Precise Synthesis of Star-Shaped Redox-Responsive Segmented Polyurethanes with Controlled Arm Sequences for Drug...

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Biomacromolecular structures inspire synthetic polymers with ordered sequences and architectures.
• Developing synthetic polymers with precise control over monomer sequence and topology is an emerging field.

Purpose of the Study:

• To synthesize a four-arm star-shaped segmented polyurethane (PU) with sequence-controlled amphiphilic arms.
• To evaluate the self-assembly, stability, and drug delivery capabilities of the star-shaped PU micelles.

Main Methods:

• Synthesized sequence-defined, seven-segment amphiphilic arms containing disulfide bonds using a liquid-phase iterative methodology.
• Conjugated arms onto a pentaerythritol core via click chemistry to create a four-arm star-shaped PU.
• Investigated self-assembly into micelles, stability under physiological conditions, and redox-responsive drug release.

Main Results:

• The star-shaped PU self-assembles into stable micelles in aqueous solution.
• These micelles exhibit enhanced stability and superior redox-responsive performance compared to linear counterparts.
• Drug-loaded star-shaped PU micelles demonstrated accelerated release, improved tissue distribution, and enhanced anticancer efficacy both in vitro and in vivo.

Conclusions:

• The four-arm star-shaped architecture significantly improves micelle stability and drug delivery performance.
• Precise control over polymer architecture is crucial for tuning the properties of self-assembled nanostructures.
• This study opens new avenues for designing advanced materials for drug delivery and other applications.