Acriflavine-loaded solid lipid nanoparticles: preparation, physicochemical characterization, and anti-proliferative properties.

Acriflavine (ACF) is an antiseptic compound with the potential antitumor activity which is used for the fluorescent staining of RNA due to its dominant fluorescent emission at ∼515 nm. Here, solid lipid nanoparticles (SLNs) containing ACF (ACF-SLNs) were prepared and their physicochemical properties, potential geno/cytotoxicity, as well as the fluorescent properties were investigated. FITC-annexin V/PI staining and cell cycle assays were carried out to find the type of cellular death caused. Particle size analysis and SEM images revealed that spherical ACF-SLNs had a homogeneous dispersion with a mean diameter of 106 ± 5.7 nm. Drug loading (DL) of 31.25 ± 4.21 mg/mL and high encapsulation efficiency (EE%) (89.75 ± 5.44) were found. ACF-SLNs physically were relatively stable in terms of dispersion, size, and EE. The uptake study demonstrated the potential use of fluorescent ACF-SLNs in bio-distribution studies. MTT assay showed that plain ACF could induce growth inhibition of A549 cells with IC50 of 8.5, 6, and 4.5 µMol after 24, 48, and 72 hours, respectively, while ACF-SLNs had stable cytotoxic effects after 48 hours. ACF-SLNs induced remarkable apoptosis and even necrosis after 48 h. Conclusively, ACF-SLNs with acceptable physicochemical features showed increased bioimpacts after 48 h compared to plain ACF.

Protective effect of l-carnitine-loaded solid lipid nanoparticles against H2O2-induced genotoxicity and apoptosis.

L-carnitine (LC) is a highly water-soluble compound involved in the ß-oxidation of lipids and transportation of long-chain fatty acids across the membrane of mitochondria. However, the higher hydrophilicity of LC limits its free diffusion across the bilayer lipid membrane of intestinal epithelium in oral administration, decreasing oral bioavailability. Drug delivery with nanoparticles enhances cargo bioavailability and cellular uptake and improves therapeutic outcomes while decreasing unwanted side effects. Here, we proposed solid lipid nanoparticles (SLNs) as a hydrophobic carrier for LC delivery, aiming at increasing LC bioavailability and its protective role against intracellular oxidative stress damages. The LC-SLNs were prepared using the hot homogenization technique, and different physicochemical properties were investigated. The inhibition of H2O2-induced ROS generation in human umbilical vein endothelial cells (HUVECs) with plain LC and LC-SLNs was investigated. Moreover, various in vitro experiments were performed to assess whether LC-SLNs can protect HUVECs from H2O2-induced genotoxicity and apoptosis. The monodispersed and spherical blank SLNs and LC-SLNs were 104 ± 1.8 and 128 ± 1.5 nm, respectively with a drug loading (DL) of 11.49 ± 0.78 mg/mL and acceptable encapsulation efficiency (EE%) (69.09 ± 1.12) of LC-SLNs. The formulation process did not affect the antioxidant properties of LC. MTT assay and comet assay demonstrated that the LC-SLNs decreased cytotoxicity and genotoxicity of H2O2, respectively on HUVECs. Besides, LC-SLNs more inhibited ROS generation, along with apoptotic events in H2O2-treated HUVECs compared to the plain LC. Altogether, our findings affirmed the protective effects of LC-SLNs against H2O2-induced genotoxicity and apoptosis in HUVECs. In conclusion, LC-SLN formulation is a promising drug delivery system to overcome the bioavailability issue of hydrophilic LC, enhancing the antioxidant and biological properties of the plain LC.

Preparation, physicochemical characterization, and anti-proliferative properties of Lawsone-loaded solid lipid nanoparticles.

Lawsone (LWS) is a naphthoquinone-type dye with potential antitumor activity. LWS is used in cosmetics for coloring hair, skin, and nails. In this study, solid lipid nanoparticles (SLNs) containing LWS were prepared using a hot homogenization technique. Physicochemical properties of LWS-SLNs including encapsulation efficiency (EE), drug loading (DL), size, zeta potential, homogeneity, in vitro release, and kinetics of release were determined. The potential cytotoxic properties of LWS-SLNs were investigated. Comet assay was done to assess the genotoxicity of LWS-SLNs. The scanning electron microscopy (SEM) images revealed that LWS-SLNs were spherical and homogeneously dispersed. The average diameter of free SLNs and LWS-SLNs were 97 ± 1.4 and 127 ± 3.1 nm, respectively with high EE% (95.88 ± 3.29) and a DL of 22.72 ± 1.39 mg/mL of LWS-SLNs. The plain LWS could induce growth inhibition of A549 cells with IC50 of 17.99 ± 1.11, 13.37 ± 1.22, and 9.21 ± 1.15 µg/mL after 24, 48, and 72 h, respectively, while LWS-SLNs had more cytotoxic effects after 48 h (9.81 ± 1.3 µg/mL). Comet assay represented clear fragmentation in the chromatin of the treated cells. Besides, LWS-SLNs (13.37 ± 1.22 µg/mL) induced ∼52 % apoptosis and even necrosis after 48 h. The qPCR results showed an enhanced downregulation of Bcl-2 and upregulation of Casp 9 due to the treatment of A549 cells with LSW-SLNs. In conclusion, a stable formulation of LWS-SLN was prepared with good physicochemical features and long-term biological effects that candidate it for in vivo trials.