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Toshikazu Bando - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the dna alkylation properties of a chlorambucil conjugated cyclic pyrrole imidazole polyamide
2021Co-Authors: Yuki Hirose, Kaori Hashiya, Toshikazu BandoAbstract:Hairpin pyrrole-imidazole polyamides (hPIPs) and their chlorambucil (Chb) conjugates (hPIP-Chbs) can alkylate DNA in a sequence-specific manner, and have been studied as anticancer drugs. Here, we conjugated Chb to a cyclic PIP (cPIP), which is known to have a higher binding affinity than the corresponding hPIP, and investigated the DNA alkylation properties of the resulting cPIP-Chb using the optimized capillary electrophoresis method and conventional HPLC product analysis. cPIP-Chb conjugate 3 showed higher alkylation activity at its binding sites than did hPIP-Chb conjugates 1 and 2. Subsequent HPLC analysis revealed that the alkylation site of conjugate 3, which was identified by capillary electrophoresis, was reliable and that conjugate 3 alkylates the N3 position of adenine as do hPIP-Chbs. Moreover, conjugate 3 showed higher cytotoxicity against LNCaP prostate cancer cells than did conjugate 1 and cytotoxicity comparable to that of conjugate 2. These results suggest that cPIP-Chbs could be novel DNA alkylating anticancer drugs.
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evaluation of the dna alkylation property of a chlorambucil conjugated cyclic pyrrole imidazole polyamide
2020Co-Authors: Yuki Hirose, Kaori Hashiya, Toshikazu BandoAbstract:Hairpin pyrrole-imidazole polyamides (hPIPs) and their chlorambucil (Chb) conjugates (hPIP-Chbs) can alkylate DNA in a sequence-specific manner, and have been studied as anticancer drugs. Here we conjugated Chb to a cyclic PIP (cPIP), which is known to have a higher binding affinity than the corresponding hPIP, and investigated the DNA alkylation properties of the cPIP-Chb using the optimized capillary electrophoresis method and conventional HPLC product analysis. cPIP-Chb conjugate 3 showed higher alkylation activity at its binding sites than did hPIP-Chb conjugates 1 and 2 . Subsequent HPLC analysis revealed that the alkylation site of conjugate 3 , which was identified by capillary electrophoresis, was reliable and that conjugate 3 alkylates the N3 position of adenine as do hPIP-Chbs. Moreover, conjugate 3 showed higher cytotoxicity against LNCaP prostate cancer cells than did conjugate 1 and cytotoxicity comparable to that of conjugate 2 . These results suggest that cPIP-Chbs could be novel DNA alkylating anticancer drugs.
Yuki Hirose - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the dna alkylation properties of a chlorambucil conjugated cyclic pyrrole imidazole polyamide
2021Co-Authors: Yuki Hirose, Kaori Hashiya, Toshikazu BandoAbstract:Hairpin pyrrole-imidazole polyamides (hPIPs) and their chlorambucil (Chb) conjugates (hPIP-Chbs) can alkylate DNA in a sequence-specific manner, and have been studied as anticancer drugs. Here, we conjugated Chb to a cyclic PIP (cPIP), which is known to have a higher binding affinity than the corresponding hPIP, and investigated the DNA alkylation properties of the resulting cPIP-Chb using the optimized capillary electrophoresis method and conventional HPLC product analysis. cPIP-Chb conjugate 3 showed higher alkylation activity at its binding sites than did hPIP-Chb conjugates 1 and 2. Subsequent HPLC analysis revealed that the alkylation site of conjugate 3, which was identified by capillary electrophoresis, was reliable and that conjugate 3 alkylates the N3 position of adenine as do hPIP-Chbs. Moreover, conjugate 3 showed higher cytotoxicity against LNCaP prostate cancer cells than did conjugate 1 and cytotoxicity comparable to that of conjugate 2. These results suggest that cPIP-Chbs could be novel DNA alkylating anticancer drugs.
