Bis-diamine administration during pregnancy induces developmental and reproductive toxicities in rats.

BACKGROUND: Bis-diamine was developed as amebicidal and male contraceptive agents; however, it is also reported to induce characteristic congenital heart defects especially in the cardiac conotruncal area of rats. Because of its characteristic congenital heart defects, bis-diamine-induced animal models can be used for studying congenital heart defects. However, comprehensive toxicological information regarding bis-diamine-induced congenital heart defects in this animal model is not available. METHODS: In this study, we investigated and characterized an animal model for bis-diamine-induced congenital heart defects. A single dose of 200-mg bis-diamine was administered by oral gavage to pregnant rats on gestation day 10, and then observed the representative toxicological endpoints for general systemic health of pregnant rats, embryo-fetal development, and parturition. RESULTS: Characteristic congenital heart defects and other birth defects similar to DiGeorge syndrome were observed in bis-diamine-administered pregnant rats. In addition, developmental and reproductive toxicity findings, including increased postimplantation loss, decreased fetal weight, increased perinatal death, and increased gestation period, were observed in bis-diamine-administered pregnant rats. In particular, these developmental and reproductive toxicities were observed without maternal toxicity findings. CONCLUSION: These results will be useful to use this animal model for further studies in congenital heart defects, cardiovascular defects, and understanding their mechanisms.

Chemical mitochondrial uncouplers share common inhibitory effect on NLRP3 inflammasome activation through inhibiting NFκB nuclear translocation.

Activation of NLRP3 inflammasome is implicated in varieties of pathologies, the aim of the present study is to characterize the effect and mechanism of mitochondrial uncouplers on NLRP3 inflammasome activation by using three types of uncouplers, niclosamide, CCCP and BAM15. Niclosamide, CCCP and BAM15 inhibited LPS plus ATP-induced increases of NLRP3 protein and IL-1ß mRNA levels in RAW264.7 macrophages and THP-1 derived macrophages. Niclosamide, CCCP and BAM15 inhibited LPS plus ATP-induced increase of NFκB (P65) phosphorylation, and inhibited NFκB (P65) nuclear translocation in RAW264.7 macrophages. Niclosamide and BAM15 inhibited LPS-induced increase of IκBα phosphorylation in RAW264.7 macrophages, and the inhibitory effect was dependent on increased intracellular [Ca2+]i; however, CCCP showed no significant effect on IκBα phosphorylation in RAW264.7 macrophages stimulated with LPS. In conclusion, chemical mitochondrial uncouplers niclosamide, CCCP and BAM15 share common inhibitory effect on NLRP3 inflammasome activation through inhibiting NFκB nuclear translocation.

A novel gemcitabine derivative-loaded liposome with great pancreas-targeting ability.

Gemcitabine (Gem) is a standard first-line treatment for pancreatic cancer (PC). However, its chemotherapeutic efficacy is hampered by various limitations such as short half-life, metabolic inactivation, and lack of tumor localizing. We previously synthesized a lipophilic Gem derivative (Gem formyl hexadecyl ester, GemC16) that exhibited improved antitumor activity in vitro. In this study, a target ligand N,N-dimethyl-1,3-propanediamine was conjugated to 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[hydroxyl succinimidyl (polyethylene glycol-2000)] (DSPE-PEG-NHS) to form DSPE-PEG-2N. Then, pancreas-targeting liposomes (2N-LPs) were prepared using the film dispersion-ultrasonic method. GemC16-loaded 2N-LPs displayed near-spherical shapes with an average size distribution of 157.2 nm (polydispersity index (PDI) = 0.201). The encapsulation efficiency of GemC16 was up to 97.3% with a loading capacity of 8.9%. In human PC cell line (BxPC-3) and rat pancreatic acinar cell line (AR42J), cellular uptake of 2N-LPs was significantly enhanced compared with that of unmodified PEG-LPs. 2N-LPs exhibited more potent in vitro cytotoxicity against BxPC-3 and AR42J cell lines than PEG-LPs. After systemic administration in mice, 2N-LPs remarkably increased drug distribution in the pancreas. In an orthotopic tumor mouse model of PC, GemC16-bearing liposomes were more effective in preventing tumor growth than free GemC16. Among these treatments, 2N-LPs showed the best curative effect. Together, 2N-LPs represent a promising nanocarrier to achieve pancreas-targeting drug delivery, and this work would provide new ideas for the chemotherapy of PC.

