Human Epithelial Colorectal Adenocarcinoma Research Articles

Toxicological Evaluation of Luminescent Silica Nanoparticles as New Drug Nanocarriers in Different Cancer Cell Lines.

Luminescent mesoporous silica nanoparticles, CdTeQDs@MNs@PEG1, SiQDs@Isoc@MNs and SiQDs@Isoc@MNs@PEG2, were successfully synthetized and characterized by SEM, TEM, XRD, N2 nitrogen isotherms, 1H NMR, IR, absorption, and emission spectroscopy. Cytotoxic evaluation of these nanoparticles was performed in relevant in vitro cell models, such as human hepatoma HepG2, human brain endothelial (hCMEC/D3), and human epithelial colorectal adenocarcinoma (Caco-2) cell lines. None of the tested nanoparticles showed significant cytotoxicity in any of the three performed assays (MTT/NR/ LDH) compared with the respective solvent and/or coating controls, excepting for CdTeQDs@MNs@PEG1 nanoparticles, where significant toxicity was noticed in hCMEC/D3 cells. The results presented reveal that SiQDs-based mesoporous silica nanoparticles are promising nanoplatforms for cancer treatment, with a pH-responsive drug release profile and the ability to load 80% of doxorubicin.

Chitosan/alginate nanoparticles as a promising approach for oral delivery of curcumin diglutaric acid for cancer treatment

Curcumin diglutaric acid (CG) is a prodrug of curcumin that shows better solubility and antinociceptive activity compared to curcumin. To improve its properties further, CG was encapsulated into polysaccharide-based nanoparticles in this study. A chitosan/alginate nanoparticulate system was chosen for encapsulation of CG due to its biocompatibility, biodegradability, non-toxicity, mucoadhisiveness and good film formation. CG-loaded chitosan/alginate nanoparticles were prepared by o/w emulsification and ionotropic gelification, with the conditions optimized using response surface methodology. A chitosan/alginate mass ratio of 0.04:1, CG concentration of 3 mg/mL and Pluronic®F127 concentration of 0.50% (w/v) were determined to be optimal for the nanoparticle preparation. FTIR and XRD confirmed encapsulation of CG into the chitosan/alginate nanoparticles. The CG-loaded chitosan/alginate nanoparticles showed better stability under UV radiation and in a simulated gastrointestinal environment, compared to a CG dispersion in water. The nanoparticles showed slow cumulative release of CG in simulated gastrointestinal fluids without enzymes and in body fluid. A Weibull model of the best fit for all conditions suggested that the release pattern of CG from CG-loaded chitosan/alginate nanoparticles was mainly controlled by Fickian diffusion and erosion of polymer materials. Finally, CG-loaded chitosan/alginate nanoparticles showed higher in vitro cellular uptake in human epithelial colorectal adenocarcinoma (Caco-2 cells) and better anticancer activity against Caco-2, human hepatocellular carcinoma (HepG2) and human breast cancer (MDA-MB-231) cells. Therefore, the CG-loaded chitosan/alginate nanoparticles are a promising approach for oral administration of CG for cancer treatment.

The Functional Properties of Preserved Eggs: From Anti-cancer and Anti-inflammatory Aspects.

Preserved egg, a kind of alkaline-fermented food, is a traditional egg product in China. Here, we investigated the nutritional functions of preserved eggs by in vivo and in vitro experiments. The results of in vivo studies showed that the levels of triglycerides (TG), total cholesterol (TCHO) and low-density lipoprotein cholesterol/high density lipoprotein cholesterol (LDL-C/HDL-C) were significantly decreased (p<0.05) in the liver of rats treated with preserved eggs. Meanwhile, the levels of two important cancer markers, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were also significantly decreased (p<0.05) in treated rats. In vitro studies were performed on Caco-2 cells, a human epithelial colorectal adenocarcinoma cell line. It demonstrated that the gastrointestinal (GI) digests of preserved eggs significantly accelerated (p<0.05) the apoptosis by upregulating caspase-3 in the Caco-2 cells. Besides, after treated with preserved eggs, the half maximal inhibitory concentration (IC50) of preserved eggs digests to Caco-2 cells was 5.75 mg/mL, indicating the significant inhibition of cell proliferation provided by preserved eggs (p<0.05). The results shown in this study demonstrated that preserved eggs may be a novel functional food involved with antilipemic, anti-inflammatory activity as well as the effect on accelarating the apoptosis of Caco-2 cells.

Oil-In-Water Microemulsions as Hosts for Benzothiophene-Based Cytotoxic Compounds: An Effective Combination.

Targeted delivery of chemotherapeutics in order to overcome side effects and enhance chemosensitivity remains a major issue in cancer research. In this context, biocompatible oil-in-water (O/W) microemulsions were developed as matrices for the encapsulation of DPS-2 a benzothiophene analogue, exhibiting high cytotoxicity in various cancer cell lines, among them the MW 164 skin melanoma and Caco-2 human epithelial colorectal adenocarcinoma cell lines. The microemulsion delivery system was structurally characterized by dynamic light scattering (DLS) and electron paramagnetic resonance (EPR) spectroscopy. The effective release of a lipophilic encapsulated compound was evaluated via confocal microscopy. The cytotoxic effect, in the presence and absence of DPS-2, was examined through the thiazolyl blue tetrazolium bromide (MTT) cell proliferation assay. When encapsulated, DPS-2 was as cytotoxic as when dissolved in dimethyl sulfoxide (DMSO). Hence, the oil cores of O/W microemulsions were proven effective biocompatible carriers of lipophilic bioactive molecules in biological assessment experiments. Further investigation through fluorescence-activated cell sorting (FACS) analysis, comet assay, and Western blotting, revealed that DPS-2, although non-genotoxic, induced S phase delay accompanied by cdc25A degradation and a nonapoptotic cell death in both cell lines, which implies that this benzothiophene analogue is a deoxyribonucleic acid (DNA) replication inhibitor.

Human Serum Albumin Is an Essential Component of the Host Defense Mechanism Against Clostridium difficile Intoxication.

The pathogenic effects of Clostridium difficile are primarily attributable to the production of the large protein toxins (C difficile toxins [Tcd]) A (TcdA) and B (TcdB). These toxins monoglucosylate Rho GTPases in the cytosol of host cells, causing destruction of the actin cytoskeleton with cytotoxic effects. Low human serum albumin (HSA) levels indicate a higher risk of acquiring and developing a severe C difficile infection (CDI) and are associated with recurrent and fatal disease. We used a combined approach based on docking simulation and biochemical analyses that were performed in vitro on purified proteins and in human epithelial colorectal adenocarcinoma cells (Caco-2), and in vivo on stem cell-derived human intestinal organoids and zebrafish embryos. Our results show that HSA specifically binds via its domain II to TcdA and TcdB and thereby induces their autoproteolytic cleavage at physiological concentrations. This process impairs toxin internalization into the host cells and reduces the toxin-dependent glucosylation of Rho proteins. Our data provide evidence for a specific HSA-dependent self-defense mechanism against C difficile toxins and provide an explanation for the clinical correlation between CDI severity and hypoalbuminemia.

In silico-in vitro discovery of untargeted kinase–inhibitor interactions from kinase-targeted therapies: A case study on the cancer MAPK signaling pathway

Protein kinase inhibitors have been widely used as therapeutic agents to treat a variety of diseases, but many of them may cause off-target effects by unexpectedly targeting other noncognate kinases due to high conversion across the protein kinase family. The mitogen-activated protein kinase (MAPK) signaling pathway plays an essential role in tumorigenesis, which has been recognized as a high priority in the druggable target candidates of anticancer therapy. Here, we attempt to investigate the untargeted kinase–inhibitor interactions (UKIIs) of kinase-targeted therapies for the cancer MAPK signaling cascade via an integration of biomolecular modeling, cell viability assay and kinase inhibition analysis. A systematic kinase–inhibitor interaction profile is created for 28 FDA-approved kinase inhibitor drugs across 9 caner-related MAPK kinases. The created profile is analyzed at structural, energetic and dynamic levels and, consequently, totally 18 promising UKII pairs with high theoretical affinity are derived, from which the noncognate inhibitors Cabozantinib, Regorafenib and Crizotinib are selected to test their cytotoxic effects on human epithelial colorectal adenocarcinoma Caco-2 cell line and inhibition activity against the recombinant protein of human p38α kinase domain. The obtained results are compared with two cognate MAPK inhibitors JNK-IN-8 and BIRB796. As might be expected, the Regorafenib, Crizotinib and Cabozantinib exhibit high, moderate and low cytotoxicities, respectively. In addition, the Regorafenib is determined to have a potent p38α-inhibitory activity. This is basically in line with the test results of positive controls JNK-IN-8 and BIRB796 and can be well confirmed by computational modeling.

