Genistein-Inhibited Cancer Stem Cell-Like Properties and Reduced Chemoresistance of Gastric Cancer

Genistein, the predominant isoflavone found in soy products, has exerted its anticarcinogenic effect in many different tumor types in vitro and in vivo. Accumulating evidence in recent years has strongly indicated the existence of cancer stem cells in gastric cancer. Here, we showed that low doses of genistein (15 μM), extracted from Millettia nitida Benth var hirsutissima Z Wei, inhibit tumor cell self-renewal in two types of gastric cancer cells by colony formation assay and tumor sphere formation assay. Treatment of gastric cancer cells with genistein reduced its chemoresistance to 5-Fu (fluorouracil) and ciplatin. Further results indicated that the reduced chemoresistance may be associated with the inhibition of ABCG2 expression and ERK 1/2 activity. Furthermore, genistein reduced tumor mass in the xenograft model. Together, genistein inhibited gastric cancer stem cell-like properties and reduced its chemoresistance. Our results provide a further rationale and experimental basis for using the genistein to improve treatment of patients with gastric cancer.     

Antibacterial activity of PVA-based nanofibers loaded with silver sulfadiazine/cyclodextrin nanocapsules

Silver sulfadiazine (SSD) is a highly insoluble drug in water with a significant antibacterial activity. Supramolecular nanocontainers of cyclodextrins (β-CD or HPβ-CD)/SSD were prepared by inclusion complex (IC) forming between CDs and SSD at various conditions. Solubility, bioavailability and in vitro dissolution of obtaining SSD were investigated and the results showed of SSD in CDs that solubility improved and its release is controllable by encapsulation cavity. Electro-spun nanofibers of PVA containing SSD/CDs inclusion complex showed significant antibacterial effect against Escherichia coli and Staphylococcus aureus, which are related to SSD     

Aqueous nanogels modified with cyclodextrin

In this work, the incorporation of reactive cyclodextrins (CDs) in aqueous nanogels based on poly(N-vinylcaprolactam) (VCL) is studied by surfactant-free precipitation polymerization process. α-, β-, γ-CDs were functionalized with acrylic groups and the average amount of vinyl bonds per CD molecule was adjusted to 2, 4, or 6. The increase of the CD concentration in the reaction mixture led to the reduction of the final hydrodynamic radius of nanogels from 227 nm to 62 nm. The increase of the vinyl groups number per CD molecule induced formation of smaller nanogels (R_h = 22.5 nm) and considerable increase of the crosslinking degree. Obtained cyclodextrin-modified nanogels show temperature sensitivity in aqueous medium with a volume transition point around 30 °C. The complexation properties of CDs incorporated in nanogel networks were proved by titration with phenolphthalein.     

Immobilization of a cyclodextrin glucanotransferase (CGTase) onto polyethylene film with a carboxylic acid group and production of cyclodextrins from corn starch using CGTase‐immobilized PE film

Carboxylic acid groups were introduced onto polyethylene (PE) film by radiation‐induced graft copolymerization. Subsequently, the clodextrin glucanotransferase (CGTase) was immobilized on the PE film with a carboxylic acid group. The activity of the immobilized CGTase on PE film was in the range of 0.40–1.04 U/cm² per min. The production of cyclodextrins (CDs) from corn starch was examined using the CGTase‐immobilized PE film. The production ratios of CDs using CGTase‐immobilized PE film was in the following order: α–CD > β–CD > γ–CD. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2451–2457, 2002     

Synthesis of β‐cyclodextrin‐based dendrimer as a novel encapsulation agent

The aim was the fabrication of glycodendrimer encapsulation agents with high proportions of cyclodextrins (CDs) to maintain the biocompatibility properties, as well as to notably improve their ability to load various suitably sized drugs. The novel glycodendrimers contained β‐CD in both core and branches, namely β‐cyclodextrin‐based dendrimer (CD‐dendrimer) prepared through a straightforward procedure using S_N2 displacement to attach multivalent β‐CDs together. The desired CD‐dendrimer was synthesized in three steps: (i) reaction of β‐CD with p‐toluenesulfonyl chloride and/or iodine to afford C‐6 mono‐ and/or per‐β‐CD derivative; (ii) reaction of the β‐CD precursors with ethylenediamine to give C‐6 mono‐ and/or per‐amino‐β‐CD derivative; and (iii) S_N2 displacement of β‐CD electrophilic derivative with β‐CD nucleophilic derivative in dimethylsulfoxide to provide the CD‐dendrimer. Then, the encapsulation behaviour of the CD‐dendrimer was examined using naproxen and naltrexone as the guest molecules. The structure of the designed CD‐dendrimer allowed two types of possible sites for encapsulation of the guest: in cavities of the dendritic structure and in hydrophobic cavities of CDs. © 2013 Society of Chemical Industry     

