Zetasizer nano zen3690

Characterization and preparation of CuONPs were performed according to our previous studies [35 (link), 36 (link)]. The morphology of CuONPs was observed with transmission electron microscope (TEM) (Hitachi-7500; Hitachi, Ltd, Tokyo, Japan). The chemical elemental composition of this CuONPs was detected by field emission scanning electron microscopy (Hitachi SU8010) with energy-dispersive spectroscopy (Oxford X-MAN 50) (FE-SEM/EDS). The hydrodynamic diameter and zeta-potential of CuONPs were determined by dynamic light scattering (DLS) with Malvern Zetasizer Nano ZEN3690 (Malvern, Massachusetts, USA). The characteristics of CuONPs used in this study were presented in Fig. 1. For preparation of CuONPs, the CuONPs were firstly diluted to the concentration of 2 mg/mL. The suspension dilution is composed of 2% heat-inactivated sibling mouse serum in MilliQ water. Then the CuONPs suspension dilution was sonicated according to sonication procedure that 20% of maximum amplitude applied for 20 min on ice with an ultrasonic cleaner. To avoid the dissolution of CuONPs in suspension solution, the CuONPs were freshly prepared before administration.

The mean particle size and size distribution of self-assembled mPEG-HTO-mPEG micelles in the aqueous phase were determined using DLS by Zetasizer Nano ZEN3690 (Malvern Instruments Ltd., Marvin, UK). All measurements were performed at 25 °C. In order to measure the mPEG-HTO-mPEG aqueous solutions, they were passed through a 0.45 m pore-sized syringe filter.

The zeta potential of cellulose and CNF (0.1 wt% aqueous solution) was measured using a Zetasizer Nano ZEN 3690 (Malvern Panalytical, UK). Three measurements were performed for each solution to determine the surface charge of the cellulose and CNFs [20 (link)].