Significance: Simple injection of a solution of amphiphilic Janus dendrimer with specific primary structure into water or buffer has been shown to yield uniform submicrometer-size onion-like vesicles denoted dendrimersomes. The size and number of alternating internally confined bilayers is predicted by the final concentration of the Janus dendrimer. Onion-like dendrimersomes provide mimics of various biological membranes and can be elaborated to provide time-dependent delivery of drugs. Their ease of preparation contrasts with conventional methods used to make onion-like vesicles that are both complicated and time-consuming.

The grafting of pegylated dendrons on 9(2) nm and 39(5) nm iron oxide nanoparticles in water, through a phosphonate group as coupling agent has been successfully achieved and its mechanism investigated, with a view to produce biocompatible magnetic nano-objects for biomedical applications. Grafting has been demonstrated to occur by interaction of negatively charged phosphonate groups with positively charged groups and hydroxyl at the iron oxide surface. The isoelectric point of the suspension of dendronized iron oxide nanoparticles is shifted towards lower pH as the amount of dendron increases. It reaches 4.7 for the higher grafting rate and for both particle size. Thus, the grafting of molecules using a phosphonate group allows stabilizing electrostatically the suspensions at physiological pH, a prerequisite for biomedical applications. Moreover the grafting step has been shown to preserve the magnetic properties of iron oxide nanoparticles due to super–super exchange interactions through the phosphonate group.