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.

ABSTRACT:In this study, we fabricated Poly(lactide-co-glycolide)/hydroxyapatite (PLGA/HAp) nanofibres using electrospinning and evaluated their potential use for bone repair applications. Analysis confirmed that the PLGA nanofibres were similar to the natural extracellular matrix and included HAp particles. Further, gelatin augmented the adhesion of electrospun nanofibres in the cell adhesion test. Therefore, electrospun PLGA/HAp nanofibres together with gelatin can be utilised for bone repair applications.

ABSTRACT:The treatment of segmental bone defects is a challenging problem for both human and veterinary medicine. Various biomaterials have successfully been used to treat these defects. Numerous recent in vitro studies have shown the potential of treating bone tissues using poly(lactide-co-glycolide)/hydroxyapatite (PLGA/HAp) nanofibres, which are fabricated using electrospinning. The purpose of this study was to evaluate the possibility of using a bone scaffold of PLGA/HAp nanofibres to repair critical-sized segmental bone defects in a canine model. The experimental bone defects were created in a 15 mm-long region of the radius. The area of the defect in each of 10 Beagle dogs was treated with a transplant of PLGA/HAp nanofibres in gelatin. The control group consisted of five Beagle dogs with similar defect sites that were not treated. Radiological and histological examinations were used to monitor the response of PLGA/HAp nanofibre-treated canine bone. Micro-computed tomography (micro-CT) was used to evaluate bone mass parameters 18 weeks after treatment in the experimental bone defect group. Our radiological and histological results showed that the PLGA/HAp nanofibre is biodegradable in the defect sites and replaces new bone tissue. Micro-CT showed that bone mass parameters were significantly (P < 0.05) increased in the critical-sized segmental bone defects of PLGA/HAp nanofibre-treated animals as compared to those of untreated animals. Based on these results, we conclude that PLGA/HAp nanofibres may be used as a bone scaffold biomaterial in canines.