Applications of Lipidic and Polymeric Nanoparticles for siRNA Delivery

The antisense technology that emerged with the discovery of RNA interference nearly 20 years ago has gained a significant place in gene therapy. siRNA, one of two important components of RNA interference, efficiently downregulates gene expression in human cells, so it has the potential to eradicate disease. siRNA delivery systems, which can be applied both systemically and locally in different diseases, have gained significant importance. Naked small RNAs can be delivered directly to cells, but because of their instability, exposure to enzyme degradation, and difficulties in reaching/entering the target cell or tissue in blood stream, these initiatives are failing. For this reason, the method of delivery or encapsulation of siRNA is usually required. Various nanoparticles, nanocapsules, emulsions, micelle systems, metal ion nanoparticles, and nanoconjugates have been used for siRNA delivery. In these transport systems, lipidic and polymeric systems are very attractive due to their advantages such as being biodegradable and biocompatible, safety, being able to electrostatically bind to RNA, long-term stability, well-illuminated structure and features, simple and easy production, etc. Issues such as particle size, zeta potential, and stability of siRNA-loaded system should be taken into consideration in the development of siRNA delivery systems

Preparation and evaluation of carvedilol-loaded solid lipid nanoparticles for targeted drug delivery

Purpose: To develop suitable solid lipid nanoparticles (SLN) containing carvedilol (CL) for controlled delivery to site of action.Methods: Solid lipid nanoparticles (SLNs) containing carvedilol (CL) were prepared by hot homogenization and ultrasonication methods. The SLNs were characterized in terms of entrapment efficiency, particle size, zeta potential, polydispersity index, cytotoxicity, solid state characterization and drug release. The stability of the formulations was investigated by monitoring their properties for a period of 3 months.Results: The mean size of the nanoparticles was in the range of 130.70 ± 1.80 to 154.40 ± 2.40 nm. Solid state analysis showed that carvedilol was uniformly dispersed in the lipid nanoparticles. Drug entrapment efficiency ranged from 96.03 ± 0.13 to 93.46 ± 0.21 % while in vitro cumulative drug release from the nanoparticles in simulated intestinal fluid (SIF) and phosphate buffer containing 30% PEG (pH 6.8) was 96.57 ± 0.40 and 75.13 ± 0.15 %, respectively, at the end of 24 h. In vitro release of carvedilol from SLNs followed fist order kinetics and Higuchi diffusion model.Conclusion: The SLNs developed in this study represent a promising safe system for the sustained and controlled delivery of carvedilol.Keywords: Carvedilol, Solid lipid nanoparticles, Antihypertensive, Sustained releas

Development of paclitaxel-loaded liposomal systems with anti-her2 antibody for targeted therapy

Purpose: To develop liposome formulations containing monoclonal antibody anti-HER2 (MabHer2), and Paclitaxel (PTX).Methods: Seven different liposomal systems containing PTX, or MabHer2 or a combination of PTX and MabHer2 were made using lipid film hydration technique and sonication. The effects of liposome preparation conditions and extraction methods on antibody structure were investigated by polyacrylamide gel electrophoresis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The characteristics of the liposomes were determined by a zetasizer, while drug-loading efficiency was evaluated by high-performance liquid chromatography. The cytotoxic effect of the liposome formulations was evaluated on MDA-MB-453 (HER2+) and MCF-7 (HER2-) breast cancer cell lines by MTT assay.Results: The antibody was not significantly affected by the stress conditions and the method of extraction. The particle size of liposomes was < 200 nm while the amount of incorporated PTX was 97.6% for liposome without cationic agent and 98.2 % for those with cationic agent. Recovery of MabHer2 was 94.38 % after extraction. Combined PTX/MabHer2 liposome was more toxic on HER2 overexpressing positive MDA-MB-453 cell line than PTX-loaded liposomes and MabHer2. MabHer2 and combined PTX/MabHer2 liposomes showed no toxic effects on HER2 overexpressing negative MCF-7 cells relative to cationic PTX-loaded liposomes.Conclusions: This results obtained show that PTX can be encapsulated successfully into liposomal systems and that owing to Her2 specific antibody, these systems can be delivered directly to the target cell.Keywords: Cancer, Anti-her2 antibody, Liposome, Paclitaxel, Targeted therapy, Cell cultur

Synthesis and characterization of 2-aminoethylphosphonic acid-functionalized graphene quantum dots: biological activity, antioxidant activity and cell viability

