TY  - JOUR
A1  - Schöne, Anne-Christin
A1  - Kratz, Karl
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Polymer architecture versus chemical structure as adjusting tools for the enzymatic degradation of oligo(epsilon-caprolactone) based films at the air-water interface
JF  - Polymer Degradation and Stability
N2  - The enzymatic degradation of oligo(epsilon-caprolactone) (OCL) based films at the air-water interface is investigated by Langmuir monolayer degradation (LMD) experiments to elucidate the influence of the molecular architecture and of the chemical structure on the chain scission process. For that purpose, the interactions of 2D monolayers of two star-shaped poly(epsilon-caprolactone)s (PCLs) and three linear OCL based copolyesterurethanes (P(OCL-U)) with the lipase from Pseudomonas cepacia are evaluated in comparison to linear OCL. While the architecture of star-shaped PCL Langmuir layers slightly influences their degradability compared to OCL films, significantly retarded degradations are observed for P(OCL-U) films containing urethane junction units derived from 2, 2 (4), 4-trimethyl hexamethylene diisocyanate (TMDI), hexamethylene diisocyanate (HDI) or lysine ethyl ester diisocyanate (LDI). The enzymatic degradation of the OCL based 2D structures is related to the presence of hydrophilic groups within the macromolecules rather than to the packing density of the film or to the molecular weight. The results reveal that the LMD technique allows the parallel analysis of both the film/enzyme interactions and the degradation process on the molecular level. (C) 2016 Elsevier Ltd. All rights reserved.
KW  - Langmuir technique
KW  - Oligo(epsilon-caprolactone)
KW  - Enzymatic degradation
KW  - Polymer architecture
Y1  - 2016
U6  - https://doi.org/10.1016/j.polymdegradstab.2016.07.010
SN  - 0141-3910
SN  - 1873-2321
VL  - 131
SP  - 114
EP  - 121
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Reiche, Jürgen
A1  - Kratz, Karl
A1  - Hofmann, Dieter
A1  - Lendlein, Andreas
T1  - Current status of Langmuir monolayer degradation of polymeric biomaterials
JF  - The international journal of artificial organs
N2  - Langmuir monolayer degradation (LMD) experiments with polymers possessing outstanding biomedical application potential yield information regarding the kinetics of their hydrolytic or enzymatic chain scission under well-defined and adjustable degradation conditions. A brief review is given of LMD investigations, including the author's own work on 2-dimensional (2D) polymer systems, providing chain scission data, which are not disturbed by simultaneously occurring transport phenomena, such as water penetration into the sample or transport of scission fragments out of the sample.
 A knowledge-based approach for the description and simulation of polymer hydrolytic and enzymatic degradation based on a combination of fast LMD experiments and computer simulation of the water penetration is briefly introduced. Finally, the advantages and disadvantages of this approach are discussed.
KW  - Monolayer
KW  - Hydrolytic degradation
KW  - Enzymatic degradation
KW  - Biomaterial
KW  - Degradable polymer
Y1  - 2011
U6  - https://doi.org/10.5301/IJAO.2011.6401
SN  - 0391-3988
VL  - 34
IS  - 2
SP  - 123
EP  - 128
PB  - Wichtig
CY  - Milano
ER  -