Food-drug interactions play an important role in the alteration of the pharmacokinetics as well as pharmacodynamics of drugs in vivo. The interaction of folic acid and tea was observed at the level of cellular uptake using Caco-2 cell monolayers. Remarkably, the clinical study with healthy human volunteers confirmed the interaction between tea and folic acid in vivo leading to lower bioavailabilities of folic acid. This outcome addresses the clinical consequences of folate deficiency caused by high intakes of tea. Folates have been employed as targeting moieties to tumor cells. Folic acid has a high affinity to folate receptors which are overexpressed in tumor cells. Therefore internalization of folic acid conjugated drugs or drug delivery systems are readily carried out via those receptors. A novel micelle platform consisting of amphiphilic DNA block copolymers was introduced for the first time for chemotherapeutic drug delivery, allowing the combinatorial testing of the drug carrier system. Folic acid conjugated nanoparticles act as a potential chemotherapeutic drug delivery system in in vitro assays.