317-323A facile, environmentally friendly one-step reaction for the preparation of luminescent N-doped graphene quantum dots (GQDs) involving a hydrothermal reaction between citric acid and 2-aminoethylphosphonic acid has been designed. Graphene quantum dots have been characterized by UV-visible absorption, FTIR spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and dynamic light scattering (DLS) techniques. Furthermore, the biological activity of the GQDs has been studied. UV-visible spectroscopy studies of the interactions between the GQDs and calf thymus DNA (CT-DNA) showed that the compound interacts with CT-DNA via intercalative binding. DNA cleavage study showed that the GQDs cleaved DNA oxidatively. In addition, antioxidant activity of N-doped GQDs was measured using the DPPH method. As the concentration of the compound increased, the antioxidant activity also has increased. According to cell viability analyses results, the N-doped GQDs showed cell viability (70%) when the concentration reaches 228 μg/mL for A549, 200 μg/mL for MDA-MB-231 and 140 μg/mL for NIH-3T3 cell lines with 24 h incubation

Development and in vitro/in vivo evaluation of thermo-sensitive in situ gelling systems for ocular allergy

Ocular allergy is one of the most common disorders of the eye surface. Following diagnosis this condition is typically treated with preparations containing antihistamines. However, anatomy of the eye and its natural protective mechanisms create challenges for ocular drug delivery. Rapid elimination of antihistamine substances due to short residency times following application can lead to insufficient treatment of ocular allergies. With this in mind, the aim of this study was to prepare a controlled ocular delivery system to extend the retention time of olopatadine hydrochloride (OLO) and in doing so to reduce the need for frequent application. We developed extended-release ocular in situ gelling systems for which in vivo retention times were determined in sheep following in vitro characterization and cytotoxicity studies. In vivo results were then compared to commercially available Patanol eye drops. the transparent gels formulated using appropriate amounts of polymers and having longer ocular retention times appear to be a viable alternative to commercially available eye drops

Synthesis and Characterization of 2-Aminoethylphosphonic Acid-Functionalized Graphene Quantum Dots: Biological Activity, Antioxidant Activity and Cell Viability

A facile, environmentally friendly one-step reaction for the preparation of luminescent N-doped graphene quantum dots (GQDs) involving a hydrothermal reaction between citric acid and 2-aminoethylphosphonic acid was designed. Graphene quantum dots were characterized by UV-Vis, FT-IR spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and dynamic light scattering (DLS). Furthermore, the biological activity of the GQDs was studied. UV-Vis spectroscopy studies of the interactions between the GQDs and calf thymus DNA (CT-DNA) showed that the compound interacts with CT-DNA via intercalative binding. DNA cleavage study showed that the GQDs cleaved DNA oxidatively. In addition, antioxidant activity of N-doped GQDs was measured using the DPPH method. As the concentration of the compound increased, the antioxidant activity also increased. According to cell viability analyses results, the N-doped GQDs showed cell viability (70 %) when the concentration reached 228 μg/mL for A549, 200 μg/mL for MDA-MB-231 and 140 μg/mL for NIH-3T3 cell lines with 24 h incubation.

Dexketoprofen trometamol-loaded poly-lactic-co-glycolic acid (PLGA) nanoparticles: Preparation, in vitro characterization and cyctotoxity

Purpose: To design, formulate and characterize sustained-release formulations of dexketoprofen trometamol (DT) nanoparticles (NPs) Methods: Dexketoprofen trometamol (DT)-loaded poly(lactic-co-glycolic acid) (PLGA) NPs were produced by double emulsion-solvent evaporation method. The NPs were variously characterized for drug loading and release, particle profile, as well as by thermal analysis, x-ray difraction (XRD), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance analysis ( 1 H-NMR). Furthermore, the NPs were evaluated for cytotoxicity against NIH-3T3 cells by 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: The DT-loaded NPs demonstrated nanostructural characteristics and extended drug release. Particle size was in the range of 243 and 295 nm which remained unchanged in drug stability testing in simulated gastrointestinal media. Encapsulation efficiency ranged from 49 – 64 % for all the formulations. Higuchi and Korsmeyer-Peppas were the best-fit release kinetic models for the NPs containing 5 and 10 % DT, respectively. The NPs with 10 % DT presented no significant cytotoxicty at the doses and periods studied. Conclusion: Stable and non-toxic DT NPs with potential for sustained and controlled release of the drug have been successfully developed.Anadolu University Scientific Research Project Foundation 1708S47