Fast and non-destructive neutron activation analysis for simultaneous determination of TiO and SiO in sunscreens with attention to regulatory and research issues.

A new instrumental neutron activation analysis (INAA) for the simultaneous determination of titanium (TiO) and silica (SiO) dioxide as UV-filters in sunscreens is described. Samples are encapsulated, neutron irradiated (30 s) and after a suitable decay (3 min), the induced Ti (T = 5.76 min) and Al (T = 6.

Genotoxicity and Immunotoxicity of Titanium Dioxide-Embedded Mesoporous Silica Nanoparticles (TiO@MSN) in Primary Peripheral Human Blood Mononuclear Cells (PBMC).

TiO nanoparticles (TiO NPs) are the nanomaterial most produced as an ultraviolet (UV) filter. However, TiO is a semiconductor and, in nanoparticle size, is a strong photocatalyst, raising concerns about photomutagenesis. Mesoporous silica nanoparticles (MSN) were synthetized incorporating TiO NPs (TiO@MSN) to develop a cosmetic UV filter.

Bismuth titanate-based UV filters embedded mesoporous silica nanoparticles: Role of bismuth concentration in the self-sealing process.

The development of new safe inorganic UV filters to effectively protect the skin from ultraviolet (UV) radiation effects is an emerging issue. Bismuth titanate-based UV filters embedded into mesoporous silica nanoparticles (MSN) represent a new class of inorganic sunscreens, with excellent UVA and UVB shielding properties. In addition, the presence of bismuth ions promotes a self-sealing process, allowing (i) the entrapment of the active phases in the deepest core of the system and (ii) the formation of an external glassy silica layer with a consequent suppression of the photocatalytic activity.

BiSiO@g-SiO upconverting nanoparticles: a bismuth-driven core-shell self-assembly mechanism.

Core-shell systems have attracted increasing interest among the research community in recent years due to their unique properties and structural features, and the development of new synthetic strategies is still a challenge. In this work, we have investigated lanthanide-doped Bi2SiO5 nanocrystal formation inside mesoporous silica nanoparticles (MSNs). The role of both synthesis temperature and concentration of the bismuth precursor impregnated into the MSNs is discussed, showing an unprecedented strategy for the simultaneous stabilization of a crystalline core and a glassy shell.

Formation and Controlled Growth of Bismuth Titanate Phases into Mesoporous Silica Nanoparticles: An Efficient Self-Sealing Nanosystem for UV Filtering in Cosmetic Formulation.

The application of nanosized inorganic UV filters in cosmetic field is limited by their high photocatalytic properties that could induce the degradation or dangerous transformation of the organic molecules in sunscreen formulations. To overcome this problem and simultaneously enlarge the window of filter's absorption, we propose the growth of bismuth titanates BiTiO into mesoporous silica nanoparticles (MSN). We investigated the chemical-physical properties by means of XRPD, TEM, UV-vis spectroscopy, N physisorption, XPS, and SF-ICP-MS analysis, while the influence on the environment was evaluated through photocatalytic tests.