Stimuli-responsive nanoparticles are regarded as an ideal candidate for anticancer drug targeting. We synthesized glutathione (GSH) and magnetic-sensitive nanocomposites for a dual-targeting strategy. To achieve this goal, methoxy poly (ethylene glycol) (MePEG) was grafted to water-soluble chitosan (abbreviated as ChitoPEG). Then doxorubicin (DOX) was conjugated to the backbone of chitosan via disulfide linkage. Iron oxide (IO) magnetic nanoparticles were also conjugated to the backbone of chitosan to provide magnetic sensitivity. In morphological observation, images from a transmission electron microscope (TEM) showed that IO nanoparticles were embedded in the ChitoPEG/DOX/IO nanocomposites. In a drug release study, GSH addition accelerated DOX release rate from nanocomposites, indicating that nanocomposites have redox-responsiveness. Furthermore, external magnetic stimulus concentrated nanocomposites in the magnetic field and then provided efficient internalization of nanocomposites into cancer cells in cell culture experiments. In an animal study with CT26 cell-bearing mice, nanocomposites showed superior magnetic sensitivity and then preferentially targeted tumor tissues in the field of external magnetic stimulus. Nanocomposites composed of ChitoPEG/DOX/IO nanoparticle conjugates have excellent anticancer drug targeting properties.
Astaxanthin (AST)-encapsulated nanoparticles were fabricated using glycol chitosan (Chito) through electrostatic interaction (abbreviated as ChitoAST) to solve the aqueous solubility of astaxanthin and improve its biological activity. AST was dissolved in organic solvents and then mixed with chitosan solution, followed by a dialysis procedure. All formulations of ChitoAST nanoparticles showed small diameters (less than 400 nm) with monomodal distributions. Analysis with Fourier transform infrared (FT-IR) spectroscopy confirmed the specific peaks of AST and Chito. Furthermore, ChitoAST nanoparticles were formed through electrostatic interactions between Chito and AST. In addition, ChitoAST nanoparticles showed superior antioxidant activity, as good as AST itself; the half maximal radical scavenging concentrations (RC50) of AST and ChitoAST nanoparticles were 11.8 and 29.3 µg/mL, respectively. In vitro, AST and ChitoAST nanoparticles at 10 and 20 µg/mL properly inhibited the production of intracellular reactive oxygen species (ROSs), nitric oxide (NO), and inducible nitric oxide synthase (iNOS). ChitoAST nanoparticles had no significant cytotoxicity against RAW264.7 cells or B16F10 melanoma cells, whereas AST and ChitoAST nanoparticles inhibited the growth of cancer cells. Furthermore, AST itself and ChitoAST nanoparticles (20 µg/mL) efficiently inhibited the migration of cancer cells in a wound healing assay. An in vivo study using mice and a pulmonary metastasis model showed that ChitoAST nanoparticles were efficiently delivered to a lung with B16F10 cell metastasis; i.e., fluorescence intensity in the lung was significantly higher than in other organs. We suggest that ChitoAST nanoparticles are promising candidates for antioxidative and anticancer therapies of B16F10 cells.
11 November 2013 in BMC Complementary and Alternative Medicine
Gami-Cheongyeul-Sodok-Eum (GCSE), an herbal formula of traditional Korean medicine, comprises nine herb components. GCSE has various biological activities such as anti-inflammatory, anti-bacterial and anti-viral activities. However, it is still unclear whether GCSE has any immunomodulatory effect on atopic dermatitis (AD).
Yohimbine (YHB) has been reported to possess anti-inflammatory, anticancer, and cardiac function-enhancing properties. Additionally, it has been reported to inhibit the proliferation, migration, and neointimal formation of vascular smooth muscle cells (VSMCs) induced by platelet-derived growth factor (PDGF) stimulation by suppressing the phospholipase C-gamma 1 pathway. However, the transcriptional regulatory mechanism of YHB controlling the behavior of VSMCs is not fully understood. In this study, YHB downregulated the expression of cell cycle regulatory proteins, such as proliferating cell nuclear antigen (PCNA), cyclin D1, cyclin-dependent kinase 4 (CDK4), and cyclin E, by modulating the transcription factor FOXO3a in VSMCs induced by PDGF. Furthermore, YHB decreased p-38 and mTOR phosphorylation in a dose-dependent manner. Notably, YHB significantly reduced the phosphorylation at Y397 and Y925 sites of focal adhesion kinase (FAK), and this effect was greater at the Y925 site than Y397. In addition, the expression of paxillin, a FAK-associated protein known to bind to the Y925 site of FAK, was significantly reduced by YHB treatment in a dose-dependent manner. A pronounced reduction in the migration and proliferation of VSMCs was observed following co-treatment of YHB with mTOR or p38 inhibitors. In conclusion, this study shows that YHB inhibits the PDGF-induced proliferation and migration of VSMCs by regulating the transcription factor FOXO3a and the mTOR/p38/FAK signaling pathway. Therefore, YHB may be a potential therapeutic candidate for preventing and treating cardiovascular diseases such as atherosclerosis and vascular restenosis.
