Folate Conjugation to Polymeric Micelles via Boronic Acid Ester to Deliver Platinum Drugs to Ovarian Cancer Cell Lines Wei Scarano Hien T. T. Duong Hongxu Lu Paul L. De Souza Martina H. Stenzel 10.1021/bm400121q.s001 https://acs.figshare.com/articles/journal_contribution/Folate_Conjugation_to_Polymeric_Micelles_via_Boronic_Acid_Ester_to_Deliver_Platinum_Drugs_to_Ovarian_Cancer_Cell_Lines/2426179 In this study, a novel technique was used for the reversible attachment of folic acid on the surface of polymeric micelles for a tumor-specific drug delivery system. The reversible conjugation is based on the interaction between phenylboronic acid (PBA) and dopamine to form a borate ester. The conjugation is fast and efficient and in vitro experiments via confocal fluorescent microscopy show that the linker is stable in for several hours. Reversible addition–fragmentation chain transfer (RAFT) polymerization was used to synthesize two various sized water-soluble block copolymer of oligoethylene glycol methylether methacylate and methyl acrylic acid (POEGMEMA<sub>35</sub>-<i>b</i>-PMAA<sub>200</sub> and POEGMEMA<sub>26</sub>-<i>b</i>-PMAA<sub>90</sub>). The platinum drug, oxoplatin, was then subsequently attached to the polymer via ester formation leading to platinum loading of 12 wt % as determined by TGA. The platinum-induced amphiphilic block copolymers that consequently led to the formation of micelles of sizes 150 and 20 nm in an aqueous environment with the longer PMAA block forming larger micelles. The small micelles were in addition cross-linked using 1,8-diaminooctane to further stabilize their structure. The targeting ability of folate conjugated polymeric micelles was investigated against two types of tumor cell lines: A549 (-FR) and OVCAR-3 (+FR). The cell line growth inhibitory efficacy of material synthesized was evaluated by using SRB method. The results revealed that folate conjugated micelles showed higher activity in FR + OVCAR-3 cells but not in FR – A549 cells. Similar results were obtained for both small and large micelles without the conjugation of folate. Comparing large and small micelles it can be observed that larger micelles are more efficient, which has been attributed to the lower stability of the smaller micelles. Micelle stabilization via cross-linking could indeed increase the toxicity of the drug carrier. 2013-04-08 00:00:00 microscopy show novel technique methyl acrylic acid POEGMEMA ester formation sizes 150 borate ester 20 nm platinum drug drug carrier tumor cell lines micelle OVCAR Ovarian Cancer Cell LinesIn block copolymer PBA folic acid FR PMAA block Folate Conjugation Platinum Drugs oligoethylene glycol methylether methacylate platinum loading Polymeric Micelles phenylboronic acid cell line growth SRB method 549 cells Similar results TGA Micelle stabilization