Transfection of urothelial cells using methyl-beta-cyclodextrin solubilized cholesterol and Dotap

Gmcsf and Ifnα gene therapy improves the response to BCG immunotherapy in a murine model of bladder cancer

Aim: To develop a strategy to improve response to bacillus Calmette-Gueri (BCG) using cytokine gene therapy (Gmcsf + Ifnα). Materials & methods: MB49-PSA tumor-bearing C57BL/6N mice were assigned into four groups: control; Gmcsf + Ifnα therapy; BCG therapy or combined therapy (Gmcsf + Ifnα and BCG). In schedule 1, cytokine gene therapy was delivered before BCG therapy (eight instillations). In schedule 2, cytokine gene and BCG therapy were instilled alternatively (eight instillations). Tumors were analyzed by immunohistochemistry and mRNA analysis and urinary immune cells by flow cytometry. Results: Combined therapy in schedule 2 reduced tumor growth, increased immune cell recruitment and was associated with reduced inflammation when compared with BCG therapy. Conclusion: Alternating cytokine gene delivery with BCG therapy modulates the tumor environment increasing receptivity to BCG.

Polymeric Gene Carriers Bearing Pendant β-Cyclodextrin: The Relevance of Glycoside Permethylation on the "In Vitro" Cell Response

The incorporation of cyclodextrins (CDs) to nonviral cationic polymer vectors is very attractive due to recent studies that report a clear improvement of their cytocompatibility and transfection efficiency. However, a systematic study on the influence of the CD derivatization is still lacking. In this work, the relevance of β-CD permethylation has been addressed by preparing and evaluating two series of copolymers of the cationic N-ethyl pyrrolidine methacrylamide (EPA) and styrenic units bearing pendant hydroxylated and permethylated β-CDs (HCDSt and MeCDSt, respectively). For both cell lines, CDs permethylation shows a strong influence on plasmid DNA complexation, "in vitro" cytocompatibility and transfection efficiency of the resulting copolymers over two murine cell lines. While the incorporation of the hydroxylated CD moiety increased the cytotoxicity of the copolymers in comparison with their homopolycationic counterpart, the permethylated copolymers have shown full cytocompatibility as well as superior transfection efficiency than the controls. This behavior has been related to the different chemical nature of both units and tentatively to a different distribution of units along the polymeric chains. Cellular internalization analysis with fluorescent copo-lymers supports this behavior.

Polyethylenimine600-β-cyclodextrin: a promising nanopolymer for nonviral gene delivery of primary mesenchymal stem cells

Genetically modified mesenchymal stem cells (MSCs) have great potential in the application of regenerative medicine and molecular therapy. In the present manuscript, we introduce a nanopolymer, polyethylenimine₆₀₀-β-cyclodextrin (PEI₆₀₀-β-CyD), as an efficient polyplex-forming plasmid delivery agent with low toxicity and ideal transfection efficiency on primary MSCs. PEI₆₀₀-β-CyD causes significantly less cytotoxicity and apoptosis on MSCs than 25 kDa high-molecular-weight PEI (PEI25kDa). PEI₆₀₀-β-CyD also exhibits similar transfection efficiency as PEI25kDa on MSCs, which is higher than that of PEI600Da. Quantum dot-labeled plasmids show that PEI₆₀₀-β-CyD or PEI25kDa delivers the plasmids in a more scattered manner than PEI600Da does. Further study shows that PEI₆₀₀-β-CyD and PEI25kDa are more capable of delivering plasmids into the cell lysosome and nucleus than PEI600Da, which correlates well with the results of their transfection-efficiency assay. Moreover, among the three vectors, PEI₆₀₀-β-CyD has the most capacity of enhancing the alkaline phosphatase activity of MSCs by transfecting bone morphogenetic protein 2, 7, or special AT-rich sequence-binding protein 2. These results clearly indicate that PEI₆₀₀-β-CyD is a safe and effective candidate for the nonviral gene delivery of MSCs because of its ideal inclusion ability and proton sponge effect, and the application of this nanopolymer warrants further investigation.

Redox-responsive molecular nanoreservoirs for controlled intracellular anticancer drug delivery based on magnetic nanoparticles

A novel redox responsive controlled drug release system based on magnetic nanoparticles for efficient intracellular anticancer drug delivery is fabricated. Disulfide bonds are employed as intermediate linkers to immobilize PEI/β-CD molecules as nanoreservoirs for drug loading onto magnetic nanoparticles. The endocytotic pathway and endosomal escape of the smart controlled drug release system is proposed.