The aim of this study is to fabricate nanophotosensitizers composed of methoxy poly(ethylene glycol) (mPEG), chlorin e6 (Ce6), and phenylboronic acid pinacol ester (PBAP) with diselenide linkages for reactive oxygen species (ROS)-sensitive photodynamic therapy (PDT) of cervical cancer cells. To fabricate nanophotosensitizers, Ce6 was conjugated with mPEG via selenocystamine linkage and then remaining carboxylic acid groups of Ce6 was attached to PBAP (mPEGseseCe6PBAP conjugates). Nanophotosensitizers of mPEGseseCe6PBAP conjugates were prepared by dialysis method. In transmission electron microscope (TEM) observation, nanophotosensitizers of mPEGseseCe6PBAP conjugates have spherical shapes and their diameters were less than 150 nm. The average diameter of mPEGseseCe6PBAP nanophotosensitizers was 92.7 ± 9.6 nm in particle size analysis. When H2O2 was added to the nanophotosensitizer solution, nanophotosensitizers were sensitively disintegrated according to the H2O2 concentration and then changed from monomodal distribution to multimodal distribution in particle size distribution. Furthermore, Ce6 release from nanophotosensitizers also increased according to the H2O2 concentration. When H2O2 was added to cell culture of HeLa human cervical cancer cells, intracellular Ce6 uptake of nanophotosensitizers were gradually increased according to the H2O2 concentration, indicating that nanophotosensitizers showed ROS-sensitive delivery of Ce6 against cancer cells.As well as free Ce6, nanophotosensitizers in the absence of light irradiation have low intrinsic cytotoxicity against RAW264.7 cells and HeLa cells. However, nanophotosensitizers induced cell death dose-dependently under light irradiation. Especially, nanophotosensitizers showed significantly higher ROS generation and phototoxicity against HeLa cells in vitro. When nanophotosensitizers were intravenously administered to animal tumor xenograft model of HeLa cells, tumor tissues revealed stronger fluorescence intensity than other tissues by light irradiation while absence of light irradiation induced relatively lower fluorescence intensity in tumor tissues, indicating that nanophotosensitizers have sensitivity against oxidative stress in tumor tissues. We suggest that nanophotosensitizers of mPEGseseCe6PBAP conjugates are promising vehicle for PDT of cervical cancer cells.
The abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are a primary cause of cardiovascular diseases such as atherosclerosis and restenosis after angioplasty. Pinocembrin (5,7-dihydroxyflavanone, PCB), a natural flavonoid compound found abundantly in propolis, has been reported to have antibacterial, anti-inflammatory, antioxidant, and anticancer effects, and cardiac function improvement in ischemic heart disease. In this study, the protective effects of PCB against the migration and proliferation of VSMCs were investigated. MTT and BrdU assays were performed to estimate the cytotoxicity and cell proliferative activity of PCB, respectively. Rat aortic VSMC migrations and neointima formation were evaluated using wound healing, boyden chamber assays, and in balloon-injured (BI) rat, respectively. PCB suppressed the phosphorylated levels of p38 in PDGF-BB-induced VSMCs followed by reducing the expression of MMP2 and 9. PCB downregulated the expression levels of cell cycle regulatory proteins such as PCNA, CDK2, CDK4, and Cyclin D1. Furthermore, the phosphorylated levels of FAK at Y397 and Y925 sites and the expression levels of FAK-related proteins such as Integrin β1, Paxillin, Talin, and Vinculin were significantly reduced by PCB in PDGF-BB-induced VSMCs. The neointima formation was markedly decreased by PCB administration in the carotid artery of a balloon-injured rat. In conclusion, PCB inhibits the proliferation and migration of VSMCs by stimulation of PDGF-BB through the regulation of the p38 and FAK signaling pathway. Therefore, PCB may be a promising therapeutic candidate for preventing and treating cardiovascular diseases such as atherosclerosis and restenosis.