Degradation of oligo(lactone) branches linked to poly(methacrylate) networks

Partially resorbable composite materials were developed for bone applicatio ns and were prepared by crosslinking copolymerization of oligo(lactone) mac romonomers with selected comonomers in the presence of hydroxy apatite. The composites were incubated in aqueous solution of different pH and electrol yte content over a period up to 300 days. The percentage of the released hy droxycarboxylic acid from the oligo(lactone) branches was determined by the titration or by high performance liquid chromatography (HPLC). A catalytic influence of cholesterol esterase (CE) on the hydrolysis of the materials was observed. Determination of CE activity in the presence of the different composite materials showed that the half-life time of CE was the lowest in the presence of the material undergoing the fastest degradation After degr adation the composite materials have preserved their coherence and have sho wn higher glass transition temperatures in the dried state than the materia ls before degradation.