Chitosan-based hydrogel nanoparticle amazing behaviors during transmission electron microscopy

Nanogels are potential polymeric nanoparticulate systems of interest in biomedical applications, including time-controlled drug delivery and active drug targeting. With the aim of preparation of a nanocarrier for brain enhancement of the BBB-restricted hydrophilic drugs, nanogel loaded with the antineoplasm drug, methotrexate was prepared using an ionic gelation process. During transmission electron microscopy imaging, hydrogel nanoparticles were found as a polymeric matrix containing aqueous vacuoles. With emitting the electrons and increase in energy intake, the vacuoles were interconnected and form a large one. Then the volume of the new vacuole grew and subsequently decreased over the time. The behavior was in good agreement with drug release kinetic findings. These results provide important guidelines for designing top-down fabricated hydrogel nanoparticles with specific drug release kinetic mechanisms for enhancing and predicting the drug delivery efficacy.