Synthesis and micellar characterization of short block length methoxy poly(ethylene glycol)-block-poly(caprolactone) diblock copolymers

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• 作者：Letchford ; Kevin ; Zastre ; Jason ; Liggins ; Richard ; Burt ; Helen
• 关键词：Copolymer ; Micelle ; Drug-delivery ; Poly(caprolactone) ; Polymerization
• 刊名：Colloids and Surfaces B: Biointerfaces
• 出版年：2004
• 出版时间：May 15, 2004
• 年：2004
• 卷：35
• 期：2
• 页码：81-91
• 全文大小：338 K

文摘

A series of short block length methoxy poly(ethylene glycol)-block-poly(caprolactone) diblock copolymers was synthesized and characterized in order to assess the potential of these copolymers as a micellar drug-delivery system. Varying the caprolactone:MePEG weight ratio in the reaction mixture allowed the synthesis of diblock copolymers with a MePEG molecular weight of 750g/mol and PCL block lengths of 2, 5 or 10 repeat units. Phase diagrams of aqueous solutions of the copolymers were constructed which displayed characteristic cloud points and Krafft points. As the degree of polymerization of PCL increased, critical micelle concentration (CMC) values decreased from 6.97×10⁻¹ to 3.38×10⁻³g/l, partition equilibrium coefficients (K_v) increased from 1.09×10⁴ to 22.2×10⁴, and hydrodynamic diameters increased from 12.2 to 19.5nm. The micelle morphology was determined to be spherical by transmission electron microscopy.