Hydrophobicity, surface tension, and zeta potential measurements of glass-reinforced hydroxyapatite composites
✍ Scribed by Lopes, M. A. ;Monteiro, F. J. ;Santos, J. D. ;Serro, A. P. ;Saramago, B.
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 154 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0021-9304
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✦ Synopsis
Wettability and zeta potential studies were performed to characterize the hydrophobicity, surface tension, and surface charge of P 2 O 5 -glass-reinforced hydroxyapatite composites. Quantitative phase analysis was performed by the Rietveld method using GSAS software applied to X-ray diffractograms. Surface charge was assessed by zeta potential measurements. Protein adsorption studies were performed using vitronectin. Contact angles and surface tensions variation with time were determined by the sessile and pendent drop techniques, respectively, using ADSA-P software. The highest (-18.1 mV) and lowest (-28.7 mV) values of zeta potential were found for hydroxyapatite (HA) and -tricalcium phosphate (-TCP), respectively, with composite materials presenting values in between. All studied bioceramic materials showed similar solid surface tension. For HA and -TCP, solid surface tensions of 46.7 and 45.3 mJ/ m 2 , respectively, were obtained, while composites presented intermediate surface tension values. The dispersive component of surface tension was the predominant one for all materials studied. Adhesion work values between the vitronectin solution and HA and -TCP were found to be 79.8 and 88.0 mJ/m 2 , respectively, while the 4.0 wt % glass composites showed slightly lower values than the 2.5 wt % ones. The presence of -TCP influenced surface charge, hydrophobicity, and protein adsorption of the glass-reinforced HA composites, and therefore indirectly affected cellbiomaterial interactions.