The proportion of alveolar type 1 cells decreases in murine hypoplastic congenital diaphragmatic hernia lungs.

BACKGROUND: Pulmonary hypoplasia, characterized by incomplete alveolar development, remains a major cause of mortality and morbidity in congenital diaphragmatic hernia. Recently demonstrated to differentiate from a common bipotent progenitor during development, the two cell types that line the alveoli type 1 and type 2 alveolar cells have shown to alter their relative ratio in congenital diaphragmatic hernia lungs. OBJECTIVE: We used the nitrofen/bisdiamine mouse model to induce congenital diaphragmatic hernia and accurately assess the status of alveolar epithelial cell differentiation in relation to the common bipotent progenitors. STUDY DESIGN: Pregnant Swiss mice were gavage-fed with nitrofen/bisdiamine or vehicle at embryonic day 8.5. The administered dose was optimized by assessing the survival, congenital diaphragmatic hernia and facial abnormality rates of the exposed mouse pups. NanoCT was performed on embryonic day 11.5 and 16.5 to assess the embryonic and early canalicular stages of lung development. At embryonic day 17.5 corresponding to late canalicular stage, congenital diaphragmatic hernia lungs were characterized by measuring the lung weight/body weight ratio, morphometry, epithelial cell marker gene expression levels and alveolar cell type quantification. RESULTS: Nitrofen/bisdiamine associated congenital diaphragmatic hernia lungs showed delayed development, hypoplasia with morphologic immaturity and thickened alveolar walls. Expression levels of distal epithelial progenitor marker Id2 increased, alveolar type 1 cell markers Pdpn and Hopx decreased, while type 2 cell markers pro-SPC and Muc1 remained constant during the canalicular stage. The number of Pdpn+ type 1 alveolar cells also decreased in congenital diaphragmatic hernia lungs. CONCLUSION: The mouse nitrofen/bisdiamine model is a potential model allowing the study of congenital diaphragmatic hernia lung development from early stages using a wide array of methods. Based on this model, the alveolar epithelium showed a decrease in the number of alveolar type 1 cell in congenital diaphragmatic hernia lungs while type 2 cell population remains unchanged.

Synthesis, Plasmodium falciparum Inhibitory Activity, Cytotoxicity and Solubility of N2 ,N4 -Disubstituted Quinazoline-2,4-diamines.

BACKGROUND: Despite the development of extensive control strategies and treatment options, approximately 200 million malaria cases, leading to approximately 450,000 deaths, were reported in 2015. Due to issue of disease resistance, additional drug development efforts are needed to produce new, more effective treatments. Quinazoline-2,4-diamines were identified as antiparasitic compounds over three decades ago and have remained of interest to date in industry and academia. OBJECTIVE: An anti-malarial SAR evaluation of previously unreported N2 ,N4 -disubstituted quinazoline- 2,4-diamines have been undertaken in this study. We have synthesized and evaluated new derivatives against P. falciparum in our attempt to better characterize their biological activity and overall physical properties. METHODS: The synthesis of N2 ,N4 -disubstituted quinazoline-2,4-diamines inhibitors is reported along with activities in a radioactive labeled hypoxanthine incorporation assay against the f Plasmodium falciparum (Pf.) K1 strain. In addition, cytotoxicity was determined in the A549 and Vero cell lines using an MTT based. The aqueous solubility of key compounds was assessed at pH 7.4 using a shake flask-based approach. RESULTS: We identified compounds 1 and 6p as sub µM inhibitors of P. falciparum, having equivalent anti-malarial activity to Chloroquine. Compounds 1 and 6m are low µM inhibitors of P. falciparum with improved cytotoxicity profiles. Compound 6m displayed the best balance between P. falciparum Inhibitory activity (2 µM) and cytotoxicity, displaying >49 fold selectivity over A549 and Vero cell lines. CONCLUSION: Twenty one N2 ,N4 -Disubstituted Quinazoline-2,4-diamines have been prepared in our group and characterized in terms of their antimalarial activity, cytotoxicity and physical properties. Compounds with good activity and reasonable selectivity over mammalian cell lines have been identified. SAR analyses suggest further exploration is are necessary to improve the balance of P. falciparum Inhibitory activity, cytotoxicity and solubility.

