Exploring the Challenges of Lipid Nanoparticle Development: The In Vitro-In Vivo Correlation Gap

Area of Science:

• Biotechnology
• Nanomedicine
• Drug Delivery

Background:

• Lipid nanoparticles (LNPs) are advanced delivery platforms for nucleic acids, revolutionizing therapeutic and vaccine development.
• Challenges in reliable in vitro-in vivo correlation (IVIVC) hinder the clinical translation of LNP-based technologies.
• This study addresses IVIVC discrepancies by evaluating LNP physicochemical properties, in vitro efficacy, and in vivo performance.

Purpose of the Study:

• To investigate discrepancies in in vitro-in vivo correlation (IVIVC) for LNP formulations.
• To evaluate the impact of different ionizable lipids on LNP performance.
• To assess LNP potential for mRNA delivery and vaccine applications.

Main Methods:

• Four LNP formulations were manufactured using microfluidics, differing in their ionizable lipids (SM-102, ALC-0315, MC3, C12-200).
• Physicochemical properties (size, PDI, zeta potential, encapsulation) were analyzed.
• In vitro mRNA expression was assessed across three cell lines.
• In vivo mRNA expression and vaccine efficacy were evaluated.

Main Results:

• All LNPs demonstrated comparable physicochemical properties (70-100 nm size, low PDI, high encapsulation).
• In vitro, SM-102 LNPs showed significantly higher protein expression (p < 0.05) in immortalized and immune cells.
• In vivo, ALC-0315 and SM-102 LNPs yielded significantly higher protein expression (p < 0.05), with no difference between them; MC3 and C12-200 showed lower expression.
• All LNP formulations elicited comparable strong immune responses as vaccine candidates.

Conclusions:

• Significant variability exists in correlating in vitro and in vivo outcomes for LNP development.
• Ionizable lipid choice critically influences LNP in vivo mRNA expression but not vaccine efficacy.
• Holistic evaluation strategies are essential for optimizing LNP clinical translation.