Degradation characteristics of poly(ϵ‐caprolactone)‐based copolymers and blends

Abstract

ABSTRACT:The hydrolytic degradation of various bioresorbable copolymers and blends derived from -caprolatcone, d,l-lactide and poly(ethylene glycol) (PEG) was investigated at 37°C in a pH 7.4 phosphate buffer. Poly(-caprolatcone) (PCL) followed a slow degradation profile due to its hydrophobicity and crystallinity. The hydrophilicity and degradability of the materials can be improved by copolymerization with PEG and/or poly-(d,l-lactide) (PLA). Homogenous degradation was shown in the cases of PCL, PCL/PEG copolymers and their blends, whereas PLA-containing copolymers followed a heterogenous degradation due to internal autocatalysis. It was also shown that PCLbased materials gradually turned to PCL-enriched residues during degradation due to preferential hydrolysis of PLA segments and to diffusion of soluble species such as PLA oligomers and detached PEG blocks bearing short PLA segments. The results are discussed in comparison with literature data.

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“…Although, when the content of PLA was greater than 40%, the rate of degradation was observe to increase as compared to that of the homopolymer 95 . The degradation kinetics of PCL extremely depends upon the molecular weight of the polymer.…”

Synthesis of PEG-PCL-based polyurethane nanoparticles by miniemulsion polymerization

“…In addition, poly(ethylene glycol) (PEG) chains may be used as hydrophilic polymer to form a shell around PU NPs. This strategy to construct PEG layers on NPs has been attracting much interest in medical, pharmaceutical and biological areas due to their unique properties as PEG chains attached to the surface or forming the corona of a nanoparticle lead to rapid chain motion in an aqueous medium [25] and establish prolonged systemic circulation [4], [24] and [26].…”

Blends as a strategy towards tailored hydrolytic degradation of poly(ɛ-caprolactone-co-d,l-lactide)–poly(ethylene glycol)–poly(ɛ-caprolactone-co-d,l-lactide) co-polymers

“…Parameters affecting the controlled degradation of blends, apart from the properties of the components, include the composition, preparation method, compatibility and miscibility of the components [3,4]. Several blend pairs of biodegradable homo-and co-polymers have been studied, including materials composed of poly(3-caprolactone) (PCL), polyanhydrides, poly(ethylene glycol) (PEG), and poly(D,L-lactic acid) (PDLLA) [1,2,4]. Morphological and thermodynamic analyses of polymer blends have shown that PCL are immiscible but compatible with PEG [2,5] and PDLLA [6], whereas PDLLA and PEG have been reported to be miscible [7].…”

“…Its simplicity makes it preferable, in some cases, to co-polymerisation, which is laborious and time consuming. In the field of tissue engineering, blending two polymers with different degradation profiles may serve to tune physical and mechanical properties [1], or to achieve a desirable rate of degradation [2]. Parameters affecting the controlled degradation of blends, apart from the properties of the components, include the composition, preparation method, compatibility and miscibility of the components [3,4].…”