Structure-Based Design of 1-Heteroaryl-1,3-propanediamine Derivatives as a Novel Series of CC-Chemokine Receptor 5 Antagonists.

CC-chemokine receptor 5 (CCR5) is an attractive target for preventing the entry of human immunodeficiency virus 1 (HIV-1) into human host cells. Maraviroc is the only CCR5 antagonist, and it was marketed in 2007. To overcome the shortcomings of maraviroc, structure-based drug design was performed to minimize CYP450 inhibition and to enhance anti-HIV potency and bioavailability. Thirty-four novel 1-heteroaryl-1,3-propanediamine derivatives (1-34) were synthesized, displaying CCR5-antagonist activities in the 2.3-296.4 nM range. Among these, compounds 21 and 34 were the most potent CCR5 antagonists, with excellent in vitro anti-HIV-1 activity, low cytotoxicity, and an acceptable pharmacokinetic profile. Furthermore, the X-ray crystal structures of compounds 21 and 34 bound to CCR5 were determined at 2.8 Å resolution. Compound 34 exhibited no CYP450-inhibition activity at 25 µM, which overcomes the potential drug-drug interaction of maraviroc. Compound 34 represents a promising drug candidate for HIV-infection treatment.

Design of PEI-conjugated bio-reducible polymer for efficient gene delivery.

The poly(cystaminebis(acrylamide)-diaminohexane) (poly(CBA-DAH)) was designed previously as a bio-reducible efficient gene delivery carrier. However, the high weight ratio required to form the polyplexes between poly(CBA-DAH) with pDNA is still a problem that needs to be addressed. To solve this problem and increase the transfection efficiency, poly(ethylenimine) (PEI, 1.8 kDa) was conjugated to poly(CBA-DAH) via disulfide bond. The PEI conjugated poly(CBA-DAH) (PCDP) can bind with pDNA at a very low weight ratio of 0.5 and above, like PEI 25 kDa, and form the polyplexes with nano-size (102-128 nm) and positive surface charge (27-34 mV). PCDP and PCDP polyplexes had negligible cytotoxicity and indicated similar or better cellular uptake than the comparison groups such as PEI 25 kDa and Lipofectamine® polyplexes. To confirm the transfection efficiency, the plasmid DNA (pDNA) encoded with the luciferase reporter gene (gWiz-Luc) and green fluorescent protein reporter gene (GFP) were used and treated with PCDP into the A549, Huh-7, and Mia PaCa-2 cells. PCDP/pDNA polyplexes showed highest transfection efficiency in all tested cell lines. In the luciferase assay, PCDP polyplexes showed 10.2 times higher gene transfection efficiency than Lipofectamine® polyplexes in mimic in vivo conditions (30% FBS, A549 cells). The VEGF siRNA expressing plasmid (pshVEGF), which is constructed as a therapeutic gene by our previous work, was delivered by PCDP into the cancer cells. The VEGF gene expression of PCDP/pshVEGF polyplexes was dramatically lower than control and the VEGF gene silencing efficiencies of PCDP/pshVEGF (w/w; 10/1) polyplexes were 54% (A549 cells), 77% (Huh-7 cells), and 66% (Mia PaCa-2 cells). In addition, PCDP/pshVEGF had reduced cell viability rates of about 31% (A549 cells), 39% (Huh-7 cells), and 42% (Mia PaCa-2 cells) and showed better results than all comparison groups. In the transfection efficiency and VEGF silencing assay, PCDP polyplexes showed better results than poly(CBA-DAH) at 4-fold lower weight ratio. The data of all experiments demonstrate that the synthesized PCDP could be used for efficient gene delivery and could be widely applied.

