Mannose-Modificated Polyethylenimine: A Specific and Effective Antibacterial Agent against Escherichia coli.

Polyethylenimine (PEI) has antimicrobial activity against Gram-positive (Staphylococcus aureus, S. aureus) and Gram-negative (Escherichia coli, E. coli), bacteria but is highly cytotoxic, and the selective antimicrobial activity against S. aureus is obviously better than that against E. coli. To reduce the cytotoxicity and improve the antibacterial activity against E. coli, we modified PEI with d-mannose through nucleophilic addition between primary amine and aldehyde groups to get mannose-modified polyethylenimine copolymer particles (Man-PEI CPs). The use of mannose may provide good targeting ability toward E. coli pili. The antibacterial activity of Man-PEI CPs was investigated. Man-PEI CPs shows specific and very strong killing capability against E. coli at a concentration of 10 µg/mL, which is the highest antimicrobial efficiency compared to that of unmodified PEI (220 µg/mL). The antibacterial mechanism demonstrated that the enhancement in antibacterial activity is due to specific recognition of the mannose and destroying the cell wall of the bacteria by PEIs. Importantly, the Man-PEI CPs show less cytotoxicity and excellent biocompatibility. The results indicate that Man-PEI CPs have great potential as novel antimicrobial materials to prevent bacterial infections and provide specific applications for killing E. coli.

Levorotatory carbohydrates and xylitol subdue Streptococcus mutans and Candida albicans adhesion and biofilm formation.

Dietary carbohydrates and polyols affect the microbial colonization of oral surfaces by modulating adhesion and biofilm formation. The aim of this study was to evaluate the influence of a select group of l-carbohydrates and polyols on either Streptococcus mutans or Candida albicans adhesion and biofilm formation in vitro. S. mutans or C. albicans suspensions were inoculated on polystyrene substrata in the presence of Tryptic soy broth containing 5% of the following compounds: d-glucose, d-mannose, l-glucose, l-mannose, d- and l-glucose (raceme), d- and l-mannose (raceme), l-glucose and l-mannose, sorbitol, mannitol, and xylitol. Microbial adhesion (2 h) and biofilm formation (24 h) were evaluated using MTT-test and Scanning Electron Microscopy (SEM). Xylitol and l-carbohydrates induced the lowest adhesion and biofilm formation in both the tested species, while sorbitol and mannitol did not promote C. albicans biofilm formation. Higher adhesion and biofilm formation was noted in both organisms in the presence of d-carbohydrates relative to their l-carbohydrate counterparts. These results elucidate, hitherto undescribed, interactions of the individually tested strains with l- and d-carbohydrates, and how they impact fungal and bacterial colonization. In translational terms, our data raise the possibility of using l-form of carbohydrates and xylitol for dietary control of oral plaque biofilms.

Preparation of glycopeptide-modified pH-sensitive liposomes for promoting antigen cross-presentation and induction of antigen-specific cellular immunity.

Cross-presentation, exogenous antigen presentation onto major histocompatibility complex class I molecules on antigen presenting cells, is crucially important for inducing antigen-specific cellular immune responses for cancer immunotherapy and for the treatment of infectious diseases. One strategy to induce cross-presentation is cytosolic delivery of an exogenous antigen using fusogenic or endosomolytic molecule-introduced nanocarriers. Earlier, we reported liposomes modified with pH-responsive polymers to achieve cytosolic delivery of an antigen. Polyglycidol-based or polysaccharide-based pH-responsive polymers can provide liposomes with delivery performance of antigenic proteins into cytosol via membrane fusion with endosomes responding to acidic pH, leading to induction of cross-presentation. Mannose residue was introduced to pH-responsive polysaccharides to increase uptake selectivity to antigen presenting cells and to improve cross-presentation efficiency. However, direct introduction of mannose residue into pH-responsive polysaccharides suppressed cytoplasmic delivery performance of liposomes. To avoid such interference, for this study, mannose-containing glycans were incorporated separately into pH-responsive polysaccharide-modified liposomes. Soybean agglutinin-derived glycopeptide was used as a ligand for lectins on antigen presenting cells. Incorporation of glycopeptide significantly increased the cellular uptake of liposomes by dendritic cell lines and increased cross-presentation efficiency. Liposomes incorporated both glycopeptide and pH-responsive polysaccharides exhibited strong adjuvant effects in vitro and induced the increase of dendritic cells, M1 macrophages, and effector T cells in the spleen. Subcutaneous administration of these liposomes induced antigen-specific cellular immunity, resulting in strong therapeutic effects in tumor-bearing mice. These results suggest that separate incorporation of glycopeptides and pH-responsive polysaccharides into antigen-loaded liposomes is an effective strategy to produce liposome-based nanovaccines to achieve antigen cross-presentation and induction of cellular immunity towards cancer immunotherapy.

