Synthesis and Properties of Poly (N-hydroxyalkyl L-glutamine) Hydrogels

Poly (N-hydroxyalkyl L-glutamine) hydrogels were prepared by carrying out arninoalcoholysis reaction of poly (γ-benzyl L-glutamate) (PBLG) membranes with aminoalcohols, , such as 2-amino-1lethanol (E), 3-amino-1-propanol (P), or 5-amino-l-pentanol (Pe), together with crosslinking reaction with octamethylene diamine (OMDA). The reactions between their bulk structures and their membrane properties, such as the swelling in water, water vapor permeability, tensile properties, and enzymatic degradation behavior of the membranes in PECF solution were studied. The effective crosslink density was shown to be proportional to the percent of crosslinker (OMDA) in the reaction mixture. The tensile properties of hydrogels were highly dependent on the degree of swelling of PECF, Qw, and on the hydrophobicity of the side chains, whose behavior was typical of an elastomer. A common relation was obtained for the rates of water per meability, Vf, and Qw of sample, in spite of the difference of the nature of side chains. Biodegradation of samples in vitro by pronase indicated that the degradation could be regarded as a bulk rather than a surface phenomenon. The rate of degradation, V (1/2), was also highly dependent on Qw of samples, as well as on the hydrophobicity of side chains of samples.