Redox-Responsive Polymersomes as Smart Doxorubicin Delivery Systems

Area of Science:

• Biomaterials Science
• Nanotechnology
• Drug Delivery

Background:

• Stimuli-responsive polymersomes offer programmed release of cytotoxic anticancer agents like doxorubicin hydrochloride (Dox·HCl).
• A novel biodegradable, redox-responsive triblock copolymer (mPEG-PDH-mPEG) with disulfide linkages was developed.

Purpose of the Study:

• To develop and characterize polymersomes for simultaneous formation and doxorubicin hydrochloride loading using a solvent-exchange method.
• To evaluate the drug encapsulation efficiency and in vitro release profile of the designed polymersomes.

Main Methods:

• Synthesis of mPEG-PDH-mPEG triblock copolymer.
• Solvent-exchange method for polymersome formation and doxorubicin hydrochloride loading.
• Characterization of polymersome morphology, size, zeta potential, encapsulation efficiency, and drug release kinetics.

Main Results:

• Uniform spherical polymersomes (120-190 nm) with negative zeta potentials were successfully prepared.
• High encapsulation efficiency of doxorubicin hydrochloride (up to 98 wt.%) was achieved.
• Prolonged, diffusion-driven drug release (~34% in 48 h) at physiological conditions was observed, with enhanced release (~77%) in the presence of glutathione (GSH) due to disulfide bond cleavage.

Conclusions:

• The designed redox-responsive polymersomes demonstrate excellent potential for controlled and selective delivery of doxorubicin hydrochloride.
• These smart nanocarriers are promising for targeted drug release in the reductive environment characteristic of cancer cells.