lipofectamine and alpha-cyclodextrin

Polyamidoamine (PAMAM) dendrimers as synthetic gene vectors are efficient gene delivery systems. In this study, a kind of α-cyclodextrin-PAMAM conjugates polymer (Cy D-G1) was synthesized as a gene delivery vector. Based on ~1H NMR detectation, about 6.4 PAMAM-G1 molecules was grafted onto an α-CD core. Agarose gel electrophoresis revealed that Cy D-G1 could efficiently bind with DNA to condense them into nano-scale particles, which showed a similar binding capacity of PEI-25 K. Besides, it could protect DNA from DNase I degradation in a low N/P ratio. When N/P ratio in the CyD-G1/DNA polyplex was 40, the average particle size of CyD-G1/DNA polyplex was about 120 nm, and zeta potential was +21 mV. This polyplex could maintain its particle size in serum-containing solution within 360 min. In comparison with PEI-25 K carrier, CyD-G1 showed low cytotoxicity in various cell lines. Cell transfection results showed that CyD-G1 efficiently delivered DNA into cells at N/P = 80 compared with Lipofectamine 2000 and PEI-25 K. Unlike Lipofectamine 2000 and PEI-25 K, in serum-containing test condition, CyD-G1/DNA polyplex could maintain the transgene activities. The results of confocal laser scanning microscopy indicated that most DNA entered into cell nuclei within 4 h, and this phenomenon was consistent with the results calculated by flow cytometry. Taken together, CyD-G1 showed good transgene activities and the gene delivery vector could be used not only in vitro but also in vivo.

Topics: alpha-Cyclodextrins; Cations; Cell Line; Dendrimers; DNA; Electrophoresis, Agar Gel; Gene Transfer Techniques; Genetic Vectors; Humans; Lipids; Particle Size; Polyamines; Polymers; Serum; Transfection; Transgenes

RNA interference has broad therapeutic potential due to its high specificity and ability to potentially evade drug resistance. Three cationic α-cyclodextrin:poly(ethylene glycol) polyrotaxanes derived from polymer axles of different sizes (MW 2,000, 3,400, and 10,000) have been synthesized for delivering siRNA. These polyrotaxanes are able to condense siRNA into positively charged particles that are <200 nm in diameter, enabling their facile internalization into mammalian cells. The cationic polyrotaxanes display cytotoxicity profiles that are >10(2)-fold lower than the commercial standard bPEI and gene silencing efficiencies that are comparable to those of both Lipofectamine 2000 and bPEI. Our findings suggest that the cationic polyrotaxanes display a size-activity relationship, wherein the higher molecular weight polyrotaxanes (PEG3,400 and 10,000) are able to condense and deliver siRNA better than the lower molecular weight material (PEG2,000).

Topics: alpha-Cyclodextrins; Animals; Cations; CHO Cells; Cricetinae; Cricetulus; Cyclodextrins; Gene Transfer Techniques; Genetic Vectors; Green Fluorescent Proteins; Lipids; Mice; Microscopy, Atomic Force; Molecular Weight; NIH 3T3 Cells; Particle Size; Polyethylene Glycols; RNA Interference; RNA, Small Interfering; Rotaxanes; Solvents