Response of living cells to nano-structured polyelectrolyte matrices studied by means of 1-, 2- photon excitation microscopy

摘要

Three-dimensional confocal laser scanning microscopy (CLSM) and two-photon excitation microscopy (TPEM) were used to study the response of cellular systems to fuzzy organized nanostructured polyelectrolytes used both as microcontainers and microcarriers for drug delivery. These nanostructured systems are named Nanocapsules and represent a new class of controllable colloids. CLSM and TPEM uniquely allow to follow the fate of encapsulated living cells and to track the pathway of nanocapsules introduced into cellular systems. For the former situation, it will be shown how living cells can be encapsulated and demonstrated the preservation of the metabolic and duplicating activity. In this case the role of the Nanocapsule is as microcontainer endowed of functionalized surface and of protective ability. The latter situation, is related to feeding living cells with Nanocapsules. This experiment serves in elucidating the comprehension of the potential cytotoxicity and of the ability of Nanocapsules to reach specific targets where active compounds can be released. Cellular systems used within this research are Saccharomyces cerevisiae and Paramecium primaurelia living cells. In the case of encapsulation of Saccharomyces cerevisiae living cells, the most relevant result is that, after encapsulation, cells preserve their metabolic activities and they are still able to divide. At this stage is also relevant the utilization of spectroscopic methods like fluorescence lifetime and second harmonic imaging. These hybrid polyelectrolyte-cells can provide a cheap model system in a wide range of biophysical and biotechnological applications, thanks to the tunable properties of the polyelectrolyte shell.