Development of EphA2 siRNA-loaded lipid nanoparticles and combination with a small-molecule histone demethylase inhibitor in prostate cancer cells and tumor spheroids.

BACKGROUND: siRNAs hold a great potential for cancer therapy, however, poor stability in body fluids and low cellular uptake limit their use in the clinic. To enhance the bioavailability of siRNAs in tumors, novel, safe, and effective carriers are needed. RESULTS: Here, we developed cationic solid lipid nanoparticles (cSLNs) to carry siRNAs targeting EphA2 receptor tyrosine kinase (siEphA2), which is overexpressed in many solid tumors including prostate cancer. Using DDAB cationic lipid instead of DOTMA reduced nanoparticle size and enhanced both cellular uptake and gene silencing in prostate cancer cells. DDAB-cSLN showed better cellular uptake efficiency with similar silencing compared to commercial transfection reagent (Dharmafect 2). After verifying the efficacy of siEphA2-loaded nanoparticles, we further evaluated a potential combination with a histone lysine demethylase inhibitor, JIB-04. Silencing EphA2 by siEphA2-loaded DDAB-cSLN did not affect the viability (2D or 3D culture), migration, nor clonogenicity of PC-3 cells alone. However, upon co-administration with JIB-04, there was a decrease in cellular responses. Furthermore, JIB-04 decreased EphA2 expression, and thus, silencing by siEphA2-loaded nanoparticles was further increased with co-treatment. CONCLUSIONS: We have successfully developed a novel siRNA-loaded lipid nanoparticle for targeting EphA2. Moreover, preliminary results of the effects of JIB-04, alone and in combination with siEphA2, on prostate cancer cells and prostate cancer tumor spheroids were presented for the first time. Our delivery system provides high transfection efficiency and shows great promise for targeting other genes and cancer types in further in vitro and in vivo studies.

Enhanced Cellular Uptake and Gene Silencing Activity of Survivin-siRNA via Ultrasound-Mediated Nanobubbles in Lung Cancer Cells.

PURPOSE: Paclitaxel is a first-line drug for the therapy of lung cancer, however, drug resistance is a serious limiting factor, related to overexpression of anti-apoptotic proteins like survivin. To overcome this phenomenon, developing novel ultrasound responsive nanobubbles - nanosized drug delivery system- for the delivery of paclitaxel and siRNA in order to silence survivin expression in the presence of ultrasound was aimed. METHODS: Paclitaxel-carrying nanobubble formulation was obtained by modifying the multistep method. Then, the complex formation of the nanobubbles - paclitaxel formulation with survivin-siRNA, was examined in terms of particle size, polydispersity index, zeta potential, and morphology. Furthermore, siRNA binding and protecting ability, cytotoxicity, cellular uptake, gene silencing, and induction of apoptosis studies were investigated in terms of lung cancer cells. RESULTS: Developed nanobubbles have particle sizes of 218.9-369.6 nm, zeta potentials of 27-34 mV, were able to protect siRNA from degradation and delivered siRNA into the lung cancer cells. Survivin expression was significantly lower compared with the control groups and enhanced apoptosis was induced by the co-delivery of survivin-siRNA and paclitaxel. Furthermore, significantly higher effects were obtained in the presence of ultrasound induction. CONCLUSION: The ultrasound responsive nanobubble system carrying paclitaxel and survivin-siRNA is a promising and effective approach against lung cancer cells.

A promising approach to develop nanostructured lipid carriers from solid lipid nanoparticles: preparation, characterization, cytotoxicity and nucleic acid binding ability.

