Neutron Reflectometry investigation of organo-rhodium complexes in model membranes.

Half-sandwich penta- and tetra-methylcyclopentadienyl (Cp*, CpxPh, CpxPhPh) Rh(III) complexes [(η5-Cp*)Rh(N,N’)Cl]+ (N,N = (4-R2-phenyl-azopyridine-5-R1)Cl]PF6, R2 = CF3/Br/H R1 = OH/NMe2 ) show potent anticancer activity against tumour cells, including, lung cancer. Our previous work using 3D cryo-imaging suggested the accumulation of these compounds in lipid membranes, which would be a novel activity pathway. DFT calculations support this finding revealing the complexes interacts with the lipid tails. We propose to use Neutron Reflectometry to study the interaction of these complexes with model membranes to experimentally and structurally resolve the interaction of these novel anti-cancer compounds with cellular membranes. From NR studies we expect to resolve the position of the complex relative to the model membrane and the mechanism of interaction. Additionally we will resolve changes in the membrane lipid distribution to elucidate any membrane perturbing effects of these compounds. This will provide valuable information on the activity of these novel drugs.