title: Synthesis and biological studies of 5-aminolevulinic acid-containing dendrimers for photodynamic therapy.
abstract: Using a convergent growth approach, a series of novel 5-aminolevulinic acid (ALA)-containing dendrimers have been synthesized. In these molecules, ALA residues are attached to the periphery by ester linkages, with amide bonds connecting the dendrons. Three first-generation dendrimers, bearing either 6 or 9 ALA residues, were synthesized by attachment of a tris(Boc-protected ALA)-containing wedge (1) to a di- or tripodent aromatic, or tripodent aliphatic core. Two second generation 18-ALA-containing dendrimers were also synthesized using a 3,3'-iminodipropionic acid spacer unit between wedge 1 and the aromatic core. These compounds differed only in the distance between the core and the linker unit. The Boc-protected dendrimers were deprotected using trifluoroacetic acid and isolated as their TFA salts. The potential of these ALA ester dendrimers as macromolecular prodrugs for photodynamic therapy has been demonstrated in the tumorigenic keratinocyte PAM 212 cell line.
authors.affiliation: Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ, UK.
authors.forename: S H
authors.initials: SH
authors.lastname: Battah
authors.forename: C E
authors.initials: CE
authors.lastname: Chee
authors.forename: H
authors.initials: H
authors.lastname: Nakanishi
authors.forename: S
authors.initials: S
authors.lastname: Gerscher
authors.forename: A J
authors.initials: AJ
authors.lastname: MacRobert
authors.forename: C
authors.initials: C
authors.lastname: Edwards
mesh_terms: D000622:Aminolevulinic Acid / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002461:Cell Line, Transformed / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D051379:Mice; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry* / Q000494:pharmacology; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011355:Prodrugs / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D017319:Photosensitizing Agents; D011108:Polymers; D011355:Prodrugs; D000622:Aminolevulinic Acid