Trimethylene carbonate and epsilon-caprolactone based (co)polymer networks: mechanical properties and enzymatic degradation.
High molecular weight trimethylene carbonate (TMC) and epsilon-caprolactone (CL) (co)polymers were synthesized. Melt pressed (co)polymer films were cross-linked by gamma irradiation (25 kGy or 50 kGy) in vacuum, yielding gel fractions of up to 70%. The effects of copolymer composition and irradiation dose on the cytotoxicity, surface properties, degradation behavior, and mechanical and thermal properties of these (co)polymers and networks were investigated. Upon incubation with cell culture medium containing extracts of (co)polymers and networks, human foreskin fibroblasts remained viable. For all (co)polymers and networks, cell viabilities were determined to be higher than 94%. The formed networks were flexible, with elastic moduli ranging from 2.7 to 5.8 MPa. Moreover, these form-stable networks were creep resistant under dynamic conditions. The permanent deformation after 2 h relaxation was as low as 1% after elongating to 50% strain for 20 times. The in vitro enzymatic erosion behavior of these hydrophobic (co)polymers and networks was investigated using aqueous lipase solutions. The erosion rates in lipase solution could be tuned linearly from 0.8 to 45 mg/(cm (2) x day) by varying the TMC to CL ratio and the irradiation dose. The copolymers and networks degraded essentially by a surface erosion mechanism.
Institute for Biomedical Technology and Department of Polymer Chemistry and Biomaterials, Faculty of Science and Technology, University of Twente, Post Office Box 217, 7500 AE, Enschede, The Netherlands.
Erhan
E
Bat
Josée A
JA
Plantinga
Martin C
MC
Harmsen
Marja J A
MJ
van Luyn
Zheng
Z
Zhang
Dirk W
DW
Grijpma
Jan
J
Feijen
D002470:Cell Survival; D004146:Dioxanes / Q000737:chemistry; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D006801:Humans; D007783:Lactones / Q000737:chemistry; D008049:Lipase / Q000378:metabolism; D018583:Pliability; D011091:Polyesters / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology
D004146:Dioxanes; D007783:Lactones; D011091:Polyesters; D011108:Polymers; C410438:TMC-ECL copolymer; C016240:polycaprolactone; C059299:polytrimethylene carbonate; D008049:Lipase