Translating a Thin-Film Rehydration Method to Microfluidics for the Preparation of a SARS-CoV-2 DNA Vaccine: When Manufacturing Method Matters

• Published in: Pharmaceutics Vol. 14; no. 7; p. 1427
• Main Authors: Peletta, Allegra, Prompetchara, Eakachai, Tharakhet, Kittipan, Kaewpang, Papatsara, Buranapraditkun, Supranee, Yostrerat, Nongnaphat, Manopwisedjaroen, Suwimon, Thitithanyanont, Arunee, Avaro, Jonathan, Krupnik, Leonard, Neels, Antonia, Ruxrungtham, Kiat, Ketloy, Chutitorn, Borchard, Gerrit
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 07.07.2022; MDPI
• Subjects: Amino acids; Antibodies; Automation; Coronaviruses; COVID-19 vaccines; delivery systems; Disease transmission; DNA vaccines; Ethanol; Experiments; Immunization; Laboratory animals; Lipids; liposomes; manufacturing method; Methods; microfluidics; Pandemics; Particle size; Proteins; R&D; Reproducibility; Research & development; Severe acute respiratory syndrome coronavirus 2; Solvents; thin-film layer rehydration; United Kingdom > UK; United States > US; Switzerland; Germany
• ISSN: 1999-4923; 1999-4923
• DOI: 10.3390/pharmaceutics14071427

Previous investigations conducted on a liposomal formulation for a SARS-CoV-2 DNA vaccine manufactured using the thin-film layer rehydration method showed promising immunogenicity results in mice. The adaptation of the liposomal formulation to a scalable and reproducible method of manufacture is necessary to continue the investigation of this vaccine candidate. Microfluidics manufacture shows high potential in method translation. The physicochemical characterization of the blank liposomes produced by thin-film layer rehydration or microfluidics were shown to be comparable. However, a difference in lipid nanostructure in the bilayer resulted in a significant difference in the hydration of the thin-film liposomes, ultimately altering their complexation behavior. A study on the complexation of liposomes with the DNA vaccine at various N/P ratios showed different sizes and Zeta-potential values between the two formulations. This difference in the complexation behavior resulted in distinct immunogenicity profiles in mice. The thin-film layer rehydration-manufactured liposomes induced a significantly higher response compared to the microfluidics-manufactured samples. The nanostructural analysis of the two samples revealed the critical importance of understanding the differences between the two formulations that resulted in the different immunogenicity in mice.