Design, development, and characterization of lipid nanocarriers-based epigallocatechin gallate delivery system for preventive and therapeutic supplementation

Figures & data

Table 1 Preparation of EGCG-loaded solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC)

Sample	Precirol^® ATO 5 (mg)	Miglyol-812 (mg)	Polysorbate 60 (mg)	Milli-Q water (mL)	EGCG (mg)
SLN	500	0	100	4.4	0
	490	0	100	4.4	10
	480	0	100	4.4	20
	470	0	100	4.4	30
	450	0	100	4.4	50
NLC	350	150	100	4.4	0
	340	150	100	4.4	10
	330	150	100	4.4	20
	320	150	100	4.4	30
	300	150	100	4.4	50

Abbreviation: EGCG, epigallocatechin gallate.

Table 2 Characterization of the hydrodynamic diameter, ζ potential, EE, and LC of the SLN, NLC, EGCG-SLN, and EGCG-NLC formulations

Sample	Z-average (nm)	Polydispersity index	ζ potential (mV)	Entrapment efficiency (%)	Loading capacity (%)
SLN	206±3	0.18±0.01	−28±1	NA	NA
EGCG-SLN	364±11a	0.19±0.03	−24±1	83±1	4.3±0.1
NLC	216±4	0.16±0.02	−30±1	NA	NA
EGCG-NLC	300±7b,c	0.15±0.02	−28±1	90±1	4.6±0.1

Notes: All values represent the mean ± standard deviation (n=3).

a Statistically different (P<0.05) between SLN and EGCG-loaded SLN.

b Statistically different (P<0.05) between NLC and EGCG-loaded NLC.

c Statistically different (P<0.05) between EGCG-loaded SLN and NLC.

Abbreviations: EE, encapsulation efficiency; EGCG, epigallocatechin gallate; EGCG-NLC, epigallocatechin gallate loaded nanostructured lipid carriers; EGCG-SLN, epigallocatechin gallate loaded solid lipid nanoparticles; LC, drug-loading capacity; NA, not applicable; NLC, nanostructured lipid carriers; SLN, solid lipid nanoparticles.

Figure 1 Cryo-scanning electron microscopy images of (A) SLN, (B) EGCG-SLN, (C) NLC, and (D) EGCG-NLC at 20,000× magnification.

Abbreviations: EGCG-NLC, epigallocatechin gallate loaded nanostructured lipid carriers; EGCG-SLN, epigallocatechin gallate loaded solid lipid nanoparticles; NLC, nanostructured lipid carriers; SLN, solid lipid nanoparticles.

Figure 2 In vitro EGCG release profiles from SLN and NLC at two different pH values, pH=1.2 (first 4 hours) and 6.5 (from 4 to 24 hours), at body temperature (37°C).

Abbreviations: EGCG, epigallocatechin gallate; NLC, nanostructured lipid carriers; SLN, solid lipid nanoparticles.

Figure 3 MTT results for Caco-2 cell line (mean ± SD) as a function of the different formulations and EGCG concentrations tested (5, 10, 50, 100, and 500 µM), and in the case of placebos the corresponding lipid amount.

Note: *P<0.05 relative to the mean positive control.
Abbreviations: EGCG, epigallocatechin gallate; EGCG-NLC, epigallocatechin gallate loaded nanostructured lipid carriers; EGCG-SLN, epigallocatechin gallate loaded solid lipid nanoparticles; NLC, nanostructured lipid carriers; SD, standard deviation; SLN, solid lipid nanoparticles.

Figure 4 LDH results for Caco-2 cell line (mean ± SD) as a function of the different formulations and EGCG concentrations tested (5, 10, 50, 100, and 500 µM), and in the case of placebos the corresponding lipid amount.

Note: *P<0.05 relative to the mean positive control.
Abbreviations: EGCG, epigallocatechin gallate; EGCG-NLC, epigallocatechin gallate loaded nanostructured lipid carriers; EGCG-SLN, epigallocatechin gallate loaded solid lipid nanoparticles; NLC, nanostructured lipid carriers; SLN, solid lipid nanoparticles.

Figure 5 Characterization of the hydrodynamic diameter (A), ζ potential (B), and EE (C) during 3 months of storage for SLN, NLC, EGCG-SLN, and EGCG-NLC formulations.

Abbreviations: EE, encapsulation efficiency; EGCG, epigallocatechin gallate; EGCG-NLC, epigallocatechin gallate loaded nanostructured lipid carriers; EGCG-SLN, epigallocatechin gallate loaded solid lipid nanoparticles; NLC, nanostructured lipid carriers; SLN, solid lipid nanoparticles.

Table S1 Value of R² obtained from the release of EGCG from SLN for different models of mechanism of drug release

Dissolution medium pH value	Zero order	First order	Hixson–Crowell	Higuchi	Korsmeyer–Peppas
pH=1.2	0.981	0.891	0.937	0.953	0.992
pH=6.5	0.995	0.939	0.955	0.891	0.996

Abbreviations: EGCG, epigallocatechin gallate; SLN, solid lipid nanoparticles.

Table S2 Value of R² obtained from the release of EGCG from NLC for different models of mechanism of drug release

Dissolution medium pH value	Zero order	First order	Hixson–Crowell	Higuchi	Korsmeyer–Peppas
pH=1.2	0.983	0.882	0.935	0.894	0.984
pH=6.5	0.996	0.964	0.981	0.861	0.996

Abbreviations: EGCG, epigallocatechin gallate; NLC, nanostructured lipid carriers.