Proteins incorporated into biomimetically prepared calcium phosphate coatings modulate their mechanical strength and dissolution rate.
In a previous investigation, we demonstrated that when bovine serum albumin (BSA) is biomimetically co-precipitated with Ca(2+) and PO(4)(3-) ions upon titanium-alloy implants, it becomes incorporated into the crystal lattice and is not merely deposited on its surface. Moreover, the protein elicited a change in crystal structure from an octacalcium phosphate type to a carbonated apatite one, which bears a closer resemblance to natural bone mineral. In the present study, we investigated the dissolution rate and mechanical strength of such BSA-containing coatings as a function of protein concentration within the bathing medium (10 ng/ml to 1.0 mg/ml). BSA-containing coatings released Ca(2+) ions more slowly (5 ppm/min) than did non-BSA-containing ones (10 ppm/min), but this rate did not change as a function of protein concentration within the bathing medium. In contrast, the strength of coatings increased almost linearly as a function of protein concentration within the bathing medium, indicating that BSA incorporated into the crystal lattice enhances its mechanical strength in a concentration-dependent manner.
Liu
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Biomaterials Research Group, Leiden University, Prof Bronkhorstlaan 10-D, 3723 MB Bilthoven, Netherlands. maria.liu@isotis.com
Hunziker
E B
EB
Randall
N X
NX
de Groot
K
K
Layrolle
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P
D000497:Alloys; D000818:Animals; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D002130:Calcium Phosphates / Q000493:pharmacokinetics; D002417:Cattle; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D018716:Molecular Mimicry; D019736:Prostheses and Implants; D012710:Serum Albumin, Bovine / Q000493:pharmacokinetics; D012995:Solubility; D013499:Surface Properties; D014025:Titanium
D000497:Alloys; D001672:Biocompatible Materials; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C031462:titanium alloy (TiAl6V4); D012710:Serum Albumin, Bovine; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; D014025:Titanium; C485829:calcium phosphate, dibasic, anhydrous