D max 2550 pc x ray diffractometer

The morphologies of the as-prepared samples were analyzed by TEM (JEM-2100F). XRD analyses were performed by using a D/max-2550 PC X-ray diffractometer (Rigaku). The XPS patterns were obtained by using an X-ray photoelectron spectrometer (ESCALab 250). UV-Vis-NIR spectra were recorded by using a UV-1902PC spectrophotometer (Phoenix).

The crystalline structure of the Fe₃O₄ and Fe₃O₄@HA nanoparticles was characterized by X-ray diffraction (XRD) in a 2θ range of 20–80°, using a D/max 2550 PC X-ray diffractometer (Japan, Rigaku Cop.) with Cu Kα radiation (λ = 0.154,056 nm) at 40 kV and 200 mA. Fourier transform infrared (FTIR) spectra of Fe₃O₄ and Fe₃O₄@HA nanoparticles were obtained by using a Nexus 670 spectrometer (Thermo Nicolet Corporation, Madison, WI). Thermogravimetric analysis (TGA) was performed in a temperature range of 30–900°C with a heating rate of 20°C/min under nitrogen using a TG209 F1 (NETZSCH Instruments Co., Ltd., Germany) thermogravimetric analyzer.

mPEG-PE (40 mg) was dissolved in 4 mL TCM and dried under vacuum. After evaporating the TCM, the residual membrane was dispersed in 4 mL of Tris-HCl (10 mM Tris-HCl pH 7.4) to form mPEG-PE micelles. The micelles were stored at 4°C.
siRNA (150 μL of 20 μM) was added to 100 μL of a 100 mM CaCl₂ solution, and was subsequently mixed with 250 μL of an mPEG-PE (1 mg/mL) solution. HBS (500 μL; 50 mM Hepes, 280 mM NaCl, 1.5 mM Na₃PO₄, pH = 7.4) was quickly added to the mPEG-PE/Ca²⁺/siRNA solution and was allowed to react for 30 min. To remove the excess Ca²⁺, the reaction mixture was centrifuged at 1000 g and 4°C for 1 h using Amicon^® Ultra-4 centrifugal filter devices (MWCO: 10 kDa). The sample solution was used in further experiments.
The particle size, polydispersity index (PDI) and zeta potential of the prepared nanoparticles were determined using dynamic light scattering (DLS) (Malvern Zetasizer nano ZS, Malvern) measurements. To observe the morphology of the nanoparticles, the nanoparticle solution was dropped onto a 300-mesh carboncoated copper grid and the excess solution was removed using a filter paper. The grid was allowed to dry at room temperature and was observed using transmission electron microscopy (TEM) (H-800, Hitachi, Japan). X-ray diffraction (XRD) measurements were carried out on a Rigaku D/Max-2550PC X-ray diffractometer using Cu Kα radiation.

XRD patterns were measured at room temperature using a RIGAKU D/MAX 2550/PC X-ray diffractometer with monochromatic Cu Kα radiation (λ = 1.54184 Å) at 18 kW.