ABSTRACT
Viral gene therapy is a very promising approach for treatment of oncological diseases. The transduction efficacy of viruses is still several orders of magnitude higher than that of any non-viral vectors. However, clinical applications of the viral vectors have been so far compromised by the poor target cell selectivity, high immunogenicity and rapid clearance of the vectors from the body. It has been demonstrated that modification of adenoviruses with hydrophilic synthetic polymers based on poly(ethylene glycol) (Eto et al., 2008) or poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA)(Fisher et al., 2007; Kreppel and Kochanek, 2008) significantly prolongs plasma circulation times and ablates the non-specific cell entry. At the same time, surface modification of the viral capsids with multivalent polymers enables retargeting of the vectors with receptor-specific ligands, such as growth factors (Morrison et al., 2008), tumor-specific peptides (Stevenson et al., 2007) or folates (Oh et al., 2006).
