The tumour microenvironment regulates tumour progression and the spread of cancer in the body. Targeting the stromal cells that surround cancer cells could, therefore, improve the effectiveness of existing cancer treatments. Here, we show that magnetic nanoparticle clusters encapsulated inside a liposome can, under the influence of an external magnet, target both the tumour and its microenvironment. We use the outstanding T2 contrast properties (r2=573-1,286 s(-1) mM(-1)) of these ferri-liposomes, which are ∼95 nm in diameter, to non-invasively monitor drug delivery in vivo. We also visualize the targeting of the tumour microenvironment by the drug-loaded ferri-liposomes and the uptake of a model probe by cells. Furthermore, we used the ferri-liposomes to deliver a cathepsin protease inhibitor to a mammary tumour and its microenvironment in a mouse, which substantially reduced the size of the tumour compared with systemic delivery of the same drug.

A neutronographic study is made of magnetic structure and spin‐orientational transitions in polycrystalline samples of the system BaCo2−xZnxFe16O27 (Co2−xZnxW). Along with this studies measurements of the macroscopic magnetic characteristics, X‐ray dilatometry, and DTA are performed. The diagram of the magnetic state is plotted in the coordinates: content‐temperature. The compounds with Zn2+ ion content, 0 ≦ x ≦ 1.6 exhibit the sequence of orientational phase transitions coneplane‐cone‐axis of easy magnitization when the temperature increases. The order of these transitions is determined and the role of Co2+ ions for creation of planar anisotropy in oxide ferrimagnetics with hexagonal structure is discussed.

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