Comparison of the Magnetic and Optical Properties of Wide‐Gap (II,Mn)VI Nanostructures Confined in Mesoporous Silica

Preparation of MSNs@Keratin as pH/GSH dual responsive drug delivery system

Designing a drug delivery system that is responsive in a tumor microenvironment is important to potentiate the efficacy and reduce the side effects of antitumor drugs. In this study, the surface of mesoporous silica nanoparticles (MSNs) were aminated with 3-aminopropyl triethoxysilane (APTES) and then coupled with keratin, as a gatekeeper, to afford MSNs-NH₂@Keratin. The average sizes and morphologies of MSNs and MSNs-NH₂@Keratin were characterized with dynamic light scattering and transmission electron microscopy, respectively. The loading content and encapsulation efficiency of doxorubicin (DOX) were calculated to be 17.1 ± 1.7% and 71.3 ± 2.1%. Drug-loaded MSNs-NH₂@Keratin exhibited pH and glutathione (GSH) dual responsiveness under tumor microenvironment. The nanoparticles could be uptaken by tumor cells to effectively inhibit tumor cell growth. Moreover, the sizes of nanoparticle were stable in the serum. Collectively, our findings demonstrated the potential of DOX-loaded MSNs-NH₂@Keratin in the treatment of cancer.

Loading and delivery of sertraline using inorganic micro and mesoporous materials

Sertraline hydrochloride (designated as sertraline from now on) is an antidepressive drug with unpleasant effects in the gastric tract. Therefore, improved means of delivery allowing for a more controlled and efficient release were looked for. Two different porous materials, montmorillonite-K10 and MCM-41, were chosen as hosts. The drug was intercalated in the interlayer spacing of the clay by cation exchange and was loaded inside the MCM-41 channels by pore volume impregnation means. Spectroscopic evidence (UV/vis, FTIR, powder X-ray diffraction (XRD) and (13)C CP/MAS and (29)Si CP/MAS and MAS solid-state NMR), as well as elemental analysis, complemented by DFT calculations, demonstrated the presence of sertraline in the composite materials. The release processes were monitored under in vitro conditions using a simulated body fluid. The release profile from the clay is fast, indicating that a concentration peak is reached in a short period of time, while the release profile from MCM is slower but lasts longer. These differences are discussed on the basis of different therapeutic indications for both materials.

Photoluminescence of Cd1-xMnxS (x ≤ 0.3) Nanowires

Cd1-xMnxS (x = 0.1-0.3) nanowires were synthesized by using the chemical vapor deposition method. They all consist of a single-crystalline wurtzite CdS structure with a [010] or [011] growth direction. The X-ray diffraction pattern reveals the contraction of the lattice constants due to the incorporation of Mn. The Mn2+ emission at approximately 2.15 eV, originating from the d-d (4T1 --> 6A1) transition, appears below 50-80 K. Its decay time is in the range of 0.55-1 ms, showing a decrease with increasing Mn content. The Mn doping reduces significantly the decay time of band-edge emission from 590 ps to 20-30 ps. Upon applying magnetic field (up to 7 T), the Mn2+ emission is suppressed and donor-acceptor pair emission becomes dominant, suggesting the energy transfer from the band electrons to the Mn2+ ions.