32 resultados para Paclitaxel -- analogs
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
Ras superfamily proteins are key regulators in a wide variety of cellular processes. Previously, they were considered to be specific to eukaryotes, and MglA, a group of obviously different prokaryotic proteins, were recognized as their only prokaryotic an
Resumo:
The effect of metal ions on the conformation of thymine-containing poly-D-lysine was studied by CD spectra in aqueous solution. Of the metal ions studied,only copper()ion affected the conformation of mucleic acid analogs .copper()ion also affected the specifically interacting system made up of thymine-containing poly-D-lysine and polyadenylic acid.
Resumo:
By means of "emulsion-electrospinning", both hydrophobic and hydrophilic drugs, paclitaxel (PTX) and doxorubicin hydrochloride (DOX), were successfully loaded into PEG-PLA nanofiber mats to realize multi-drug delivery. The release behaviors of both the drugs from the same fiber mats were ascribed to their solubility properties and distribution status in the fibers. Due to its high hydrophilicity, DOX was easy to diffuse out from the fibers, and its release rate was always faster than that of hydrophobic PTX. Moreover, the release rate of PTX was accelerated by DOX's release from the same drug-loaded fibers. In vitro cytotoxicity against rat Glioma C6 cells indicated that the dual drug combination showed a higher inhibition and apoptosis against C6 cells than a single drug-loaded system, which suggests the promise for multi-drug delivery on combination therapy.
Resumo:
Paclitaxel-loaded poly(ethylene glycol)-b-poly(L-lactide (LA)) (PEG-PLA) micelles were prepared by two methods. One is physical encapsulation of paclitaxel in micelles composed of a PEG-PLA block copolymer and the other is based on a PEG-PLA-paclitaxel conjugate, abbreviated as "conjugate micelles" Their physicochemical characteristics, e.g. critical micelle concentration (CMC), morphology, and micelle size distribution were then evaluated by means of fluorescence spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS). The results show that the CMC of PEG-PLA-paclitaxel and PEG-PLA are 6.31 x 10(4) and 1.78 x 10(-3) g L-1, respectively. Both micelles assume a spherical shape with comparable diameters and have unimodal size distribution. Moreover, in vitro drug delivery behavior was studied by high performance liquid chromatography (HPLC). The antitumor activity of the paclitaxel-loaded micelles against human liver cancer H7402 cells was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method.
Resumo:
Docetaxel (DX) is one of the most effective antineoplastic drugs. Its current clinical administration is limited because of its hydrophobicity and Serious side effects. A polymer/DX conjugate is designed and successfully prepared to solve these problems. It is monomethoxy-poly(ethylene glycol)-block-poly(L-lactide)/DX (MPEG-PLLA/DX) It was synthesized by reacting DX with carboxyl-terminated copolymer MPEG-PLLA, which was prepared by reacting succinic anhydride with hydroxyl-terminated copolymer monomethoxy-poly(ethylene glycol)-block-poly (L-lactide) (MPEG-PLLA). Its structure and molecular weight was confirmed by H-1 NMR and GPC. The MPEG-PLLA/DX micelles in aqueous solution were prepared Using a SO]vent displacement method and characterized by dynamic light scattering for size and size distribution, and by transmission electron microscopy for surface morphology. Its antitumor activity against HeLa cancer cells evaluated by MTT assay showed that it had a similar antitumor activity to Pure D at the same drug content.
Resumo:
A triblock poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid) (PLA-PEG-PLA)/paclitaxel (PTX) conjugate was synthesized by the reaction of carboxyl-terminated copolymer PLA-PEG-PLA with PTX in the presence of dicyclohexylcarbodiimide and dimethylaminopyridine. Carboxyl-terminated copolymer PLA-PEG-PLA was prepared by the reaction of the hydroxyl end groups in copolymer PLA-PEG-PLA with succinic anhydride. Its structure was confirmed by NMR and gel permeation chromatography. The PLA-PEG-PLA/PTX conjugates could self-assemble into micelles in aqueous solutions with a low critical micelle concentration. Dynamic light scattering and environmental scanning electron microscopy analyses of the PLA-PEG-PLA/PTX micelles revealed their spherical structure and size of 220 nm. The antitumor activity of the conjugate against woman Hela cancer cells, evaluated by the 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyl tetrazolium bromide method, showed that the conjugates had an antitumor activity similar to that of pure PTX. The obtained PLA-PEG-PLA/PTX conjugates are expected to be used in clinical practice.
