Development of a Radiolabeled Folate-Mediated Drug Delivery System for Effective Delivery of Docetaxel

Many preclinical studies are carried out with the aim of developing new formulations for the effective delivery of taxane class drugs, one of the most important anticancer drugs used clinically today. In this study, a radiolabeled folate-mediated solid lipid magnetic nanoparticle (SLMNP) system was developed by loading superparamagnetic iron oxide nanoparticles (MNP) and docetaxel (DTX) into the solid lipid nanoparticles as a drug delivery system that will function both in cancer treatment and diagnosis. For this purpose, first, SLMNP was synthesized by the hot homogenization method, and the surface of the particles was modified with a folate derivative to carry the particles to tissues with folate receptors. The synthesized magnetic solid lipid nanoparticles were loaded with DTX, and then radiolabeling was carried out with technetium-99 m (^99mTc-DTX-SLMNP). Structural characteristics of these nanoparticles were determined by characterization methods. According to the TEM images of MNPs, SLN, and SLMNPs, MNPs were observed between 25and 35 nm, SLNs between 400 and 500 nm, and SLMNPs between 350 and 450 nm. The drug entrapment efficiency of SLMNPs loaded with DTX was found to be 19%, and the percentage efficiency of radiolabeling was found to be 98.0 ± 2.0%. The biological behavior of this radiolabeled system was investigated in vitro and in vivo. Folate receptor-positive SKOV-3 and folate receptor-negative A549 cancer cell lines were studied. The IC₅₀ values of DTX-SLMNP in SKOV-3 and A549 cells were 50.21 and 172.27 μM at 48 h, respectively. Gamma camera imaging studies of ^99mTc-DTX-SLMNP and magnetically applied ^99mTc-DTX-SLMNP compounds were performed on tumor-bearing CD-1 nude mice. The uptake in the folate receptor-positive tumor region was higher than that in the folate receptor negative tumor region. We proposed that the drug delivery system we prepared in this study be evaluated for preclinical studies of new drug carrier formulations of the taxane class of anticancer drugs.

Design and evaluation of erucic acid-phytosphingosine structured cationic nanoemulsions as a plasmid DNA delivery system against breast cancer cells

This study is focused on the preparation and characterization of erucic acid (EA) and phytosphingosine (PS) containing cationic nanoemulsions (NEs) for plasmid DNA (pDNA) delivery. Repurposing of cationic agents guided us to PS, previously used for enhanced interaction with negatively charged surfaces. It was reported that EA might act anti-tumoral on C6 glioma, melanoma, neuroblastoma, and glioblastoma. However, there is only one study about mixed oleic acid-EA liposomes. This gap attracted our interest in the possible synergistic effects of PS and EA on MDA-MB-231 and MCF-7 breast cancer cells. Three cationic NEs (NE 1, NE 2, and NE 3) were prepared and characterized in terms of droplet size (DS), polydispersity index (PDI), and zeta potential (ZP) before and after complexation with pDNA, long-term stability, SDS release, cytotoxicity, and transfection studies. The cationic NEs had DSs of <200 nm, PDIs <0.3, and ZPs > +30 mV. Long-term stability studies revealed that NE 2 and NE 3 were stable. NE 1-pDNA had appropriate particle properties. NE 2 reduced the viability of MDA-MB-231 cells to 11% and of MCF-7 cells to 13% and resulted in the highest number of transfected cells. To sum up, NE 2 containing PS and EA is appropriate for delivering pDNA.

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.