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.

Novel Magnesium Oxide (MgO) nanoparticles (NPs) modified with the polymer poliethylene 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. 12March 15, 2019 1/9 2-Metoxyestradiol (2ME) has antitumor activity in several types of cancer of the 13 reproductive tract as prostate, cervix, ovary or endometrium. 2ME exerts its anticancer 14 activity via anti-proliferative, apoptotic or antiangiogenic effects on tumor cells [7]. 15 Despite to be considerate as a promising anticancer drug it has an unfavorable kinetic 16 with a low solubility in water; Thus, it is necessary to find new ways to facilitate its 17 administration to the human body. In this context, the nanoparticles (NPs) as drug 18 carriers can play a fundamental role to improvement biological parameters. Actually, it 19 has been proposed that polymeric NPs [8] or TiO 2 NPs coated with polyethylene glycol 20 (PEG) could be useful tools to load 2ME [9]. In the searching for new NPs suitable for 21 medical use, MgO NPs are also an excellent candidate because they are bio-friendly [10]. 22 It has been shown that MgO NPs are not toxic for a variety of human cell lines at 23 concentrations under 300 µg/ml [10]. MgO NPs has been also used as a carrier for the 24 antincancer drug doxorubicin indicating its utility for a controlled system of drugs 25 delivery [11, 12]. In this work, we first performed the physicochemical characterization 26 of MgO NPs coated with PEG and loaded with 2ME (MgO-PEG-2ME). The efficiency 27 of absortion and liberation of 2ME was then analyzed. Finally, the effect of 28 MgO-PEG-2ME NPs on the prostate cell line LnCap was assessed. 29 Materials and Methods 30 Synthesis MgO nanoparticles 31 The MgO NPs were obtained by the sol-gel method route assisted with cetyltrimethyl 32 ammonium bromide C 19 H 4 2BrN (CTAB) as a surfactant to reduce the agglomeration of 33 the NPs [13]. 1:1 molar solution of magnesium acetate, Mg(CH 3 COO) 2 4H 2 O (99,5 %, 34 MERK, USA) and tartaric acid C 4 H 6 O 6 to (99,5 %, MERK, USA) was prepared in 35 ethanol and added dropwise over 10 ml of a 0.001 M of CTAB in water at 60 • C. The 36solution was stirred vigorously for 20 hours to achieve gel formation. Once the gel is 37 formed, it was dried and before calcined at 600 • C for 6 hours to give MgO [14]. 38MgO nanoparticles functionalized with PEG and 2ME loading. 39MgO NPs were covered with poliethylene glycol 600 (PEG600; Sigma...

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Commensurable twisted bilayers can drastically change the magnetic properties of chromium trihalide layered compounds, which opens novel opportunities for tuning magnetic states through layer rotations. Here, a mathematical approach to obtain moiré patterns in twisted hexagonal bilayers by performing a certain commensurable rotation 𝜽 over one layer is presented. To test the approach, moiré structures with 𝜽 = 21.79 • and 32.20 • in the phases R 3 and C2/m of CrI 3 are obtained via the related methodology. For comparison purposes, a non-shifted CrI 3 structure is also considered. Electronic and magnetic properties of the so-obtained systems are computed by ab initio methodologies. Results show the presence of rotation-angle-dependent magnetic configurations and steep modifications of the dispersion bands due to variations in the nearest and next nearest distances among layers of Cr atoms. Modifications obtained from these commensurable rotations are discussed on the basis of competition among different energy contributions due to changes in the atomic neighborhood.

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