Reversible polyelectrolyte capsules as carriers for protein delivery.

Area of Science:

• Materials Science
• Biotechnology
• Nanotechnology

Background:

• Protein delivery systems face challenges in maintaining protein integrity and achieving controlled release.
• Polyelectrolyte microcapsules offer potential for encapsulating and delivering sensitive biomolecules.

Purpose of the Study:

• To develop a reversible drug delivery system for proteins using pH-sensitive polyelectrolyte microcapsules.
• To investigate the spontaneous loading and controlled release of bovine serum albumin (BSA) from these microcapsules.

Main Methods:

• Layer-by-Layer assembly of poly(allylamine hydrochloride) (PAH) and poly(methacrylic acid) (PMA) on CaCO3 particles.
• Core removal to form hollow microcapsules, followed by pH-dependent loading and release studies.
• Characterization using confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), scanning electron microscopy (SEM), circular dichroism (CD), and Fourier transform infrared spectroscopy (FTIR).

Main Results:

• Hollow microcapsules demonstrated pH-dependent reversible opening and closing for protein loading.
• BSA loading capacity increased significantly at pH values below its isoelectric point.
• No significant conformational changes were observed in the released BSA.
• In vitro studies confirmed the biocompatibility of the microcapsules.

Conclusions:

• pH-sensitive polyelectrolyte microcapsules provide a promising platform for the reversible delivery of water-soluble proteins and peptides.
• The spontaneous deposition mechanism allows for efficient protein loading.
• The system exhibits controlled release kinetics and preserves protein integrity.