Investigation on the properties of linear PLA-poloxamer and star PLA-poloxamine copolymers for temporary biomedical applications.
Investigation on the properties of linear PLA-poloxamer and star PLA-poloxamine copolymers for temporary biomedical applications.
Materials Science and Engineering: C 33, 4133–4139 (2013).
Leroy, A., Pinese, C., Bony, C., Garric, X., Noël, D., Nottelet, B. & Coudane, J.
ABSTRACT
The objective of this work was to develop and study new biodegradable thermoplastics with improved mechanical properties for potential use as temporary implantable biomaterials. Linear Poloxamer and star-shaped Poloxamine have been used as macroinitiators for the Ring-Opening Polymerization (ROP) of lactide to yield high molecular weight PLA-based thermoplastic block copolymers. The influence of the nature of the macroinitiator, PLA crystallinity and initial molecular weight on the copolymers properties was investigated by performing a 7-week degradation test in PBS. The evaluation of water uptakes and molecular weights during the degradation pointed out an early hydrolytic degradation of the 100 kg∙mol-1 copolymers compared to the 200 kg/mol ones (molecular weight decrease of ca. 40 % and 20 %, respectively). A dramatic loss of tensile mechanical properties was also observed for the 100 kg/mol copolymers whereas the 200 kg∙mol-1 copolymers showed stable or even slightly improved properties with Young’s moduli around 500 MPa and yield strains around 3 to 4%. Finally, the cytocompatibility of the more stable 200 kg∙mol-1 copolymers was confirmed by murine mesenchymal stem cells (MSCs) culture.