Efficient suppression of murine intracellular adhesion molecule-1 using ultrasound-responsive and mannose-modified lipoplexes inhibits acute hepatic inflammation.

UNLABELLED: Hepatitis is often associated with the overexpression of various adhesion molecules. In particular, intracellular adhesion molecule-1 (ICAM-1), which is expressed on hepatic endothelial cells (HECs) in the early stage of inflammation, is involved in serious illnesses. Therefore, ICAM-1 suppression in HECs enables the suppression of inflammatory responses. Here, we developed an ICAM-1 small interfering RNA (siRNA) transfer method using ultrasound (US)-responsive and mannose-modified liposome/ICAM-1 siRNA complexes (Man-PEG(2000) bubble lipoplexes [Man-PEG(2000) BLs]), and achieved efficient HEC-selective ICAM-1 siRNA delivery in combination with US exposure. Moreover, the sufficient ICAM-1 suppression effects were obtained via this ICAM-1 siRNA transfer in vitro and in vivo, and potent anti-inflammatory effects were observed in various types of inflammation, such as lipopolysaccharide, dimethylnitrosamine, carbon tetrachloride, and ischemia/reperfusion-induced inflammatory mouse models. CONCLUSION: HEC-selective and efficient ICAM-1 siRNA delivery using Man-PEG(2000) BLs and US exposure enables suppression of various types of acute hepatic inflammation. This novel siRNA delivery method may offer a valuable system for medical treatment where the targeted cells are HECs.

Magnetic liposome as a dual-targeting delivery system for idiopathic pulmonary fibrosis treatment.

Idiopathic pulmonary fibrosis (IPF) is the most common form of idiopathic interstitial pneumonia, where M2 macrophages play an irreplaceable role in the anti-inflammatory progress. Targeting M2 macrophages and regulating their polarization may be a potential treatment strategy for IPF. Herein, we designed a magnetic liposome based dual-targeting delivery system for the IPF treatment, constructed by mannose-modified magnetic nanoparticles (MAN-MNPs) loaded on the surface of the liposome (MAN-MNPs@LP). The delivery system is capable of responding to a static magnetic field (SMF) and then recognizing in situ of M2 macrophages through the mannose receptor-dependent internalization. Firstly, a series of physical and chemical assays were used to characterize these nanoparticles. Subsequently, magnetic liposomes accumulation in the damaged lung with/without mannose modification and SMF were compared by in vivo imaging system. Finally, the reduction of M2 macrophages and inhibition of their polarization confirmed that the development of IPF was retarded due to the in situ release of encapsulated dexamethasone (Dex) in lungs under the SMF. Further investigation demonstrated that the expression of α-SMA and collagen deposition was reduced. Altogether, this dual-targeting delivery system can effectively deliver Dex into M2 macrophages in the lung, making it a novel and promising therapeutic system for the IPF treatment.

Investigations into an alternate approach to target mannose receptors on macrophages using 4-sulfated N-acetyl galactosamine more efficiently in comparison with mannose-decorated liposomes: an application in drug delivery.

In this study the potential of 2 different ligands, i.e., palmitoyl mannose (Man-Lip) and 4-SO(4)GalNAc (Sulf-Lip) to target resident macrophages was investigated after surface decoration of Amphotericin B (AmB) loaded liposomes. In the case of Sulf-Lip, the 4-SO(4)GalNAc was adsorbed through electrostatic interaction on cationic liposomes, which was confirmed by change in zeta potential from +48.2 ± 3.7 mV for Lip to +12.2 ± 1.3 mV for Sulf-Lip. The mean particle size of Sulf-Lip and Man-Lip was found to be 139.4 ± 7.4 nm and 147.4 ± 8.6 nm, respectively. Flow cytometric data reveal enhanced uptake of Sulf-Lip in both J774 and RAW cell lines in comparison with the uptake of Man-Lip. Intracellular localization studies indicate that the fluorescence intensity of Sulf-Lip was much higher in comparison with that of Man-Lip and Lip formulations. Sulf-Lip and Man-Lip showed significantly higher localization of AmB at all time points in comparison with Lip (P < 0.05) after intravenous (IV) administration. The studies provide evidence that 4-SO(4)GalNAc possesses a promising feature for targeting resident macrophages and its application in the conditions of leishmaniasis is in the offing. FROM THE CLINICAL EDITOR: This in vivo study compares two different ligands to deliver Amphotericin B l(AmB) loaded liposomes to resident macrophages. Targeted approaches showed significantly higher localization of AmB at all time points in comparison to non-targeted liposomes, and future applications in leishmaniasis are already under preparation.

