Surface Modification of Calcium Hydroxyfluor Carbonate Apatites by Bisphosphonates

Abstract:

Hydroxyapatite has been frequently described as an osteoconductive but not osteoinductive material based on failure to observe bone formation in nonbony sites. Bisphosphonates (BPs) are stable pyrophosphate analogs, that enhance the proliferation, differentiation and bone forming activity of osteoblasts and are potent inhibitors of bone resorption. In this paper, the modification of a calcium hydroxyfluor carbonate apatite with sodium alendronate and (4-(aminomethyl)benzene)bisphosphonic acid is described. The surface modification is carried out by refluxing the apatite in a bisphosphonate acetone solution. Modified particles are characterized by thermal analysis, ATR-IR spectroscopy and contact angle between other techniques. A weight loss between 150 and 500°C can be observed for the modified apatites. IR spectra show the appearance of bisphosphonate bands on modified powders. The surface energy of the modified apatite is reduced up to a 74% from the total apatite value after the alendronate surface modification with a decrease of 58% of the polar component main responsible of the cellular interaction of biomaterials.

• Periodical: Key Engineering Materials (Volumes 284-286)
• Pages: 357-360
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.284-286.357
• Online since: April 2005
• Authors: Luis M. Rodríguez-Lorenzo, Blanca Vázquez, Julio San Román
• Keywords: Apatite, Bisphosphonates, Surface Modification

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[84] [86] [88] [90] [92] [94] [96] [98] %T 1000 2000 3000 Wavenumbers (cm-1) 100 200 300 400 500 600.

[60] [70] [80] [90] 100 Wt% ºC Temperature Apatite Apatite + 6mM Na-alendronate Apatite + 60mM Na-alendronate 1046 1122 1175 1233 3479.

[84] [86] [88] [90] [92] [94] [96] [98] %T 1000 2000 3000 Wavenumbers (cm-1) 1046 1122 1175 1233 3479.

[84] [86] [88] [90] [92] [94] [96] [98] %T.

[84] [86] [88] [90] [92] [94] [96] [98] %T 1000 2000 3000 Wavenumbers (cm-1) 100 200 300 400 500 600.

[60] [70] [80] [90] 100 Wt% ºC Temperature Apatite Apatite + 6mM Na-alendronate Apatite + 60mM Na-alendronate 100 200 300 400 500 600.

[60] [70] [80] [90] 100 Wt% ºC Temperature 100 200 300 400 500 600.

[60] [70] [80] [90] 100 Wt% ºC Temperature Apatite Apatite + 6mM Na-alendronate Apatite + 60mM Na-alendronate.