Gellan/hydroxyapatite composites for preparation of temporary structures for bone reconstruction

Gellan solution in hot water (1% w/v) was mixed with solid hydroxyapatite under stirring, and the hot suspensions rapidly quenched in liquid nitrogen; the gels so obtained were lyophilised. The material, tested by SEM, appears quite porous. FT-IR spectra show that the carboxylate band at about 1600 cm-1 is slightly altered, likely due to some interaction with the ionic hydroxyapatite structure. Thermogravimetric analysis of the composites shows a slight shift towards higher temperatures of the main signal of the gellan decomposition at 258°C; that shift increases with increasing hydroxyapatite to gellan ratio. Such behaviour may be indicative of a slight thermal stabilisation of gellan, due to interaction with hydroxyapatite.