Dissolution/reprecipitation and protein adsorption studies of calcium phosphate coatings by FT-IR/ATR techniques.
The surfaces of bioactive Ca-P ceramics immediately change when exposed to proteinaceous solutions. The dissolution behavior and protein interactions of these bioactive materials at the bone/implant interface need to be investigated to understand their material-cellular interactions fully. In this study, FT-IR/ATR techniques were used to study the in situ phosphate release kinetics of Ca-P coatings. The net loss of phosphate molecules from coatings was slower in saline solutions compared with alpha-MEM solutions. Coatings exposed to alpha-MEM solutions containing fibronectin released phosphate molecules slower than coatings exposed to alpha-MEM solutions containing albumin. Conformational changes in fibronectin and albumin adsorbed onto Ca-P and uncoated germanium surfaces were also investigated using FT-IR/ATR spectroscopy. Analysis of changes in the amide I bands indicated that there was a greater loss of beta-sheet structure in adsorbed fibronectin on Ca-P coatings when compared with bare germanium surfaces. Although albumin did change its structure upon adsorption on both Ca-P and germanium, unlike fibronectin, adsorbed albumin structure was similar on Ca-P coatings and germanium. Furthermore, with time the conformation of adsorbed fibronectin and albumin appeared to be very stable on Ca-P coatings, whereas albumin adsorbed to germanium exhibited an increase in ratio of alpha-helix to beta-turn.
Ong
J L
JL
University of Alabama, Department of Biomedical Engineering, Birmingham 35294.
Chittur
K K
KK
Lucas
L C
LC
D000327:Adsorption; D000418:Albumins / Q000378:metabolism*; D002130:Calcium Phosphates / Q000378:metabolism* / Q000493:pharmacokinetics; D002516:Ceramics / Q000378:metabolism* / Q000493:pharmacokinetics; D005353:Fibronectins / Q000378:metabolism*; D005857:Germanium / Q000378:metabolism / Q000493:pharmacokinetics; D008422:Materials Testing; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared
D000418:Albumins; D002130:Calcium Phosphates; D005353:Fibronectins; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; D005857:Germanium; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous