Page 292 - IJB-9-1

International Journal of Bioprinting 3D-Printed scaffolds

Through the porosity test, we found that the porosity of scaffolds displayed good biocompatibility, high cell
3D-printed PCL/25%TCP, PTMC/25%TCP, and PTMC/ proliferation performances, high metabolic activity, and
PCL/25%TCP scaffolds was 66.43 ± 2.56%, 58.9 ± 2.81%, gene expression of actin, ALP, COL, RUNX2, and OCN.
and 48.0 ± 1.84%, respectively.
3.8. In vivo bone regeneration
MC3T3-E1 cells were evenly distributed in 3D-printed
PCL/25%TCP, PTMC/25%TCP, and PTMC/PCL/25%TCP All scaffolds were embedded in thigh bone defects for
scaffolds, which provided microenvironment for cell 12 weeks. New bone tissue data, including bone tissues
adhesion and regeneration. MC3T3-E1 cells scattered volume/total tissue volume (BV/TV, %), trabecular space
−1
uniformly, adhered, grew and proliferated in scaffolds, (Tb.Sp, mm), number of trabecula (Tb.N, mm ), and
and afterward, the cells synthesized and secreted matrix trabecular thickness (Tb.Th, mm) were evaluated. As
proteins. MC3T3-E1 cells appeared to have good shown in Figure 11A, plenty of new bone tissues were
attachment states and proliferated in PCL/25%TCP, found in thigh defects of the rats and gradually penetrated
PTMC/25%TCP, and PTMC/PCL/25%TCP scaffolds. into either PCL/25%TCP, PTMC/25%TCP, or PTMC/
TCP also promoted the expression of osteoblast-related PCL/25%TCP scaffolds after 6 and 12 weeks. Moreover,
genes, alkaline phosphatase gene, and bone adhesion bone tissues continued growing to form a network,
gene, leading to the differentiation of osteoblasts as well as which repaired bone defects in pace with biodegradation
the mineralization and formation of bone. Moreover, the of scaffolds. Figure 11B indicates the new formed bone
degraded Ca and P from TCP in the body can enter the parameters after 6 weeks and 12 weeks of surgery.
living circulatory system, which can promote the formation More formation of new bones appeared in thigh defects
of new bone. PTMC/PCL/25%TCP scaffolds displayed of the rats implanted with PTMC/PCL/25%TCP and
better biocompatibility and stimulated a greater extent of PCL/25%TCP scaffolds than in those with PTMC/25%TCP
cell regeneration than PTMC/25%TCP and PCL25%TCP scaffolds after 6 weeks and 12 weeks. The formation of
scaffolds. new bone in PCL/25%TCP and PTMC/PCL/25%TCP

3.7. Osteogenic gene expression scaffolds was higher than that in PTMC/25%TCP scaffold.
Therefore, PCL/25%TCP and PTMC/PCL/25%TCP
Metabolic activity of rBMSCs was studied after 1 and scaffolds can display high osteogenic activity, suggesting
2 days of post-culturing in 3D-printed PCL/25%TCP, its role in bone repair.
PTMC/25%TCP, and PTMC/PCL/25%TCP scaffolds.
mRNA expression results are presented in Figure 10. 4. Conclusion
Cell proliferation on all scaffolds at 1 day was higher
than that at 2 days. Moreover, PTMC/PCL/25%TCP and 3D-printed PCL/TCP, PTMC/TCP, and PTMC/PCL/TCP
PTMC/25%TCP scaffolds demonstrated higher levels of scaffolds provide good porous growth microenvironments
cellular metabolic activity than PCL/25%TCP scaffolds and mechanic supports for MC3T3-E1 cells and rBMSCs,
at 1 day and 2 days. Meanwhile, PTMC/PCL/25%TCP and also enhance the proliferation of osteoblast cells.
scaffolds showed slightly higher metabolic activity than Moreover, PTMC/PCL/TCP and PCL/TCP scaffolds
PTMC/25%TCP at 2 days. display good biodegradability, good biocompatibility, and
high osteogenic activity, which can be used to repair bone
The PCL/25%TCP, PTMC/25%TCP, and PTMC/ defects in vivo.
PCL/25%TCP scaffolds promoted rBMSCs growth
and improved the gene expression of actin, ALP, COL, Acknowledgments
RUNX2, and OCN. Moreover, rBMSCs scattered
uniformly and induced adhesion and regeneration in Not applicable.
the scaffolds (Figure 10). PTMC/PCL/25%TCP and Funding
PTMC/25%TCP scaffolds evidently enhanced gene
expression of actin, ALP, COL, RUNX2, and OCN. This work was supported by the Key National
However, PCL/25%TCP scaffolds appeared to have Research and Development Program (Grant
almost no gene expression at 7 days post-culturing. No. 2018YFB1105502, 2016YFB1101302), Frontier
Meanwhile, PTMC/25%TCP scaffolds showed higher Project of Application Foundation of Wuhan Former
gene expression than PTMC/PCL/25%TCP scaffolds at Funded Science and Technology Program (Grant
7 days post-culturing. Moreover, PTMC/PCL/25%TCP No. 2020020601012252), Innovative Talents Project
scaffolds demonstrated higher level of gene expression at of Yellow Crane Talents Plan of Wuhan City (Grant
14 days post-culturing than that at 7 days post-culturing. [2017] No.1), Scientific research projects for high level
Therefore, PTMC/PCL/25%TCP and PTMC/25%TCP talents in the new century of Hubei Province (Grant

Volume 9 Issue 1 (2023) 284 https://doi.org/10.18063/ijb.v9i1.641