Electrospinning of nanofibers from non-polymeric systems: polymer-free nanofibers from cyclodextrin derivatives

High molecular weight polymers and high polymer concentrations are desirable for the electrospinning of nanofibers since polymer chain entanglements and overlapping are important for uniform fiber formation. Hence, the electrospinning of nanofibers from non-polymeric systems such as cyclodextrins (CDs) is quite a challenge since CDs are cyclic oligosaccharides. Nevertheless, in this study, we have successfully achieved the electrospinning of nanofibers from chemically modified CDs without using a carrier polymer matrix. Polymer-free nanofibers were electrospun from three different CD derivatives, hydroxypropyl-β-cyclodextrin (HPβCD), hydroxypropyl-γ-cyclodextrin (HPγCD) and methyl-β-cyclodextrin (MβCD) in three different solvent systems, water, dimethylformamide (DMF) and dimethylacetamide (DMAc). We observed that the electrospinning of these CDs is quite similar to polymeric systems in which the solvent type, the solution concentration and the solution conductivity are some of the key factors for obtaining uniform nanofibers. Dynamic light scattering (DLS) measurements indicated that the presence of considerable CD aggregates and the very high solution viscosity were playing a key role for attaining nanofibers from CD derivatives without the use of any polymeric carrier. The electrospinning of CD solutions containing urea yielded no fibers but only beads or splashes since urea caused a notable destruction of the self-associated CD aggregates in their concentrated solutions. The structural, thermal and mechanical characteristics of the CD nanofibers were also investigated. Although the CD derivatives are amorphous small molecules, interestingly, we observed that these electrospun CD nanofibers/nanowebs have shown some mechanical integrity by which they can be easily handled and folded as a free standing material.     

Inclusion complexes containing poly(?-caprolactone)diol and cyclodextrins. Experimental and theoretical studies

Inclusion complexes (ICs) between poly(?-caprolactone)diol (PEC) with α-cyclodextrin (α-CD) (α-CD-PEC) and γ-cyclodextrin (γ-CD) (γ-CD-PEC) were prepared and characterized by FT-IR, ¹H NMR, thermogravimetry, surface activity and wettability measurements. The thermal stabilities of the inclusion complexes are very similar. The thermal stability of PEC is better than ICs and CDs. Stable monolayers of PEC and α-CD-PEC and γ-CD-PEC complexes have been obtained at the air-water interface using the Langmuir Technique. The surface pressure-area isotherms (π-A) were found to be of different types, depending on the CD utilized. From the surface free energy values of PEC and ICs it was possible to conclude that ICs are more hydrophobic than cyclodextrins. PEC is the most hydrophobic. The surface parameters the minimum area A₀, the critical surface pressure π_c, and static elasticity ?₀ were also estimated for ICs and PEC. In order to describe the experimental results, molecular dynamic simulation (MDS) was performed. In addition, the physical properties that stabilize CD-CD, CD-polymer and CD-solvent interactions were elucidated by MDS. Theoretical results have demonstrated that complexes are stabilized by hydrophobic interactions between the cavity of CDs and the -(CH₂)₅-units of PEC, and also by hydrogen-bond formation between the hydroxyl groups situated along the rim of CD molecules threaded onto the PEC chain. CD-CD hydrogen-bond formation is maximized in 1:2 γ-CD-PEC complex and 1:1 α-CD-PEC complexes.     

Resolution of Racemic Propranolol in Liquid Membranes Containing TA‐β‐cyclodextrin

Abstract

The pharmacological properties of propranolol enantiomers are quite different, the β‐adrenergic blocking activity resides in the (S)‐(?) isomer, while the (R)‐(+)‐enantiomer has only a membrane stabilizing effect. The inherent chirality of cyclodextrins (CDs) allows them to form diastereomeric complexes. In this work, a peracetylated β‐CD (TA‐β‐CD) that preferentially interacts with the (S)‐(?) isomer of propranolol was used. Two liquid membranes, bulk liquid membrane (BLM) and supported liquid membrane (SLM) were tested. A recovery of 30% and a enantiomeric excess of 12% were obtained, using a SLM with 10 mM of propranolol and a pH gradient between feed and stripping phases.     

Poly(ε-caprolactone) electrospun nanofibers containing curcumin nanocontainers: enhanced solubility,dissolution and physical stability of curcumin via formation of inclusion complex with cyclodextrins

Supramolecular nanocontainers of cyclodextrins (α- and β-CD)/curcumin (CUR) were prepared by inclusion complex (IC) forming between CDs and guest molecule at two conditions. Formation of the inclusion complex between CDs and CUR at various conditions in solid phase was characterized by various methods. Solubility and in vitro dissolution of obtaining CUR nanocapsules were investigated and results showed that encapsulation of CUR, improved CUR bioavailability with a controllable release. Electrospun nanofibers of poly-ε-caprolactone (PCL) containing CUR/CDs inclusion complex of various conditions have been fabricated using a conventional electrospinning process and indicated that these nanofibers are bead-free.     

Chloroplast-Expressed MSI-99 in Tobacco Improves Disease Resistance and Displays Inhibitory Effect against Rice Blast Fungus

Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplastomic by PCR and Southern hybridization. In planta assays demonstrated that the transgenic tobacco plants displayed an enhanced resistance to the fungal disease. The evaluation of the antimicrobial activity revealed that the crude protein extracts from the transgenic plants manifested an antimicrobial activity against E. coli, even after incubation at 120 °C for 20 min, indicating significant heat stability of MSI-99. More importantly, the MSI-99-containing protein extracts were firstly proved in vitro and in vivo to display significant suppressive effects on two rice blast isolates. These findings provide a strong basis for the development of new biopesticides to combat rice blast.     

Systemic Delivery of Protein Nanocages Bearing CTT Peptides for Enhanced Imaging of MMP-2 Expression in Metastatic Tumor Models

Matrix metalloproteinase 2 (MMP-2) in metastatic cancer tissue, which is associated with a poor prognosis, is a potential target for tumor imaging in vivo. Here, we describe a metastatic cancer cell-targeted protein nanocage. An MMP-2-binding peptide, termed CTT peptide (CTTHWGFTLC), was conjugated to the surface of a naturally occurring heat shock protein nanocage by genetic modification. The engineered protein nanocages showed a binding affinity for MMP-2 and selective uptake in cancer cells that highly expressed MMP-2 in vitro. In near-infrared fluorescence imaging, the nanocages showed specific and significant accumulation in tumor tissue after intravenous injection in vivo. These protein nanocages conjugated with CTT peptide could be potentially applied to a noninvasive near-infrared fluorescence detection method for imaging gelatinase activity in metastatic tumors in vivo.     

BRCAA1 antibody- and Her2 antibody-conjugated amphiphilic polymer engineered CdSe/ZnS quantum dots for targeted imaging of gastric cancer

Successful development of safe and highly effective nanoprobes for targeted imaging of in vivo early gastric cancer is a great challenge. Herein, we choose the CdSe/ZnS (core-shell) quantum dots (QDs) as prototypical materials, synthesized one kind of a new amphiphilic polymer including dentate-like alkyl chains and multiple carboxyl groups, and then used the prepared amphiphilic polymer to modify QDs. The resultant amphiphilic polymer engineered QDs (PQDs) were conjugated with BRCAA1 and Her2 monoclonal antibody, and prepared BRCAA1 antibody- and Her2 antibody-conjugated QDs were used for in vitro MGC803 cell labeling and in vivo targeted imaging of gastric cancer cells. Results showed that the PQDs exhibited good water solubility, strong photoluminescence (PL) intensity, and good biocompatibility. BRCAA1 antibody- and Her2 antibody-conjugated QD nanoprobes successfully realized targeted imaging of in vivo gastric cancer MGC803 cells. In conclusion, BRCAA1 antibody- and Her2 antibody-conjugated PQDs have great potential in applications such as single cell labeling and in vivo tracking, and targeted imaging and therapeutic effects'' evaluation of in vivo early gastric cancer cells in the near future.     

