Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5636_Библиотеки_им_академика_М_И_Перельмана

Small cationic DNA–protamine complexes of ~120 nm behaved similarly to the HIV-TAT protein that is responsible for the cellular entry of the virus, HIV (Park et al. 2003). The protamine–DNA nanocomplexes had efficient intracellular uptake in the nucleus and the cytoplasm on a similar timescale to that of HIV-TAT protein. The mechanism by which the TAT-HIV protein allows cellular and nuclear entry is unknown, but there is evidence that cationic charge is a major player in uptake. Incorporation of nuclear localization signals on nanoparticle surface is a useful approach for nuclear targeting. Gold nanoparticles were functionalized with nuclear localization signal peptides derived from the SV40 virus T protein (M1), HIV-TAT protein (M2), adenoviral NLS protein (M3), and a synthetic peptide with a nuclear binding site and lysine amino acids (M4) (Tkachenko et al. 2004). The peptide­conjugated gold nanoparticles were fabricated by ligating commercially available 20 nm gold nanoparticles with BSA conjugated to one of three peptides, resulting in a final size of 24 nm. The intracellular location of these four conjugated gold nanoshells was investigated in three cell lines: HeLa, 3T3/NIH, and HepG2. In vitro, the M1-conjugated gold nanoparticles were found in clusters in the cytoplasm (most likely in endosomes) and they accumulated on the outside of the nuclear membrane of all cell types after 3 h. Gold nanoparticles conjugated with the M2 peptide were found only in the cytoplasm of HeLa and HepG2 cells after 3 h, but were not found in any compartment in the 3T3/NIH cells. The M3 peptide-conjugated gold nanoparticles were found in the nucleus of HeLa cells and were able to escape the endosome, but were only found in the cytoplasm of 3T3/NIH cells and were absent in HepG2 cells after 3 h. The M4 peptide-conjugated nanoparticles were found in the nucleus of HeLa and HepG2 cells, but only in the cytoplasm of 3T3/NIH cells after 3 h. Cytoplasm and nuclear trafficking of these gold nanoshells is largely dictated by the structure of the peptide and cell type. However, cationic charge is playing a role in cytoplasm and nuclear uptake. Thus, by careful selection of nano­systems and functionalizing ligands, intracellular trafficking and organelle targeting can be controlled.