Ruthenium complex delivery using liposomes to improve bioactivity against HeLa cells via the mitochondrial pathway.

AIM: The aim of this study was to encapsulate a ruthenium complex [Ru(ttbpy)2PIP](ClO4)2 (Ru) in liposomes to enhance their antitumor effect on human cervical cancer. METHODS: The Ru-loaded PEGylated liposomes (Ru-Lip) were prepared using thin-film hydration method. The mechanism of action was studied. RESULTS: A novel Ru was successfully synthesized. Ru-Lip showed stronger cytotoxic activity against HeLa cells than Ru. Ru-Lip demonstrated a more significant increase in apoptosis, reactive oxygen species production and apoptosis-associated processes (intracellular calcium concentration, cytochrome c release and activation of Bax and caspase-3) than Ru. Ru-Lip exhibited greater blockade efficacy in the cell cycle G1 phase and greater DNA damage than Ru. CONCLUSION: Ru-Lip significantly elevates the anticancer effect via reactive oxygen species-mediated mitochondrial dysfunctional pathway.

Preliminary study on conjugation of formononetin with multiwalled carbon nanotubes for inducing apoptosis via ROS production in HeLa cells.

BACKGROUND: The present work was conducted to prepare and evaluate multiwalled carbon nanotube-formononetin (MWCNT-FMN) composite for sustained delivery and inducing apop-tosis via reactive oxygen species (ROS) production in HeLa cells. METHODS: The composite was prepared by solution mixing with short carboxylic group-functionalized multiwalled carbon nanotubes (MWCNT-COOH). Then the composite was characterized by laser particle size analysis, Fourier transform infrared spectrometry, X-ray diffractometry, differential scanning calorimetry, and scanning electron microscopy. Drug release rates in vitro were determined by dialysis method. The in vitro cytotoxicity study was performed using water soluble tetrazolium assay. The cellular apoptosis assay, ROS, and mitochondrial membrane potential (MMP) of HeLa cells were investigated by acridine orange and ethidium bromide double dye, 2',7'-dichlorodihydrofluorescein diacetate, and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide probe, respectively. RESULTS: The entrapment efficiency was 28.77%±0.15%, and the loading capacity was 12.05%±0.20%. The release of MWCNT-FMN was sustained, and the cumulative release rate of formononetin (FMN) from MWCNT-COOH was higher at pH 7.4 than at pH 5.3. The in vitro cytotoxicity assay demonstrated that FMN, MWCNT-COOH, and MWCNT-FMN had no significant effects on the proliferation and viability of mouse fibroblast 3T3 cells over 48 hours, while the cell growth inhibition of the three samples showed concentration-dependent for HeLa cells. Biological assay suggested FMN and MWCNT-FMN could induce apoptosis in HeLa cells, meanwhile the cells exhibited stronger ROS signal and more depolarized MMP than that of the control group. CONCLUSION: These results preliminarily demonstrated that MWCNT-FMN exerted anticancer efficacy through cellular apoptosis induced by ROS-mediated mitochondrial dysfunctions in HeLa cells.

Iridium (III) complex-loaded liposomes as a drug delivery system for lung cancer through mitochondrial dysfunction.

BACKGROUND AND AIM: Iridium (Ir)-based complex is a potential antitumor ingredient, but its poor physicochemical properties such as hydrophobicity and low biocompatibility hamper further application. Liposome provides a potential delivery approach for improving the poor physicochemical property and reducing the side effects of antitumor drug. In this study, we aimed at incorporating Ir ([Ir(ppy)2(BTCP)]PF6) into liposomes to enhance the biocompatibility and sustained release of Ir for intravenous administration and to elucidate the mechanism in A549 cells. MATERIALS AND METHODS: Ir-loaded PEGylated liposomes (Lipo-Ir) were formulated by thin-film dispersion and ultrasonic method. Morphology, size distribution, and zeta potential of Lipo-Ir were examined by transmission electron microscopy (TEM) and Zetasizer. The released profile and biocompatibility were investigated by dialysis method and hemolysis test, respectively. Additionally, the cytotoxic activity and mechanism of Lipo-Ir and Ir inducing apoptosis in A549 cells were evaluated. RESULTS: Lipo-Ir can keep sustained release, excellent biocompatibility, and physical stability. The average particle size, polydispersity index, zeta potential, encapsulation efficiency, and drug loading are 112.57±1.15 nm, 0.19±0.02, -10.66±0.61 mV, 94.71%±3.21%, and 4.71%±0.41%, respectively. 3-(4,5-dimethylthiazole)-2,5-diphenltetraazolium bromide (MTT) assay show that Lipo-Ir and Ir display high cytotoxicity against selected cancer cells. Furthermore, the apoptotic features of morphology, depolarization of mitochondrial membrane potential, increase in the reactive oxygen species (ROS) levels, and disorder of Ca2+ homeostasis are observed after treating A549 cells with Ir and Lipo-Ir. Besides, Lipo-Ir can arrest the cell growth in G0/G1 phase. CONCLUSION: The studies demonstrate that Lipo-Ir can trigger apoptosis in A549 cells via ROS-mediated mitochondrial dysfunctions, and the biocompatible and sustained Lipo-Ir will be a promising drug delivery system.