γ-Secretase Inhibition Induces Muscle Hypertrophy in a Notch-Independent Mechanism.

A wide variety of cellular processes and signaling events are regulated by the proteolytic enzyme γ-secretase. Notch-1 is one of the substrates of γ-secretase and its role in the regulation of muscle differentiation has been well described. Importantly, besides Notch-1, a number of proteins have been identified to undergo proteolysis by γ-secretase. To date, the specific role of γ-secretase during embryonic skeletal muscle differentiation has not been studied. Therefore, we address this question through the analysis of in vitro grown chick myogenic cells during the formation of multinucleated myotubes. The γ-secretase inhibitor DAPT (N-N[-(3,5-Difluorophenacetyl-l-alanyl)]-S-328 phenylglycine-t-butyl-ester) induces muscle hypertrophy. Knockdown of Notch-1 using siRNA specific to chick shows no significant effect in myotube size, suggesting that γ-secretase-dependent effects on muscle hypertrophy in chick myogenic cells are Notch-1-independent. We also investigate the effects of γ-secretase inhibition in the whole proteomic profile of chick myogenic cells. We identified 276 differentially expressed proteins from Label-free proteomic approach. Data overview of interaction network obtained from STRING show that after γ-secretase inhibition cells exhibited imbalance in protein metabolism, cytoskeleton/adhesion, and Sonic Hedgehog signaling. The collection of these results provides new insights into the role of γ-secretase in skeletal muscle hypertrophy.

Mitochondrion to endoplasmic reticulum apposition length in zebrafish embryo spinal progenitors is unchanged in response to perturbations associated with Alzheimer's disease.

Mutations in the human genes PRESENILIN1 (PSEN1), PRESENILIN2 (PSEN2) and AMYLOID BETA A4 PRECURSOR PROTEIN (APP) have been identified in familial Alzheimer's disease (AD). The length of mitochondrion-endoplasmic reticulum (M-ER) appositions is increased in Psen1-/-/Psen2-/- double knockout murine embryonic fibroblasts and in fibroblasts from AD-affected individuals. Development of an easily accessible, genetically manipulable, in vivo system for studying M-ER appositions would be valuable so we attempted to manipulate M-ER apposition length in zebrafish (Danio rerio) embryos. We injected fertilized zebrafish eggs with antisense morpholino oligonucleotides (MOs) that inhibit expression of zebrafish familial AD gene orthologues psen1 and psen2. Furthermore, we treated zebrafish embryos with DAPT (a highly specific γ-secretase inhibitor) or with sodium azide (to mimic partially hypoxic conditions). We then analyzed M-ER apposition in an identified, presumably proliferative neural cell type using electron microscopy. Our analysis showed no significant differences in M-ER apposition lengths at 48 hours post fertilization (hpf) between psen1 & psen2 MO co-injected embryos, embryos treated with DAPT, or sodium azide, and control embryos. Instead, the distribution of M-ER apposition lengths into different length classes was close to identical. However, this indicates that it is feasible to reproducibly measure M-ER size distributions in zebrafish embryos. While our observations differ from those of murine and human studies, this may be due to differences in cellular differentiation and metabolic state, cell age, or species-specific responses. In particular, by focusing on a presumably proliferative embryonic cell type, we may have selected a cell heavily already reliant on anaerobic glycolysis and less responsive to factors affecting M-ER apposition. Future examination of more differentiated, more secretory cell types may reveal measurable responses of M-ER apposition to environmental and genetic manipulation.

Development of a chronic inhalation reference value for hexamethylenediamine using an exposure model based on the dihydrochloride salt.

