In vitro release characteristics and cellular uptake of poly(D,L-lactic-co-glycolic acid) nanoparticles for topical delivery of antisense oligodeoxynucleotides

Figures & data

Table 1.  Effect of PLGA concentration and volume ratio (Va1/Vo/Va2) on the physical properties of blank nanoparticles (data represents mean values ± SD, n = 3).

Formulation	Particle Size (nm)	PDI	ZP (mV)
PLGA2.5%-1:10:20	138.03 ± 2.16	0.15 ± 0.01	−21.47 ± 3.38
PLGA2.5%-1:20:50	146.67 ± 1.55	0.10 ± 0.01	−22.20 ± 0.93
PLGA3%-1:10:20	140.60 ± 1.06	0.11 ± 0.01	−33.01 ± 1.73
PLGA3%-1:20:50	159.83 ± 2.25	0.10 ± 0.02	−29.56 ± 1.86
PLGA3.5%-1:10:20	165.93 ± 2.38	0.14 ± 0.01	−28.67 ± 0.39
PLGA3.5%-1:20:50	149.70 ± 1.54	0.11 ± 0.02	−20.07 ± 0.40

Table 2.  Effect of storage time on the physical properties of blank nanoparticles with different PLGA concentrations and volume ratios (Va1/Vo/Va2) (data represents mean values ± SD, n = 3).

Formulation	PLGA3%-1:10:20	PLGA3%-1:20:50	PLGA3.5%-1:10:20	PLGA3.5%-1:20:50
Particle size (nm)
day 0	140.62 ± 1.06	159.83 ± 2.25	165.93 ± 2.38	149.71 ± 1.26
day 3	151.93 ± 0.13	171.37 ± 1.71	167.21 ± 1.64	148.62 ± 0.95
day 8	156.67 ± 2.26	168.83 ± 1.78	195.41 ± 2.42	159.32 ± 1.65
day 15	148.67 ± 2.25	148.42 ± 2.12	109.93 ± 0.59	168.07 ± 4.62
PDI
day 0	0.11 ± 0.01	0.09 ± 0.02	0.14 ± 0.01	0.11 ± 0.01
day 3	0.21 ± 0.01	0.16 ± 0.01	0.19 ± 0.01	0.14 ± 0.03
day 8	0.21 ± 0.01	0.13 ± 0.01	0.31 ± 0.03	0.21 ± 0.00
day 15	0.23 ± 0.02	0.18 ± 0.00	0.30 ± 0.03	0.30 ± 0.00
ZP (mV)
day 0	−33.07 ± 1.73	−29.56 ± 1.86	−28.67 ± 0.39	−20.01 ± 0.33
day 3	−24.51 ± 0.62	−26.37 ± 0.98	−23.37 ± 1.30	−22.63 ± 0.69
day 8	−26.63 ± 1.24	−25.03 ± 2.46	−21.71 ± 1.20	−21.33 ± 0.84
day 15	−25.93 ± 1.95	−20.11 ± 0.43	−27.77 ± 0.90	−16.07 ± 0.59

Figure 1.  SEM micrograph of freeze-dried nanoparticles prepared with 3% w/v PLGA and a volume ration of 1:10:20 (8000× magnification, scale bar = 200 nm)

Table 3.  Physicochemical properties of AsODN-loaded nanoparticles (data represents mean values ± SD, n = 3)

Formulation	Particle size (nm)	PDI	ZP (mV)	EE (%)
Cx31.1-PLGA3%-1:10:20	128.81 ± 1.21	0.26 ± 0.02	−29.00 ± 0.44	54.95 ± 9.01
Cx31.1-PLGA3%-1:20:50	165.97 ± 0.95	0.18 ± 0.01	−14.03 ± 0.21	54.53 ± 6.91
Cx31.1-PLGA2.5%-1:20:50	145.69 ± 0.39	0.11 ± 0.01	−22.53 ± 0.85	49.97 ± 0.87
Cx43-PLGA2.5%-1:20:50	183.07 ± 13.11	0.41 ± 0.04	−24.97 ± 0.66	54.03 ± 7.56

Figure 2.  In vitro release profiles of various AsODN-loaded nanoparticles (data points represents mean values + SD, n = 3)

Table 4.  Kinetic parameters for the hypothesized release model (data represents mean values ± SD, n = 3), *(P < 0.05)).

Formulation	Cx31.1-PLGA3%-1:10:20	Cx31.1-PLGA3%-1:20:50	Cx31.1-PLGA2.5%-1:20:50	Cx43-PLGA2.5%-1:20:50
fA (%)	28.15 ± 1.84	23.01 ± 1.82	28.48 ± 1.25	11.19 ± 5.34*
kA (day^−1)	2.40 ± 1.42	4.10 ± 0.11	4.46 ± 2.80	27.31 ± 15.56*
t1/2 A (day)	0.35 ± 0.14	0.17 ± 0.00	0.26 ± 0.20	0.04 ± 0.03
fB (%)	34.28 ± 8.95	15.87 ± 0.73	41.23 ± 18.21	32.08 ± 9.46
kB (day^−1)	0.17 ± 0.08	0.23 ± 0.03	0.26 ± 0.19	0.68 ± 0.33
t1/2 B (day)	4.55 ± 1.03	3.05 ± 0.35	4.89 ± 1.44	1.20 ± 0.45
tlag (h)	< 1	< 1	< 1	< 1
R^2	0.999 ± 0.00	0.996 ± 0.00	0.996 ± 0.00	0.983 ± 0.01

Figure 3.  Cellular uptake of Cx31.1-PLGA3% nanoparticles incubated at 4 °C (left) and 34 °C (right) respectively for 8 h; merged images of Cy3-AsODN-loaded nanoparticles (red), cell nuclei stained with DAPI (blue) and cell membranes labeled with WGA Alexa 488 (green); (scale bar = 10 µm)

Figure 4.  Confocal 3D cross-section of Cx31.1-PLGA3% nanoparticles incubated at 34 °C for 8 h; merged images of Cy3-AsODN-loaded nanoparticles (red), cell nuclei stained with DAPI (blue) and cell membranes labeled with WGA Alexa 488 (green), with the yellow color signifying an overlay of red and green; (scale bar = 10 µm)