Nanoparticles for urothelium penetration and delivery of the histone deacetylase inhibitor belinostatfor treatment of bladder cancer
Martin DT, Hoimes CJ, Kaimakliotis HZ, Cheng CJ, Zhang K, Liu J, Wheeler MA, Kelly WK, Tew GN, Saltzman WM, Weiss RM.Nanomedicine. 2013 Jun 11.pii: S1549-9634(13)00268-2. doi: 10.1016/j.nano.2013.05.017. [Epub ahead of print]


Department of Urology, Yale University, New Haven, CT.


Nearly 40% of patients with non-invasive bladder cancer will progress to invasive disease despite locally-directed therapy. Overcoming the bladder permeability barrier (BPB) is a challenge for intravesical drug delivery. Using the fluorophorecoumarin (C6), we synthesized C6-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs), which were surface modified with a novel cell penetrating polymer, poly(guanidiniumoxanorbornene) (PGON). Addition of PGON to the NP surface improved tissue penetration by 10-fold in intravesically-treated mouse bladder and ex vivo human ureter. In addition, NP-C6-PGON significantly enhanced intracellular uptake of NPs compared to NPs without PGON. To examine biological activity, we synthesized NPs that were loaded with the histone deacetylase (HDAC) inhibitor belinostat (NP-Bel-PGON). NP-Bel-PGON exhibited a significantly lower IC50 in cultured bladder cancer cells, and sustained hyperacetylation, when compared to unencapsulatedbelinostat. Xenograft tumors treated with NP-Bel-PGON showed a 70% reduction in volume, and a 2.5-fold higher intratumoral acetyl-H4, when compared to tumors treated with unloaded NP-PGON.