Tomoaki Kurosaki

Kyoto University, Kyoto, Kyoto-fu, Japan

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Publications (15)61.71 Total impact

  • Article: Ocular gene delivery systems using ternary complexes of plasmid DNA, polyethylenimine, and anionic polymers.
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    ABSTRACT: In this experiment, we developed anionic ternary complexes for effective and safe ocular gene delivery. Ternary complexes were constructed by coating plasmid DNA (pDNA)/polyethylenimine (PEI) complex with anionic polymers such as γ-polyglutamic acid (γ-PGA) and chondroitin sulfate (CS). The cationic pDNA/PEI complex showed high gene expression on the human retinal pigment epithelial cell line, ARPE-19 cells. The pDNA/PEI complexes, however, also showed high cytotoxicity on the cells and aggregated strongly in the vitreous body. On the other hand, the anionic ternary complexes showed high gene expression on ARPE-19 cells without such cytotoxicity and aggregation. After intravitreous administration of the complexes, the anionic ternary complexes showed high gene expression in the retina. These results strongly indicate that anionic ternary complexes are suitable for effective and safe ocular gene therapy.
    Biological & Pharmaceutical Bulletin 01/2013; 36(1):96-101. · 1.66 Impact Factor
  • Article: Self-assemble gene delivery system for molecular targeting using nucleic acid aptamer.
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    ABSTRACT: We have developed a novel vector constructed with pDNA, polyethylenimine (PEI), and mucin 1 (MUC1) aptamer for tumor-targeted gene delivery. The MUC1 aptamer and non-specific aptamer were employed to coat the pDNA/PEI complexes electrostatically and stable nanoparticles were formed. The addition of a non-specific aptamer to the pDNA/PEI complex decreased gene expression in the human lung cancer cell line, A549 cells expressing MUC1 regularly. At the same time, the pDNA/PEI/MUC1 aptamer complex showed higher gene expression than pDNA/PEI/non-specific aptamer complex. Furthermore, the pDNA/PEI/MUC1 aptamer complex showed markedly high gene expression in tumor-bearing mice; thus, pDNA/PEI/MUC1 aptamer complexes are useful as a tumor-targeted gene delivery system with high transfection efficiency.
    Gene 01/2012; 491(2):205-9. · 2.34 Impact Factor
  • Article: Immunogenicity of novel nanoparticle-coated MSP-1 C-terminus malaria DNA vaccine using different routes of administration.
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    ABSTRACT: An important aspect in optimizing DNA vaccination is antigen delivery to the site of action. In this way, any alternative delivery system having higher transfection efficiency and eventual superior antibody production needs to be further explored. The novel nanoparticle, pDNA/PEI/γ-PGA complex, is one of a promising delivery system, which is taken up by cells and is shown to have high transfection efficiency. The immunostimulatory effect of this novel nanoparticle (NP) coated plasmid encoding Plasmodium yoelii MSP1-C-terminus was examined. Groups of C57BL/6 mice were immunized either with NP-coated MSP-1 plasmid, naked plasmid or NP-coated blank plasmid, by three different routes of administration; intravenous (i.v.), intraperitoneal (i.p.) and subcutaneous (s.c). Mice were primed and boosted twice at 3-week intervals, then challenged 2 weeks after; and 100%, 100% and 50% mean of survival was observed in immunized mice with coated DNA vaccine by i.p., i.v. and s.c., respectively. Coated DNA vaccine showed significant immunogenicity and elicited protective levels of antigen specific IgG and its subclass antibody, an increased proportion of CD4(+) and CD8(+) T cells and INF-γ and IL-12 levels in the serum and cultured splenocyte supernatant, as well as INF-γ producing cells in the spleen. We demonstrate that, NP-coated MSP-1 DNA-based vaccine confers protection against lethal P. yoelii challenge in murine model across the various route of administration and may therefore, be considered a promising delivery system for vaccination.
    Vaccine 09/2011; 29(48):9038-50. · 3.77 Impact Factor
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    Article: Development of effective cancer vaccine using targeting system of antigen protein to APCs.
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    ABSTRACT: To develop a novel cancer vaccine using the targeting system of antigen protein to antigen-presenting cells (APCs) for efficient and safe cancer therapy. The novel delivery system was constructed with antigen protein, benzalkonium chloride (BK), and γ-polyglutamic acid (γ-PGA), using ovalbumin (OVA) as a model antigen protein and evaluating its immune induction effects and utilities for cancer vaccine. BK and γ-PGA enabled encapsulation of OVA and formed stable anionic particles at nanoscale, OVA/BK/γ-PGA complex. Complex was taken up by dendritic cell line DC2.4 cells efficiently. We subcutaneously administered the complex to mice and examined induction of IgGs. The complex induced not only Th2-type immunoglobulins but also Th1-type immunoglobulins. OVA/BK/γ-PGA complex inhibited tumor growth of E.G7 cells expressing OVA regularly; administered OVA/BK/γ-PGA complex completely rejected tumor cells. The novel vaccine could be platform technology for a cancer vaccine.
    Pharmaceutical Research 09/2011; 29(2):483-9. · 4.09 Impact Factor
  • Article: Secure and effective gene vector of polyamidoamine dendrimer pharmaceutically modified with anionic polymer.
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    ABSTRACT: The purpose of this study was to develop a new type of gene vector, polyamidoamine (PAMAM) dendriplex pharmaceutically modified, based on electrostatic interactions, by various anionic polymers. The γ-polyglutamic acid (γ-PGA)/PAMAM dendriplex and the α-PGA/PAMAM dendriplex formed a stable complex, although α-polyaspartic acid and heparin released pDNA from the complex. The addition of anionic polymer decreased the ζ-potential, although it did not greatly affect the size of the complex. As a result of an in vitro gene expression study of mouse melanoma cells, we found that the γ-PGA/PAMAM dendriplex showed high gene expression comparable to the PAMAM dendriplex, although the α-PGA/PAMAM dendriplex showed lower gene expression. Tail vein injection of the γ-PGA/PAMAM dendriplex into mice also led to high gene expression in the spleen and lung. The γ-PGA/PAMAM dendriplex showed no cytotoxicity and no agglutination, although severe cytotoxicity and agglutination were observed in the PAMAM dendriplex. Thus, we discovered that complexes of pDNA, PAMAM dendrimers, and γ-PGA showed higher gene expression in vitro and in vivo, and markedly lower toxicity. This complex is valuable and is expected to be a safe and effective gene vector.
    Journal of Pharmaceutical Sciences 07/2011; 100(11):4855-63. · 3.06 Impact Factor
  • Article: Nanoparticles electrostatically coated with folic acid for effective gene therapy.
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    ABSTRACT: We developed a novel vector, electrostatically coated poly(ethylenimine) (PEI)/pDNA complexes with folic acid (FA). Without covalent binding, the FA molecules could coat the PEI/pDNA complexes, and stable anionic nanoparticles were formed at a charge ratio greater than 60. The addition of FA markedly decreased the cytotoxicity of the cationic PEI/pDNA complexes to the melanoma cell line, B16-F10 cells, which regularly expressed FA-specific receptor (FR). Furthermore, the anionic FA60/PEI/pDNA complexes showed high transgene efficiency via the FR-mediated pathway in B16-F10 cells. The FA60/PEI/pDNA complexes did not show agglutination with erythrocytes. After the intravenous injection of FA60/PEI/pDNA complexes into mice, a higher transgene efficiency than PEI/pDNA complexes was observed in the liver, kidney, spleen, and lung with FR. The gene expressions of FA60/PEI/pDNA complexes were significantly inhibited by preadministration of FA. Thus, the FA60/PEI/pDNA complexes were useful for effective gene therapy.
    Molecular Pharmaceutics 06/2011; 8(3):913-9. · 4.78 Impact Factor
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    Article: Chondroitin sulfate capsule system for efficient and secure gene delivery.
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    ABSTRACT: In this study, we developed various ternary complexes of encapsulated polyplexes and lipoplexes using chondroitin sulfate (CS) and investigated their universal usefulness for gene delivery. To prepare the cationic complexes, pDNA was mixed with some cationic vectors such as poly-L-arginine, poly-L-lysine, N-[1-(2, 3-dioleyloxy) propyl]-N, N, N-trimethylammonium chloride (DOTMA)-cholesterol liposomes, and DOTMA- dioleylphosphatidylethanolamine (DOPE) liposomes. CS was added to the cationic complexes for constructions of ternary complexes. We examined in vitro transfection efficiency, cytotoxicity, hematotoxicity, and in vivo transfection efficiency of the ternary complexes. The cationic polymers and cationic liposomes bound to pDNA and formed stable cationic polyplexes and lipoplexes, respectively. Those cationic complexes showed high transgene efficiency in B16-F10 cells; however, they also had high cytotoxicity and strong agglutination with erythrocytes. CS could encapsulate the polyplexes and lipoplexes and form stable anionic particles without disrupting their structures. The ternary complexes encapsulated by CS showed high transgene efficiency in B16-F10 cells with low cytotoxicity and agglutination. As the result of animal experiments, the polyplexes had little transgene efficiency after intravenous administration in mice, whereas polyplexes encapsulated by CS showed specifically high transgene efficiency in the spleen. The capsulation of CS, however, reduced the high transgene efficiency of the lipoplexes. These results indicate that CS can contribute to polyplex-mediated gene delivery systems for effective and safe gene therapy.
