Synthesis of Amphiphilic Comb-Shape Copolymers Via Ring-Opening Polymerization of a Macromonomer

Abstract

Amphiphilic comb‐shape copolymers PCL‐co‐P(MTC‐mPEG16) (where PCL, MTC, and mPEG refer to poly(ε‐caprolactone), 2‐methyltrimethylene carbonate, and methoxy poly(ethylene glycol), respectively) are synthesized by ring‐opening polymerization of ε‐caprolactone and cyclic carbonate‐terminated PEG macromonomer (MTC‐mPEG16) with benzyl alcohol as an initiator and Sn(Oct)2 as a catalyst. Amphiphilic copolymers PCL‐co‐P(MTC‐mPEG16) can form micelles in aqueous solution by self‐assembly. The diameters of PCL‐co‐P(MTC‐mPEG16) micelles characterized by dynamic light scattering area few dozens of nanometers with a narrow size distribution and the morphology of the micelles observed through transmission electron microscopy are nanosized spheres. The in vitro drug release of comb‐shape copolymer PCL‐co‐P(MTC‐mPEG16) micelles is more stable and sustained than that of linear block copolymers mPEG‐b‐PCL.

Synthesis and Self-Assembly of the pH-Responsive Anionic Copolymers for Enhanced Doxorubicin-Loading Capacity

“…Considering the zeta potential of DOX-loaded micelles, except for 0.17COOH-PCEC micelles, the zeta potential of DOX-loaded copolymers 0.50COOH-PCEC and 0.83COOH-PCEC micelles changed significantly. We speculate that DOX was loaded into the hydrophobic core of 0.17COOH-PCEC micelles by the hydrophobic interaction between PCL and DOX, while DOX-loaded 0.50COOH-PCEC and 0.83COOH-PCEC micelles were formed mainly through electrostatic attraction force between anionic −COO – and protonated DOX (p K a 7.6–8.4). ,, To the best of our knowledge, the LC and EE for DOX-loaded micelles from PCL/PEG diblock or triblock copolymers were below 5 and 40%, respectively, − which was consistent with PCEC micelles (LC: 4.9%; EE: 34%). Interestingly, except 0.17COOH-PCEC micelles, 0.50COOH-PCEC and 0.83COOH-PCEC micelles both achieved higher LC and EE than.…”