Bone repair by cell-seeded 3D-bioplotted composite scaffolds made of collagen treated tricalciumphosphate or tricalciumphosphate-chitosan-collagen hydrogel or PLGA in ovine critical-sized calvarial defects

The aim of this study was to investigate the osteogenic effect of three different cell-seeded 3D-bioplotted scaffolds in a ovine calvarial critical-size defect model The choice of scaffold-materials was based on their applicability for 3D-bioplating and respective possibility to produce tailor-made scaffolds for the use in cranio-facial surgery for the replacement of complex shaped boneparts Scaffold raw-materials are known to be osteoinductive when being cell-seeded [poly(L-lactide-co-glycolide) (PLGA)] or having components with osteoinductive properties as tricalciumphosphate (TCP) or collagen (Col) or chitosan The scaffold-materials PLGA, TCP/Col, and HYDR (TCP/Col/chitosan) were cell-seeded with osteoblast-like cells whether gained from bone (OLB) or from periost (OLP) In a prospective and randomized design nine sheep underwent osteotomy to create four critical-sized calvarial defects Three animals each were assigned to the HYDR-, the TCP/Col-, or the PLGA-group In each animal, one defect was treated with a cell-free, an OLB- or OLP-. seeded group-specific scaffold, respectively The fourth defect remained untreated as control (UD) Fourteen weeks later, animals were euthanized for histo-morphometrical analysis of the defect healing OLB- and OLP-seeded HYDR and OLB-seeded TCP/Col scaffolds significantly increased the amount of newly formed bone (NFB) at the defect bottom and OLP-seeded HYDR also within the scaffold area, whereas PLGA-scaffolds showed lower rates The relative density of NFB was markedly higher in the HYDR/OLB group compared to the corresponding PLGA group TCP/Col had good stiffness to prepare complex structures by bioplotting but HYDR and PLGA were very soft HYDR showed appropriate biodegradation, TCP/Col and PLGA seemed to be nearly undegraded after 14 weeks 3D-bioplotted, cell-seeded HYDR and TCP/Col scaffolds increased the amount of NFB within ovine critical-size calvarial defects, but stiffness, respectively, biodegradation of materials is not appropriate for the application in cranio-facial surgery and have to be improved further by modifications of the manufacturing process or their material composition (C) 2010 Wiley Periodicals, Inc J Biomed Mater Res Part B Appl Biomater 93B 520-530, 2010