    Journal of pharmacy & pharmaceutical sciences: a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques 01/2010; 13(3):351-61. · 1.65 Impact Factor
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    Article: Gamma-polyglutamic acid-coated vectors for effective and safe gene therapy.
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    ABSTRACT: In the present study, we developed some novel gene delivery vectors, coated cationic complexes with gamma-polyglutamic acid (gamma-PGA) for effective and safe gene therapy. Cationic complexes were constructed with pDNA and cationic vectors, such as poly-L-arginine hydrochloride (PLA), poly-L-lysine hydrobromide (PLL), N-[1-(2, 3-dioleyloxy) propyl]-N, N, N-trimethylammonium chloride (DOTMA)-cholesterol (Chol) liposomes, and DOTMA-dioleylphosphatidylethanolamine (DOPE) liposomes. The cationic complexes showed high gene expression with strong cytotoxicity in melanoma B16-F10 cells. The cationic complexes were also strongly toxic to erythrocytes. On the other hand, the gamma-PGA was able to coat all cationic complexes and form stable nano-sized particles with negative charges. These gamma-PGA-coated complexes had high gene expression without cytotoxicity and toxicities to the erythrocytes. In in vivo transfection experiments, polyplexes showed high transfection efficiency over 10(5) RLU/g in the lung tissue after intravenous injection, although gamma-PGA-coated polyplexes showed a high value in the spleen. High transfection efficiency in lipoplexes and gamma-PGA-coated lipoplexes was observed in the spleen and lung. Thus, gamma-PGA-coated vectors are useful for clinical gene therapy.
    Journal of Controlled Release 11/2009; 142(3):404-10. · 5.73 Impact Factor
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    Article: The development of a gene vector electrostatically assembled with a polysaccharide capsule.
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    ABSTRACT: The purpose of this study was to develop a gene vector electrostatically assembled with a polysaccharide capsule. We used pDNA/polyethylenimine (PEI) complexes as efficient non-viral vectors. The pDNA/PEI complex was electrostatically encapsulated with various polysaccharides such as fucoidan, lambda-carrageenan, xanthan gum, alginic acid, hyaluronic acid, and chondroitin sulfate (CS). The pDNA/PEI complex was shown as nanoparticles with positive zeta-potential, although the ternary complexes encapsulated with polysaccharides were shown as nanoparticles with negative zeta-potential. The pDNA/PEI complex showed high agglutination activity and cytotoxicity, although the ternary complexes encapsulated with polysaccharides had no agglutination activities and lower cytotoxicities. The pDNA/PEI complex showed high uptake and high transgene efficiency in B16-F10 cells. On the other hand, most of the ternary complexes show little uptake and gene expression. The ternary complex encapsulated by CS, however, showed comparable transgene efficiency to the pDNA/PEI complex. The uptake and gene expression of the ternary complex encapsulated by CS were significantly inhibited by hypothermia and the addition of CS, suggesting that the ternary complex was taken by CS-specific receptor-mediated energy-dependent process.
    Biomaterials 06/2009; 30(26):4427-34. · 7.40 Impact Factor
  • Article: Cationic liposomes-mediated plasmid DNA delivery in murine hepatitis induced by carbon tetrachloride.
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    ABSTRACT: In order to elucidate the influence of hepatic disease stage on cationic liposomes-mediated gene delivery, we investigated the cationic liposomes-mediated plasmid DNA delivery with time in murine hepatitis induced by subcutaneous injection of CCl(4). Liver injury after injection of CCl(4) was confirmed by the determination of serum aspartate aminotransferase and alanine aminotransferase activities. Two kinds of liposomes constructed with N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethlylammoniumchloride and dioleylphosphatidylethanolamine (DOTMA-DOPE) or DOTMA and cholesterol (DOTMA-CHOL) were used for the gene-delivery vector. We determined luciferase activities in various organs after the intravenous administration of the lipoplexes. The CCl(4)-treated mice administered with DOTMA-DOPE lipoplexes showed the more significant decreases of transgene expression in the liver and spleen at 18 hours after CCl(4) injection. On the other hand, the CCl(4)-treated mice administered with DOTMA-CHOL lipoplexes showed a significant increase in the liver at 48 hours. In conclusion, our findings demonstrate that murine hepatitis induced by CCl(4) can influence cationic liposomes-mediated plasmid DNA delivery. The extent of influences was also affected by lipid contents. These results indicate the necessity of considering the timing and the formulation for gene therapy according to the disease stage.
