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Enzymatic degradation of PLLA-PEOz-PLLA triblock copolymers

Paper ID Volume ID Publish Year Pages File Format Full-Text
12230 786 2005 9 PDF Available
Title
Enzymatic degradation of PLLA-PEOz-PLLA triblock copolymers
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 μm, 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.

Keywords
PLLA-PEOz-PLLA; Proteinase k; Biodegradable; Enzymatic degradation
First Page Preview
Enzymatic degradation of PLLA-PEOz-PLLA triblock copolymers
Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 26, Issue 16, June 2005, Pages 2803–2811
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering