Seeing Multifunctional Nano-& Microparticles Suitable for Therapy & Imaging by Freeze-fracture Electron Microscopy

The potency of nanoparticles, loaded with drugs, genes, and/or diagnostics, is frequently depending upon their morphology adopted in a biological relevant environment. Freeze-fracture electron microscopy is a powerful techniques to monitor the self-assembling of lipid-, polymer-, as well as protein/peptide-based drug and gene carries on a nano-size resolution scale. Freeze-fracture electron microscopy allows not only the characterization of nanoand micoparticles suitable for therapy and imaging but also is the method of choice to study their fate related to their pay load, application milieu, and during their interaction with cells. Using freezefracture elelctron microscopy we studied the morphology of a wide variety of nanoand microparticles suitable for contrast enhancement as well as drug and gene delivery. This study includes quantum dots, micelles (spherical-, disc-, and wormtype micelles), small unilamellar liposomes, multilamellar liposomes, niosomes, lipid-stabilized gas bubbles, cochleate cylinder, depofoam particles, and drug crystals. Additionally we recorded the interaction of selected drug/gene carries with bacteria or cultured skin cells.