New flavonoid glycosides from two Astragalus species (Fabaceae) and validation of their antihyperglycaemic activity using molecular modelling and in vitro studies

Phytochemical investigation of the methanol extracts of the aerial parts of Astragalus turkestanus and A. xапthomeloides using various chromatographic techniques resulted in the isolation and structural elucidation of two new flavonoid glycosides, namely, 7-methoxy kaempferol-3-O-α-l-arabinosyl-(1 → 6)-β-d-galactopyranoside (3) from the former and kaempferol-3-O-α-l-rhamnopyranosyl-7-O-α-l-rhamnopyranosyl-(1 → 6)-β-d- galactopyranoside (6) from the latter. In addition five other known compounds were isolated for the first time from these species. In silico molecular modeling study was carried out on α-glucosidase (PDB ID 3TOP; 2.88 A°) to assess the α-glucosidase inhibitory activity of the isolated compounds. Both compounds 3 and 6 displayed the highest fitting score with ΔG equals to −82.10 and −67.66 Kcal/mol in the pH-based ionization method and −68.55 and −67.83 Kcal/mol in the rule-based ionization method, respectively. α-Glucosidase inhibitory activity was further asserted in vitro using an ELISA assay that is measured colorimetrically at 405 nm. Compound 3 showed a significant α-glucosidase inhibitory activity displaying IC50 of 50.31 μg/mL approaching that of acarbose (IC50 = 30.57 μg/mL). All the tested samples showed no significant cytotoxic activity against Caco-2 (human epithelial colorectal adenocarcinoma) cells using the MTT assay (IC50 > 400 μg/mL). Thus; both new compounds could offer promising natural antihyperglycaemic entities without any marked toxicity, which could be useful in the pharmaceutical industry.

Antiproliferative hydrogen sulfide releasing evodiamine derivatives and their apoptosis inducing properties

To explore antitumor agents with high efficiency and selectivity, two series of 16 H2S donating evodiamine derivatives 8–12 were synthesized and characterized by 1H NMR, 13C NMR and HRMS. Their antiproliferative activities were tested against five cancer cell lines (Bel-7402, MCF-7, SGC-7901, Caco-2 and HL-60) and human normal peripheral blood mononuclear cells. Among them, compound 12c showed the most potent inhibitory activities against human leukemia HL-60 and epithelial colorectal adenocarcinoma Caco-2 cells with IC50 values of 0.58 and 2.02 μM, respectively. Additionally, high selectivity was also observed between human normal peripheral blood mononuclear cells and human leukemia HL-60 cells. Further mechanism studies confirmed that 12c could induce apoptosis, arrest cell cycle at the G2/M phase and lead to mitochondrial dysfunction in HL-60 cells. Furthermore, western blot assay demonstrated that 12c induced the intrinsic apoptotic mitochondrial pathway by upregulating protein expression of Bax, cytochrome c, caspase-3, -9 and p53, and downregulating the relative levels of Bcl-2. The levels of cell cycle related proteins cyclin B1 and cdc2 were also downregulated in which G2/M phase arrest was confirmed. Overall, 12c possessed immense potential for the discovery of antitumor candidates with high efficiency and selectivity.

FTY720P Increases, at 2 hrs, the Activity of the Na+/K+ ATPase in Caco‐2 cells via PKC and PI3K

