Quantifying and Modulating Protein Encapsulation in Guanosine-Based Supramolecular Particles.

Area of Science:

• Biotechnology
• Materials Science
• Biochemistry

Background:

• Protein encapsulation preserves structure and function.
• Tailoring protective agents to protein characteristics can modulate properties.
• Supramolecular hacky sacks (SHS) particles offer a novel encapsulation platform.

Purpose of the Study:

• To adapt a flow cytometry method for quantifying protein encapsulation in SHS particles.
• To assess the tunability of SHS particles for specific protein binding.
• To investigate the impact of particle modification on protein affinity.

Main Methods:

• Developed a flow cytometry assay to quantify encapsulation of fluorescein isothiocyanate (FITC)-labeled proteins in SHS particles.
• Utilized confocal laser scanning microscopy (CLSM) for imaging protein distribution.
• Investigated avidin-biotin interactions to tune SHS particle affinity.

Main Results:

• Quantified protein encapsulation with apparent association constants in the micromolar range, with hydrophobicity as a key factor.
• CLSM confirmed protein distribution within particles.
• Tuning SHS particle avidin affinity with biotin demonstrated saturation effects, likely due to cross-linking.

Conclusions:

• The flow cytometry method is effective for high-throughput, reproducible quantification of protein encapsulation.
• SHS particles can be tuned for specific protein binding, with potential for drug delivery applications.
• Further optimization using lower-affinity ligands could enhance protein affinity modulation.