Tumor and microenvironment modification during progression of murine orthotopic bladder cancer

The aim of this study was to monitor changes in the expression of immune-related genes in the bladder after tumor implantation. Mice were orthotopically implanted with MB49-PSA cells (C57BL/6 mice) on day 1 and terminated on days 7, 14, 21, and 28. Another mouse model (MBT-2/C3H mice) was examined at day 7. Gene expression analysis was performed using a TaqMan Low Density Mouse Immune Panel (Applied Biosystems, USA) on RNA extracted from the bladders. Selected genes were reconfirmed by real-time PCR analysis and RT-PCR on the mRNA from other animals. Immune suppressive (IL13, IL1β, PTGS2, NOS2, IL10, CTLA4, and CCL22) and immune stimulatory genes (CSF2, GZMB, IFNγ, CXCL10, TNFα, CD80, IL12a, and IL6) and AGTR2 were increased by day 7. By day 28, IL10, CCL2, CCL5, CXCL11, CTLA4, GZMB, IFNγ, CSF2, and IL6 were significantly increased. Therapeutic strategies involving TH1 induction and TH2 dampening may improve responses to immunotherapy.

Cyclodextrin-PEI-Tat Polymer as a Vector for Plasmid DNA Delivery to Placenta Mesenchymal Stem Cells

This study aims to modify a cyclodextrin-PEI-based polymer, PEI-β-CyD, with the TAT peptide for plasmid DNA delivery to placenta mesenchymal stem cells (PMSCs). By using the disulfide exchange between the SPDP-activated PEI-β-CyD and TAT peptide, the TAT-PEI-β-CyD polymer was fabricated and the success of this was confirmed by the presence of characteristic peaks for PEI (at δ 2.8-3.2 ppm), CyD (at δ 5.2, 3.8-4.0 and 3.4-3.6 ppm) and TAT (at δ 1.6-1.9 and 6.8-7.2 ppm) in the (1)H NMR spectrum of TAT-PEI-β-CyD. The polymer-plasmid-DNA polyplex could condense DNA at an N/P ratio of 7.0-8.0, and form nanoparticles with the size of 150.6±5.6 nm at its optimal N/P ratio (20/1). By examining the transfection efficiency and cytotoxicity of TAT-PEI-β-CyD, conjugation of the TAT peptide onto PEI-β-CyD was demonstrated to improve the transfection efficiency of PEI-β-CyD in PMSCs after 48 and 96 hours of post-transfection incubation. The viability of PEI-β-CyD-treated PMSCs was shown to be over 80% after 5 h of treatment and 24 h of post-treatment incubation. In summary, this study showed that the TAT-PEI-β-CyD polymer as a vector for plasmid DNA delivery to PMSCs and other cells warrants further investigations. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12668-011-0010-9) contains supplementary material, which is available to authorized users.

Effects of mTOR inhibitor everolimus (RAD001) on bladder cancer cells

PURPOSE

We investigated the effect of the mTOR inhibitor RAD001 (everolimus) on human bladder cancer (BC) cells in vitro and in vivo.

EXPERIMENTAL DESIGN

The effect of RAD001 on the growth of UM-UC-3, UM-UC-6, UM-UC-9, and UM-UC-14 BC cells were assessed by crystal violet and [(3)H]thymidine incorporation assays. Flow cytometric cell-cycle analyses were done to measure the apoptotic cell fraction. Protein synthesis was measured using tritium-labeled leucine incorporation assays. The effects of RAD001 on the mTOR pathway were analyzed by Western blotting. To test the effects of RAD001 in vivo, UM-UC-3, UM-UC-6, and UM-UC-9 cells were subcutaneously implanted into nude mice. Tumor-bearing mice were treated orally with RAD001 or placebo. Tumors were harvested for immunohistochemical analysis.

RESULTS

In vitro, RAD001 transiently inhibited BC cell growth in a dose-dependent manner. This effect was augmented by re-treatment of cells after 3 days. UM-UC-14 cells were the most sensitive to RAD001, whereas UM-UC-9 cells were the least sensitive. After re-treatment with RAD001, only sensitive cell lines showed G(1)-phase arrest, with no evidence of apoptosis. RAD001 significantly inhibited the growth of tumors that were subcutaneously implanted in mice. Inhibition of protein synthesis through the S6K and 4EBP1 pathways seems to be the main mechanism for the RAD001-induced growth inhibition. However, inhibition of angiogenesis was the predominant mechanism of the effect of RAD001 on UM-UC-9 cells.

