Biodegradable zwitterionic nanoparticles with tunable UCST-type phase separation under physiological conditions.

Area of Science:

• Nanomedicine
• Polymer Chemistry
• Materials Science

Background:

• Thermo-responsive polymeric nanoparticles (NPs) are key in nanomedicine for controlled drug release.
• Zwitterionic polymers offer stability and immune evasion, but biodegradable options with physiological temperature response are lacking.

Purpose of the Study:

• To develop novel biodegradable zwitterionic NPs with an upper critical solution temperature (UCST) phase transition within the physiological range (30-45 °C).
• To enable tunable drug release for advanced nanomedicine applications.

Main Methods:

• Synthesis of block copolymers via reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization.
• Incorporation of a zwitterionic block for UCST behavior and a biodegradable oligoester block for tunable NP properties.

Main Results:

• Demonstrated the synthesis of highly controlled, biodegradable zwitterionic NPs with UCST phase transition in physiological conditions.
• Showcased tunable NP properties (size, degradation rate) by modifying copolymer components.
• Controlled release of a drug-mimic molecule over a wide range (minutes to 20 hours) by temperature variation.

Conclusions:

• Introduced a new class of biodegradable zwitterionic NPs with tunable, temperature-controlled drug release.
• These NPs hold significant potential for advanced drug delivery systems in nanomedicine.