Surface modification of calcium metaphosphate fibers

beta-calcium metaphosphate fibers having high aspect ratios of 10-120 with diameters of 2-10 microm show high strength and good biocompatibility. When the fibers are soaked in simulated body fluid at 37 degrees C, however, no calcium phosphate phase is newly formed on the fibers. In the present work, by treating the fibers at 70 degrees C with dilute NaOH aqueous solution, the surface phase was converted successfully into the orthophosphate phase that was in fine sizes and was adhered. After soaking the treated fibers in simulated body fluid at 37 degrees C for 30 days, a new calcium phosphate phase was precipitated. This was attributed to the surface phase modified using dilute NaOH. The treated fibers are expected to show bone-bonding ability, i.e. bioactivity.