Highly crystalline β-SnWO(4) truncated rhombic dodecahedrons with sharp edges and smooth faces are prepared via a wet-chemical route. The compound exhibits a much higher photocatalytic activity than spherical β-SnWO(4) nanoparticles or conventionally prepared bulk β-SnWO(4) as well as faceted microcrystals of m-BiVO(4) and Ag(3)PO(4).

The nanoparticulate inorganic photosensitizer β-SnWO4 is suggested for photodynamic therapy (PDT) of near-surface tumors via reiterated 5 min blue-light LED illumination. β-SnWO4 nanoparticles are obtained via water-based synthesis and comprise excellent colloidal stability under physiological conditions and high biocompatibility at low material complexity. Antitumor and antimetastatic effects were investigated with a spontaneously metastasizing (4T1 cells) orthotopic breast cancer BALB/c mouse model. Besides protamine-functionalized β-SnWO4 (23 mg/kg of body weight, in PBS buffer), chemotherapeutic doxorubicin was used as positive control (2.5 mg/kg of body weight, in PBS buffer) and physiological saline (DPBS) as a negative control. After 21 days, treatment with β-SnWO4 resulted in a clearly inhibited growth of the primary tumor (all tumor volumes below 3 cm(3)) as compared to the doxorubicin and DPBS control groups (volumes up to 6 cm(3)). Histological evaluations of lymph nodes and lungs as well as the volume of ipsilateral lymph nodes show a remarkable antimetastatic effect being similar to chemotherapeutic doxorubicin but-according to blood counts-at significantly reduced side effects. On the basis of low material complexity, high cytotoxicity under blue-light LED illumination at low dark and long-term toxicity, β-SnWO4 can be an interesting addition to PDT and the treatment of near-surface tumors, including skin cancer, esophageal/gastric/colon tumors as well as certain types of breast cancer.

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The nanoparticulate photocatalyst β-SnWO4 is transfected into human liver carcinoma cells (HepG2). CLSM images and MTT assays validate a high phototoxicity under artificial daylight illumination at low systemic cytotoxicity and without long-term effects. β-SnWO4 offers multifunctionality, including high colloidal stability and intrinsic fluorescence.

A distinct morphology of β-SnWO 4 with hierarchically multiarmed architecture and overall hexahedral symmetry − entitled as spikecube − is fabricated for the first time via a polyol-mediated synthesis. The growth of the β-SnWO 4 spikecubes is investigated and attributed to thermodynamic and kinetic control. In a sequential reaction, crystalline cubes of β-SnWO 4 enclosed by {100} facets grow in a first Ostwald ripening-based step. A kinetically controlled growth process to spikecubes follows under formation of multiarmed spikes on the facets of the cubic seeds. Such a growth process differs significantly from the literature concerning highly branched crystals. The synergistic effect of morphological modification (i.e., introducing more surface reaction sites) and textural alteration (i.e., incorporation of the p-block Sn 2+ into simple tungsten oxide to reframe its band structure) leads to an enhanced photocatalytic activity of the β-SnWO 4 spikecubes being 150% higher in comparison to benchmark WO 3 photocatalysts.