

Siyi Wang; Ranli Gu; Feilong Wang; Xiao Zhao; Fan Yang; Yuqian Xu; Fanyu Yan; Yuan Zhu; Dandan Xia; Yunsong Liu

doi:10.1016/j.mtbio.2021.100202

3D-Printed PCL/Zn scaffolds for bone regeneration with a dose-dependent effect on osteogenesis and osteoclastogenesis

Mater Today Bio. 2022 Jan 1:13:100202. doi: 10.1016/j.mtbio.2021.100202. eCollection 2022 Jan.

Authors

Siyi Wang^{1

2}, Ranli Gu^{1

2}, Feilong Wang^{1

2}, Xiao Zhao^{1

2}, Fan Yang^{1

2}, Yuqian Xu^{1

2}, Fanyu Yan^{1

2}, Yuan Zhu^{1

2}, Dandan Xia^{2

3}, Yunsong Liu^{1

2}

Affiliations

¹ Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, 100081, China.
² National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, Research Center of Engineering and Technology for Computerized Dentistry Ministry of Health, NMPA Key Laboratory for Dental Materials, No.22, Zhongguancun South Avenue, Haidian District, Beijing, 100081, PR China.
³ Department of Dental Materials, Peking University School and Hospital of Stomatology, Beijing, 100081, China.

Abstract

Polycaprolactone (PCL) is a polymer material suitable for being prepared into porous scaffolds used in bone tissue engineering, however, insufficient osteogenic ability and mechanical strength limit its application. Zinc (Zn) alloy with proper mechanical strength and osteogenesis is a promising biodegradable metal that have attracted much attention. Herein, we combined the advantages of PCL and Zn by fabricating PCL/Zn composite scaffolds with different Zn powder contents (1 wt%, 2 wt%, 3 wt%) through fused deposition modelling. The mechanical property, cytocompatibility and Zn ions release behavior of PCL/Zn scaffolds were analyzed in vitro. The osteogenesis and osteoclastogenesis properties of the scaffolds were evaluated by being implanted into Sprague-Dawley rats calvaria defect. Results showed that the PCL/Zn scaffolds exhibited improved mechanical properties and cytocompatibility compared with the pure PCL scaffolds. At 8 weeks after in vivo implantaion, the addition of Zn powder promoted new bone formation, in a dose-dependent manner. The scaffolds with 2 wt% Zn displayed the best osteogenic effect, while the osteogenic effect was slightly reduced in the scaffolds with 3 wt% Zn. In the studied Zn contents, the PCL/Zn scaffolds gradually promoted osteoclastogenesis with increasd Zn content. In the 3 wt% Zn group, TRAP-positive cells were observed on the newly formed bone edges around the scaffolds. These dose-dependent effects were verified in vitro using MC3T3-E1 and RAW264.7 cells. Finally, we revealed that Zn²⁺ regulated osteogenesis and osteoclastogenesis by activation of the Wnt/β-catenin and NF-κB signalling pathways, respectively.

Keywords: 3D-printed scaffolds; Osteoclastogenesis; Osteogenesis; Polycaprolactone; Zinc.