Metal-based inorganic nanocrystals for biological sonodynamic therapy applications:recent progress and perspectives

With the fast development of technology for the treatment of tumor and bacteria,photo-therapeutic strate-gies emerge as a kind of highly effective and common treatment,but the low tissue penetration depth of light limits their development.Sonodynamic therapy(SDT),as an efficient and non-invasive treatment,attracts more people's attention due to the inherent property of high tissue penetration.The soft tissue penetration depth of ultrasound(US)can even reach more than 10 cm,which has great advantage over that of light.Therefore,many sonosensitizers are studied and applied to SDT-based therapy.Metal-based inorganic nanocrystals are able to generate more reactive oxygen species(ROS)due to the special composition and band structure.The representative achievements and the specific functions of the nanocrystals sonosensitizers are summarized in this work,and the relationship of structure/composition-SDT performance and the internally regulated composite is revealed.Syner-gistic effects of SDT in combination with other therapeutic modalities are mainly highlighted.At the same time,the critical and potential issues and future perspectives are addressed.

Low-Temperature Synthesis of Crystalline Inorganic/Metallic Nanocrystal-Halloysite Composite Nanotubes

We have demonstrated a facile approach for the low-temperature synthesis of crystalline inorganic/metallic nanocrystal-halloysite composite nanotubes by employing the bulk controlled synthesis of inorganic/metallic nanocrystals on halloysite nanotubes.The halloysite clay nanotubes can adsorb the target precursor and induce inorganic/metallic nanocrystals to grow in situ.The crystalline phase and morphology of the composite clay nanotubes is tunable.By simply tuning the acidity of the titania sol,the crystalline titania-clay nanotubes with tunable crystalline phases of anatase,a mixture of anatase and rutile or rutile are achieved.The approach is general and has been extended to synthesize the representative perovskite oxide(barium and strontium titanate)-halloysite composite nanotubes.Metallic nickel nanocrystal can also be grown on the surface of halloysite nanotubes at low temperature.The traditional thermal treatment for crystallite transformation is not required,thus intact contour of halloysite nanotubes and the crystallinity structure of halloysite nanotubes can be guaranteed.The combined properties from inorganic/metallic nanocrystal(high refractive index,high dielectric constant and catalytic ability)and the halloysite clay nanotubes are promising for applications such as photonic crystals,high-k-gate dielectrics,photocatalysis and purification.

Cooperative effects at the interface of nanocrystalline metal-organic frameworks

Controlling the chemistry at the interface of nanocrystalline solids has been a challenge and an important goal to realize desired properties. Integrating two different types of materials has the potential to yield new functions resulting from cooperative effects between the two constituents. Metal-organic frameworks （MOFs） are unique in that they are constructed by linking inorganic units with organic linkers where the building units can be varied nearly at will. This flexibility has made MOFs ideal materials for the design of functional entities at interfaces and hence allowing control of properties. This review highlights the strategies employed to access synergistic functionality at the interface of nanocrystalline MOFs （nMOFs） and inorganic nanocrystals （NCs）.