title: Biorecognizable HPMA copolymer-drug conjugates for colon-specific delivery of 9-aminocamptothecin.
abstract: N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates for colon-specific delivery of 9-aminocamptothecin (9-AC) were designed. They hold 9-AC bound via spacers containing amino acid residues and aromatic azo bonds. In vitro release profiles of 9-AC from HPMA copolymer conjugates were evaluated under artificial conditions that simulated large intestinal azoreductase and peptidase activities. The studies indicated that the azo bond was reduced first, followed by the release of unmodified 9-AC from the 9-AC containing fragment by peptidases. Release profiles depended on the chemical structure of the peptide part of the spacer. Conjugates containing leucylalanine showed high colon-specific release of 9-AC when compared to alanine containing conjugates. It appears that the studied conjugates are suitable as colon-specific drug delivery systems.
authors.affiliation: Department of Pharmaceutics and Pharmaceutical Chemistry/CCCD, University of Utah, 30 South 2000 East, Rm. 301, Salt Lake City, UT 84112, USA.
authors.forename: S
authors.initials: S
authors.lastname: Sakuma
authors.forename: Z R
authors.initials: ZR
authors.lastname: Lu
authors.forename: P
authors.initials: P
authors.lastname: Kopecková
authors.forename: J
authors.initials: J
authors.lastname: Kopecek
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D002166:Camptothecin / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D003106:Colon / Q000378:metabolism*; D008297:Male; D008689:Methacrylates / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000970:Antineoplastic Agents; D008689:Methacrylates; C080125:9-aminocamptothecin; C032802:hydroxypropyl methacrylate; D002166:Camptothecin