Abstract
Suicide gene delivery is significant in cancer therapy but has not been fully investigated on a cellular scale. Here, Peak Force Quantitative Nanomechanical atomic force microscopy (PFQNM-AFM) was applied to visualize the effect of herpes simplex virus thymidine kinase dendriplexes (G4AcFaHSTK) on the morphological and nanomechanical properties of individual live and dividing HeLa cells. Cells were then exposed to G4AcFaHSTK, followed by ganciclovir, and directly imaged by real-time PFQNM-AFM. Cell membrane liquefaction, cytoplasmic shrinkage, and cytoskeleton structure loss were observed during cell division. The average Young's modulus of the nuclear region increased with time as the cell continued from metaphase (6.29 kPa) to telophase (13.6 kPa) and then decreased (2.25 kPa) upon apoptosis. In contrast, cells exposed to either ganciclovir or G4AcFaHSTK alone have no changes. Thus, understanding the real-time effects of suicide dendriplexes on the cytoskeletal and nanomechanical behaviors of cancer cells may provide new methods for cancer treatment.
This figure shows the formation of G4AcFaHSTK compact nanoparticles from the interaction between HSTK-based plasmids and partially acetylated, folic acid-conjugated, cationic 4th-generation polyamidoamine dendrimers (G4AcFa). Also, it shows the application of the real-time PFQNM mode of AFM to visualize the morphological and nanomechanical changes of individual live and dividing HeLa cells in their native environment upon their attack by G4AcFaHSTK. [Display omitted]