Fingolimod phosphate (FTY720P), an analogue of sphingosine‐1‐phosphate (S1P), was shown previously to modulate, in a time‐dependent manner, the activity of hepatic Na+/K+ ATPase with an inhibitory effect appearing at 15 min and a stimulatory one at 2hrs. Because in the colon, the ATPase plays a pivotal role in the absorption of sodium and water, a time response study was conducted in human epithelial colorectal adenocarcinoma (Caco‐2) cells to examine if FTY720P regulates the activity of the ATPase in a similar fashion. An inhibitory effect was already demonstrated at 15 min. This work investigates the effect of FTY720P at 2 hrs and attempts to determine the major signaling molecules involved. The activity of the Na+/K+ ATPase was assayed by measuring the amount of inorganic phosphate released in presence and absence of ouabain, a specific inhibitor of the enzyme. FTY720P exerted a significant and prominent stimulatory effect on the ATPase at 2 hours. This effect disappeared completely in presence of JTE‐013, a blocker of S1P receptor 2 (S1PR2), as well as in presence of each of calphostin and wortmannin, respective inhibitors of protein kinase C (PKC) and phosphoinositide 3‐kinase (PI3K). Moreover, Phorbol‐12‐Myristate‐13‐Acetate (PMA), an activator of PKC, simulated the stimulatory effect of FTY720P on Na+/K+ ATPase further confirming the involvement of PKC. BAPT/AM, a chelator of calcium ions, cancelled the effect of FTY720P on the ATPase, indicating thus an involvement of calcium ions in the signaling pathway. Since only conventional PKC isomers require the presence of calcium ions for their activation, FTY720P probably acts via a conventional PKC isomer. The stimulatory effect of PMA disappeared in presence of wortmannin, suggesting that PKC is upstream of PI3K. It was concluded that at 2 hours, FTY720‐P binds to S1PR2 leading to the activation of conventional PKC which, in turn, activates directly or indirectly PI3K, resulting in Na+/K+ ATPase stimulation.Support or Funding InformationUniversity Research BoardThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Synthesis, characterization, anticancer and antimicrobial study of arene ruthenium(II) complexes with 1,2,4-triazole ligands containing an α-diimine moiety

Abstract The reaction of the ruthenium arene dimers [(η 6-arene)Ru(μ-Cl)Cl]2 (where arene=benzene or p-cymene) with the ligands 4-benzylidene-3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole (L1 ), 2-methoxybenzylidene-3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole (L2 ), 4-methylbenzylidene-3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole (L3 ) and indole-3-carbaldehyde-3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole (L4 ) in a 1:2 ratio gives the new complexes [(η 6-arene)RuCl(L)]+ [arene=C6H6 (with L=L1(1), L2(3), L4(7), with PF6 − as a counter ion, and L4 (6), with Cl− as a counter ion) or p-cymene with L=L1(2), L2(4), L3(5), L4(8) with PF6 − as a counter ion]. All complexes were fully characterized using 1H and 13C NMR, elemental analyses, UV/Vis and IR spectroscopy. The single crystal X-ray structures of ligand L2 and complex 1 have been determined. The structure of 1 has the Ru atom coordinated with the arene group and to the N,N′-bidentate ligand and to the Cl atom. The arene group occupies the apex, while the ligand and the Cl atom are at the base of a pseudo-octahedral three-legged piano stool. The cytotoxicity of these mononuclear complexes was established in the human epithelial colorectal adenocarcinoma cell line (Caco-2) and for selectivity in the non-cancerous human embryonic kidney cell line (HEK293), using 5-fluorouracil (5-FU) as the reference anticancer drug. Compounds 1 and 7 were relatively inactive toward the Caco-2 tumor cells (IC50&gt;200), while complexes 2–5 showed moderate anti-proliferative properties (IC50&gt;100–200). Compound 6, however, displayed better anti-proliferative properties with an IC50 value lower than that of the reference drug, 5-FU, and was therefore further investigated for its antimicrobial activity against six Gram-positive and four Gram-negative bacteria.

Synthesis, characterization, antiproliferative, and antimicrobial activity of osmium(II) half-sandwich complexes

New osmium(II)-arene complexes [(η6-C6H6)OsCl(C5H4N-2-CH=N-C6H5X)](PF6) (X = p-flouro (1), p-chloro (2), p-methyl (3)) were synthesized by reaction of the corresponding bidentate N,N′-ligands with the osmium-arene precursor [(η6-C6H6)Os(μ-Cl)Cl]2 in a 2:1 ratio. These complexes were characterized by UV–Vis, IR, 1H, 13C NMR spectroscopy, and elemental analysis and, for compound 1, a single crystal X-ray structure was also obtained. The complexes were investigated for antiproliferative activity in vitro against MCF-7 (human breast adenocarcinoma), Caco-2 (human epithelial colorectal adenocarcinoma), and HepG2 (human hepatocellular carcinoma) tumor cell lines. To test their selectivity, the non-tumor HEK293 (human embryonic kidney) cell line was used. The compounds were selective toward the tumor cell lines when compared to the known anticancer drug 5-fluorouracil which displayed low selectivity. The compounds were substantially more active against Caco-2 than 5-fluorouracil. They also showed moderate activity against the other two tumor cell lines. In addition, the antimicrobial activity of complex 2 was explored against a panel of antimicrobial-susceptible and -resistant Gram-negative and Gram-positive bacteria. Complex 2 showed anti-mycobacterial activity against Mycobacterium smegmatis and bactericidal activity against drug-resistant Enterococcus faecalis and methicillin-resistant Staphylococcus aureus ATCC 43300.