We aimed to develop nanostructured lipid carriers (NLCs) displaying similar characteristics - particle size, polydispersity index, and zeta potential - with the model solid lipid nanoparticles (SLNs) for better comparability. By considering the hydrophilic-lipophilic balance values of solid and liquid lipids, five out of six NLCs and eight out of eight cationic NLCs (cNLCs) were successfully prepared with similar characteristics to their precursor SLN and cationic SLNs (cSLNs), respectively. Among cationic formulations, two cSLNs containing different surfactant/co-surfactant concentrations (4% and 8% S/CoS; w/w) and their cNLC versions prepared with Labrafac lipophile WL 1349 (LWL) or Labrafac PG were selected to compare cytotoxicity, stability, and nucleic acid binding ability. All formulations are well-tolerated by L-929 cells, cSLNs being least toxic. The formulations containing 4% S/CoS had higher stability after 24-months. All nanoparticles formed complexes with pDNA (Binding ability: cNLCs > cSLNs). cSLN and LWL-cNLC containing 4% S/CoS showed the highest pDNA binding capacity in each group, and their spherical/oval shape was revealed by electron microscopy. However, they did not form complexes with siRNA. The developed approach has the potential to simplify the production of (c)NLCs having similar physicochemical properties with the optimum (c)SLN and may provide better insight for (c)SLN vs.

Development and characterization of nanobubbles containing paclitaxel and survivin inhibitor YM155 against lung cancer.

Lung cancer remains 23% of cancer-related death worldwide, ranking on first place for men and second place for women. Almost each cancer type has a great deal in common, overexpression of the apoptosis inhibitor survivin. Chemotherapy with anticancer drugs is leading to side effects. Drug targeting by the use of nanobubbles is a useful strategy to reduce side effects. Nanobubbles in cancer are one of the most investigated carriers in the last years. The size of nanobubbles (1-500 nm) is bigger than the pore size of healthy tissues, but smaller than the pores of cancer tissues. Thus, it is not possible for the drug to leave the blood stream and enter the tissue, but it can enter the cancer tissue through the pores, where it can accumulate. Therefore, the probability of undesired side effects decreases. For that reason, the development of nanobubbles containing paclitaxel and survivin inhibitor sepantronium bromide (YM155) were carried out. Characterization studies in terms of particle size, size distribution, zeta potential and morphology, and investigation of their effects on lung cancer cells were performed. To the best of our knowledge, there is no information in the literature about combining paclitaxel and YM155 loaded nanobubbles with ultrasound exposure.

Nutlin3a-Loaded Nanoparticles Show Enhanced Apoptotic Activity on Prostate Cancer Cells.

Escape from apoptosis, one of the characteristic features of cancer cells, is a case that reduces the therapeutic efficacy of apoptosis-inducing molecules used in the cancer treatment. Stabilization of the P53 protein, which is responsible for the regulation of apoptosis mechanism in the cell, is therefore an important therapeutic goal. Nutlin3a inhibits the degradation of the P53 protein, triggers P53-mediated apoptosis in cancer cells and enhances the effectiveness of chemotherapeutics. However, its low aqueous solubility is the major disadvantage when it comes to in vivo administration. In order to facilitate an aqueous formulation of Nutlin3a and to enhance its apoptotic activity on cancer cells, Nutlin3a was encapsulated in solid lipid nanoparticles (SLNs) prepared by Ouzo method. Physicochemical characterization was performed and activity of apoptosis induction on wild-type P53 expressing LNCaP prostate cancer cell line was evaluated. Nutlin3a-loaded cationic solid lipid nanoparticles were found to stabilize functional P53 at protein level. In addition, induction rate of apoptosis by nanoparticles was higher than Nutlin3a solution in DMSO, proving this nanoparticle formulation is a promising candidate for increasing the efficiency of Nutlin3a for P53(+) cancer cases. Thus, it is anticipated that the results will contribute to evaluate the use of lipid-based nanocarriers to enhance the therapeutic potential of small molecules that are important in cancer cure.

Formulation, characterization, cytotoxicity and Salmonella/microsome mutagenicity (Ames) studies of a novel 5-fluorouracil derivative.

