Kinetex 5u evo c18 100a 250 4.6 mm

The supernatant and the washing solutions were collected together and diluted with ethanol about 1:4 ratio to determine the concentrations of OMC by high-performance liquid chromatography (Agilent HP-1200, Agilent, Santa Clara, CA, USA) with UV-vis (Agilent UV-1575, Agilent, Santa Clara, CA, USA). OMC separation was carried out on a C18 column (Kinetex 5u EVO C18 100A 250 × 4.6 mm, Phenomenex Inc, Torrance, CA, USA) using a mobile phase consisting of methanol-water (80:20, v/v) at a flow rate of 1.0 mL/min. The detection wavelength was set at 310 nm. The sample was passed through a 0.45 μm polytetrafluoroethylene (PTFE) membrane filter. The OMC entrapment efficiency (EE) and loading capacity (LC) were calculated using the following equations [25 (link)]: $\mathrm{EE}(\%)=\frac{\mathrm{total}\mathrm{OMC}\mathrm{amount}-\mathrm{free}\mathrm{OMC}\mathrm{amount}}{\mathrm{total}\mathrm{OMC}\mathrm{amount}}\times 100$
$\mathrm{LC}(\%)=\frac{\mathrm{total}\mathrm{OMC}\mathrm{amount}-\mathrm{free}\mathrm{OMC}\mathrm{amount}}{\mathrm{total}\mathrm{nanospheres}\mathrm{weight}}\times 100$

The sample was centrifuged at 10,000 rpm for 15 min, and the supernatant was diluted with methanol. The sample was filtered by Phree^TM Phospholipid Removal (Phenomenex, Torrance, CA, USA) to remove impurities and phospholipids and determine the concentrations of RSV by HPLC (Pump: V6815, UV–VIS: V6830, KNAUER, Berlin, Germany). RSV separation was carried out on a C18 column (Kinetex 5u EVO C18 100A 250 × 4.6 mm, Phenomenex, Torrance, CA, USA) using a mobile phase consisting of methanol containing 0.5% acetic acid in water (80:20, v/v) at a flow rate of 0.8 mL/min. The detection wavelength was set at 310 nm.
The RSV EE was calculated by Equation (1) [27 (link)]: $\mathrm{EE}(\%)=\left(\frac{\mathrm{total}\mathrm{RSV}\mathrm{amount}-\mathrm{free}\mathrm{RSV}\mathrm{amount}}{\mathrm{total}\mathrm{RSV}\mathrm{amount}}\right)\times 100$