Caging metal ions with visible light-responsive nanopolymersomes

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Polymersomes are versatile nanocarriers derived from amphiphilic diblock copolymers.
• They offer advantages like environmental compatibility, mechanical stability, and tunable properties for molecule delivery.
• Existing polymersome systems lack efficient photoresponsive mechanisms for controlled release.

Purpose of the Study:

• To develop a nanoscale photoresponsive polymersome system for controlled molecule release.
• To investigate the photoresponsive behavior of polymersomes incorporating a specific fluorophore.
• To demonstrate the system's capability for delivering and photoreleasing various molecules.

Main Methods:

• Self-assembly of amphiphilic diblock copolymers into polymersomes.
• Incorporation of a meso-to-meso ethyne-bridged bis[(porphinato)zinc] (PZn2) fluorophore into the hydrophobic membrane.
• Encapsulation of dextran, FITC, Zn(2+), and Ca(2+) within the aqueous core.
• Irradiation with 488 nm light in solution and in zebrafish embryos.
• Monitoring deformation via PZn2 emission spectrum and cryo-transmission electron microscopy (cryo-TEM).

Main Results:

• The developed polymersomes exhibited nanoscale photoresponsiveness upon 488 nm irradiation.
• Polymersome deformation was observed, indicated by a red-shifted PZn2 emission spectrum.
• Cryo-TEM confirmed the structural changes in the polymersomes.
• Successful encapsulation and light-induced release of FITC, Zn(2+), and Ca(2+) were demonstrated.

Conclusions:

• The novel photoresponsive polymersome system offers precise control over molecule release triggered by light.
• This system shows potential for advanced drug delivery and biomedical applications.
• The demonstrated versatility in releasing different molecules highlights its broad applicability.