title: Effect of diisocyanate linkers on the degradation characteristics of copolyester urethanes as potential drug carrier matrices.
abstract: In this study, the effect of three aliphatic diisocyanate linkers, L-lysine diisocyanate ethyl ester (LDI), hexamethylene diisocyanate (HDI), and racemic 2,2,4-/2,4,4-trimethyl hexamethylene diisocyanate (TMDI), on the degradation of oligo[(rac-lactide)-co-glycolide] (64:36 mol%) based polyester urethanes (PEU) was examined. Samples were characterized for their molecular weight, mass loss, water uptake, sequence structure, and thermal and mechanical properties. Compared to non-segmented PLGA, the PEU showed higher water uptake and generally degraded faster. Interestingly, the rate of degradation was not directly correlating with the hydrophilicity of the diisocyanate moieties; instead, competing intra-/intermolecular hydrogen bonds in between urethane moieties appear to substantially decrease the rate of degradation for LDI-derived PEU. By comparing microparticles (μm) and films (mm) as matrices of different dimensions, it was shown that autocatalysis remains a contributor to degradation of the larger-sized PEU matrices as it is typical for non-segmented lactide/glycolide copolymers. The shown capacity of lactide/glycolide-based multiblock copolymers to degrade faster than PLGA and exhibit improved elastic properties could be of interest for medical implants and drug release systems.
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstrasse 55, 14153 Teltow, Germany.
authors.forename: Simi
authors.initials: S
authors.lastname: Mathew
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstrasse 55, 14153 Teltow, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Baudis
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstrasse 55, 14153 Teltow, Germany.
authors.forename: Axel T
authors.initials: AT
authors.lastname: Neffe
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstrasse 55, 14153 Teltow, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Behl
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstrasse 55, 14153 Teltow, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Wischke
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Kantstrasse 55, 14153 Teltow, Germany. Electronic address: andreas.lendlein@hzg.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lendlein
mesh_terms: D003485:Cyanates / Q000737:chemistry* / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism; D019344:Lactic Acid / Q000737:chemistry* / Q000378:metabolism; D011091:Polyesters / Q000737:chemistry* / Q000378:metabolism; D011100:Polyglycolic Acid / Q000737:chemistry* / Q000378:metabolism; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D014520:Urethane / Q000737:chemistry* / Q000378:metabolism
chemical_list: D003485:Cyanates; D004337:Drug Carriers; D011091:Polyesters; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D014520:Urethane
keywords: Degradation; Microparticles; Multiblock copolymer; PLGA; Polyester urethanes