The importance of inter-species cell-cell co-aggregation between Lactobacillus plantarum ML11-11 and Saccharomyces cerevisiae BY4741 in mixed-species biofilm formation.

Cells of Lactobacillus plantarum ML11-11, an isolate from Fukuyama pot vinegar, and the yeast Saccharomyces cerevisiae formed significant mixed-species biofilms with concurrent inter-species co-aggregation. The co-aggregation did not occur with heated or proteinase K-treated ML11-11 cells, or in the presence of D-mannose, suggesting that surface proteins of ML11-11 and mannose-containing surface substance(s) of yeast were the predominant contributing factors. Sugar fatty acid ester inhibited mixed-species biofilm formation, but did not inhibit co-aggregation, suggesting that the cell-cell adhesion and cell-polystylene adhesion are controlled by different mechanisms. Microscopic observation and microflora analysis revealed that inter-species co-aggregation plays an important role in the formation of the mixed-species biofilm.

Glyco-Nanoadjuvants: Sugar Structures on Carriers of a Small Molecule TLR7 Ligand Affect Their Immunostimulatory Activities.

Toll-like receptors (TLRs) are pattern recognition receptors that activate innate immunity, and their ligands are promising adjuvants for vaccines and immunotherapies. Small molecule TLR7 ligands are ideal vaccine adjuvants as they induce not only proinflammatory cytokines but also type I interferons. However, their application has only been approved for local administration due to severe systemic immune-related adverse events. In a previous study, we prepared the gold nanoparticles coimmobilized with synthetic small molecule TLR7 ligand, 1V209, and α-mannose (1V209-αMan-GNPs). 1V209-αMan-GNPs were selectively delivered via a cell surface sugar-binding protein, mannose receptor, which enabled selective delivery of TLR7 ligands to immune cells. Besides the mannose receptor, immune cells express various sugar-binding proteins such as macrophage galactose binding lectins and sialic acid-binding immunoglobulin-type lectins and recognize distinct sugar structures. Hence, in the present study, we investigated whether sugar structures on GNPs affect the efficiency and selectivity of intracellular delivery and subsequent immunostimulatory potencies. Five neutral sugars and two sialosides were selected and each sugar was coimmobilized with 1V209 onto GNPs (1V209-SGNPs) and their innate immunostimulatory potencies were compared to that of 1V209-αMan-GNPs. The in vitro study using mouse bone marrow derived dendritic cells (BMDCs) demonstrated that α-glucose, α-N-acetylglucosamine, or α-fucose immobilized 1V209-SGNPs increased interleukin-6 and type I interferon release similar to that of 1V209-αMan-GNPs, whereas galacto-type sugar immobilized 1V209-SGNPs predominantly enhanced type I interferon release. In contrast, sialoside immobilized 1V209-SGNPs did not enhance the potency of 1V209. In the in vivo immunization study using ovalbumin as a model antigen, neutral sugar immobilized 1V209-SGNPs induced comparable T helper-1 immune response to that of 1V209-αMan-GNPs and by 10-fold higher than that of sialoside immobilized 1V209-SGNPs. These results indicate that the sugar structures on 1V209-SGNPs affect their immunostimulatory activities, and functionalization of the carrier particles is important to shape immune responses.

Glyco-pseudopolyrotaxanes: carbohydrate wheels threaded on a polymer string and their inhibition of bacterial adhesion.

