Nuclear fusion target design

Viruses are complex particles, entering the cells by fusion of their envelope to the plasma membrane or by endocytosis followed by the escape of the capsid by membrane fusion or lysis (Sodeik, 2000). The diameter of the viral particle could be several hundred nanometers, implying a very inefficient diffusional movement in the cytoplasm, based on those physicochemical considerations that were discussed above (Kasamatsu and Nakanishi, 1998). Despite these limitations, those viruses that replicate in the nucleus have evolved sophisticated mechanisms to ensure a highly efficient nuclear delivery of their genetic material. Since these mechanisms may provide a conceptual framework to design novel non-viral delivery systems, we shall review some of the key elements that account for the nuclear targeting of certain viruses. 

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