Enzymatic hydrolysis of copoly-(N-hydroxyalkyl L-glutamine/gamma-methyl L-glutamate) fibres.

Fibres from random copolypeptides consisting of N-hydroxyalkyl L-glutamine and gamma-methyl L-glutamate with different monomer ratios were prepared by aminoalcoholysis of a poly(gamma-methyl L-glutamate) fibre with 2-amino-1-ethanol or 5-amino-1-pentanol, both with 1,8-octamethylenediamine as cross-linking agent. The initial tensile properties as well as the in vitro hydrolysis of these hydrophilic fibres were highly dependent on the degree of swelling in phosphate buffer solution. The in vitro hydrolysis was carried out using pronase E as protease. The kinetic study on the weight loss of the fibre accompanying the enzymatic hydrolysis suggested that the degradation of these fibres proceeds gradually from the surface of the fibres into their core. Scanning electron microscopy also supported the surface, not bulk, hydrolysis. The weight loss of the fibres in the course of hydrolysis took place almost in parallel with the strength loss of the fibres.