Impact of Citric Acid Etching on Biocompatibility and Osseous Organisation of a Natural Bovine Bone Mineral: Preliminary Results of an InVitro/In-Vivo Study

摘要

Within the last years it was shown that etching of biomaterials can improve hydrophilicity and cell proliferation which in turn may accelerate the osseointegration of implants. The aim of the present study was to evaluate the influence of superficial etching of a xenogenous bone mineral on cell proliferation and bone regeneration. A granular bone substitute material [BSMj (Cerabone® [CB], botiss medical, Berlin, Germany) was superficially etched using citric acid (Cerabone Acid [CBA]). CB and CBA were allocated into 96 non-binding well plates (Costar No. 3474, Corning Incorp., Schipol-Rijk, Netherlands) and incubated with ixlO4 human osteoblast-like cells (SaOs-2) per well under standardized conditions. After 2 hours, 3 and 7 days a LDH-Assay (CytoTox 96®, Promega, Mannheim, Germany) was used for photometric evaluation of cell proliferation (n=8). LDH values were transferred into cell amounts using a standard curve and analyzed for statistical difference. Additionally, cell morphology was investigated using scanning electron microscopy (SEM) (n=3). In the in-vivo part, CB and CBA granules were used for lateral augmentation of the maxillae of four beagle dogs and covered with a collagen membrane (Jason® Membrane, botiss medical). Healing periods were set at 3 and 8 weeks (n=2, respectively). In-vitro evaluation revealed statistically significant higher cell proliferation after 3 and 7 days on CBA compared to CB (p<0.05, Wilcoxon test). SEM observation presented flat and star-shaped SaOs-2-osteoblasts displaying high numbers of lamellopodia on both CB and CBA surfaces. In vivo, both BSM showed osteoconductive properties and osseous organisation after 8 weeks. However, the number of the in-vivo applications did not allow further statistical analysis. Within the limits of the present study it was concluded that superficial etching of natural bone minerals using citric acid may support osteoblast-like cell proliferation. Further studies are necessary to specify the impact on bone regeneration.