Preparation and Characterization of Novel Perfluorooctyl Bromide Nanoparticle as Ultrasound Contrast Agent via Layer-by-Layer Self-Assembly for Folate-Receptor-Mediated Tumor Imaging

Table 1

Factors and levels of orthogonal design.

Factors	PFOB (μL)	Egg lecithin (%, w/v)	LutrolF68 (%, w/v)	Oleic acid (%, w/v)
Level 1	100	1.8	0	0.1
Level 2	150	2.4	0.6	0.2
Level 3	200	3.0	1.3	0.3