In Vivo Immunotoxicity of SiO2@(Y0.5Gd0.45Eu0.05)2O3 as Dual-Modality Nanoprobes

We have successfully synthesized SiO₂@(Y_0.5Gd_0.45Eu_0.05)₂O₃ nanocomposites as a potential dual-modality nanoprobe for molecular imaging in vitro. However, their immunotoxicity assessment in vivo remains unknown. In this article, the in vitro biocompatibility of our dual-modality nanoprobes was assayed in terms of cell viability and apoptosis. In vivo immunotoxicity was investigated by monitoring the generation of reactive oxygen species (ROS), cluster of differentiation (CD) markers and cytokines in Balb/c mice. The data show that the in vitro biocompatibility was satisfactory. In addition, the immunotoxicity data revealed there are no significant changes in the expression levels of CD11b and CD71 between the nanoprobe group and the Gd in a diethylenetriaminepentaacetic acid (DTPA) chelator (Gd-DTPA) group 24 h after injection in Balb/c mice (p > 0.05). Importantly, there are significant differences in the expression levels of CD206 and CD25 as well as the secretion of IL-4 and the generation of ROS 24 h after injection (p < 0.05). Transmission electron microscopy (TEM) images showed that few nanoprobes were localized in the phagosomes of liver and lung. In conclusion, the toxic effects of our nanoprobes may mainly result from the aggregation of particles in phagosomes. This accumulation may damage the microstructure of the cells and generate oxidative stress reactions that further stimulate the immune response. Therefore, it is important to evaluate the in vivo immunotoxicity of these rare earth-based biomaterials at the molecular level before molecular imaging in vivo.     

TM4SF1 Promotes Proliferation,Invasion, and Metastasis in Human Liver Cancer Cells

Transmembrane 4 superfamily member 1 (TM4SF1) is a member of tetraspanin family, which mediates signal transduction events regulating cell development, activation, growth and motility. Our previous studies showed that TM4SF1 is highly expressed in liver cancer. HepG2 cells were transfected with TM4SFl siRNA and TM4SF1-expressing plasmids and their biological functions were analyzed in vitro and in vivo. HepG2 cells overexpressing TM4SF1 showed reduced apoptosis and increased cell migration in vitro and enhanced tumor growth and metastasis in vivo, whereas siRNA-mediated silencing of TM4SF1 had the opposite effect. TM4SF1 exerts its effect by regulating a few apoptosis- and migration-related genes including caspase-3, caspase-9, MMP-2, MMP-9 and VEGF. These results indicate that TM4SF1 is associated with liver tumor growth and progression, suggesting that TM4SF1 may be a potential target for treatment of liver cancer in future.     

Potential Effects of Phytoestrogen Genistein in Modulating Acute Methotrexate Chemotherapy-Induced Osteoclastogenesis and Bone Damage in Rats

Chemotherapy-induced bone damage is a frequent side effect which causes diminished bone mineral density and fracture in childhood cancer sufferers and survivors. The intensified use of anti-metabolite methotrexate (MTX) and other cytotoxic drugs has led to the need for a mechanistic understanding of chemotherapy-induced bone loss and for the development of protective treatments. Using a young rat MTX-induced bone loss model, we investigated potential bone protective effects of phytoestrogen genistein. Oral gavages of genistein (20 mg/kg) were administered daily, for seven days before, five days during, and three days after five once-daily injections (sc) of MTX (0.75 mg/kg). MTX treatment reduced body weight gain and tibial metaphyseal trabecular bone volume (p < 0.001), increased osteoclast density on the trabecular bone surface (p < 0.05), and increased the bone marrow adipocyte number in lower metaphyseal bone (p < 0.001). Genistein supplementation preserved body weight gain (p < 0.05) and inhibited ex vivo osteoclast formation of bone marrow cells from MTX-treated rats (p < 0.001). However, MTX-induced changes in bone volume, trabecular architecture, metaphyseal mRNA expression of pro-osteoclastogenic cytokines, and marrow adiposity were not significantly affected by the co-administration of genistein. This study suggests that genistein may suppress MTX-induced osteoclastogenesis; however, further studies are required to examine its potential in protecting against MTX chemotherapy-induced bone damage.     

Iron-doped brushite bone cement scaffold with enhanced osteoconductivity and antimicrobial properties for jaw regeneration