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evaluation of the dna alkylation property of a chlorambucil conjugated cyclic pyrrole imidazole polyamide
2020Co-Authors: Yuki Hirose, Kaori Hashiya, Toshikazu BandoAbstract:Hairpin pyrrole-imidazole polyamides (hPIPs) and their chlorambucil (Chb) conjugates (hPIP-Chbs) can alkylate DNA in a sequence-specific manner, and have been studied as anticancer drugs. Here we conjugated Chb to a cyclic PIP (cPIP), which is known to have a higher binding affinity than the corresponding hPIP, and investigated the DNA alkylation properties of the cPIP-Chb using the optimized capillary electrophoresis method and conventional HPLC product analysis. cPIP-Chb conjugate 3 showed higher alkylation activity at its binding sites than did hPIP-Chb conjugates 1 and 2 . Subsequent HPLC analysis revealed that the alkylation site of conjugate 3 , which was identified by capillary electrophoresis, was reliable and that conjugate 3 alkylates the N3 position of adenine as do hPIP-Chbs. Moreover, conjugate 3 showed higher cytotoxicity against LNCaP prostate cancer cells than did conjugate 1 and cytotoxicity comparable to that of conjugate 2 . These results suggest that cPIP-Chbs could be novel DNA alkylating anticancer drugs.
Kaori Hashiya - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the dna alkylation properties of a chlorambucil conjugated cyclic pyrrole imidazole polyamide
2021Co-Authors: Yuki Hirose, Kaori Hashiya, Toshikazu BandoAbstract:Hairpin pyrrole-imidazole polyamides (hPIPs) and their chlorambucil (Chb) conjugates (hPIP-Chbs) can alkylate DNA in a sequence-specific manner, and have been studied as anticancer drugs. Here, we conjugated Chb to a cyclic PIP (cPIP), which is known to have a higher binding affinity than the corresponding hPIP, and investigated the DNA alkylation properties of the resulting cPIP-Chb using the optimized capillary electrophoresis method and conventional HPLC product analysis. cPIP-Chb conjugate 3 showed higher alkylation activity at its binding sites than did hPIP-Chb conjugates 1 and 2. Subsequent HPLC analysis revealed that the alkylation site of conjugate 3, which was identified by capillary electrophoresis, was reliable and that conjugate 3 alkylates the N3 position of adenine as do hPIP-Chbs. Moreover, conjugate 3 showed higher cytotoxicity against LNCaP prostate cancer cells than did conjugate 1 and cytotoxicity comparable to that of conjugate 2. These results suggest that cPIP-Chbs could be novel DNA alkylating anticancer drugs.
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evaluation of the dna alkylation property of a chlorambucil conjugated cyclic pyrrole imidazole polyamide
2020Co-Authors: Yuki Hirose, Kaori Hashiya, Toshikazu BandoAbstract:Hairpin pyrrole-imidazole polyamides (hPIPs) and their chlorambucil (Chb) conjugates (hPIP-Chbs) can alkylate DNA in a sequence-specific manner, and have been studied as anticancer drugs. Here we conjugated Chb to a cyclic PIP (cPIP), which is known to have a higher binding affinity than the corresponding hPIP, and investigated the DNA alkylation properties of the cPIP-Chb using the optimized capillary electrophoresis method and conventional HPLC product analysis. cPIP-Chb conjugate 3 showed higher alkylation activity at its binding sites than did hPIP-Chb conjugates 1 and 2 . Subsequent HPLC analysis revealed that the alkylation site of conjugate 3 , which was identified by capillary electrophoresis, was reliable and that conjugate 3 alkylates the N3 position of adenine as do hPIP-Chbs. Moreover, conjugate 3 showed higher cytotoxicity against LNCaP prostate cancer cells than did conjugate 1 and cytotoxicity comparable to that of conjugate 2 . These results suggest that cPIP-Chbs could be novel DNA alkylating anticancer drugs.
Rangaramanujam M Kannan - One of the best experts on this subject based on the ideXlab platform.
