Peptide CY11 conjugated polyethylenimine-beta-cyclodextrin for gene delivery / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a novel non-viral gene delivery vector CY11-PEI-beta-CyD and to test its gene transfection efficiency.</p><p><b>METHODS</b>CY11 (CGMQLPLATWY) was conjugated to polyethylenimine-beta-cyclodextrin to form CY11-PEI-beta-CyD with a cross-linker [N-succinimidy-3-(2-pyridyldithio) propionate, SPDP]. (1)H-NMR and TGA were used to confirm the structure of vector. The DNA condensing ability of CY11-PEI-beta-CyD was investigated by gel retardation assay. Cytotoxicity of CY11-PEI-beta-CyD was determined by MTT assay and transfection efficiency was investigated in COS-7, Hela and B16 cells.</p><p><b>RESULT</b>CY11 was conjugated onto PEI-beta-CyD successfully, confirmed by(1)H NMR and TGA. The novel vector effectively condensed DNA at N/P ratio of 4îIt showed low cytotoxicity up to the concentration was 160 Mgr;g/ml. The transfection efficiency was 17-fold higher than that of PEI 25 kDa at N/P ratio of 20.</p><p><b>CONCLUSION</b>The novel vector CY11 -PEI-beta-CyD with low cytotoxic and high transfection efficiency may be used as a potential carrier for gene delivery.</p>

Poly-aspartamide-glutamic acid grafted low molecular weight polyethylenimine as a novel non-viral gene vector / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a novel gene delivery vector with poly-aspartamide-glutamic acid and polyethylenimine as the backbone.</p><p><b>METHODS</b>alpha, beta-poly-(N-2-hydroxypropyl)-D, L-aspartamide-glutamic acid (PHPAG) was synthesized and low molecular weight polyethylenimine (PEI 1.8 kDa) was grafted to form PHPAG-PEI 1800. Chemical and biological characterization of the polymer was identified.</p><p><b>RESULT</b>The polymer was confirmed by (1)H-NMR, and the molecular weight was about 1.2 x 10(4). The ability of DNA binding was showed by gel retardation assay at N/P ratio of 3. 5. MTT assay showed that the polymer was non toxic in COS-7 and A293 cell lines. In vitro test demonstrated that it had high transfection efficiency in B16 and Hela cell lines.</p><p><b>CONCLUSION</b>PHPAG-PEI 1800 was successfully synthesized,which might be a potential vector for gene delivery.</p>

Lentinan-graft-polyethylenimine-a novel vector for gene delivery / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a novel vector for gene delivery with low molecular weight polyethylenimine grafted to the natural polysaccharide and conjugated to folic acid (LNT-PEI-FA).</p><p><b>METHODS</b>The properties of LNT-PEI-FA were characterized by (1)H-NMR, FT-IR and TGA, respectively. The particle size of LNT-PEI-FA/DNA complex was measured. The DNA binding ability of LNT-PEI-FA was detected by gel electrophoresis retardation assay.</p><p><b>RESULT</b>The particle size of LNT-PEI-FA/DNA complex was about 200 nm. Gel electrophoresis showed that at N/P ratio of 1.8 (W/W) the polymer was able to completely condense DNA. In vitro experiments showed a high efficiency of gene transfection in A293 and B16 cell lines.</p><p><b>CONCLUSION</b>A novel non-viral vector LNT-PEI-FA was successfully synthesized and characterized, which may be applied in gene transfection research in the future.</p>

Preparation of floxuridine loaded polycation and its antitumor activity / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop a new prodrug of 5-fluorouracil-polyethylenimine-beta-cyclodextrin-floxuridine (PEI-beta-CyD-Fd) and to test its antitumor activity.</p><p><b>METHODS</b>Floxuridine was conjugated to polyethylenimine-beta-cyclodextrin to form prodrug PEI-beta-CyD-Fd. The structure of synthesized PEI-beta-CyD-Fd was confirmed by (1)H-NMR, FT-IR and UV. MTT assay and cell wound healing assay were performed on human hepatic carcinoma cell line HepG2.</p><p><b>RESULT</b>The drug loading was 2 %. The MTT assay and cell wound healing assay indicated that PEI-beta-CyD-Fd significantly inhibited proliferation and migration of HepG2 cells.</p><p><b>CONCLUSION</b>The synthesized prodrug PEI-CyD-Fd has a significant antitumor activity on HepG2 cells.</p>