Disulfide Cross-Linked Micelles for the Targeted Delivery of Vincristine to B-Cell Lymphoma Jason Kato Yuanpei Li Kai Xiao Joyce S. Lee Juntao Luo Joseph M. Tuscano Robert T. O’Donnell Kit S. Lam 10.1021/mp300128b.s001 https://acs.figshare.com/articles/journal_contribution/Disulfide_Cross_Linked_Micelles_for_the_Targeted_Delivery_of_Vincristine_to_B_Cell_Lymphoma/2517496 Vincristine (VCR) is a potent anticancer drug, but its clinical efficacy is limited by neurotoxicity. The field of drug delivery may provide an opportunity to increase the therapeutic index of VCR by delivering the drug specifically to tumor sites while sparing normal tissue. We have recently developed a telodendrimer (PEG<sup>5k</sup>-Cys<sub>4</sub>-L<sub>8</sub>-CA<sub>8</sub>) capable of forming disulfide cross-linked micelles (DCMs) which can encapsulate a variety of chemotherapeutics. In the present study, we encapsulated VCR into these micelles (DCM-VCR) and used them to treat lymphoma bearing mice. DCM-VCR particles have a size of 16 nm, which has been shown to be optimal for their accumulation into tumor via the enhanced permeability and retention (EPR) effect. Compared to our first-generation non-cross-linked micelles (NCMs), DCM-VCR demonstrated greater stability and slower drug release under physiological conditions. In addition, DCM-VCR exhibited a maximum tolerated dose (MTD) of 3.5 mg/kg while the MTD for conventional VCR was only 1.5 mg/kg. Using a near-infrared cyanine dye (DiD) as the surrogate drug, we showed that DCM-VCR accumulated at the tumor site starting 1 h after injection and persisted up to 72 h in lymphoma xenografted nude mice. In an <i>in vivo</i> efficacy study, high dose (2.5 mg/kg) DCM-VCR produced the greatest reduction in tumor volume. High dose DCM-VCR was well tolerated with no significant changes in complete blood count, serum chemistry and histology of the sciatic nerve. Mice treated with an equivalent dose (1 mg/kg) of conventional VCR and DCM-VCR controlled tumor growth equally; however, in combination with on-demand addition of the reducing agent <i>N</i>-acetylcysteine, DCM-VCR exhibited a superior antitumor effect compared to conventional VCR. 2012-06-04 00:00:00 vivo efficacy study EPR dose DCM PEG 5k drug release 16 nm sciatic nerve tumor sites antitumor effect tumor site serum chemistry micelle encapsulated VCR tumor growth 72 h blood count mg 1 h anticancer drug lymphoma xenografted tumor volume MTD Targeted Delivery drug delivery NCM