title: Optimization of the N-lost drugs melphalan and bendamustine: synthesis and cytotoxicity of a new set of dendrimer-drug conjugates as tumor therapeutic agents.
abstract: Bendamustine and melphalan are very promising alkylating drugs with applicability in the treatment of various tumoral diseases, e.g., chronic lymphocytic leukemia (CLL) or breast cancer. However, numerous adverse effects limited their use. Therefore, 1,3,5-tris(3-aminopropyl)benzene (G0) and its G1 analogue 3,5-bis(3-aminopropyl)-N-(3-{3,5-bis[3-{3,5-bis(3-aminopropyl)benzoylamino}propyl]phenyl}propyl)benzamide were selected to design cytostatic drug-dendrimer conjugates to achieve tumor cell accumulation by endocytosis as already demonstrated for platinum complexes. The dendrimers act as carriers and an N-(2-hydroxyethyl)maleimide spacer between drug and carrier should guarantee a selective release of the cytostatics in the tumor cells. The resulting cytotoxicity was determined in vitro using the human MCF-7 and MDA-MB-231 breast cancer cell lines. It was demonstrated that melphalan caused cytotoxic effects depending on its free amino group (Boc protection strongly decreased the activity) but independent of a derivation of the carboxylic group (dendrimers and spacer binding). Esterification of bendamustine with the N-(2-hydroxyethyl)maleimide spacer strongly increased the hydrolytic stability of the N-lost moiety, so antiproliferative effects were yet observed in vitro.
authors.affiliation: Institute für Pharmazie, Freie Universität Berlin, Berlin, Germany.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Scutaru
authors.forename: Maxi
authors.initials: M
authors.lastname: Wenzel
authors.forename: Heike
authors.initials: H
authors.lastname: Scheffler
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wolber
authors.forename: Ronald
authors.initials: R
authors.lastname: Gust
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D000069461:Bendamustine Hydrochloride; D045744:Cell Line, Tumor; D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry*; D004705:Endocytosis; D006801:Humans; D020128:Inhibitory Concentration 50; D008558:Melphalan / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D008958:Models, Molecular; D008968:Molecular Conformation; D058726:Nanoconjugates / Q000737:chemistry*; D009588:Nitrogen Mustard Compounds / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D010316:Particle Size; D010539:Permeability
chemical_list: D018906:Antineoplastic Agents, Alkylating; D050091:Dendrimers; D058726:Nanoconjugates; D009588:Nitrogen Mustard Compounds; D000069461:Bendamustine Hydrochloride; D008558:Melphalan