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drug release characteristics of pamam dendrimer drug conjugates with different linkers
2010Co-Authors: Yunus E Kurtoglu, Sujatha Kannan, Manoj K Mishra, Rangaramanujam M KannanAbstract:Drug release from polymer-drug conjugates plays a crucial role on the efficacy. This is especially true for dendrimers where there is a steric crowding at the surface. The drug release characteristics of G4-polyamidoamine (PAMAM) dendrimer-ibuprofen conjugates with ester, amide, and peptide linkers were investigated, in addition to a linear PEG-ibuprofen conjugate to understand the effect of architecture and linker on drug release. Ibuprofen was directly conjugated to NH(2)-terminated dendrimer by an amide bond and OH-terminated dendrimer by an ester bond. A tetra-peptide-linked dendrimer conjugate and a linear mPEG-ibuprofen conjugate were also studied for comparison to direct linked dendrimer conjugates. Amide-linked conjugates were relatively stable against hydrolysis, whereas the ester-linked conjugates showed pH-dependent release and the extent of release varied with pH from 3% (pH 5) to 38% (pH 8.5) for the 10-day period studied. Direct amide- and ester-linked conjugates did not release ibuprofen enzymatically in cathepsin B buffer and diluted human plasma. In contrast, mPEG conjugate released 65% of its payload within 12 h in diluted plasma by esterase activity, and the peptide-linked dendrimer conjugate released 40% of its payload within 48 h by cathepsin B activity. It is demonstrated that the steric crowding at the surface of PAMAM dendrimer-drug conjugates, along with linking chemistry govern the drug release mechanisms as well as kinetics. Understanding these structural and steric effects on their drug release characteristics is crucial for the design of dendrimer conjugates with high efficacy.
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effects of branching architecture and linker on the activity of hyperbranched polymer drug conjugates
2009Co-Authors: Omathanu P Perumal, Jayant Khandare, Parag Kolhe, Sujatha Kannan, Mary Liehlai, Rangaramanujam M KannanAbstract:Drug release from hyperbranched polymer−drug conjugates and the subsequent activity are influenced by the branching architecture and the linker. To gain an understanding of these effects, we used hyperbranched polyol and G4-OH polyamidoamine (PAMAM) dendrimer with methyl prednisolone (MP) as the model drug. The drug was conjugated to dendrimer or polyol using a glutaric acid (GA) or a succinic acid (SA) spacer. Drug payload was the highest with polyol, while in the case of dendrimer, a higher payload was achieved with the GA than the SA spacer. Cell uptake of the polymer conjugates in A549 lung epithelial cells was higher than that of the free drug, and the conjugates largely localized in the cytosol. The anti-inflammatory activity of polymer conjugated MP, as measured by inhibition of prostaglandin synthesis, was the highest for MP-SA-dendrimer conjugate, followed by MP-GA-polyol conjugate, and then MP-GA-dendrimer conjugate. This study suggests that the branching architecture and spacer influence the dr...
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preparation cellular transport and activity of polyamidoamine based dendritic nanodevices with a high drug payload
2006Co-Authors: Parag Kolhe, Jayant Khandare, Sujatha Kannan, Mary Liehlai, Omathanu Pillai, Rangaramanujam M KannanAbstract:Dendrimers are emerging as a relatively new class of polymeric biomaterials with applications in drug delivery, and imaging. Achieving a high drug payload in dendrimers, and understanding the therapeutic effect of the dendrimer-drug conjugates are receiving increasing attention. A high drug payload nanodevice was obtained by covalent conjugation of ibuprofen to a polyamidoamine (PAMAM-G4-OH) dendrimer. Using DCC as a coupling agent, 58 molecules of ibuprofen were covalently conjugated to one molecule of generation 4 PAMAM-OH dendrimer. Cellular entry of the fluoroisothiocynate (FITC)-labeled dendrimer-drug conjugate was evaluated in vitro by using human lung epithelial carcinoma A549 cells by flow cytometry, confocal microscopy and UV/Visible spectroscopy. The pharmacological activity of the dendrimer-ibuprofen conjugate was compared to pure ibuprofen at various time points by measuring the suppression of prostaglandin E2. Significant amounts of the conjugate entered the cells rapidly within 15 min. Suppression of prostaglandin was noted within 30 min for the dendrimer-drug conjugates versus 1 h for the free ibuprofen. The results suggest that dendrimers with high drug payload improve the drug's efficacy by enhanced cellular delivery, and may produce a rapid pharmacological response. These dendrimer-drug conjugates can potentially be further modified by attaching antibodies and ligands for targeted drug delivery.
