<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "A versatile prodrug approach for liposomal core-loading of water-insoluble camptothecin anticancer drugs"^^ . "We describe a versatile prodrug strategy for loading the liposomal lumen with water-insoluble camptothecins. The procedure involves conversion of an active camptothecin analogue to a 20-OR ω-aminoalkanoanic ester prodrug in which R = CO[CH2]nNH2 and n = 1-3. The basic amino group of the prodrug serves three roles. First, at pH ranges of 3-5, the amine enhances aqueous solubility. Second, it enhances responsiveness to a transmembrane ammonium sulfate gradient across the liposomal bilayer, thereby facilitating active loading of the agent into the liposomal aqueous core. Third, at a physiological pH of 7 or above (the pH to be encountered following drug release at the tumor site), the nucleophilicity of the amine manifests itself and cyclization to the C-21 carbonyl carbon occurs. This cyclization triggers a rapid and convenient nonenzymatic decomposition process that releases active camptothecin. Accordingly, this novel liposomal approach offers a potential system for tumor-targeting prodrugs of many water-insoluble camptothecins, including the highly lipophilic and clinically attractive analogues SN-38, 9-nitrocamptothecin and DB-67. The rate of formation of the active agent at the tumor site can be controlled through the selection of n (the length of the alkyl spacer group). Copyright © 2002 American Chemical Society."^^ . "2002-07-03" . . "124" . "26" . . "Journal of the American Chemical Society"^^ . . . "00027863" . . . . . . . . . . . . . . . . . . . . . . . . . . . . "BC"^^ . "Lynn"^^ . "BC Lynn"^^ . . "TG"^^ . "Burke"^^ . "TG Burke"^^ . . "X"^^ . "Liu"^^ . "X Liu"^^ . . "L"^^ . "Song"^^ . "L Song"^^ . . "DP"^^ . "Curran"^^ . "DP Curran"^^ . . "D"^^ . "Bom"^^ . "D Bom"^^ . . "W"^^ . "Du"^^ . "W Du"^^ . . "J"^^ . "Zhang"^^ . "J Zhang"^^ . . . . . . "A versatile prodrug approach for liposomal core-loading of water-insoluble camptothecin anticancer drugs (Plain Text)"^^ . . . "licence.txt"^^ . . . "A versatile prodrug approach for liposomal core-loading of water-insoluble camptothecin anticancer drugs (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #20488 \n\nA versatile prodrug approach for liposomal core-loading of water-insoluble camptothecin anticancer drugs\n\n" . "text/html" . .