Double-Hydrophilic Block Copolymers Based on Functional Poly(ε-caprolactone)s for pH-Dependent Controlled Drug...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Degradability is a key limitation for double-hydrophilic block copolymers (DHBCs) in biomedical uses.
• Previous methods for introducing degradability involved complex, low-yield chemical strategies.

Purpose of the Study:

• To develop a straightforward synthesis for bioeliminable and degradable DHBCs.
• To investigate the pH-dependent self-assembly and drug delivery capabilities of these novel copolymers.

Main Methods:

• Synthesis of DHBCs with poly(ethylene glycol) (PEG) and functionalized poly(ε-caprolactone) (PCL) blocks (PEG-b-PCL(COOH), PEG-b-PCL(NH2), PEG-b-PCL(OH)) in three steps.
• Characterization of pH-dependent self-assembly, including critical micelle concentration (CMC) and micellar diameter.
• Evaluation of drug-loaded polyion complex micelles using doxorubicin (DOX) for encapsulation, release, and cytotoxicity.

Main Results:

• Successful synthesis of DHBCs with 50% functional group substitution in only three steps.
• Demonstrated pH-responsive self-assembly with significant variations in CMC and micellar diameter.
• Effective doxorubicin encapsulation, controlled release, and potent cytotoxicity against cancer cells using PEG-b-PCL(COOH) micelles.

Conclusions:

• The proposed synthesis offers an efficient route to bioeliminable and partly degradable DHBCs.
• These DHBCs exhibit promising potential as pH-responsive drug delivery systems.