Novel osteoconductive β-tricalcium phosphate/poly(L-lactide-co-e-caprolactone) scaffold for bone regeneration: a study in a rabbit calvarial defect
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The advantages of synthetic bone graft substitutes over autogenous bone grafts include abundant graft volume, lack of complications related to the graft harvesting, and shorter operation and recovery times for the patient. We studied a new synthetic supercritical CO2 –processed porous composite scaffold of β-tricalcium phosphate and poly(L-lactide-co-caprolactone) copolymer as a bone graft substitute in a rabbit calvarial defect. Bilateral 12 mm diameter critical size calvarial defects were successfully created in 18 rabbits. The right defect was filled with a scaffold moistened with bone marrow aspirate, and the other was an empty control. The material was assessed for applicability during surgery. The follow-up times were 4, 12, and 24 weeks. Radiographic and micro-CT studies and histopathological analysis were used to evaluate new bone formation, tissue ingrowth, and biocompatibility. The scaffold was easy to shape and handle during the surgery, and the bone-scaffold contact was tight when visually evaluated after the implantation. The material showed good biocompatibility and its porosity enabled rapid invasion of vasculature and full thickness mesenchymal tissue ingrowth already at four weeks. By 24 weeks, full thickness bone ingrowth within the scaffold and along the dura was generally seen. In contrast, the empty defect had only a thin layer of new bone at 24 weeks. The radiodensity of the material was similar to the density of the intact bone. In conclusion, the new porous scaffold material, composed of microgranular β-TCP bound into the polymer matrix, proved to be a promising osteoconductive bone graft substitute with excellent handling properties.
This study was financially supported by the Finnish Funding Agency for Technology and Innovation (40326/13) and by grants from the Finnish Foundation of Veterinary Research and The Finnish Veterinary Foundation. The authors kindly acknowledge DVM Mikael Morelius for the help with surgical procedures.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 14.Zijderveld S, Zerbo I, van den Bergh J, Schulten E, ten Bruggenkate C. Maxillary sinus floor augmentation using a β-tricalcium phosphate (Cerasorb) alone compared to autogenous bone grafts. Int J Oral Maxillofac Implants. 2005;20:432–40.Google Scholar
- 20.Nandi SK, Roy S, Mukherjee P, Kundu B, De DK, Basu D. Orthopaedic applications of bone graft & graft substitutes: a review. Indian J Med Res. 2010;132:15–30.Google Scholar
- 25.Hernandes C. J. Cancellous bone. In: Murphy W, Black J, Hastings G, editors. Handbook of biomaterial properties. New York: Springer-Verlag; 2016. pp 15–21.Google Scholar
- 29.Lappalainen O, Karhula SS, Haapea M, Kauppinen S, Finnilä M, Saarakkala S, et al. Micro-CT analysis of bone healing in rabbit calvarial critical-sized defects with solid bioactive glass, tricalcium phosphate granules or autogenous bone. J Oral Macillofac Res. 2016;7:e4.Google Scholar
- 31.Ghanaati S, Barbeck M, Willershausen I, Thimm B, Stuebinger S, Korzinskas T, et al. Nanocrystalline hydroxyapatite bone substitute leads to sufficient bone tissue formation already after 3 months: histological and histomorphometrical analysis 3 and 6 months following human sinus cavity augmentation. Clin Implant Dent Relat Res. 2013;15:883–92.CrossRefGoogle Scholar
- 39.Schmitz JP, Hollinger JO. The critical size defect as an experimental model for craniomandibulofacial nonunions. Clin Orthop Relat Res. 1986;205:299–308.Google Scholar
- 44.Pelegrine AA, Aloise AC, Zimmermann A, Mello e Oliveira R, Ferreira LM. Repair of critical‐size bone defects using bone marrow stromal cells: a histomorphometric study in rabbit calvaria. Part I: Use of fresh bone marrow or bone marrow mononuclear fraction. Clin Oral Implants Res. 2014;25:567–72.CrossRefGoogle Scholar