Characterization and optimization of the non-viral gene transfer vehicle Artificial viral particles (AVP)
In this work the non-viral gene transfer vehicle artificial viral particles (AVP) was characterized in greater detail, improved and used for new cell culture applications. The former conception of AVP as filled particle with a liposomal hull was expanded. The described filled particles with a smooth liposomal hull are contained in AVP but they are not the only particle species. Ultracentrifugation in combination with cell culture experiments showed that a mix of those filled particles with small PEI-DNA particles is responsible for transfection success. AVP could be traced on their way into the cell by electron microscopy and confocal laser scanning microscopy. Results indicated that AVP are able to escape from endosomes and supported the “proton sponge” theory. Transfer of AVP preparation from manual pipetting to a mini mixer system is possible, allowing production upscale. AVP prove that they are a successful transfection system also suitable for new applications such as siRNA transfection and stable expression of a recombinant protein. They have a potential as they can be optimized for their specific task by selection of the proper condensation agent and type of AVE liposomes. However, AVP in their presently characterized form will have their main field of application in cell culture.