title: Eggshells as natural calcium carbonate source in combination with hyaluronan as beneficial additives for bone graft materials, an in vitro study.
abstract: BACKGROUND
  In bone metabolism and the formation especially in bone substitution, calcium as basic module is of high importance. Different studies have shown that the use of eggshells as a bone substitute material is a promising and inexpensive alternative. In this in vitro study, the effects of eggshell granulate and calcium carbonate towards primary bovine osteoblasts were investigated. Hyaluronan (HA) was used as artificial extracellular matrix (ECM) for the used cells to facilitate proliferation and differentiation and to mimic the physiological requirements given by the egg in vivo.
  
  
  METHODS
  Hyaluronan, eggshells, a combination of hyaluronan and eggshells and CaCO3 were applied to the cells as additive to the used standard medium (modified High Growth Enhancement Medium) in a concentration of 0,1 g/l. The effect of the additives in the culture medium was examined by proliferation tests, immunohistochemical staining (anti-collagen type I, anti-osteopontin, anti-osteonectin and anti-osteocalcin) and kinetic oxygen measurements.
  
  
  RESULTS
  Our investigations revealed that all investigated additives show beneficial effect on osteoblast activity. Cell proliferation, differentiation and the metabolic activity of the differentiated cells could be influenced positively. Especially in the case cell cultures treated with eggshells the strongest effects were detected, while for the hyaluronan compared with eggshells, a weaker increase in cell activity was observed.
  
  
  CONCLUSIONS
  In summary, it can be stated that the investigated components come into consideration as beneficial supplements for bone graft materials especially for maxillo facial surgery application.
authors.affiliation: Technische Universität Dresden, Institute of Material Science, Chair for Biomaterials, Budapester Strasse 27, D-01069, Dresden, Germany. joerg.neunzehn@tu-dresden.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Neunzehn
authors.affiliation: Department of Cranio-Maxillofacial Surgery, University Hospital of Muenster, Research Group Vascular Biology of Oral Structures (VABOS), Waldeyerstr 30, Muenster, 48149, Germany. szuwart@uni-muenster.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Szuwart
authors.affiliation: Technische Universität Dresden, Institute of Material Science, Chair for Biomaterials, Budapester Strasse 27, D-01069, Dresden, Germany. hans-peter.wiesmann@tu-dresden.de.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Wiesmann
mesh_terms: D000818:Animals; D016025:Bone Transplantation; D002119:Calcium Carbonate / Q000494:pharmacology*; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D004531:Eggs; D006820:Hyaluronic Acid / Q000494:pharmacology*; D066298:In Vitro Techniques; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects; D012680:Sensitivity and Specificity
chemical_list: D017077:Culture Media, Conditioned; D006820:Hyaluronic Acid; D002119:Calcium Carbonate