We report glyco-pseudopolyrotaxanes composed of cucurbit[6]uril-based mannose wheels (ManCB[6]) threaded on polyviologen (PV), which not only effectively induce bacterial aggregation, but also exhibit high inhibitory activity against bacterial binding to host cells. Three glyco-pseudopolyrotaxanes (1-3), which have 10, 5, and 3 ManCB[6] wheels, respectively, on a PV string, were prepared and characterized. Bacterial aggregation assays and hemagglutination inhibition assays illustrated the specific and multivalent interaction between the glyco-pseudopolyrotaxanes and E. coli ORN178. Compound 3 was especially effective at inducing bacterial aggregation and showed 300 times higher inhibitory potency than monomeric methyl-α-mannoside (Me-αMan) for ORN178-induced hemagglutination. Furthermore, we demonstrated their inhibitory activities for the adhesion of ORN178 bacteria to urinary epithelial cells as a model of urinary tract infection. Our findings suggest that these supramolecular carbohydrate clusters are potentially useful in antiadhesion therapy.

Mucosal adjuvant activity of oligomannose-coated liposomes for nasal immunization.

In the present study, we investigated the effectiveness of liposomes coated with a neoglycolipid consisting of mannotriose and dipalmitoylphosphatidylcholine (Man3-DPPE) as an adjuvant for induction of mucosal immunity. Immunization of BALB/c mice with ovalbumin (OVA)-encapsulated Man3-DPPE-coated liposomes (oligomannose-coated liposomes; OMLs) by a nasal route produced high levels of OVA-specific IgG and IgA antibodies in serum of immunized mice 1 week after the last nasal immunization, whereas no significant serum antibody responses were observed in mice that received OVA in uncoated liposomes or OVA alone. Seven weeks after the last nasal immunization, nasal challenge with an excess amount of OVA in mice that had received OVA/OMLs led to an anamnestic response to the antigen that resulted in 5- to 10-fold increases of antigen-specific serum IgG and IgA antibodies. Only mice immunized nasally with OML/OVA secreted antigen-specific secretory IgA in nasal washes and produced interferon-gamma secreting cells in nasopharyngeal-associated lymphoreticular tissue. Taken together, these results show that nasal administration of OMLs induces mucosal and systemic immunity that are specific for the entrapped antigen in the liposomes. Thus, liposomes coated with synthetic neoglycolipids might be useful as adjuvants for induction of mucosal immunity.

Recent advancements in cytotoxic T lymphocyte generation methods using carbohydrate-coated liposomes.

Both tumor-specific CD4(+) and CD8(+) T cells have been identified, and the latter is known as a major effector of adaptive antitumor immune responses. Optimal antitumor immune responses are considered to require the concomitant activation of both CD8(+) and CD4(+) T cells and the additional selective activation of CD4(+) T cells with helper, but not regulatory function. As optimal antitumor immune responses are generated by the concomitant activation of both T cell types, it is necessary for vaccine methods involving cytotoxic T-lymphocytes (CTLs) generation to possess a mechanism whereby antigen presenting cells can present administrated exogenous antigens on not only Major histocompatibility complex (MHC) class II, but also MHC class I molecules.

Immune responses to polyethylenimine-mannose-delivered plasmid DNA encoding a Fasciola gigantica fatty acid binding protein in mice.

Fasciola gigantica fatty acid binding protein (FABP) was evaluated for evoking an immune response in mice, by delivering the gene coding for this protein with mannosylated-polyethylenimine (PEI) to peritoneal cells. Mice were immunized with 50 microg recombinant plasmid DNA (Group I) or DNA-PEI-mannose (a 22 kDa linear cationic polymer with mannose ligand) (Group II) via the intraperitoneal route. Antibody studies showed no significant humoral immune response evoked to this DNA immunization with either PEI-mannose-delivered or naked DNA. However, on protein boosting of these DNA-primed mice there was a significant enhancement of antibody titre. Flow cytometric bead array was used to measure quantities of interleukin (IL)-2, IL-4, IL-5, interferon-gamma (IFN-gamma) and tumour necrosis factor (TNF) cytokines. Overexpression of T-helper 1 (Th1) cytokines such as IFN-gamma and TNF, with a lower but significant expression of the T-helper 2 (Th2) cytokine IL-5 was detected. Gene delivery using polyethylenimine-mannose ligand showed significant expression of IFN-gamma and TNF (P < 0.05), but no significant difference in IL-2, IL-4 and IL-5 (P>0.05) cytokine expression was observed between naked-DNA- and mannosylated PEI-DNA-delivered mice. Naked- or PEI-delivered-DNA immunization produced insignificant levels of IL-2 and IL-4 (P>0.05) cytokines in both groups of mice.

