[Synthesis of a supermolecular nanoparticle γ-hy-PC/Ada-Dox and its antitumor activity].

OBJECTIVE: To synthesize a (2-Hydroxypropyl)-γ-cyclodextrin-polyethylenimine/adamantane-conjugated doxorubicin (γ-hy-PC/Ada-Dox) based supramolecular nanoparticle with host-guest interaction and to identify its physicochemical characterizations and antitumor effect. METHODS: A novel non-viral gene delivery vector γ-hy-PC/Ada-Dox was synthesized based on host-guest interaction. 1H-NMR, NOESY, UV-Vis, XRD and TGA were used to confirm the structure of the vector. The DNA condensing ability of complexes was investigated by particle size, zeta potential and gel retardation assay. Cytotoxicity of complexes was determined by MTT assay in BEL-7402 and SMMC-7721 cells. Cell wound healing assay was performed in HEK293 and BEL-7404 cells. The transfection efficiency was investigated in HEK293 cells. H/E staining and cell uptake assay was performed in BEL-7402 cells. RESULTS: The structure of γ-hy-PC/Ada-Dox was characterized by 1H-NMR, NOESY, UV-Vis, XRD, TGA. The drug loading was 0.5% and 5.5%. Gel retardation assay showed that γ-hy-PC was able to completely condense DNA at N/P ratio of 2; 0.5% and 5.5% γ-hy-PC/Ada-Dox was able to completely condense DNA at N/P ratio of 3 and 4,respectively. The cytotoxicity of polymers was lower than that of PEI25KDa. The transfection efficiency of γ-hy-PC was higher than that of γ-hy-PC/Ada-Dox at N/P ratio of 30 in HEK293 cells; and the transfection efficiency was decreasing when Ada-Dox loading was increasing. Cell uptake assay showed that γ-hy-PC/Ada-Dox was able to carry drug and FAM-siRNA into cells. CONCLUSION: The novel vector γ-hy-PC/Ada-Dox has been developed successfully, which has certain transfection efficiency and antitumor activity.

[Modified montmorillonite as multifunction gene and drug delivery system].

OBJECTIVE: To develop polyethylenimine-Doxorubicin-montmorillonite (PEI-Dox-MTT) as a novel multifunction delivery system. METHODS: Dox was intercalated into montmorillonite, PEI covered to the surface of Dox/MMT to make the nano-particle. XRD, FT-IR and TGA were used to confirm chemical property of the nano-particle. SEM was used to observe the morphology. The capability of drug release was investigated by PBS buffer solution (pH 7.4). The DNA binding ability of nano-particle was detected by gel electrophoresis retardation assay. The cell viability in COS-7 and SKOV3 cell lines was tested using MTT assay. The gastric mucosa protection was evaluated in vitro. RESULTS: XRD image showed that Dox was intercalated into montmorillonite, inter space of which increased to 31.3Å; the FT-IR spectra showed the vibration bands of PEI at 1 560 cm(-1) and 2 850 cm(-1), the vibration band of Dox at 1 350 cm(-1). Size analysis and SEM revealed that the size of nano-particle was 600 nm, and the zeta-potential was 30 mV. Drug release experiment explored that the nano-particle stably released drug in range of 6 X10(-4) ≊ 8 X10(-4) mg/ml within 72 h. MTT assay showed that the cell viability was over 80% in experiment condition in COS-7 and SKOV3 cell lines. 0.3 mg PEI-MMT nano-particle was able to protect gastric mucosa from alcohol. CONCLUSION: Multifunction system of PEI/Dox/MMT has been prepared successfully.

[Platinum tetrachloride coupled PEG-PEI as drug carrier and gene delivery vector].

OBJECTIVE: To construct a drug carrier and gene vector PEG-PEI-Pt. METHODS: Polyethyleneglycol (PEG) was coupled to polyethylenimine (PEI 600) and platinum tetrachloride; PEG-PEI-Pt complex was formed in ethanol. The complex was characterized by XRD, UV-VIS and FT-IR and the DNA condensation was tested by electrophoretic mobility shift assay. The cell viability was evaluated by MTT assay in Hela, B16, A293 and COS-7 cells and in vitro transfection efficiency was measured in A293 and B16 cells. RESULT: The structure of PEG-PEI-Pt was characterized by XRD, UV-VIS and FT-IR. PEG-PEI-Pt complex was able to bind DNA at N/P weight ratio of 0.4:1; the complex showed cytotoxicity on Hela and B16 cells. The complex had higher transfection efficiency in A293 and B16 cells than PEI 600. CONCLUSION: A novel drug carrier and gene vector PEG-PEI-Pt was constructed successfully.

[Peptide CY11 conjugated polyethylenimine-beta-cyclodextrin for gene delivery].

OBJECTIVE: To develop a novel non-viral gene delivery vector CY11-PEI-beta-CyD and to test its gene transfection efficiency. METHODS: 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. RESULT: 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. CONCLUSION: The novel vector CY11 -PEI-beta-CyD with low cytotoxic and high transfection efficiency may be used as a potential carrier for gene delivery.