Rhodamine/nanodiamond as a system model for drug carrier

In this paper we present some strategies thai are being developed in our labs towards enabling nanodiamond-based applications tor drug delivery. Rhodamine B (RhB) has been choosen as model molecule to study the loading ot nanodiamonds with active moieties and the conditions tor their controlled release. In order to test the chemical/physical interactions between tunctionalized deto-nation nanodiamond (DND) and complex molecules, we prepared and tested different RhB@DND systems, with RhB adsorbed or linked by ionie bonding to the DND surface. The chemical state ot the DND surfaces betore conjugation with the RhB molecules, and the chemical teatures ot the DND-RhB interactions have been deeply analysed by coupling DND with Au nanoparticles and tak-ing advantage ot surface enhanced Raman spectroscopy SERS. The effects due to temperature and pH variations on the process ot RhB release from the DND carrier have been also investigated. The amounts ot released molecules are consistent with those required tor effective drug action in conventional therapeutic applications, and this makes the DND promising nanostructured cargos tor drug delivery applications.