Grafting cyclodextrins to calcium phosphate ceramics for biomedical applications

The grafting of hydroxyapatite/beta-tricalcium phosphate with b-cyclodextrin was achieved using a two step reaction with (3-glycidyloxypropyl)trimethoxysilane as a linker. Firstly, the silane group was brought to react with the hydroxyl groups at the surface of the hydro- xyapatite/beta-tricalcium phosphate and secondly, the epoxy group was brought to react with the b-cyclodextrin. The amount and distribution of covalently bound b-cyclo- dextrin were investigated by thermogravimetric analysis, colorimetric total sugar assay, fluorescence spectroscopy and confocal laser scanning microscopy. The concentration of grafted b-cyclodextrin was found to be approximately 3.5 lmol per gram of material corresponding to an almost complete surface coverage, when assuming a closed hex- agonal packed monolayer.