J. Xu (Rotterdam, NL)
Erasmus Medical Center Department of Orthopedics and Sports MedicinePresenter Of 1 Presentation
P052 - Acceleration of Osteochondral Repair with a Growth Factor Loaded Collagen/Magnesium-hydroxyapatite Scaffold
Abstract
Purpose
A scaffold with a top layer of collagen layer and a bottom layer of collagen/Magnesium-hydroxyapatite (Mg-HA) layer has demonstrated good clinical results in osteochondral defects. Subchondral bone repair, however, remained suboptimal. In this study, we investigated the effect of the Mg-HA and addition of Bone Morphogenetic Protein 2 (BMP-2) or Platelet-Derived Growth Factor-BB (PDGF-BB) on the capacity of the scaffold to repair bone in an osteochondral defect.
Methods and Materials
Osteochondral defects were created in bovine osteochondral biopsies and implanted subcutaneously in athymic mice. To investigate the effect of the Mg-HA, osteochondral defects were filled with scaffolds consisting either of collagen-only or collagen/Mg-HA. To investigate the effect of growth factors 4μg BMP-2 or 100ng or 2μg PDGF-BB was loaded into the layered scaffold. The percentage of the defect filled with repair tissue was quantified on histology. Immunohistochemistry was performed to investigate inflammation. In vitro release of growth factors from the separate layers was measured with ELISA.
Results
Slightly more repair tissue, neutrophils and macrophages were observed after 4 weeks in defects filled with collagen/Mg-HA compared to collagen-only (Fig.1), indicating a positive effect of Mg-HA on tissue repair. The majority of PDGF-BB was burst released from both scaffold layers, whereas BMP-2 was bound and largely retained for 2 weeks in-vitro (Fig.2A,B). Moreover, the collagen-only layer released more BMP-2 than the layer with Mg-HA. In-vivo both growth factors might increase tissue repair after 4 weeks (Fig.2C,D), albeit statistical significance was not reached and after 8 weeks, bone was completely healed in this model, with and without growth factors.
Conclusion
Inclusion of Mg-HA in the collagen scaffold might accelerate tissue repair by a stronger initial inflammatory response. Loading BMP-2 or PDGF-BB into the scaffold might be promising to further accelerate bone repair and is further investigated in a goat model.
Presenter Of 1 Presentation
P052 - Acceleration of Osteochondral Repair with a Growth Factor Loaded Collagen/Magnesium-hydroxyapatite Scaffold
Abstract
Purpose
A scaffold with a top layer of collagen layer and a bottom layer of collagen/Magnesium-hydroxyapatite (Mg-HA) layer has demonstrated good clinical results in osteochondral defects. Subchondral bone repair, however, remained suboptimal. In this study, we investigated the effect of the Mg-HA and addition of Bone Morphogenetic Protein 2 (BMP-2) or Platelet-Derived Growth Factor-BB (PDGF-BB) on the capacity of the scaffold to repair bone in an osteochondral defect.
Methods and Materials
Osteochondral defects were created in bovine osteochondral biopsies and implanted subcutaneously in athymic mice. To investigate the effect of the Mg-HA, osteochondral defects were filled with scaffolds consisting either of collagen-only or collagen/Mg-HA. To investigate the effect of growth factors 4μg BMP-2 or 100ng or 2μg PDGF-BB was loaded into the layered scaffold. The percentage of the defect filled with repair tissue was quantified on histology. Immunohistochemistry was performed to investigate inflammation. In vitro release of growth factors from the separate layers was measured with ELISA.
Results
Slightly more repair tissue, neutrophils and macrophages were observed after 4 weeks in defects filled with collagen/Mg-HA compared to collagen-only (Fig.1), indicating a positive effect of Mg-HA on tissue repair. The majority of PDGF-BB was burst released from both scaffold layers, whereas BMP-2 was bound and largely retained for 2 weeks in-vitro (Fig.2A,B). Moreover, the collagen-only layer released more BMP-2 than the layer with Mg-HA. In-vivo both growth factors might increase tissue repair after 4 weeks (Fig.2C,D), albeit statistical significance was not reached and after 8 weeks, bone was completely healed in this model, with and without growth factors.
Conclusion
Inclusion of Mg-HA in the collagen scaffold might accelerate tissue repair by a stronger initial inflammatory response. Loading BMP-2 or PDGF-BB into the scaffold might be promising to further accelerate bone repair and is further investigated in a goat model.