Table 2.

Effect of PEG incorporation on physical characteristics of microbubbles (Average ± standard error).

	Unloaded PLA	PLA with 3 wt% GEM	PLA with 6 wt% GEM	Unloaded 5% PEG-PLA	5% PEG-PLA with 3 wt% GEM	5% PEG-PLA with 6 wt% GEM
Average Diameter (μm) and Polydispersity	2.2 ± 0.1	1.3 ± 0.1	1.4 ± 0.1	1.9 ± 0.1	2.2 ± 0.1	2.5 ± 0.1
	PDI	PDI	PDI	PDI	PDI	PDI
	0.2 ± 0.0	0.3 ± 0.0	0.2 ± 0.0	0.3 ± 0.0	0.3 ± 0.0	0.1 ± 0.0
Average Zeta Potential (mV)	−23.2 ± 1.1	−34.0 ± 0.8	−34.1 ± 1.2	−32.7 ± 0.3	−22.0 ± 0.9	−17.7 ± 1.1