5-Fluorouracil is one of the first line drugs for the systemic therapy of solid tumors like breast, colorectal, oesophageal, stomach, pancreatic, head and neck. It could be shown that sugars can improve the absorption across cell membranes and can help to bypass some pharmacokinetic problems. Carbohydrates as most common organic molecules are an important issue of plant and animal metabolisms. They are non toxic and have important duties in the body like participating in DNA and RNA synthesis and being responsible for energy production. In addition, they have many hydroxyl, aldehyde and ketone groups that attract attention for synthesis as a potential drug derivative. 1,2,3,-Triazole compounds have also important role in heterocyclic chemistry because of their pharmaceutical properties and their high reactivity, which could be used as a building block for complex chemical compounds. In this study, following the "Click Reaction" of 5-FU and tetra-O-acetylglycose the 5-fluorouracil derivative 1-[{1'-(2″,3″,4″,6″-tetra-O-acetyl-ß-d-glycopyronosyl)-1'H-1',2',3'-triazole-4'-yl} methyl]5-fluorouracil was synthesized. Following, a micellar formulation of 5-Fluorouracil derivative was prepared and characterized in terms of particle size, polydispersity index, zeta potential, refractive index and pH. Furthermore, the cytotoxicity and mutagenicity of the 5-fluorouracil derivative was investigated using an in vitro cell culture model and the AMES test. According to the results of this study, the novel 5-fluorouracil derivative could be a drug candidate for the therapy of cancer and needs further in vivo investigations.

Preparation and characterization of non-viral gene delivery systems with pEGFP-C1 Plasmid DNA

ABSTRACT In recent years, non-viral delivery systems for plasmid DNA have become particularly important. They can overcome the disadvantages of viral systems such as insertional mutagenesis and unpredicted immunogenicity. Some additional advantages of non-viral gene delivery systems are; good stability, low cost, targetability, delivery of a high amount of genetic materials. The aim of the study was to develop novel non-viral nanosystems suitable for gene delivery. Two formulations were developed for this purpose: water-in-oil microemulsion (ME) and solid lipid nanoparticles (SLN). The microemulsion was composed of Peceol, Tween 80, Plurol oleique, ethanol and water. The SLN was consisting of Precirol, Esterquat-1 (EQ1), Tween 80, Lecithin, ethanol and water. Characterization studies were carried out by measuring particle size, zeta potential, viscosity and pH. TEM imaging was performed on SLN formulations. Protection against DNase I degradation was examined. Cytotoxicity and transfection efficacy of selected formulations were tested on L929 mouse fibroblast cells. Particle sizes of complexes were below 100 nm and with high positive zeta potential. TEM images revealed that SLNs are spherical. The SLN:DNA complexes have low toxicity and good transfection ability. All results showed that the developed SLN formulations can be considered as suitable non-viral gene delivery systems.

Preparation and characterization of lipid nanoparticle/pDNA complexes for STAT3 downregulation and overcoming chemotherapy resistance in lung cancer cells.

Developments in the field of molecular oncology have revealed that resistance to chemotherapeutics is acqured through several mechanisms including overexpression of common oncogenic proteins. Signal Transducer and Activator of Transcription 3 (STAT3) is one of these oncogenes that is overexpressed in many cancer types. RNA interference (RNAi) is proven powerful tool for downregulating STAT3, allowing re-sensitization of resistant cancer cells. However, delivery of RNA interference-mediating molecules for STAT3 downregulation in lung cancer cells is limited to a small number of studies most of which employ commercially available transfection kits. The aim of this study was to develop and evaluate cationic solid lipid nanoparticles for delivery of RNAi-mediating plasmid DNA in order to down regulate STAT3 in cisplatin resistant lung cancer cells. We focused on obtaining cSLN:plasmid DNA complexes with size below or equal to 100nm, and a positive zeta potential. Two successful candidate cSLN:plasmid DNA complexes (K2 and K3) were selected for in vitro tests and cell culture studies. These formulations have particle sizes of 98 and 93nm, and zeta potential values of 10.5 and 8.9mV, respectively. Plasmid DNA in these complexes was protected against DNaseI and serum-mediated degradation. Substantial part of DNA retained its supercoiled and circular conformation. TEM images showed nearly spherical complex structure. Both formulations reduced STAT3 expression by approx. 5-fold in cisplatin resistant Calu1 cell line and increased the sensitivity of cells to cisplatin.