CONCLUSIONS

The mTOR inhibitor RAD001 inhibits growth of BC cells in vitro. RAD001 is effective in treating BC tumors in an in vivo nude mouse model despite the heterogeneity of in vitro responses.

In Vitro Gene Delivery Mediated by Asialofetuin-Appended Cationic Liposomes Associated with γ-Cyclodextrin into Hepatocytes

The purpose of this study is to evaluate in vitro gene delivery mediated by asialofetuin-appended cationic liposomes (AF-liposomes) associating cyclodextrins (CyD/AF-liposomes) as a hepatocyte-selective nonviral vector. Of various CyDs, AF-liposomes associated with plasmid DNA (pDNA) and γ-cyclodextrin (γ-CyD) (pDNA/γ-CyD/AF-liposomes) showed the highest gene transfer activity in HepG2 cells without any significant cytotoxicity. In addition, γ-CyD enhanced the encapsulation ratio of pDNA with AF-liposomes, and also increased gene transfer activity as the entrapment ratio of pDNA into AF-liposomes was increased. γ-CyD stabilized the liposomal membrane of AF-liposomes and inhibited the release of calcein from AF-liposomes. The stabilizing effect of γ-CyD may be, at least in part, involved in the enhancing gene transfer activity of pDNA/γ-CyD/AF-liposomes. Therefore, these results suggest the potential use of γ-CyD for an enhancer of transfection efficiency of AF-liposomes.

Cyclodextrin-based gene delivery systems

Cyclodextrin (CD) history has been largely dominated by their unique ability to form inclusion complexes with guests fitting in their hydrophobic cavity. Chemical funcionalization was soon recognized as a powerful mean for improving CD applications in a wide range of fields, including drug delivery, sensing or enzyme mimicking. However, 100 years after their discovery, CDs are still perceived as novel nanoobjects of undeveloped potential. This critical review provides an overview of different strategies to promote interactions between CD conjugates and genetic material by fully exploiting the inside-outside/upper-lower face anisotropy of the CD nanometric platform. Covalent modification, self-assembling and supramolecular ligation can be put forward with the ultimate goal to build artificial viruses for programmed and efficient gene therapy (222 references).

A novel co-polymer based on hydroxypropyl alpha-cyclodextrin conjugated to low molecular weight polyethylenimine as an in vitro gene delivery vector

A novel co-polymer based on 2-hydroxypropyl-alpha-cyclodextrin cross-linked by low molecular weight polyethylenimine was synthesized as a gene delivery vector. The copolymer could bind and condense DNA tightly. It showed lower cytotoxicity than PEI 25kDa in SK-BR-3 cells. Transfection efficiency was increased over 5.5-fold higher than PEI 25 kDa in SK-BR-3 cells in complete serum medium. It is a potential candidate vector for gene therapy.

Low molecular weight polyethylenimines linked by β-cyclodextrin for gene transfer into the nervous system

BACKGROUND

Polyethylenimines (PEIs) with high molecular weights are effective nonviral gene delivery vectors. However, the in vivo use of these PEIs can be hampered by their cellular toxicity. In the present study we developed and tested a new PEI polymer synthesized by linking less toxic, low molecular weight (MW) PEIs with a commonly used, biocompatible drug carrier, beta-cyclodextrin (CyD).

METHODS AND RESULTS

The terminal CyD hydroxyl groups were activated by 1,1'-carbonyldiimidazole. Each activated CyD then linked two branched PEI molecules with MW of 600 Da to form a CyD-containing polymer with MW of 61 kDa, in which CyD served as a part of the backbone. The PEI-CyD polymer developed was soluble in water and biodegradable. In cell viability assays with sensitive neurons, the polymer performed similarly to low-MW PEIs and displayed much lower cellular cytotoxicity compared to PEI 25 kDa. The gene delivery efficiency of the polymer was comparable to, and at higher polymer/DNA ratios even higher than, that offered by PEI 25 kDa in neural cells. Attractively, intrathecal injection of plasmid DNA complexed by the polymer into the rat spinal cord provided levels of gene expression close to that offered by PEI 25 kDa.

CONCLUSIONS

The polymer reported in the current study displayed improved biocompatibility over non-degradable PEI 25 kDa and mediated gene transfection in cultured neurons and in the central nervous system effectively. The new polymer would be worth exploring further as an in vivo delivery system of therapeutic genetic materials for gene therapy of neurological disorders.