Format

Send to

Choose Destination
See comment in PubMed Commons below
Biomaterials. 2005 Jun;26(16):2803-11.

Enzymatic degradation of PLLA-PEOz-PLLA triblock copolymers.

Author information

1
Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan.

Abstract

The enzymatic degradation of poly(L-lactide)-block- poly(2-ethyl-2-oxazoline)-block-poly(L-lactide) triblock copolymer (PLLA-PEOz-PLLA) was investigated using efficient enzyme proteinase K. PLLA-PEOz-PLLA solution-cast film lost a considerable amount of hydrophilic copolymers in the first 2 h, and the degradation after 2 h proceeded predominantly by surface erosion. The two faces of the hydrolyzed film exhibited different morphologies following enzymatic degradation. The lower face showed many spherulites, which are the superstructural morphology of polymer crystals. Porous spheres based on crystalline PLLA were observed on the upper face, because they were more resistant to enzymatic attack. The crystallinity of the films increased monotonously with the hydrolysis time, thus, the absorption of water gradually decreased. The analysis of degradation residues revealed that many colloids of poly(2-ethyl-2-oxazoline)-co-polyethylenimine (PEOz-co-PEI) copolymers were dispersed in the buffer solution. The average diameter, 1 microm, of the colloids was reduced to 200 nm by advanced degradation. The proteinase K exhibited remarkable hydrolysis not only at the ester bond but also the amide bond.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center