Encapsulation stability and temperature-dependent release kinetics from hydrogel-immobilised liposomes

Area of Science:

• Materials Science
• Biotechnology
• Chemical Engineering

Background:

• Liposomes are crucial for drug delivery but require stable encapsulation.
• Hydrogel-liposome composites offer potential for controlled release systems.

Purpose of the Study:

• To investigate factors influencing liposome stability within calcium alginate hydrogels.
• To characterize the on-demand release of encapsulated substances from these composites.

Main Methods:

• Fabrication of calcium alginate gel microparticles with embedded cholesterol:dipalmitoylphosphatidylcholine (DPPC) liposomes.
• Systematic investigation of temperature and cholesterol:DPPC ratio on liposome stability during gelation.
• Quantification of fluorescent dye release triggered by temperature pulses.

Main Results:

• Liposomes demonstrated stability in the hydrogel matrix, particularly with cholesterol present and below the phase transition temperature.
• Ionic cross-linking with Ca(2+) did not compromise liposome integrity.
• On-demand, repeatable release of encapsulated dye was achieved using controlled temperature pulses.

Conclusions:

• Hydrogel-liposome composites provide a stable platform for encapsulating liposomes.
• Temperature-controlled, on-demand release is feasible, indicating potential for advanced drug delivery systems.
• These composites are suitable for controlled release and studying reaction-diffusion phenomena.