Shape Effects of Filaments Versus Spherical Particles in Flow and Drug Delivery

Micelles morphology study is fundamental for predicting their behavior in vivo as the shape of these nanocarriers plays a key role in influencing circulation time, biodistribution and cellular uptake.

“Micelles morphology study has been recognized as fundamental for predicting their behavior in vivo as the shape of these nanocarriers plays a key role in influencing circulation time, biodistribution and cellular uptake [73,75].”

Differences in micellar shape are mainly related to the structure of polymers used and to the characteristics of the surrounding environment in terms of temperature, pH and composition.

“The differences in micellar shape are mainly related to the structure of polymers used [22,74] and to the characteristics of the surrounding environment in terms of temperature, pH and composition [74].”

Maintenance of controlled conditions, including temperature and humidity, is strictly required for collecting reproducible cryo-TEM data.

“maintenance of controlled conditions is strictly required for collecting reproducible data; thus, it should be always taken into account that during specimen preparation a rigorous control of environmental conditions including temperature and humidity rate is necessary [74,166].”

Cryo-TEM has high resolution (0.02 Å) and easy sample preparation, and has recently emerged as a powerful tool for describing the morphology of micelles.

“Due to the high resolution (0.02 Å) and easy sample preparation [74,164], Cryo-Transmission Electron Microscopy has recently emerged as a powerful tool for describing the morphology of micelles.”

TEM imaging requires complete sample dehydration to ensure high vacuum in the microscope column, whereas cryo-TEM is based on rapid freezing of samples at temperatures of at least -170°C using liquid nitrogen, liquid propane or liquid helium, allowing observation of specimens in their hydrated and native state and reducing artifacts related to water removal.

“However, while TEM imaging requires complete samples dehydration in order to ensure high vacuum in the microscope column, cryo-TEM is based on the rapid freezing of samples at temperatures of at least -170 • C using liquid nitrogen, liquid propane or liquid helium [74,164], allowing for the observation of specimens in their hydrated and native state and reducing artifacts related to water removal”