Lysozyme encapsulation into nanostructured CaCO₃ microparticles using a supercritical CO₂ process and comparison with...

Area of Science:

• Materials Science
• Biotechnology
• Chemical Engineering

Background:

• Protein encapsulation is crucial for drug delivery and biomaterials.
• Calcium carbonate (CaCO3) microparticles are versatile carriers.
• Developing efficient encapsulation methods is an ongoing challenge.

Purpose of the Study:

• To evaluate supercritical CO2 (SC-CO2) as a novel process for protein encapsulation into CaCO3 microparticles.
• To compare SC-CO2 encapsulation with a conventional water-based method.
• To characterize the resulting protein-loaded CaCO3 microparticles.

Main Methods:

• Lysozyme was encapsulated into CaCO3 microparticles using both SC-CO2 and a conventional water-based precipitation method.
• Particles were analyzed for size, zeta potential, and morphology (SEM).
• Crystal polymorph and lysozyme encapsulation efficiency were quantified (HPLC, bioassay).

Main Results:

• SC-CO2 processing yielded CaCO3 microparticles with encapsulated lysozyme in a core-shell structure.
• A high encapsulation efficiency of 50% was achieved with SC-CO2.
• The conventional method resulted in only 2% lysozyme encapsulation.
• SC-CO2 processed particles showed increased zeta potential, indicating successful protein entrapment.

Conclusions:

• Supercritical CO2 is a highly effective technique for encapsulating proteins, like lysozyme, into nanostructured calcium carbonate particles.
• This method significantly outperforms traditional approaches in terms of encapsulation efficiency.
• The SC-CO2 process holds potential for encapsulating various macromolecules and bioactive substances.