Effect of Particle Synthesis Method on Protein Release and Stability

Area of Science:

• Biomaterials Science
• Vaccine Technology
• Nanotechnology

Background:

• Polyanhydride particles offer advantages for vaccines, including payload encapsulation, tunable release, and broad immunity.
• Current vaccine production methods face limitations that novel particle-based systems aim to address.

Purpose of the Study:

• Compare flash nanoprecipitation and spray drying for synthesizing protein-loaded polyanhydride particles.
• Analyze the structure, release kinetics, and antigenicity of proteins encapsulated using these two methods.
• Evaluate the potential of spray drying for scalable, future vaccine manufacturing.

Main Methods:

• Synthesized polyanhydride particles using flash nanoprecipitation (lab-scale) and spray drying (scalable).
• Encapsulated model (bovine serum albumin) and clinically relevant proteins (SARS-CoV-2 spike, bovine RSV post-F).
• Analyzed protein release kinetics, structural integrity (gel electrophoresis, fluorescence spectroscopy), and antigenicity (mouse serum binding).

Main Results:

• Both synthesis methods yielded particles with an initial burst release followed by sustained protein release.
• The primary and tertiary structures of the encapsulated proteins were preserved across both methods.
• The antigenicity of SARS-CoV-2 spike and bovine RSV post-F proteins remained intact after encapsulation and release.

Conclusions:

• Flash nanoprecipitation and spray drying are effective methods for creating polyanhydride particles that stabilize encapsulated antigens.
• Protein structure and antigenicity are maintained regardless of the synthesis method used.
• Spray drying is a viable, scalable method for producing antigen-stabilizing particles for future vaccine applications.