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.
Haders
Daniel J
DJ
Department of Material Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
Kazanecki
Christian C
CC
Denhardt
David T
DT
Riman
Richard E
RE
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