The Texas Commission on Environmental Quality has developed a chronic inhalation Reference Value (ReV) for hexamethylenediamine (HMDA, CAS 124-09-4) based on respiratory effects identified in an animal study. HMDA is used in the fiber and plastics industry as an intermediate in the production of nylon, high-strength resins and polyamide adhesives. As a toxicant, HMDA acts primarily as a respiratory irritant with effects occurring in the upper respiratory tract, although systemic effects have been noted at higher concentrations. ReVs are chemical-specific air concentrations derived to protect human health. Acute and chronic ReVs were developed for HDMA based on an inhalation study conducted by the National Toxicology Program (NTP), which used the salt of HMDA, hexamethylenediamine dihydrochloride (HDDC, CAS 6055-52-3). For the chronic evaluation, rats and mice were exposed to 0, 1.6, 5, 16, 50 and 160 mg HDDC/m(3) for 13 weeks. The critical effect identified for the most sensitive species was hyaline degeneration in the olfactory epithelium in mice. The data provided in this study were suitable to benchmark concentration (BMC) modeling. Dosimetric adjustments using the rat and mouse Multiple-Path Particle Dosimetry Model (version 3.0) were made to the 95% lower limit of the BMC(10) to determine the human equivalent point of departure. Uncertainty factors were applied to account for variation in sensitivity within the human population, toxicodynamic differences between mice and humans, and use of a subchronic study. The ReV was initially calculated for HDDC and then adjusted for HMDA. The chronic ReV is 1.8 µg/m(3) for respirable HMDA ≤ 10 µm in diameter.

Synthesis, spectral, structural characterization and biological investigation of m-Xylylenediaminium-bis (p-toluenesulfonate) monohydrate.

Novel organic charge transfer complex, m-xylylenediaminium-bis (p-toluenesulfonate) monohydrate (XDPTS) have been synthesized and crystallized to the triclinic system with space group P-1 and the lattice parameters obtained are a=9.9265(7) Å, b=9.9676(6) Å, c=13.4948(10) Å, α=71.95(6)°, ß=77.02(6)°, γ=76.851(5)°. The synthesized complex structure was confirmed by IR, (1)H NMR and (13)C NMR spectral analysis. Pharmacology activities of charge transfer complex were evaluated through antimicrobial, DNA binding/cleavage, antioxidant and cytotoxicity studies. The results reveal that the compound shows good antimicrobial activity against various antibacterial and antifungal species. The DNA interaction indicated that the compound could interact with DNA through intercalation, which is further confirmed by viscosity measurements. The compound should have weak to moderate capacity of scavenging with DPPH, Hydroxyl and ABTS radicals. The cytotoxicity has been evaluated by MTT assay method against MCF-7 cancer cell line.

The in vitro impact of toothpaste extracts on cell viability.

Toothpastes contain three main components: detergents, abrasives, and fluoride. Detergents, particularly sodium lauryl sulfate, have been proposed as components that enable toothpastes to produce cytotoxic effects in vitro. However, not all toothpastes contain sodium lauryl sulfate, and almost no studies have found an association between detergents and the in vitro cytotoxicity of toothpastes. The present study examined the in vitro cytotoxicity of nine commercially available toothpastes containing four different detergents. Toothpastes were diluted in serum-free medium, centrifuged, and filter sterilized. The half-lethal concentration of the toothpaste-conditioned medium (TCM) was calculated based on the formation of formazan by gingival fibroblasts, oral squamous cell carcinoma HSC-2 cells, and L929 cells. Cell proliferation was analyzed, and live-dead staining was performed, after exposure of cells to conditioned medium prepared with 1% toothpaste (1% TCM). It was found that toothpastes containing sodium lauryl sulfate and amine fluoride strongly inhibited cell viability with the half-lethal concentration being obtained with conditioned medium prepared with approximately 1% toothpaste (1% TCM). Toothpastes containing cocamidopropyl betaine and Steareth-20 showed higher half-lethal concentration values, with the half-lethal concentration being obtained with conditioned medium prepared with 10% (10% TCM) and 70% (70% TCM) toothpaste, respectively. Proliferation and live-dead data were consistent with the cell-viability analyses. These results demonstrate that the type of detergent in toothpastes can be associated with changes in in vitro cell toxicity.

Covalent IR820-PEG-diamine nanoconjugates for theranostic applications in cancer.

