title: Protein adsorption and osteoblast precursor cell attachment to hydroxyapatite of different crystallinities.
abstract: OBJECTIVE
  The effect of hydroxyapatite (HA) crystallinity on protein adsorption and osteoblast precursor cell attachment to HA was investigated.
  
  
  METHODS
  Different weight ratios of 100% crystalline HA and 100% amorphous calcium phosphate powders were mixed and pressed into disks (0.5 g) of different crystallinities--either 0% (HAO), 30% (HA30), 50% (HA50), 70% (HA70), or 100% (HA100).
  
  
  RESULTS
  X-ray diffraction indicated differences in HA crystallinities. In addition, dissolution of the HA was dependent on its crystallinity, with an increase in phosphorus dissolution as the degree of crystallinity was decreased. No significant difference in albumin adsorption and initial osteoblast precursor cell attachment was observed in the range of HA0 to HA70 surfaces. However, a significantly lower albumin adsorption and initial osteoblast precursor cell attachment were observed on HA100.
  
  
  CONCLUSIONS
  It was suggested that changes in ionic interactions as a result of a change in crystallinity affect the amount of calcium ion ligands readily available to electrostatically bind to proteins.
  
  
  CONCLUSIONS
  It was thus concluded from this study that HA crystallinity affects the amount of albumin adsorbed and initial osteoblast attachment.
authors.affiliation: Departments of Biomedical Engineering and Orthopedic Surgery, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA. yyang19@utmem.edu
authors.forename: Yunzhi
authors.initials: Y
authors.lastname: Yang
authors.forename: David
authors.initials: D
authors.lastname: Dennison
authors.forename: Joo L
authors.initials: JL
authors.lastname: Ong
mesh_terms: D000327:Adsorption; D002118:Calcium / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D002448:Cell Adhesion; D002478:Cells, Cultured; D003460:Crystallization; D017886:Durapatite / Q000737:chemistry*; D004563:Electrochemistry; D006801:Humans; D008024:Ligands; D059630:Mesenchymal Stem Cells / Q000502:physiology; D010006:Osteoblasts / Q000502:physiology*; D010758:Phosphorus / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D002130:Calcium Phosphates; D008024:Ligands; C519480:amorphous calcium phosphate; D012710:Serum Albumin, Bovine; D010758:Phosphorus; D017886:Durapatite; D002118:Calcium