Crystallographically engineered, hydrothermally crystallized hydroxyapatite films: an in vitro study of bioactivity.
The aim of this study was to evaluate the bioactivity of hydroxyapatite films composed of hexagonal single crystals that display {1010} and {0001} crystallographic faces. The effect of engineered [0001] crystallographic orientation was investigated in parallel. Films were deposited by triethyl phosphate/ethylenediamine-tetraacetic acid doubly regulated hydrothermal crystallization on Ti6Al4V substrates (10, 14, 24 h). Bioactivity was investigated by analysis of MC3T3-E1 pre-osteoblast spreading using scanning electron microscopy and quantitative analysis of cell metabolic activity (Alamar Blue) (0-28 days). Scanning electron microscopy and X-ray diffraction were used to evaluate the ability of films to support the differentiation of MC3T3-E1 pre-osteoblasts into matrix-secreting, mineralizing osteoblasts. Results demonstrated that all films enabled MC3T3-E1 cells to spread, grow, and differentiate into matrix-secreting osteoblasts, which deposited biomineral that could not be removed after extraction of organic material. Differences in [0001] HA crystallographic orientation were not, however, found to significantly affect bioactivity. Based on these results, it is concluded that these hydrothermal hydroxyapatite films are non-toxic, bioactive, osteoconductive, and biomineral bonding. The lack of a relationship between reported hydroxyapatite crystallographic face specific protein adsorption and bulk HA bioactivity are discussed in terms of crystallographic texture, surface roughness, assay robustness, and competitive protein adsorption.
Department of Material Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
Daniel J
DJ
Haders
Christian C
CC
Kazanecki
David T
DT
Denhardt
Richard E
RE
Riman
D000497:Alloys; D000818:Animals; D002128:Calcium Metabolism Disorders / Q000378:metabolism; D002999:Clone Cells; D003460:Crystallization / Q000379:methods; D003461:Crystallography; D017886:Durapatite / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010078:Oxazines; D014025:Titanium; D014961:X-Ray Diffraction; D014965:X-Rays; D014966:Xanthenes
D000497:Alloys; D010078:Oxazines; D014966:Xanthenes; C031462:titanium alloy (TiAl6V4); C005843:resazurin; D017886:Durapatite; D014025:Titanium