Near-infrared dyes can be used as theranostic agents in cancer management, based on their optical imaging and localized hyperthermia capabilities. However, their clinical translatability is limited by issues such as photobleaching, short circulation times, and nonspecific biodistribution. Nanoconjugate formulations of cyanine dyes, such as IR820, may be able to overcome some of these limitations. We covalently conjugated IR820 with 6 kDa polyethylene glycol (PEG)-diamine to create a nanoconjugate (IRPDcov) with potential for in vivo applications. The conjugation process resulted in nearly spherical, uniformly distributed nanoparticles of approximately 150 nm diameter and zeta potential -0.4±0.3 mV. The IRPDcov formulation retained the ability to fluoresce and to cause hyperthermia-mediated cell-growth inhibition, with enhanced internalization and significantly enhanced cytotoxic hyperthermia effects in cancer cells compared with free dye. Additionally, IRPDcov demonstrated a significantly longer (P<0.05) plasma half-life, elimination half-life, and area under the curve (AUC) value compared with IR820, indicating larger overall exposure to the theranostic agent in mice. The IRPDcov conjugate had different organ localization than did free IR820, with potential reduced accumulation in the kidneys and significantly lower (P<0.05) accumulation in the lungs. Some potential advantages of IR820-PEG-diamine nanoconjugates may include passive targeting of tumor tissue through the enhanced permeability and retention effect, prolonged circulation times resulting in increased windows for combined diagnosis and therapy, and further opportunities for functionalization, targeting, and customization. The conjugation of PEG-diamine with a near-infrared dye provides a multifunctional delivery vector whose localization can be monitored with noninvasive techniques and that may also serve for guided hyperthermia cancer treatments.

A novel selenadiazole derivative induces apoptosis in human glioma cells by dephosphorylation of AKT.

Selenadiazole derivatives are synthetic organoselenium compounds with improved anticancer activity and greater selectivity than inorganic selenium. In this study, 4-(benzo[c][1,2,5]selenadiazol-6-yl)-benzene-1,2-diamine (BSBD) was shown to induce time- and dose-dependent apoptosis in SWO-38 human glioma cells by accumulation of a sub-G1 cell population, DNA fragmentation, nuclear condensation, caspase activation and poly(ADP-ribose) polymerase (PARP) cleavage. Further mechanistic investigation showed that BSBD treatment induced dephosphorylation of AKT and DNA damage-mediated activation of p53, leading to extensive apoptosis through the mitochondrial pathway. Our findings suggest that BSBD represents a potential human glioma therapeutic.

N-Polybenzylated alicyclic 1,2-diamines: cytotoxicity and G1 phase arrest in cancer cell line.

Cytotoxicity in the µM range was observed in cancer cell lines treated with N,N,N',N'-tetrabenzyl-4,5-diamino-2-cyclopentenone. Cell cycle analysis on HeLa cells showed a clear G1 phase arrest. A preliminary SAR on structural analogs was performed in order to identify the pharmacophores.

Synthesis and biological evaluation of N,N'-squaramides with high in vivo efficacy and low toxicity: toward a low-cost drug against Chagas disease.

Access to basic drugs is a major issue in developing countries. Chagas disease caused by Trypanosoma cruzi is a paradigmatic example of a chronic disease without an effective treatment. Current treatments based on benznidazole and nifurtimox are expensive, ineffective, and toxic. N,N'-Squaramides are amide-type compounds that feature both hydrogen bond donor and acceptor groups and are capable of multiple interactions with complementary sites. When combined with amine and carboxylic groups, squaramide compounds have increased solubility and therefore make suitable therapeutic agents. In this work, we introduce a group of Lipinski's rule of five compliant squaramides as candidates for treating Chagas disease. The in vivo studies confirmed the positive expectations arising from the preliminary in vitro studies, revealing compound 17 to be the most effective for both acute and chronic phases. The activity, stability, low cost of starting materials, and straightforward synthesis make amino squaramides appropriate molecules for the development of an affordable anti-Chagasic agent.

Labeling of human hepatocellular carcinoma cells by hexamethylene diamine modified fluorescent carbon dots.