Resumo:
A paclitaxel/MPEG-PLA block copolymer conjugate was prepared in three steps: (1) hydroxyl-terminated diblock copolymer of monomethoxy-poly(ethylene glycol)-b-poly(lactide) (MPEG-PLA) was synthesized by ring-opening polymerization of L-lactide using MPEG as a maroinitiator, (2) it was converted to carboxyl-terminated MPEG-PLA by reacting with mono-i-butyl ester of diglycolic acid and subsequent deprotecting the t-butyl group with TFA; (3) the latter was reacted with paclitaxel in the presence of dicyclohexylcarbodiimide and dimethylaminopyridine. Structures of the polymers synthesized were confirmed by H-1 NMR, and their molecular weights were determined by gel permeation chromatography. The antitumor activity of the conjugate against human liver cancer H7402 cells was evaluated by MTT method. The results showed that paclitaxel can be released from the conjugate without losing cytotoxicity.
Resumo:
The identification of six synthesized diosgenyl saponin analogs with up to five sugars was accomplished by NMR studies. A combination of homo- and heteronuclear two-dimensional NMR techniques was utilized to achieve the complete H-1 and C-13 NMR assignments. Copyright (C) 2000 John Wiley & Sons, Ltd.
Resumo:
In continuation of our program aimed at the discovery and development of compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, 21N-arylsulfonyl-3-acetylindole analogs (2a-u) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro. Among of all the analogs, several compounds exhibited significant anti-HIV-1 activity, especially N-phenylsulfonyl-3-acetyl-6-methylindole (2j) and N-(p-ethyl)phenylsulfonyl-3-acetyl-6-methylindole (2n) showed the most potent anti-HIV-1 activity with EC50 values of 0.36 and 0.13 mu g/mL, and TI values of >555.55 and 791.85, respectively. It demonstrated that introduction of the acetyl group at the 3-position of N-arylsulfonyl-6-methylindoles could generally lead to the more potent analogs. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
Peptide nucleic acids (PNAs) are nucleic acid analogs with the deoxyribose phosphate backbone replaced by pseudo-peptide polymers to which the nucleobases are linked. The achiral, uncharged and rather flexible properties of the peptide backbone permit peptide nucleic acids more potential than oligonucleotides in application to antisence and antigenic reagents. The process of PNA binding to DNA duplex and forming triplex is the first step of PNA interacting with PNA. But there are no PNA.2DNA triplex crystal data up to date and little has been reported on the structure features and the force of the PNA.2DNA triplex. In this work, PNA(T).DNA(AT) triplexes are successfully built and the structures and forces to stabilize the triplex after optimizations and molecule dynamics are systematically examined, which are expected to aid in the application of PNAs as anticense and antigene agents.
Resumo:
PGAPLAPCL122-1H NMRFTIRDSCTmTg1500235-3--25-BEMDPEGSnOct2LLABEMDPLGBG-PEG-PLGBG10PLGG-PEG-PLGGPLGG-PEG-PLGGPLGG-PEG4600-PLGGPLGG-PEG2000-PLGGKPLGG-PEG-PLGGPLAPLGG-PEG-PLGG3DCCDMAPPLGOPEG-PLGGPLGG-paclitaxel-PEG-PLGG-paclitaxel119.4nmpHpH7.4PLGG-Paclitaxel-PEG-PLGG-paclitaxelPEGEPR4MBCMPEGZnEt2LLAMBCMPEG-b-PLA-co-MBC13C NMRLLAcDSCMPEG-b-PLA-co-MBCTg20-50MBcMPEG-b-PLA-co-MBCMPEG-b-PLA-co-MCCTgKMPEG-b-PLA-co-MCCMPEG-b-PLA-co-MBCMPEG-b-PLA-co-MCC5Sr-POPCL-b-PMBCWAXD PCL-b-PMBcPCLPMBCDSCPCL-b-PMBCPCLTm5752PMBCPCL-b-PMBC-41.6 -23.3PMBCPMBCPCL PCL-b-PMBC10PCL-b-PMCCPCL-b-PMCC