Lactobacillus plantarum induces genomic DNA-dependent and TLR9-mediated elafin secretion from Caco-2 cells

Lactobacilli show anti-inflammatory effects in the human intestine, and their genomic DNA was identified as one of the anti-inflammatory components. Increased levels of the natural protease inhibitor elafin in the intestine plays an important role in protection against intestinal inflammation. However, there have been no previous reports regarding whether lactobacilli increase elafin levels. This study was performed to investigate whether Lactobacillus plantarum induces elafin secretion from the human epithelial colorectal adenocarcinoma cell line, Caco-2. Moreover, we examined the roles of bacterial genomic DNA and toll-like receptor 9 (TLR9), a specific receptor of bacterial DNA, in this effect. Elafin secretion from Caco-2 cells by live and heat-killed L. plantarum was measured. The analysis was also performed using DNase-treated L. plantarum and genomic DNA extracted from L. plantarum. We examined the role of TLR9 in elafin secretion by L. plantarum and its genomic DNA by suppressing TLR9 expression using RNAi in Caco-2 cells. Heat-killed L. plantarum time- and dose-dependently increased elafin secretion, whereas live L. plantarum had no such effect. The elafin secretion by heat-killed L. plantarum was partially abolished by DNase treatment of the bacterium. In addition, L. plantarum genomic DNA also increased elafin secretion. Furthermore, suppression of TLR9 expression partially or completely abolished elafin secretion by heat-killed L. plantarum and its genomic DNA. Our results indicated that heat-killed L. plantarum induced genomic DNA-dependent and TLR9-mediated elafin secretion. The anti-inflammatory effects of lactobacilli may be mediated by increases in the levels of elafin in the intestine.

Farmed edible bird’s nest in malaysia: proximate analysis, safety profile, epidermal growth factor content and effect on cancer cells