    Journal of Liposome Research 03/2009; 19(2):141-7. · 1.71 Impact Factor
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    Article: Pulmonary gene delivery of hybrid vector, lipopolyplex containing N-lauroylsarcosine, via the systemic route.
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    ABSTRACT: We newly prepared lipopolyplexes containing N-lauroylsarcosine (LS) as a hybrid vector for pulmonary gene delivery via the systemic route. Lipopolyplexes were composed of polyethylenimine (PEI), N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethlylammonium chloride (DOTMA), LS, and plasmid DNA (pDNA). The particle size of lipopolyplex of PEI, DOTMA, and pDNA (lipopolyplex 2P-2D) was not largely changed by the addition of LS, although the addition of LS decreased the high zeta potential. Lipopolyplexes containing LS with low zeta potential showed little aggregation with erythrocytes and low cytotoxicity. In HepG2 cells, lipopolyplexes containing LS showed high transgene efficiency comparable to lipopolyplex 2P-2D. After intravenous injection of the complexes into mice, lipopolyplexes containing LS showed high transgene efficiency, comparable to lipopolyplex 2P-2D. In particular, lipopolyplexes containing LS showed extremely high transgene efficiency in the lung. As a result of the analysis to identify optimum formulations, we discovered that LS contributed to the high transgene efficiency in the lung as 76.7% of the contribution index. These results suggest that lipopolyplexes containing LS are safe and useful gene delivery vectors with lung directivity.
    Journal of Controlled Release 03/2009; 136(3):213-9. · 5.73 Impact Factor
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    Article: Ternary complexes of pDNA, polyethylenimine, and gamma-polyglutamic acid for gene delivery systems.
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    ABSTRACT: We discovered a vector coated by gamma-polyglutamic acid (gamma-PGA) for effective and safe gene delivery. In order to develop a useful non-viral vector, we prepared several ternary complexes constructed with pDNA, polyethylenimine (PEI), and various polyanions, such as polyadenylic acid, polyinosinic-polycytidylic acid, alpha-polyaspartic acid, alpha-polyglutamic acid, and gamma-PGA. The pDNA/PEI complex had a strong cationic surface charge and showed extremely high transgene efficiency although it agglutinated with erythrocytes and had extremely high cytotoxicity. Those polyanions changed the positive zeta-potential of pDNA/PEI complex to negative although they did not affect the size. They had no agglutination activities and lower cytotoxicities but most of the ternary complexes did not show any uptake and gene expression; however, the pDNA/PEI/gamma-PGA complex showed high uptake and gene expression. Most of the pDNA/PEI/gamma-PGA complexes were located in the cytoplasm without dissociation and a few complexes were observed in the nuclei. Hypothermia and the addition of gamma-PGA significantly inhibited the uptake of pDNA/PEI/gamma-PGA by the cells, although l-glutamic acid had no effect. These results strongly indicate that the pDNA/PEI/gamma-PGA complex was taken up by gamma-PGA-specific receptor-mediated energy-dependent process. Thus, the pDNA/PEI/gamma-PGA complex is useful as a gene delivery system with high transfection efficiency and low toxicity.
    Biomaterials 03/2009; 30(14):2846-53. · 7.40 Impact Factor
  • Article: Hybrid vector including polyethylenimine and cationic lipid, DOTMA, for gene delivery.
