Controlled release behaviour of protein-loaded microparticles prepared via coaxial or emulsion electrospray

Figures & data

Table 1.  Preparation parameters of coaxial electrospray used in this study.

		Compositions
	Theoretical drug	Core solution (v/v = 1/5)		Shell solution	Diameter	Loading
Sample	loading (w/w%)	BSA/DI water (w/v%)	PLGA/TFE (w/v%)	PLGA/TFE (w/v%)	(µm)	efficiency (%)
a-0% PLGAin	5	0.15	0	3	–	83.15 ± 2.78
b-6% PLGAin		4.65	6	3	2.25 ± 0.56	82.04 ± 3.46
c-5% PLGAin		4.15	5	3	2.37 ± 0.56	82.57 ± 3.02
d-4% PLGAin		3.65	4	3	2.41 ± 0.60	82.35 ± 3.08
e-4% PLGAin	3	2.19	4	3	2.39 ± 0.33	87.51 ± 3.53
f-4% PLGAin	1	0.73	4	3	2.39 ± 0.56	88.93 ± 3.77
g-4% PLGAin	0	0	4	3	2.37 ± 0.60	0

Table 2.  Preparation parameters of emulsion electrospray used in this study.

	Theoretical drug	Compositions of emulsion (W/O = 1/10 in v/v)		Diameter	Loading
Sample	loading (w/w%)	BSA/H2O (w/v%)	PLGA/THM (w/v%)	(µm)	efficiency (%)
h-2% PLGA	5	1	2	22.26 ± 5.40	74.65 ± 4.32
i-4% PLGA		2	4	22.12 ± 5.25	73.97 ± 3.98
j-6% PLGA		3	6	22.75 ± 8.05	74.34 ± 4.02
k-8% PLGA		4	8	23.12 ± 4.73	74.39 ± 3.24
l-6% PLGA	3	1.8	6	22.82 ± 4.95	75.83 ± 4.36
m-6% PLGA	1	0.6	6	22.34 ± 4.68	82.31 ± 4.34
n-6% PLGA	0	0	6	22.77 ± 4.79	0

Figure 1. TEM images of microparticles prepared by coaxial electrospray technique. (A) Formula a-0% PLGAin; (B) formula b-6% PLGAin; (C) formula c-5% PLGAin and (D) formula d-4% PLGAin.

Figure 2. SEM image (A) and LCSM image (B) and the diameter distributions (C) of microparticles prepared by coaxial electrospray technique of formula d-4% PLGAin.

Figure 3. SEM images of microparticles prepared by emulsion electrospray technique. (A) formula h-2% PLGA; (B) formula i-4% PLGA; (C) formula j-6% PLGA and (D) formula k-8% PLGA.

Figure 4. TEM image (A) and LCSM image (B) of microparticles prepared by emulsion electrospray technique and the diameter distributions of formula j-6% PLGA (C).

Figure 5. Protein release profiles for the electrospray microparticles. (A) Protein release profiles for the emulsion electrospray microparticles theoretically loaded with 1wt%, 3wt% and 5wt% BSA. (B) Protein release profiles for the coaxial electrospray microparticles theoretically loaded with 1wt%, 3wt% and 5wt% BSA. (*p < 0.05).