Folate-decorated poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) nanoparticles for targeting delivery: optimization and in vivo antitumor activity

Figures & data

Figure 1. The schedule of preparing DOX/FA-PEG-P(HB-HO) NPs.

Table 1. Factors and levels of the orthogonal design L₉ (3⁴).

	Factors
Levels	A	B	C	D
1	10	1:1	1	2.5
2	15	3:1	3	6.5
3	20	5:1	5	10.5

Table 2. Design of orthogonal design L₉ (3⁴).

No.	A	B	C	D	EE (%)
1	1	1	1	1	71.02
2	1	2	2	2	84.62
3	1	3	3	3	69.72
4	2	1	2	3	57.98
5	2	2	3	1	59.32
6	2	3	1	2	62.47
7	3	1	3	2	59.81
8	3	2	1	3	54.66
9	3	3	2	1	48.48
X1	75.12	62.94	62.72	59.61
X2	59.92	66.20	63.69	68.97
X3	54.32	60.22	62.95	60.79
S	20.80	5.98	0.98	9.36

X_i is the average EE of level i for each factor; S is the difference between the maximum value and the minimum value of X_i.

Figure 2. Particle size and distribution of DOX/FA-PEG-P(HB-HO) NPs.

Figure 3. In vitro release study of DOX/FA-PEG-P(HB-HO) NPs. (A) In vitro cumulative release of DOX from DOX/FA-PEG-P(HB-HO) NPs in pH 7.4 PBS, (B) Higuchi model of DOX/FA-PEG-P(HB-HO) NPs, (C) zero-order model of DOX/FA-PEG-P(HB-HO) NPs and (D) first-order model of DOX/FA-PEG-P(HB-HO) NPs.

Table 3. Fitting of drug release data of optimized formulation according to various models.

Model	Fitting equation	R^2
Higuchi	Q=0.2408t^1/2	0.9938
First-order	ln(1−Q)= −0.1562t	0.9780
Zero-order	Q=0.0872t	0.8263

Figure 4. Observation of HeLa cells in different groups by optical microscope. (A) control group; (B) free DOX group; (C) DOX/P(HB-HO) NPs group and (D) DOX/FA-PEG-P(HB-HO) NPs group. The black line represents a distance of 100 μm.

Figure 5. Observation of HeLa cells in different groups by fluorescence microscope. (A) control group; (B) free DOX group; (C) DOX/P(HB-HO) NPs group and (D) DOX/FA-PEG-P(HB-HO) NPs group.

Table 4. The results of in vivo antitumor activity.

Groups	N	Tumor weight (g)	TIR (%)
I	6	0.4416 ± 0.0201	–
II	6	0.3031 ± 0.0112^a	31.35
III	6	0.2056 ± 0.0300^a	53.44
IV	6	0.1020 ± 0.0223^a^,^b	76.91

I: normal saline group; II: free DOX group; III: DOX/P(HB-HO) NPs group; IV: DOX/FA-PEG-P(HB-HO) NPs group.

^ap < 0.05 compared with normal saline group.

^bp < 0.01 compared with normal saline group.

Table 5. Organ/body weight ratios of different groups.

		Organ/body weight ratio (mg/g)
Groups	N	Heart	Liver	Spleen	Lungs	Kidneys
I	6	6.67 ± 0.80	62.89 ± 40.30	5.82 ± 0.87	7.62 ± 2.82	17.95 ± 0.96
II	6	5.25 ± 1.44^a	53.82 ± 31.22^a	4.22 ± 0.85^a	5.84 ± 0.44^a	14.39 ± 0.48^a
III	6	6.68 ± 1.04	60.34 ± 28.91	4.85 ± 1.10	7.89 ± 0.39	16.10 ± 1.39
IV	6	6.26 ± 1.05	60.36 ± 20.44	5.14 ± 0.46	7.15 ± 1.20	17.16 ± 2.96

I: normal saline group; II: free DOX group; III: DOX/P(HB-HO) NPs group; IV: DOX/FA-PEG-P(HB-HO) NPs group.

^ap < 0.05 compared with normal saline group.

Figure 6. Photomicrograph of tumors in different groups after mice sacrifaced (H&E stain). Magnification, 200×. (A) Normal saline group; (B) free DOX group; (C) DOX/P(HB-HO) NPs group and (D) DOX/FA-PEG-P(HB-HO) NPs group.