Facile Synthesis of Lecithin-Sophorolipid Liponiosomes Encapsulating SARS-CoV‑2 Proteins for Therapeutic Applications

The major structural proteins of SARS-CoV-2 (spike and nucleocapsid) hold higher immunogenicity and have the potential to offer protective immunity. However, development of a biogenic and biocompatible delivery vehicle for subunit vaccine candidates remains a critical gap. The study was aimed to synthesize and evaluate liponiosomes encapsulating SARS-CoV-2 proteins as a novel delivery system. The SARS-COV-2 nucleocapsid and spike proteins were expressed in the mammalian cell line. The purified proteins were encapsulated into novel liponiosome (based on biogenic lecithin-sophorolipid) nanoparticles using ultrasonication. The resulting nanoparticles were characterized for size, morphology, dispersity, and encapsulation using dynamic light scattering, transmission electron microscopy, and confocal microscopy. The cytotoxicity of the fabricated liponiosomes was assessed using cell culture assays. The synthesized liponiosomes demonstrated a uniform nanoscale size (100 ± 10 nm). The encapsulation efficiency was observed to be more than 95%, ensuring potential in delivery capacity. The confocal imaging confirmed the effective encapsulation of the viral proteins. The cytotoxicity analyses on cells revealed the negligible toxicity of the synthesized nanoparticles. The lecithin-sophorolipid liponiosome platform provides an eco-friendly, biocompatible delivery system for SARS-CoV-2 proteins, combining high encapsulation efficiency and nanoscale stability. This formulation shows potential for therapeutic or vaccine application.