Event Abstract Back to Event Farmed edible bird’s nest in malaysia: proximate analysis, safety profile, epidermal growth factor content and effect on cancer cells Sin N. Tan1*, Careena Shobana1, Sani Dahiru1, Chee W. Lim1, Ideris Aini1, Stanslas Johnson1 and Thiam S. Christopher Lim1 1 Putra Malaysia University, Malaysia Background Edible bird’s nest (EBN), a solidified swiftlet's saliva, is the most expensive animal products consumed by humans worldwide. EBN exhibits multiple medicinal properties and contains many bioactive compounds such as sialic acid, amino acids, fatty acids, minerals and antioxidants. In recent years, many safety issues which included high nitrate and nitrite contents, presence of heavy metal, adulteration, fungal infection and cancer cell stimulation were found to be associated with EBN. Hence, this study was carried out to determine the proximate analysis, safety profile, epidermal growth factor content and its effect on cancer cells of Malaysia EBN. Methods Proximate analysis and safety profile were performed by using official AOCA methods according to the Malaysia Standard MS 2509:2012. Coupled Plasma Optical Emission Spectrophotometer was adopted for heavy metals analysis. Enzyme-linked immunosorbent assay was used for quantification of EGF content. Microculture tetrazolium assay was utilised for assessment of growth stimulation by different concentration of human epidermal growth factor (hEGF) in comparison to EBN in 4 different cancer cell lines: MCF-7 (human breast adenocarcinoma cells), Caco-2 (human epithelial colorectal adenocarcinoma cells), HCT116 (human colorectal carcinoma), and A549 (human alveolar adenocarcinoma cells) for 24 hours, 48 hours, and 72 hours. Results Our results showed a consistency of high protein (53.03% - 56.37%) and carbohydrate (27.97%-31.68%) with acceptable level of moisture (10.80-14.04%) and ash (2.22%-3.38%). Besides, a good safety profile was obtained with low nitrite and nitrate level, undetectable heavy metals and no significant growth for pathogenic microorganism. The present study found above tolerance level of yeast and moulds in EBN. Haze contaminated EBN exhibited no significant differences in terms of nutritional, heavy metal and microbiology profiles. EFG (30.7pg/mL and 74.5pg/mL) were detected in crude EBN01 and EBN02, respectively but not in all digested EBN samples and even post 10 times concentrated EBN. Cancer cell growths were significantly increased after treatment with hEGF. No significant growth was observed after treatment with EBN. Conclusion EBN in Malaysia is free from heavy metals, within tolerance level of nitrate and nitrite, and also microbiology profile. Furthermore, in vitro study indicated that EBN is not associated with cancer cell stimulation. Keywords: Cancer, Epidermal Growth Factor, Safety, nutritional, Edible bird's nest Conference: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”, Putrajaya, Malaysia, 3 Dec - 5 Feb, 2019. Presentation Type: Poster Presentation Topic: Cancer Citation: Tan SN, Shobana C, Dahiru S, Lim CW, Aini I, Johnson S and Christopher Lim TS (2019). Farmed edible bird’s nest in malaysia: proximate analysis, safety profile, epidermal growth factor content and effect on cancer cells. Front. Pharmacol. Conference Abstract: International Conference on Drug Discovery and Translational Medicine 2018 (ICDDTM '18) “Seizing Opportunities and Addressing Challenges of Precision Medicine”. doi: 10.3389/conf.fphar.2018.63.00130 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Sep 2018; Published Online: 17 Jan 2019. * Correspondence: Dr. Sin N Tan, Putra Malaysia University, Seri Kembangan, Malaysia, christine0507@live.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Sin N Tan Careena Shobana Sani Dahiru Chee W Lim Ideris Aini Stanslas Johnson Thiam S Christopher Lim Google Sin N Tan Careena Shobana Sani Dahiru Chee W Lim Ideris Aini Stanslas Johnson Thiam S Christopher Lim Google Scholar Sin N Tan Careena Shobana Sani Dahiru Chee W Lim Ideris Aini Stanslas Johnson Thiam S Christopher Lim PubMed Sin N Tan Careena Shobana Sani Dahiru Chee W Lim Ideris Aini Stanslas Johnson Thiam S Christopher Lim Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Didodecyldimethylammonium bromide (DMAB) stabilized poly(lactic-co-glycolic acid) (PLGA) nanoparticles: Uptake and cytotoxic potential in Caco-2 cells

Surface cationization of nanoparticulate drug delivery systems represents one important strategy in the field of novel drug development to enable enhanced cellular uptake in vitro and consequently an improved bioavailability in vivo. The aim of this study is the characterization of a new cationic nanoparticle system, which provides an improved cellular uptake in epithelial cells of the gastrointestinal tract as well as low cytotoxicity. We have successfully prepared fluorescent-labeled didodecyldimethylammonium bromide (DMAB)-stabilized poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles, which were additionally modified using two hydrophilic polymers: polyvinyl alcohol (PVA) and polyethylene glycol (PEG). The nanoparticles were examined with regard to stability of fluorescence labeling, DMAB content, cellular uptake, and cytotoxicity. Consequently, we could show, that the surface modifications lead to a decreased cytotoxic activity in contrast to unmodified nanoparticles against human epithelial colorectal adenocarcinoma cells (Caco-2) as well as a promising increase in cellular uptake in comparison to negatively charged PLGA nanoparticles combining the advantages of a superior uptake of a positively charged nanoparticle system with the biological safety of negatively charged systems.

Extracellular Signals of a Human Epithelial Colorectal Adenocarcinoma (Caco-2) Cell Line Facilitate the Penetration of Pseudomonas aeruginosa PAO1 Strain through the Mucin Layer.

