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Synthesis of peptide-grafted comb polypeptides via polymerisation of NCA-peptides.

Synthesis of peptide-grafted comb polypeptides via polymerisation of NCA-peptides.

Chem. Commun. 49, 409–411 (2013).

Enomoto, H., Nottelet, B., Al Halifa, S., Enjalbal, C., Dupre, M., Tailhades, J., Coudane, J., Subra, G., Martinez, J. & Amblard, M

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.