The differentiation of leukaemia cells is a therapeutic strategy often used in the clinic to eradicate blood cancers. The concentration of the agent used for inducing leukaemia cell differentiation and the spatio-temporal control of its application are important variables for the success of this therapeutic approach1. Induction of leukaemia cell differentiation by RA is a therapeutic strategy that has been used with great success in the treatment of acute promyelocytic leukaemia (APL)2,3. RA activates nuclear RA receptors (RARs) that induce cell growth arrest and differentiation4. Despite its clear therapeutic efficacy, approximately 25% of patients receiving RA will develop serious complications, such as ‘differentiation syndrome’5. Hence, there is a need for more effective formulations to deliver RA into leukaemia cells while preventing RA side effects. In addition, leukaemia cells resistant to conventional therapies reside in microenvironmental niches in the bone marrow that are difficult to access by therapeutic interventions6. New strategies are required to address these problems.