Pseudomonas aeruginosa can penetrate the layer of mucus formed by host intestinal epithelial cells, often resulting in sepsis in immunocompromised patients. We have previously demonstrated that P. aeruginosa can penetrate the mucin layer by flagellar motility and the degradation of the mucin layer. However, it remains unclear how P. aeruginosa initially recognizes epithelial cells. Using the human epithelial colorectal adenocarcinoma (Caco-2) cell line, we investigated extracellular signaling that could facilitate the penetration of P. aeruginosa through the mucin layer. The supernatant from Caco-2 cell cultures increased penetration of P. aeruginosa through an artificial mucin layer. The Caco-2 cell supernatant increased bacterial flagella-dependent swarming motility, but it did not influence P. aeruginosa growth or protease activity. Filtering of the Caco-2 cell supernatant indicated that proteins weighing <10 kDa increased mucin penetration, swarming motility, and, based on a tethered cell assay, induced acceleration of the flagellar filament rotational rate. Furthermore, a capillary assay showed that <10 kDa proteins in the Caco-2 cell supernatant attracted P. aeruginosa cells. Finally, we identified that growth-regulated oncogene-α (GRO-α) secreted by Caco-2 cells was a factor facilitating flagellar filament rotation and swarming motility, although it did not attract the bacteria. We conclude that penetration of the mucin layer by P. aeruginosa is facilitated by small proteins (<10 kDa) secreted by Caco-2 cells, both by inducing acceleration of flagellar motility and increasing chemotaxis.

Using PVA and TPGS as combined emulsifier in nanoprecipitation method improves characteristics and anticancer activity of ibuprofen loaded PLGA nanoparticles.

In the preparation of nanoparticles (NPs) by the nanoprecipitation method, emulsifiers play a key role for NPs' characteristics. The present study aimed to investigate the combined emulsifier effect on ibuprofen loaded poly(lactic-co-glycolic acid) (PLGA) NPs' characteristics and anticancer activity. Ibuprofen loaded PLGA NPs were prepared by nanoprecipitation using different concentrations of PVA (poly(vinyl alcohol)) or PVA-TPGS (d-α-tocopherol polyethylene glycol 1000 succinate) combination as emulsifier. It was found that encapsulation efficiencies of NPs varied between 17.9 and 41.9 % and the highest encapsulation efficiency was obtained with 0.5% PVA + 0.1% TPGS (coded as PLGA PVA/TPGS NPs). PLGA PVA/TPGS NPs were characterized and compared with PLGA PVA NPs, which was obtained by 0.5% PVA alone. Polydispersity index of PLGA PVA/TPGS and PLGA PVA NPs were found to be 0.08 and 0.15, respectively. Incorporation of TPGS with PVA slightly decreased the initial ibuprofen release. Transmission electron microscopy analyses demonstrated a nearly uniform particle size distribution and spherical particle shape of the PLGA PVA/TPGS NPs. Additionally, PLGA PVA/TPGS NPs were significantly more cytotoxic than PLGA PVA NPs on the MCF-7 (human breast adenocarcinoma cells) and Caco-2 (human epithelial colorectal adenocarcinoma) cells (p<0.05). Also PLGA PVA/TPGS NPs were not cytotoxic on normal cells (L929, mouse healthy fibroblast cells) (p>0.05). In conclusion, these results indicated that using a combination of TPGS and PVA as an emulsifier in nanoprecipitation could be a promising approach for preparing ibuprofen loaded PLGA NPs because of their improved characteristics and anticancer activity.

Trictide, a tricellulin-derived peptide to overcome cellular barriers.

The majority of tight junction (TJ) proteins restrict the paracellular permeation of solutes via their extracellular loops (ECLs). Tricellulin tightens tricellular TJs (tTJs) and regulates bicellular TJ (bTJ) proteins. We demonstrate that the addition of recombinantly produced extracellular loop 2 (ECL2) of tricellulin opens cellular barriers. The peptidomimetic trictide, a synthetic peptide derived from tricellulin ECL2, increases the passage of ions, as well as of small and larger molecules up to 10 kDa, between 16 and 30 h after application to human epithelial colorectal adenocarcinoma cell line 2. Tricellulin and lipolysis-stimulated lipoprotein receptor relocate from tTJs toward bTJs, while the TJ proteins claudin-1 and occludin redistribute from bTJs to the cytosol. Analyzing the opening of the tricellular sealing tube by the peptidomimetic using super-resolution stimulated-emission depletion microscopy revealed a tricellulin-free area at the tricellular region. Cis-interactions (as measured by fluorescence resonance energy transfer) of tricellulin-tricellulin (tTJs), tricellulin-claudin-1, tricellulin-marvelD3, and occludin-occludin (bTJs) were strongly affected by trictide treatment. Circular dichroism spectroscopy and molecular modeling suggest that trictide adopts a β-sheet structure, resulting in a peculiar interaction surface for its binding to tricellulin. In conclusion, trictide is a novel and promising tool for overcoming cellular barriers at bTJs and tTJs with the potential to transiently improve drug delivery.

