Biodegradable polymersomes as a basis for artificial cells: encapsulation, release and targeting

Area of Science:

• Polymer chemistry
• Nanotechnology
• Biomaterials science

Background:

• Amphiphilic block-copolymers form polymersomes for encapsulating biofunctional compounds.
• Poly(ethylene glycol) (PEG) based polymersomes offer tunable properties for drug delivery.

Purpose of the Study:

• To describe the encapsulation, release properties, and targetability of biodegradable polymersomes.
• To investigate the influence of copolymer composition on drug release kinetics.
• To demonstrate the potential for targeted delivery of these polymersomes.

Main Methods:

• Polymersomes were prepared using amphiphilic block-copolymers of PEG and biodegradable polyesters/polycarbonate.
• Carboxyfluorescein (CF) was used as a model hydrophilic biofunctional compound for encapsulation studies.
• Release kinetics were studied in PBS at different temperatures, and interactions were assessed using immobilized polymersomes and sensor surfaces.

Main Results:

• Carboxyfluorescein was successfully encapsulated in polymersomes.
• Release rates of encapsulated CF were modulated by altering copolymer composition, particularly the hydrophobic block.
• Plasma proteins, excluding albumin, reduced CF release, indicating a membrane-controlled reservoir system.
• Polymersomes functionalized with anti-human serum albumin showed specific binding to albumin-coated surfaces, demonstrating targetability.

Conclusions:

• Biodegradable polymersomes provide a versatile platform for encapsulating hydrophilic biofunctional compounds.
• The release of encapsulated cargo can be precisely controlled by adjusting polymer architecture.
• These polymersomes exhibit potential for targeted delivery applications in vivo, as evidenced by specific protein interactions.