Evaluation of a poly(lactic-acid) scaffold filled with poly(lactide-co-glycolide)/hydroxyapatite nanofibres for reconstruction of a segmental bone defect in a canine model

Abstract

Critical-sized bone defects are a difficult problem in both human and veterinary medicine. To address this issue, synthetic graft materials have been garnering attention. Abundant in vitro studies have proven the possibilities of poly(lactic-acid) (PLA) scaffolds and poly(lactide-co-glycolide)/hydroxyapatite (PLGA/HAp) nanofibres for treating bone defects. The present study aimed at conducting an in vivo assessment of the biological performance of a three dimensional (3D)-printed PLA scaffold filled with a PLGA/HAp nanofibrous scaffold to estimate its potential applications in bone defect reconstruction surgery. Defects were created in a 20 mm-long region of the radius bone. The defects created on the right side in six Beagle dogs (n = 6) were left untreated (Group 1). The defects on the left side (n = 6) were filled with 3D-printed PLA scaffolds incorporated with PLGA/Hap nanofibres with gelatine (Group 2). The other six Beagle dog defects were made bilaterally (n = 12) and filled with the same material as that used in Group 2 along with recombinant bone morphogenetic protein 2 (rhBMP-2) (Group 3). Both the radiological and histological examinations were performed for observing the reaction of the scaffold and the bone. Micro-computed tomography (CT) was utilised for the evaluation of the bone parameters 20 weeks after the experiment. The radiological and histological results revealed that the scaffold was biodegradable and was replaced by new bone tissue. The micro-CT revealed that the bone parameters were significantly (P < 0.05) increased in Group 3. Based on these results, our study serves as a foundation for future studies on bone defect treatment using synthetic polymeric scaffolds.

Active Materials for 3D Printing in Small Animals: Current Modalities and Future Directions for Orthopedic Applications

“…After creating a 20 mm-long defect in the radius bone, the 3D scaffold was replaced and subsequently fixed with an LC-DCP plate. The results indicated the biodegradability of the scaffold and its replacement by new bone tissue [69]. Three-dimensional-printed PCL/β-TCP scaffold was used in a bone defect resulting of limb-sparing surgery in a dog with distal radial OSA.…”

“…Three-dimensional-printed implants can also be designed with scaffold structure which can enhance osteointegration. In veterinary clinical models, scaffold structures have been used as lower extremity implants as well as in limb-sparing surgeries, tibial tuberosity advancement (TTA), and the reconstruction of critical-sized bone defects [4,8,10,14,69]. Critical-sized bone defects are difficult to treat; in cases where allograft bone is unavailable for the required dimension of the defect, 3D-printed scaffolds may be considered.…”

“…Various in vitro studies have shown the potential application of 3D-printed scaffolds in BTE [6,22,27,33]. CaP ceramics and bioactive glasses are introduced as promising osteoinductive and osteoconductive substitutes for large orthopedic defect remolding or regeneration [4,6,69,70]. The custom-made scaffolds can be manufactured using FDM and electrospinning 3D-printing technology [69].…”

“…CaP ceramics and bioactive glasses are introduced as promising osteoinductive and osteoconductive substitutes for large orthopedic defect remolding or regeneration [4,6,69,70]. The custom-made scaffolds can be manufactured using FDM and electrospinning 3D-printing technology [69]. The potential application of a 3D-printed PLA scaffold filled with PLGA/HA nanofibers was assessed in an in vivo study on the reconstruction of bony defects in the radius of six beagle dogs.…”

Effect of Keratin-Based Biocomposite Hydrogels as a RhBMP-2 Carrier in Calvarial Bone Defects Mouse Model

“…Of these, BMP-2 is the most powerful osteoplastic facilitator and is characterized by play-ing an important role in many stages of the osteoplastic process. However, results are reported that excessive concentration of BMP promotes cell death and hinders bone formation (3,4,27).…”