Influence of Halogen Substitution in the Ligand Sphere on the Antitumor and Antibacterial Activity of Half-sandwich Ruthenium(II) Complexes [RuX(η6 -arene)(C5 H4 N-2-CH=N-Ar)]+

New complexes [(η6-p-cymene)Ru(C5H4N-2-CH=N–Ar)X]PF6 [X = Br (1), I (2); Ar = 4-fluorophenyl (a), 4-chlorophenyl (b), 4-bromophenyl (c), 4-iodophenyl (d), 2,5-dichlorophenyl (e)] were prepared, as well as 3a–3e (X = Cl) and the new complexes [(η6-arene)RuCl(N-N)]PF6 (arene = C6H5OCH2CH2OH, N-N = 2,2′-bipyridine (4), 2,6-(dimethylphenyl)-pyridin-2-yl-methylene amine (5), 2,6-(diisopropylphenyl)-pyridin-2-yl-methylene amine (6); arene = p-cymene, N-N = 4-(aminophenyl)-pyridin-2-yl-methylene amine (7)]. X-ray diffraction studies were performed for 1a, 1b, 1c, 1d, 2b, 5, and 7. Cytotoxicities of 1a–1d and 2 were established versus human cancer cells epithelial colorectal adenocarcinoma (Caco-2) (IC50: 35.8–631.0 μM), breast adenocarcinoma (MCF7) (IC50: 36.3–128.8.0 μM), and hepatocellular carcinoma (HepG2) (IC50: 60.6–439.8 μM), 3a–3e were tested against HepG2 and Caco-2, and 4–7 were tested against Caco-2. 1–7 were tested against non-cancerous human epithelial kidney cells. 1 and 2 were more selective towards tumor cells than the anticancer drug 5-fluorouracil (5-FU), but 3a–3e (X = Cl) were not selective. 1 and 2 had good activity against MCF7, some with lower IC50 than 5-FU. Complexes with X = Br or I had moderate activity against Caco-2 and HepG2, but those with Cl were inactive. Antibacterial activities of 1a, 2b, 3a, and 7 were tested against antibacterial susceptible and resistant Gram-negative and -positive bacteria. 1a, 2b, and 3a showed activity against methicillin-resistant S. aureus (MIC = 31–2000 μg·mL–1).

New Bis(dihydropyridine‐3,5‐dicarbonitrile) Derivatives: Green Synthesis and Cytotoxic Activity Evaluation

A synthesis of bis(dihydropyridine‐3,5‐dicarbonitrile) by a three‐component reaction of one equivalent of bis‐cyanoacetamides with two equivalents of both arylaldehydes and malononitrile in ethanol‐containing piperidine is reported. Bis‐cyanopyridones could also be obtained by the condensation of bis‐cyanoacetamides with substituted arylidenemalononitriles in the presence of piperidine, chitosan, or montmorillonite as basic catalysts. The cytotoxicity of the synthesized products against the heterogeneous human epithelial colorectal adenocarcinoma cell line (Caco‐2) was assessed by WST‐1 assay with concentration dependent cellular growth inhibitory effect especially for compounds 5l, 5h, and 5d. The dose response curves indicate that IC50 were 87 ± 3.11 μg/mL, 104 ± 4.78 μg/mL, and 108 ± 5.12 μg/mL, respectively.

New compounds based on a benzimidazole nucleus: synthesis, characterization and cytotoxic activity against breast and colon cancer cell lines

Benzimidazolium salts and their Pyridine Enhanced Precatalyst Preparation Stabilization and Initiation (PEPPSI) palladium N-heterocyclic carbene (Pd-NHC) based complexes have been synthesized and their structures characterized with a number of different instrumental techniques including NMR (1H and 13C), IR, EI-MS (for 2), X-ray (for 1, 2 and 4) and elemental analysis. The cytotoxicity of all the compounds was tested using the human embryonic kidney (HEK-293T), human breast epithelial adenocarcinoma (MDA-MB-231), and human colon epithelial colorectal adenocarcinoma (DLD-1) cell lines. The benzimidazolium salts (2–5) had more cytotoxic activity against cancerous cells compared with the metal complexes (6–9), which curiously exhibited no activity against any of the cell lines. Based on the IC50 values, compound 5 displayed the highest in vitro anticancer activity among compounds 2–9.