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synthesis cellular transport and activity of polyamidoamine dendrimer methylprednisolone conjugates
2005Co-Authors: Jayant Khandare, Parag Kolhe, Sujatha Kannan, Mary Liehlai, Omathanu Pillai, Rangaramanujam M KannanAbstract:Dendrimers have emerged as promising multifunctional nanomaterials for drug delivery due to their well-defined size and tailorability. We compare two schemes to obtain methylprednisolone (MP)−polyamidoamine dendrimer (PAMAM-G4-OH) conjugate. Glutaric acid (GA) was used as a spacer to facilitate the conjugation. In scheme A, PAMAM-G4-OH was first coupled to GA and then further conjugated with MP to obtain PAMAM-G4−GA−MP conjugates. This scheme yields a lower conjugation ratio of MP, presumably because of lower reactivity and steric hindrance for the steroid at the crowded dendrimer periphery. In scheme B, this steric hindrance was overcome by first preparing the MP−GA conjugate, which was then coupled to the PAMAM-G4-OH dendrimer. The 1H NMR spectrum of the conjugate from scheme B indicates a conjugation of 12 molecules of MP with the dendrimer, corresponding to a payload of 32 wt %. In addition, conjugates were further fluorescent-labeled with fluoroisothiocynate (FITC) to evaluate the dynamics of cellula...
Kazutetsu Nojima - One of the best experts on this subject based on the ideXlab platform.
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direct determination of naturally occurring biologically active compound serum albumin conjugate by matrix assisted laser desorption ionization mass spectrometry
2001Co-Authors: Hiroyuki Tanaka, R Isobe, Lijiang Xuan, Yukihiro Shoyama, Satoshi Morimoto, Kazutetsu NojimaAbstract:Opium alkaloids were conjugated with bovine serum albumin (BSA) to give individual antigen conjugates which were analyzed using BSA as an internal standard by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. It became clear that 9 molecules of thebaine were conjugated in a thebaine–BSA conjugate. Codeine and morphine contents in individual conjugates were determined to be 12 and 6 molecules, respectively. Using a relative molecular mass of BSA, 11.5 molecules of forskolin conjugated with BSA. Tetrahydrocannabinolic acid (THCA)–carrier protein conjugates using β-alanine or without β-alanine as a linker were analyzed. From these results it became evident that the hapten molecules of THCA–β-alanine–BSA, THCA–BSA, THCA–β-alanine–human serum albumin (HSA) and THCA–HSA were 17.2, 12.7, 27.8 and 54.4, respectively. Crocin–HSA conjugates were synthesized by two methods using succinate and NaIO4 cleavage of sugar moiety. A broad molecular peak of crocin–HSA conjugate appeared at around m/z 98,342 resulting in 30 molecules of crocin-hemisuccinate conjugated with HSA. The crocin–HSA synthesized via NaIO4 oxidation showed a sharp molecular peak around 69,504 compared to that of hemisuccinate preparation. The number of crocin combined with HSA was, however, smaller 3.1 molecules.
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direct determination of opium alkaloid bovine serum albumin conjugate by matrix assisted laser desorption ionization mass spectrometry
1993Co-Authors: Yukihiro Shoyama, Akihiko Kusai, Tomohiro Fukada, Takashi Tanaka, Kazutetsu NojimaAbstract:Opium alkaloids (thebaine, codeine and morphine) have been conjugated with bovine serum albumin (BSA) to give individual antigen conjugates which are analyzed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. It became clear that 9 molecules of thebaine were contained in a thebaine-BSA conjugate. Codeine and morphine contents in individual conjugates were determined to be 12 and 6 molecules, respectively.
