Page 81 - IJB-9-2

International Journal of Bioprinting Clinical applications of bioprinted active bone

A B C

D E F

Figure 4. Post-operative X-ray and CT examination of the lower left extremity. (A–C) Two days after the operation. (D–F) Seven-month follow-up.
However, there are still many challenges and β-TCP has a moderate absorption rate in the body and is
shortcomings in the application of bioprinting technology effective at stimulating osteogenesis, making it a good bone
in clinical practice. In the bioprinting process, the defect repair material . Therefore, a composite material
[17]
selection of bioinks with suitable properties, such as the formed by melting and mixing PCL and β-TCP in a certain
biocompatibility of materials, osteoinductive properties, proportion has a suitable degradation rate, facilitates
and mechanical properties, is the first problem that osteogenesis, and promotes bone fusion. However, due
needs to be addressed . Second, from the perspective to the lack of biological activity of a single PCL/β-TCP
[11]
of printing technology, the material must be cured at composite scaffold, it has a limited effect on promoting the
room temperature without affecting the activity of cells or repair of bone defects. Therefore, it is necessary to add a
growth factors . In addition, vascularization is a major safe and effective active factor to induce endothelial and
[12]
challenge for tissue engineering at present. Vascularization mesenchymal stem cells so that they grow into the scaffold,
is a complex physiological process that requires the proliferate, and differentiate, thereby accelerating the
participation of cells, scaffolds, and growth factors [13-15] . process of angiogenesis and the osteogenic repair of the
Therefore, bioinks that can support vascularization are in bone defect site.
urgent need of development. Osteogenesis-inducing factors such as bone
To quickly heal the bone defect formed after the morphogenetic protein (BMP) and angiogenesis-
patient’s limb tumor was removed, we designed and promoting growth factors such as vascular endothelial
printed a PCL/β-TCP/PRP active bone scaffold based on growth factor (VEGF) are expensive, unstable in their
the CT scan data of the affected limb. PCL is one of the physical and chemical properties and have potential to
most widely used biomaterials in bone tissue scaffolds. trigger heterotopic ossification complications, such as
It has good biocompatibility and is non-toxic, non- tumor formation, limiting their application in the field
immunogenic, and able to be degraded for absorption, of bone tissue engineering. It is extremely important to
making it a good implant material. However, studies have find an alternative, safe, and effective factor to regulate
found that PCL degrades slowly and has no osteogenic the growth, proliferation, and differentiation of cells that
activity as a replacement material for bone tissue filling . grow into 3D-bioprinted active bone. Therefore, to make
[16]
Compared with calcium sulfate and hydroxyapatite, the printed bone scaffold bioactive, we added the patient’s

Volume 9 Issue 2 (2023) 73 https://doi.org/10.18063/ijb.v9i2.654