Glass scaffolds with controlled resorption rates and methods for making same

A method for making a tissue scaffold used in repairing an injury to bone or cartilage, said method comprising the steps of:

• (a) selecting a glass composition for making both a first fiber and a second glass fiber having different resorption rates;
• (b) melting a first amount of the selected glass composition to yield a first glass in a melted state;
• (c) maintaining the first glass in a melted state for a first melt hold time to confer a first resorption rate to the first glass;
• (d) forming the first glass into a first resorbable fiber having the first resorption rate, the first resorption rate being matched to a predetermined rate of bone growth into the scaffold;
• (e) melting a second amount of the selected glass composition from step (a) to yield a second glass in a melted state;
• (f) maintaining the second glass in a melted state for a second melt hold time to confer a second resorption rate to the second glass;
• (g) forming the second glass into a second resorbable fiber having the second resorption rate, the second resorption rate being slower than the first resorption rate;
• (h) including both the first resorbable fiber and the second resorbable fiber having the same glass composition in the bone or cartilage scaffold, whereby the first resorbable fiber resorbs to promote bone in-growth while the second resorbable fiber persists for a predetermined time in order to maintain structural support for the scaffold.