Abstract:The aim of this study was to prepare a novel targeting drug delivery system for 2-Methoxyestradiol (2ME) in order to improve the clinical application of this antitumor drug. It is based in nanoparticles (NPs) of titanium dioxide (TiO 2 ) coated with polyethylene glycol (PEG) and loaded with 2ME. A complete IR and Raman characterization have been made to confirm the formation of TiO 2 -PEG-2ME composite. Vibrational modes have been assigned for TiO 2 , PEG, and 2ME and functionalized TiO 2 -PEG and TiO 2 -PEG-2ME. The observed variation in peak position of FTIR and Raman of each for these composites has been elucidated in terms of intermolecular interactions between PEG-2ME and TiO 2 , obtaining step-by-step the modification processes that were attributed to the conjugation of PEG and 2ME to TiO 2 NPs. Modifying TiO 2 NPs with PEG loaded with the 2ME drug revealed that the titanium dioxide nanocarrier possesses an effective adsorption capability, and we discuss their potential application as a system of drug delivery.

A monolayer of CrI3 is a two-dimensional crystal in its equilibrium configuration is a ferromagnetic semiconductor. In contrast, two coupled layers can be ferromagnetic, or antiferromagnetic depending on the stacking. We study the magnetic phase diagram upon the strain of the antiferromagnetically coupled bilayer with C2/m symmetry. We found that strain can be an efficient tool to tune the magnetic phase of the structure. A tensile strain stabilizes the antiferromagnetic phase, while a compressive strain turns the system ferromagnetic. We associate that behavior to the relative displacement between layers induced by the strain. We also study the evolution of the magnetic anisotropy, the magnetic exchange coupling, and how the Curie temperature is affected by the strain.I.

Recently intrinsic ferromagnetism in two-dimensional(2D) van der Waals materials was discovered [1,2,3]. A monolayer of Chromiun triiodide(CrI 3 ) is ferromagnetic while a bilayer structure was reported to be anti-ferro magnetic, moreover an external electric field changes its magnetic phase [4]. We have studied the two found in nature stackings of CrI 3 bilayers and found that indeed the magnetic phase of one of them can be tuned by an external electric field while the other remains ferromagnetic. We simulate those results with ab initio calculations and explain them with a simple model based on a rigid shift of the bands associated with different spins. The model can be applied to similar van der Waal stacked insulating bilayer anti-ferromagnets. arXiv:1811.11910v1 [cond-mat.mtrl-sci] 29 Nov 2018Control of magnetism in bilayer CrI 3 by an external electric field.

Novel Magnesium Oxide (MgO) nanoparticles (NPs) modified with the polymer polyethylene glycol (PEG) were synthesized as carrier for the anticancer drug 2-Methoxyestradiol (2ME) to improve its clinical application. The functionalized NPs were characterized by Infrared spectroscopy with Fourier transform to elucidate the vibration modes of this conjugate, indicating the formation of the MgO-PEG-2ME nanocomposite. The studies of absorption and liberation determined that MgO-PEG-2ME NPs incorporated 98.51 % of 2ME while liberation of 2ME was constant during 7 days at pH 2, 5 and 7.35. Finally, the MgO-PEG-2ME NPs decreased the viability of the prostate cancer cell line LNCap suggesting that this nanocomposite is suitable as a drug delivery system for anticancer prostate therapy.