Bone Morphogenetic Protein-2-Activated 3D-Printed Polylactic Acid Scaffolds to Promote Bone Regrowth and Repair

Uneven distribution of pores, lack of connection between holes, low reproducibility, insufficient mechanical strength, and incomplete volatility of organic solvents are some problems associated with traditional tissue engineering methods for bone defect repair. These characteristics reduce the quality and stability of products. This study uses 3D printing (3DP) to fabricate a biocompatible poly(lactic) acid-based scaffold for repairing bone tissue. Hence, three different types of scaffolds are assessed: a freeze-dried polylactic acid (PLA) scaffold constructed using the traditional freeze-extraction method; a 3D-PLA scaffold produced through the 3DP technique; and a 3D-PLA-bone morphogenetic protein-2 (BMP-2) scaffold that is prepared using 3DP technology, with the addition of BMP-2. To enhance biological activity, polydopamine (pDA) is used to graft BMP-2 on the surface of the 3D-PLA-BMP-2 scaffold. Then, the scaffolds are implanted into the bilateral femoral condyles of rabbits, and their ability to repair the bone tissue defects is tested. The results of the experiments reveal that the 3DP scaffolds are more biocompatible than the ones produced through the traditional manufacturing methods because they enhance cell adhesion and differentiation after pDA modification and BMP-2 fixation. In the future, the 3DP products may be applied for the repair of larger bone defects in the clinical setting.