Aloe-emodin loaded solid lipid nanoparticles: formulation design and in vitro anti-cancer study

Figures & data

Figure 1. (A) Chemical structure of AE. (B) Effect of HPH pressure and cycle times on particle size. (C) Effect of lipid concentration on particle size and zeta-potential of AE-SLNs at 10, 20 and 30 mg/ml. (D) Effect of different proportion of surfactant to lipid on particle size and zeta-potential.

Table 1. Effect of lipid materials on particle size and zeta potential of AE-SLNs.

Lipid material	Particles size	Store at 4 °C overnight
Glyceryl monostearate	87.19	Clear
Glyceryl behenate	94.25	Clear
Glyceryl tristearate	203.2	Flocculation
Glyceryl trimyristate	173.1	Flocculation
Soybean lecithin	586.6	Turbidity
Stearic acid	117.6	Flocculation

Table 2. Effect of different surfactants on particle size and zeta potential of AE-SLNs.

Emulsifier	Particle size	Zeta potential (mV)
F68	66.67	−27.6
F127	123.7	−21.2
Tween-20	292.9	−12
Tween-80	87.19	−32

Figure 2. Physical characterization result of AE-SLNs. (A) The particle size distribution of AE-SLNs. (B) Transmission electron microscopy of AE-SLNs.

Table 3. The results of formulation assay.

Formulation assay	Result
Particle size (nm)	88.9 ± 5.2
PDI	0.298 ± 0.007
Zeta potential (mV)	−42.8 ± 1.6
Entrapment efficiency (%)	97.7 ± 0.5

Figure 3. DSC thermogram of free AE, lipid material, physical mixture and AE-SLNs. The characteristic peaks of AE crystals and lipid material appeared at 224 °C and 62 °C respectively, but the thermogram of AE-SLNs presented only one characteristic peak at 51 °C, revealing that AE-SLNs have been successfully prepared.

Figure 4. In vitro drug release profiles of free AE and AE-SLNs.

Figure 5. Cytotoxicity analysis of free AE, B-SLNs and AE-SLNson MCF-7, HepG2 and MCF-10 A cells at the concentration of 0.1–2.5 μM. Data are shown as mean ± S.D. (n = 3). *p < 0.05, **p < 0.01, AE-SLNs versus Free AE.

Figure 6. Hoechst 33342 fluorescent staining to detect apoptotic morphology in breast cancer cells, MCF-7 cells were treat with B-SLNs, Free AE and AE-SLNs at 2.5 μM for 48 h. The cell morphology was observed by Incell Analyzer 2000 (GE Healthcare Life Sciences, USA).

Figure 7. Quantitative apoptotic measurement in MCF-7 cells with treatment of Free AE, B-SLNs and AE-SLNs. (A). Results of dose dependent effect are expressed as dot plot of AnnexinV-FITC versus PI and representative values are shown. (B). The results are expressed as bar chart. Data as mean ± S.D. (n = 3). **p < 0.01, AE-SLNs versus Free AE.

Figure 8. Cellular uptake amount of AE treated with free AE and AE-SLNs at 5 μMwithin 4 h by MCF-7 cells. Data were expressed as mean ± S.D. (n = 3). *p < 0.05, AE-SLNs versus free AE.