Improved Method for Solid Lipid Nanoparticle Preparation Based on Hot Microemulsions: Preparation, Characterization, Cytotoxicity, and Hemocompatibility Evaluation.

The ease of application and no requirement of extra energy input make the microemulsion method favorable for solid lipid nanoparticles (SLNs) production. Very limited data are available to date on preparation of SLNs from pre-screened microemulsion phase diagrams. The purpose of this study was to investigate the microemulsion formation area with solid lipids using hot ternary phase diagrams at elevated temperatures and to use selected microemulsions for SLN production. Also, we aimed to characterize obtained SLNs in terms of physicochemical properties, in vitro cell toxicity, and hemolysis. Phase diagrams of solid lipids were screened at elevated temperatures and oil-in-water microemulsion regions were determined. Microemulsions were selected, and SLNs were produced by modification of the microemulsion dilution method and characterized in terms of visual appearance, turbidity, particle size, and zeta potential. Cytotoxicity of nanoparticles was tested on L929 mouse skin fibroblast cells. Hemolytic potential was assessed in vitro using freshly isolated erythrocytes. The phase diagram screening and the modified hot microemulsion dilution method enabled production of SLNs with particle size below 100 nm. We found evidence that the solid lipids in the SLNs produced by the new method remain in supercooled liquid state. Nanoparticles prepared by the new method exhibit lower toxicity on L929 cells and have lower hemolytic potential than the formulations prepared by direct mixing of the components. The method can be used to prepare SLNs with controllable composition and small particle size below 100 nm. These SLNs are low toxic and can be used for drug delivery purposes.

Extracellular Vesicles as Natural Nanosized Delivery Systems for Small-Molecule Drugs and Genetic Material: Steps towards the Future Nanomedicines.

A new platform for drug, gene and peptide-protein delivery is emerging, under the common name of "extracellular vesicles". Extracellular vesicles (EVs) are 30-1000 nm-sized cell-derived, liposome-like vesicles. Current research on EVs as nano-delivery systems for small-molecule drugs and genetic material, reveal that these tiny, biologically-derived vesicles carry a great potential to boost the efficacy of many therapeutic protocols. Several features of EVs; from efficacy to safety, from passive to active targeting ability, the opportunity to be biologically or chemically labelled, and most importantly, their eobiotic origin make them promising candidate for development of the next generation personalized nanomedicines. The aim of this article is to provide a view on the current research in which EVs are used as drug/genetic material delivery systems. Their application areas, drug loading and targeting strategies, and biodistribution properties are discussed.

Determination of in vivo behavior of mitomycin C-loaded o/w soybean oil microemulsion and mitomycin C solution via gamma camera imaging.

In this study, a microemulsion system was evaluated for delivery of mitomycin C (MMC). To track the distribution of the formulated drug after intravenous administration, radiochemical labeling and gamma scintigraphy imaging were used. The aim was to evaluate a microemulsion system for intravenous delivery of MMC and to compare its in vivo behavior with that of the MMC solution. For microemulsion formulation, soybean oil was used as the oil phase. Lecithin and Tween 80 were surfactants and ethanol was the cosurfactant. To understand the whole body localization of MMC-loaded microemulsion, MMC was labeled with radioactive technetium and gamma scintigraphy was applied for visualization of drug distribution. Radioactivity in the bladder 30 minutes after injection of the MMC solution was observed, according to static gamma camera images. This shows that urinary excretion of the latter starts very soon. On the other hand, no radioactivity appeared in the urinary bladder during the 90 minutes following the administration of MMC-loaded microemulsion. The unabated radioactivity in the liver during the experiment shows that the localization of microemulsion formulation in the liver is stable. In the light of the foregoing, it is suggested that this microemulsion formulation may be an appropriate carrier system for anticancer agents by intravenous delivery in hepatic cancer chemotherapy.