ABSTRACT
Polyamidoamine (PAMAM) dendrimers as synthetic gene vectors are efficient gene delivery systems. In this study, a kind of α-cyclodextrin-PAMAM conjugates polymer (CyD-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 CyD-G1 could efficiently bind with DNA to condense them into nano-scale particles, which showed a similar binding capacity of PEI-25K. 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-25K 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-25K.Unlike Lipofectamine 2000 and PEI-25K, 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.
ABSTRACT
Currently, polyethylenimine(PEI) is one of the most promising non-viral gene delivery vectors. However, high relative molecular mass PEI has obvious toxicity and is short of targeting or specificity to cells or tissues. As we know targeting or specificity is the key property of ideal gene delivery systems. Therefore, PEI should be modified to become a gene vector with targeting and low toxicity. Up to now investgations on modification of PEI for targeting effect mainly include:1.modification with endogenous ligands such as transferrin Tf RGD peptide etc 2.modification with carbohydrate such as galactose etc 3.modification with specific antibody. Of these, the specific antibody-directed PEI is anticipated to be one of promising and distinctive targeting gene delivery carriers. The present paper summarises literature on PEI as targeted gene delivery vectors.
ABSTRACT
Currently, polyethylenimine(PEI) is one of the most promising non-viral gene delivery vectors. However, high relative molecular mass PEI has obvious toxicity and is short of targeting or specificity to cells or tissues. As we know, targeting or specificity is the key property of ideal gene delivery systems. Therefore, PEI should be modified to become a gene vector with targeting and low toxicity. Up to now, investgations on modification of PEI for targeting effect mainly include:1.modification with endogenous ligands such as transferrin(Tf),RGD peptide, etc;2.modification with carbohydrate such as galactose,etc;3.modification with specific antibody. Of these, the specific antibody-directed PEI is anticipated to be one of promising and distinctive targeting gene delivery carriers. The present paper summarises literature on PEI as targeted gene delivery vectors.
ABSTRACT
Objective To modify polyargine (PLR) with polyethylene glycol (PEG) and to observe the effect of PEG modilication on PLR cytotoxicity and efticiency of PLR-mediated RNA interference. Methods1 HNMR was used to characterize PLR-PEG and gel electrophoresis was adopted to determine the siRNA-packing capacity of PLR-PEG. The cytotoxicity of PLR-PEG, cellular uptake and RNA interference efficiency of PLR-PEG/siRNA complexes were investigated using prostate cancer stem-like cells(RC-92a/hTERT). Results1 HNMR results showed the successful synthesis of PLR-PEG. It was found that PEG modiiication decreased cytotoxicity of PLR and reduced cellular uptake of PLR/siRNA complexes, but the reduction of cellular uptake was limited when N/P was high. The modiiication also inhibited the efticiency of PLR-mediated RNA interference, but the influence of PEG moditication was not notable within a certain range. Conclusion PEG-moditied PLR may be a promising vector for gene therapy targeting prostate cancer stem cells.