Fluorescent carbon dots (CDs) were synthesized by a solvothermal method with glucose as carbon source and surface-modified with 1,6-hexamethylene diamine. In this hybrid CDs, the modification played important role for improving the fluorescent performance by introducing nitrogenous compound to passivate CD's surface, making the CDs emit strong fluorescence. The as-prepared CDs were linked with mouse anti-human Alpha fetoprotein (AFP) antibody and goat anti-mouse immunoglobulin (IgG) to directly and indirectly label fixed human hepatocellular carcinoma cells, respectively. The cytotoxicity of these CDs were also tested using the human hepatocellular carcinoma cells. No apparent cytotoxicity was observed, which suggested the potential application of the as-prepared CDs in bioimaging.

Synthesis of N(4)-(substituted phenyl)-N(4)-alkyl/desalkyl-9H-pyrimido[4,5-b]indole-2,4-diamines and identification of new microtubule disrupting compounds that are effective against multidrug resistant cells.

A series of fourteen N(4)-(substituted phenyl)-N(4)-alkyl/desalkyl-9H-pyrimido[4,5-b]indole-2,4-diamines was synthesized as potential microtubule targeting agents. The synthesis involved a Fisher indole cyclization of 2-amino-6-hydrazinylpyrimidin-4(3H)-one with cyclohexanone, followed by oxidation, chlorination and displacement with appropriate anilines. Compounds 6, 14 and 15 had low nanomolar potency against MDA-MB-435 tumor cells and depolymerized microtubules. Compound 6 additionally had nanomolar GI(50) values against 57 of the NCI 60-tumor panel cell lines. Mechanistic studies showed that 6 inhibited tubulin polymerization and [(3)H]colchicine binding to tubulin. The most potent compounds were all effective in cells expressing P-glycoprotein or the ßIII isotype of tubulin, which have been associated with clinical drug resistance. Modeling studies provided the potential interactions of 6, 14 and 15 within the colchicine site.

Novel lipoidal amine-based nanocarrier formulations for siRNA delivery.

BACKGROUND: Lack of safe and efficient delivery of siRNA remains the greatest hurdle for the therapeutic application of siRNA. This article reports synthesis and evaluation of novel lipoidal amine-based nanocarrier (LANC) formulations for siRNA delivery. METHOD: Physicochemical properties were analyzed for LANC formulations. siRNA delivery efficiency of LANC-siRNA complexes was determined using a luciferase reporter gene assay. Cytotoxicity of the LANC-siRNA complexes was measured by the MTS assay. Finally, cellular uptake and cytoplasmic release of siRNA were analyzed using flow cytometry. CONCLUSION: The LANC formulation facilitated siRNA uptake and release into the cytoplasm, mediating significant luciferase knockdown (70% inhibition).

Synthesis, cytotoxicity, and in vitro antileishmanial activity of mono-t-butyloxycarbonyl-protected diamines.

Leishmania amazonensis is the etiologic agent of the cutaneous and diffuse leishmaniasis. This species is often associated with drug resistance, and the conventional treatments exhibit high toxicity for patients. Therefore, the search for new antileishmanial compounds is urgently needed since there is no vaccine available. In this study, using the in vitro traditional drug screening test, we have analyzed the effects of a series of diaminoalkanes monoprotected with t-butyloxycarbonyl (BOC) against L. amazonensis. Among the 18 tested compounds, 6 exhibited antileishmanial activity (2, 7-9, 17, and 18). Best IC(50) values (10.39 ± 0.27 and 3.8 ± 0.42 µg/mL) were observed for compounds 17 and 18 (H(2)N(CH(2))nNHBoc, n = 10 and 12), respectively. Although those compounds had higher lipophilicity as indicated by their cLog P values, compound 17 was very toxic. Determination of the selective indexes indicated that 50% of the active compounds were very toxic for HepG2 cells. However, compounds 2, 8, and 18 had good lipophilicity and were less toxic among all polyamine derivatives tested. The chemical properties of antileishmanial diamine derivatives, such as lipophilicity and cytotoxicity, are relevant factors for the design of new drugs. A higher lipophilicity is likely to improve the chances of reaching this intracellular parasite.