The Research And Evaluation Of Supra-Molecular Nanoparticles As Chemotherapy Drug And Gene Co-delivery System

Objective:To synthesize aβ-cyclodextrin/adamantane based supramolecular nanoparticles(SNPs) with host-guest interaction which could perform co-delivery of anti-cancer drug and gene plasmid. To explore the drug release profile and transfection efficiency and evaluate the therapeutic effects on the inhibition of tumor growth. Methods:1-Adamantanecarboxylic acid was conjugated with doxorubicin by carbonyldiimidazole activation and then mixed with PEI-CD to form supramolecular structure of PEI-CD/Ad-Dox by host-guest self-assembly reaction. The supramolecular structure were analyzed by chemical, physical and biological characterization. After combining and condensing the TRAIL-encoding gene to form the SNPs, the cellular uptake, expression of TRAIL protein, influence on cellular apoptosis and cytotoxicity of the nanoparticles was examined to comfirm their in vitro anti-tumor effect. To explore the in vivo anti-cancer effect of SNPs the tumor growth and survival time was observed after intratumorally injection on SKOV-3 xenografted tumor-bearing BALB/c nude mice.Results:According to the results of 1H NMR, NOESY spectrum and TGA, doxorubicin was coupled with adamantane successfully and conjugated with PEI-CD to form supramolecular complexes via host-guest interaction. The results of gel retardation assay showed that the condensation and complete retardation of pDNA occurred at the nitrogen/phosphorus (N/P) ratio lower than 3. The SNPs were visulized under TEM and SEM, they showed a spherical morphology with high dispersity and suitable particle size and zeta potential for gene transfection in water, normal saline and RPMI 1640 culture medium. The in vitro drug release profile showed the pH-dependent and sustained release process with first-order kinetics followed by zero-order release. The cellular uptake and western blot analysis further conformed the cooperative process of drug delivery and gene expression. MTT assay indicated the efficient inhibition of SKOV-3 cell proliferation and enhanced cytotoxicity. FCM analysis showed cell cycle was blocked in G0/G1 phase and the cell apoptosis rate was increased when SKOV-3 cells were treated with SNPs comparing to the untreated cells. The TUNNEL assay further confirmed the increased amount of apoptotic cells. Prolonged drug retention and gene expression in tumor tissue were identified after the SNPs were given intratumorally. The in vivo anti-cancer effect was evaluated on SKOV-3 tumor bearing BALB/c nude mice with in situ treatment. The SNP-treated group showed the most effective inhibition of tumor growth. HE staining examination revealed the increased amount of apoptotic tumor cells in the tissue. The mice survival was prolonged significantly.Conclusion:SNPs of PEI-CD/Ada-Dox conjugated with DNA, which performed co-delivery of anti-cancer drug and gene plasmid, were constructed. It's the first time to use the SNPs to treat the ovarian cancer. The SNPs could improve the sensibility of cancer cells and show the synergistic therapeutic effect, indicating a promising future of the collaborative applications of chemotherapeutic agents and gene drugs.