Novel drug carriers: from grafted polymers to cross-linked vesicles

Jiangtao Xua, Qiang Fua, Jing M. Rena, Gary Bryantb and Greg G. Qiao*a

^aDepartment of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, VIC 3010, Australia. 

^bSchool of Applied Sciences, RMIT University, Melbourne, VIC 3000, Australia

http://pubs.rsc.org/en/content/articlehtml/2012/cc/c2cc37319j

This papers describes the synthesis of cross-linked particles via thiol-ene chemistry.  The authors make diblock copolymers via ROMP using oxonorbornene anhydride and a norbornene-PEG MM as monomers.  Next, they hydrolize the anhydride to to give free -COOH and then the block copolymers self-assemble into nanoparticles (~150 nm) at pH 4.  The self-assembled nanoparticles are then crosslinked using a tetrafunctional thiol crosslinker and the double bonds in the backbone of the polymer.  Finally, cisplatin (18.9% drug loading) is conjugated to the free -COOH from the hyrdolized oxonorbornene anhydride.  They showed the crosslinked nanoparticles hardly change size in different pH solutions and the drug loaded nanoparticles release cisplatin at a steady rate.