Critical success factors for the restoration of jaw defects depend on scaffolds with high levels of osteoconductivity and antimicrobial properties due to the special oral microenvironment. Brushite cement (dicalcium phosphate dihydrate, DCPD) is a bioceramic with good self-setting properties, plasticity, bioabsorbability, and biocompatibility, but with poor osteoconductive and antimicrobial properties. It has been reported that elemental iron doped into DCPD is effective for overcoming this critical deficiency. Herein, iron-doped dicalcium phosphate dihydrate (Fe-DCPD) was prepared and its physicochemical properties characterized. The time required for Fe-DCPD to set was significantly prolonged, and its in vitro degradability increased compared with DCPD. Additionally, the effects of Fe-DCPD on cell adhesion, migration, proliferation, alkaline phosphatase activity, biomineralization, its antimicrobial properties and relative expression of osteogenic genes in MC3T3-E1 cells were evaluated. In addition, the ability to promote restoration of the jaw in vivo was evaluated, to provide the experimental basis for its preclinical application. The incorporation of iron promoted the adhesion, proliferation, and migration of MC3T3-E1 cells, and increased their ALP activity and expression of osteogenic-related genes. Furthermore, both agar plate and broth anti-bacterial tests revealed that Fe-DCPD displayed a significantly greater antibacterial effect on typical Gram-negative and Gram-positive bacteria than DCPD. The in vivo study indicated that Fe-DCPD scaffolds displayed superior antimicrobial and bone repair properties in a rabbit jaw defect. The study established that DCPD doped with iron is a suitable modification for conferring antimicrobial and osteoconductive properties on scaffolds. Thus, the Fe-DCPD scaffold has excellent potential for applications in jaw repair.     

β-Cyclodextrin Inclusion Complex to Improve Physicochemical Properties of Pipemidic Acid: Characterization and Bioactivity Evaluation

The aptitude of cyclodextrins (CDs) to form host-guest complexes has prompted an increase in the development of new drug formulations. In this study, the inclusion complexes of pipemidic acid (HPPA), a therapeutic agent for urinary tract infections, with native β-CD were prepared in solid state by kneading method and confirmed by FT-IR and ¹H NMR. The inclusion complex formation was also characterized in aqueous solution at different pH via UV-Vis titration and phase solubility studies obtaining the stability constant. The 1:1 stoichiometry was established by a Job plot and the inclusion mechanism was clarified using docking experiments. Finally, the antibacterial activity of HPPA and its inclusion complex was tested on P. aeruginosa, E. coli and S. aureus to determine the respective EC_50s and EC_90s. The results showed that the antibacterial activity of HPPA:β-CD against E. coli and S. aureus is higher than that of HPPA. Furthermore, HPPA and HPPA:β-CD, tested on human hepatoblastoma HepG2 and MCF-7 cell lines by MTT assay, exhibited, for the first time, antitumor activities, and the complex revealed a higher activity than that of HPPA. The use of β-CD allows an increase in the aqueous solubility of the drug, its bioavailability and then its bioactivity.     

Hydrolysate from Eggshell Membrane Ameliorates Intestinal Inflammation in Mice

Inflammatory bowel diseases (IBD) comprises of ulcerative colitis (UC) and Cohn’s disease (CD) as two main idiopathic pathologies resulting in immunologically mediated chronic inflammatory conditions. Several bioactive peptides and hydro lysates from natural sources have now been tested in animal models of human diseases for potential anti-inflammatory effects. Eggshell membrane (ESM) is a well-known natural bioactive material. In this study, we aim to study the anti-inflammatory activity of ESM hydro lysate (AL-PS) in vitro and in vivo. In vitro, AL-PS was shown to inhibit pro-inflammatory cytokine IL-8 secretion. In vivo treatment with AL-PS was shown to reduce dextran sodium sulphate (DSS)-induced weight loss, clinical signs of colitis and secretion of interleukin (IL)-6 (p < 0.05). In addition, treatment with AL-PS also attenuated the severity of intestinal inflammation via down-regulation of IL-10 an anti-inflammatory cytokine. This validates potential benefits of AL-PS as a novel preventative target molecule for treatment of IBD.     

Enhanced Production of Bioactive Isoprenoid Compounds from Cell Suspension Cultures of Artemisia annua L. Using β-Cyclodextrins

Plant cell cultures as valuable tools for the production of specific metabolites can be greatly improved by the application of elicitors including cyclodextrins (CDs) for enhancing the yields of the desired plant compounds. Here the effects of 2,6-dimethyl-β-cyclodextrins (DIMEB) on the production of carotenoids and quinones from Artemisia annua L. cell suspension cultures were investigated. The addition of 50 mM DIMEB induced an early increase of intracellular carotenoid and quinone contents, which could be observed to a higher extent for lutein (10-fold), Q9 (3-fold) and Q10 (2.5-fold). Real Time PCR analysis revealed that the expression of 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR) gene in DIMEB treated cell cultures after three days was 2.5-fold higher than in untreated samples, thus suggesting that the DIMEB induced increase of carotenoids and quinones could be due to the induction of the plastidial isoprenoid biosynthetic route. In addition, the DIMEB treatment induced an enhanced release of carotenoids and quinones into the culture medium of A. annua cell suspension cultures possibly due to the ability of CDs to form inclusion complexes with hydrophobic molecules.