59 / 2018-07-27 19:16:07

Evaluation of the PLGA/TCP/Mg Porous Scaffold Fabricated by 3D printing for In vivo Bone Regeneration

PLGA/TCP/Mg,Porous Scaffold,3D printing,Bone Regeneration

全体主题 > v. Design of therapeutic products, cellular products, and macromolecular products

Introduction: Bone regeneration is a significant event in bone tissue engineering. The beta-tricalcium phosphate (TCP) and poly(L-lactide-co-glycolide) (PLGA) are well known for their exllent biodegradability, bioabsorbability and osteogenic properties. They can be combined to fabricate a porous scaffold, and used as a bone substitute for bone defect repair. In order to promote bone regeneration, we designed and fabricated an innovative bioactive porous scaffold composed of PLGA, TCP and magnesium (Mg) with well-defined biomimic microstructure through the low-temperature 3D printing technology. The effect of Mg in angiogensis and osteogenesis was observed in this study.
Materials & Methods: Firstly, Porous scaffolds were fabricated at -30℃ using an advanced low-temperature rapid-prototyping machine. Then, a steroid–associated osteonecrosis rabbit model with 3 mm bone defect tunnel in both distal femora was developed. The samples were randomly divided into three groups: control group without any implantation, PLGA/TCP group and PLGA/TCP/Mg group implanted into the bone tunnel. Finally, DCE-MRI was used to observe the blood perfusion function at the defect sites at 0,2,4,8 weeks post surgery. X-ray were used to analysis the in vivo osteogenetic effect of the PLGA/TCP/Mg. Micro-CT based angiography was used to evaluate the vascular architecture by injecting Microfil into the abdominal aorta. Bone tissue volume density (BV/TV, %), connectivity density (Conn.D, 1/mm3), trabecular number (Tb.N, 1/mm), in bone tunnel were measured by Micro-CT.
Results & Discussion: Acording to the DCE-MRI results, we found that at week 2 and 4, PLGA/TCP/Mg group performed good blood perfusion and showed significantly higher “maximum enhancement” than the PLGA/TCP group and control group(p<0.05, n=3). Micro-CT data showed that at week 12, the BV/TV, Conn.D and Tb.N of PLGA/TCP/Mg group increased significantly than those in control group (p<0.05, n=8).
Conclusions: The in vivo study shows that the PLGA/TCP/Mg scaffolds have good osteogenetic and angiogenic effect and the scaffold is a promising biomaterial for bone regeneration.