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    ABSTRACT: We developed polyethylenimine (PEI) lipopolyplexes with N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethlylammonium chloride (DOTMA) and pDNA to investigate their usefulness for in vitro and in vivo gene delivery. The charge ratio of the complex to pDNA was calculated with molar values of nitrogen of PEI, and nitrogen of DOTMA to phosphate of pDNA. The polyplexes were prepared at charge ratio 2 (polyplex 2P) and 8 (polyplex 8P). DOTMA solution was added to polyplex 2P to prepare lipopolyplexes at charge ratio 1 (lipopolyplex 2P-1D), 2 (lipopolyplex 2P-2D), and 4 (lipopolyplex 2P-4D). The particle size of the complex was significantly reduced by the addition of DOTMA and settled to 74-114nm, indicating pDNA compaction. The addition of DOTMA to polyplex 2P decreased pDNA dissociation from the complex and degradation in serum. The addition of DOTMA to polyplex 2P remarkably increased gene expression in HepG2 cells in the absence or presence of FBS. These lipopolyplexes showed little cytotoxicity in the presence of FBS. After intravenous injection of the lipopolyplexes into mice, high-gene expression in the liver, spleen, and lung was observed with lipopolyplex 2P-2D, lipopolyplex 2P-4D, and polyplex 8P. In particular, lipopolyplex 2P-4D showed the highest gene expression.
    International Journal of Pharmaceutics 08/2008; 363(1-2):58-65. · 3.35 Impact Factor
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    Article: Exploitation of De Novo helper-lipids for effective gene delivery.
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    ABSTRACT: In gene delivery, a fusogenic lipid such as dioleyl phosphatidylethanolamine (DOPE) which is a component of cationic liposomal vector is important factor for effective transfection efficiency. We investigated the effect of penetration enhancers as alternative helper-lipids to DOPE. Transdermal penetraion enhancers such as N-lauroylsarcosine (LS), (R)-(+)-limonene (LM), vitamin E (VE), and phosphatidyl choline from eggs (EggPC) were used in this experiments as helper-lipids with N-[1-(2, 3-dioleyloxy) propyl]-N, N, N-trimethlylammonium chloride (DOTMA) and cholesterol (CHOL). We examined in vitro transfection efficiency, cytotoxicity, hematotoxicity, and in vivo transfection efficiency of plasmid DNA/cationic liposomes complexes. In transfection experiments in vitro, the cationic lipoplexes containing LS had highest transfection efficiency among the other lipoplexes independently of FBS. Furthermore, the lipoplexes containing LS had lowest cell toxicity among the other lipoplexes in the presence of FBS. As the results of erythrocytes interaction experiment, DOTMA/LS/CHOL, DOTMA/VE/CHOL, and DOTMA/EggPC/CHOL lipoplexes showed extremely lower hematotoxicity. On the basis of these results, the in vivo transfection efficiencies of the lipoplexes were examined. The lipoplexes containing LS had the highest transfection activity among the other lipoplexes. In conclusion, several transdermal penetration enhancers are available for alternative helper-lipids to DOPE in cationic liposomal vectors. Among them, DOTMA/LS/CHOL lipoplexes showed superior characteristics in in vitro transfection efficiency, cell toxicity, hematotoxicity, and in vivo transfection efficiency.
    Journal of pharmacy & pharmaceutical sciences: a publication of the Canadian Society for Pharmaceutical Sciences, Societe canadienne des sciences pharmaceutiques 02/2008; 11(4):56-67. · 1.65 Impact Factor
  • Article: Ternary complexes of pDNA, polyethylenimine, and γ-polyglutamic acid for gene delivery systems
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    ABSTRACT: We discovered a vector coated by γ-polyglutamic acid (γ-PGA) for effective and safe gene delivery. In order to develop a useful non-viral vector, we prepared several ternary complexes constructed with pDNA, polyethylenimine (PEI), and various polyanions, such as polyadenylic acid, polyinosinic–polycytidylic acid, α-polyaspartic acid, α-polyglutamic acid, and γ-PGA. The pDNA/PEI complex had a strong cationic surface charge and showed extremely high transgene efficiency although it agglutinated with erythrocytes and had extremely high cytotoxicity. Those polyanions changed the positive ζ-potential of pDNA/PEI complex to negative although they did not affect the size. They had no agglutination activities and lower cytotoxicities but most of the ternary complexes did not show any uptake and gene expression; however, the pDNA/PEI/γ-PGA complex showed high uptake and gene expression. Most of the pDNA/PEI/γ-PGA complexes were located in the cytoplasm without dissociation and a few complexes were observed in the nuclei. Hypothermia and the addition of γ-PGA significantly inhibited the uptake of pDNA/PEI/γ-PGA by the cells, although l-glutamic acid had no effect. These results strongly indicate that the pDNA/PEI/γ-PGA complex was taken up by γ-PGA-specific receptor-mediated energy-dependent process. Thus, the pDNA/PEI/γ-PGA complex is useful as a gene delivery system with high transfection efficiency and low toxicity.
    Biomaterials 30(14):2846-2853. · 7.40 Impact Factor