Cryogenic Transmission Electron Microscopy for the Evaluation of Lipid-Based Nanomedicines: Principles, Applications, and Challenges

Abstract

Lipid-based nanomedicines (LBNs), including liposomes and mRNA-lipid nanoparticles, have propelled modern drug delivery research; however, they possess significant challenges regarding structural characterization. Cryogenic transmission electron microscopy (cryo-TEM) preserves LBNs in a near-native, hydrated state, enabling high-resolution imaging of both external and internal features. This review discusses the key principles of cryo-TEM, highlights its advantages in characterizing LBNs, and addresses challenges such as precise sample preparation, beam-induced damage, and complexities in analyzing polydisperse specimens. Nevertheless, ongoing advances in instrumentation and workflow automation continue to expand the accessibility and data quality of cryo-TEM. Standardizing protocols and developing reference materials would further strengthen data reproducibility and facilitate regulatory considerations. By offering unparalleled insight into LBN morphology and functionality, cryo-TEM stands at the forefront of nanomedicine development, guiding both fundamental research and the optimization of next-generation therapeutic carriers.