title: Janus PEG-based dendrimers for use in combination therapy: controlled multi-drug loading and sequential release.
abstract: The increasing use of drug combinations to treat disease states, such as cancer, calls for improved delivery systems that are able to deliver multiple agents. Herein, we report a series of novel Janus dendrimers with potential for use in combination therapy. Different generations (first and second) of PEG-based dendrons containing two different "model drugs", benzyl alcohol (BA) and 3-phenylpropionic acid (PPA), were synthesized. BA and PPA were attached via two different linkers (carbonate and ester, respectively) to promote differential drug release. The four dendrons were coupled together via (3 + 2) cycloaddition chemistries to afford four Janus dendrimers, which contained varying amounts and different ratios of BA and PPA, namely, (BA)(2)-G1-G1-(PPA)(2), (BA)(4)-G2-G1-(PPA)(2), (BA)(2)-G1-G2-(PPA)(4), and (BA)(4)-G2-G2-(PPA)(4). Release studies in plasma showed that the dendrimers provided sequential release of the two model drugs, with BA being released faster than PPA from all of the dendrons. The different dendrimers allowed delivery of increasing amounts (0.15-0.30 mM) and in exact molecular ratios (1:2; 2:1; 1:2; 2:2) of the two model drug compounds. The dendrimers were noncytotoxic (100% viability at 1 mg/mL) toward human umbilical vein endothelial cells (HUVEC) and nontoxic toward red blood cells, as confirmed by hemolysis studies. These studies demonstrate that these Janus PEG-based dendrimers offer great potential for the delivery of drugs via combination therapy.
authors.affiliation: Department of Chemistry, Reading School of Pharmacy, University of Reading, Whiteknights, Reading, United Kingdom.
authors.forename: Aaron L
authors.initials: AL
authors.lastname: Acton
authors.forename: Cristina
authors.initials: C
authors.lastname: Fante
authors.forename: Brian
authors.initials: B
authors.lastname: Flatley
authors.forename: Stefano
authors.initials: S
authors.lastname: Burattini
authors.forename: Ian W
authors.initials: IW
authors.lastname: Hamley
authors.forename: Zuowei
authors.initials: Z
authors.lastname: Wang
authors.forename: Francesca
authors.initials: F
authors.lastname: Greco
authors.forename: Wayne
authors.initials: W
authors.lastname: Hayes
mesh_terms: D019905:Benzyl Alcohol / Q000378:metabolism*; D001672:Biocompatible Materials; D002478:Cells, Cultured; D003692:Delayed-Action Preparations; D050091:Dendrimers / Q000138:chemical synthesis* / Q000737:chemistry*; D004337:Drug Carriers; D004338:Drug Combinations; D004912:Erythrocytes / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects; D006801:Humans; D010666:Phenylpropionates / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D050091:Dendrimers; D004337:Drug Carriers; D004338:Drug Combinations; D010666:Phenylpropionates; D011108:Polymers; D011092:Polyethylene Glycols; C035253:3-phenylpropionic acid; D019905:Benzyl Alcohol