Sharp pH-responsive mannose prodrug polypeptide nanoparticles encapsulating a photosensitizer for enhanced near infrared imaging-guided photodynamic therapy.

Mannose has been reported as a novel drug to kill cancer cells. The prodrug of mannose will promote its targeted delivery and enrichment at the tumor site and cancer cells. Here, a pH-sensitive polypeptide copolymer with a tertiary amine group has been prepared and a mannose molecule was conjugated to the polymer through the formation of a Schiff base. At the same time, an iodinated boron dipyrromethene (BDPI) photosensitizer with high singlet oxygen generation efficacy and near infrared (NIR) fluorescence was encapsulated by the nanoparticles, which makes it a potential pH-sensitive NIR imaging-guided chemotherapy/PDT agent. In vitro and in vivo studies reveal that in a tumor acidic environment, the protonation of the tertiary amine group destroyed the nanostructure of the nanoparticles, resulting in increased BDPI release. Meanwhile, the bond cleavage of the Schiff base led to the release of conjugated mannose and synergistic inhibition of tumor cell growth with the PDT effect was realized. The combination of these two kinds of tumor suppression effects and photodynamic therapy made this pH-sensitive polypeptide delivery system show great potential for further cancer therapy.

Itraconazole encapsulated PLGA-nanoparticles covered with mannose as potential candidates against leishmaniasis.

Leishmaniasis is a neglected disease threatening over 350 million people. Antimonials are first-line drugs due to resistance and side effects there is a demand for alternative chemotherapy. Itraconazole (ITZ) is an antimycotic. It was encapsulated into poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) and covered with mannose. The NPs were 250 nm and -1.1 mV ± 0.7. PLGA-ITZ-mannose NPs presented a toxicity of 20.7% for J774 cells, and no toxicity for THP 1. The J774 cells were infected with three Leishmania promastigotes strains and treated with ITZ loaded PLGA NPs with/without mannose. The parasite percentage of L.(V.) panamensis intracellular amastigotes significantly (p < 0.01) decreased from 34.4% to 13.7% and 5.7% for PLGA-ITZ-mannose NPs and PLGA-ITZ NPs, respectively. For L.(L.) infantum there was a reduction (p < 0.001) from 18.1% to 4.8% and 8.3% for PLGA-ITZ-mannose NPs and PLGA-ITZ NPs, respectively. Further with L.(L.) braziliensis amastigotes there was a significant reduction (p < 0.001) from 54.9% to 28% and 21.1% for PLGA-ITZ-mannose NPs and PLGA-ITZ NPs, respectively. Adding mannose increased the efficacy PLGA-ITZ NPs against L.(L.) infantum, while it had no effect against L(V.) panamensis and L.(L.) braziliensis amastigotes. We recommend further investigation of PLGA-ITZ-mannose NPs in animal models to evaluate their potential. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 00B: 000-000, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 680-687, 2019.

Medium composition optimization, structural characterization, and antioxidant activity of exopolysaccharides from the medicinal mushroom Ganoderma lingzhi.

To contribute towards effective exploitation and utilization of natural antioxidants, response surface methodology (RSM) was employed to optimize the medium composition for the production of exopolysaccharides from the medicinal mushroom Ganoderma lingzhi (GLEPS). An optimal medium for GLEPS production was gave through Plackett-Burman design, path of steepest ascent, and Box-Behnken design as follows: glucose (59.62 g/L), yeast extract (10.03 g/L), CaCO3 (0.2 g/L), thiamine (45.13 mg/L), KH2PO4 (1.0 g/L), peptone (1.5 g/L), Tween 80 (10.26 mL/L), ZnSO4 (0.3 g/L), mannitol (1.5 g/L), MgSO4 (0.5 g/L), and aspartate (8.86 g/L). The GLEPS yield obtained was 3.57 ±â€¯0.21 g/L-3.16-fold higher than that produced in basal medium alone. The resulting GLEPS rich in uronic acid, d-mannose, l-rhamnose, and d-glucose, was a heteropolysaccharide with high-molecular weights (475,000 kDa and 21.6 kDa, 87.97%). It was demonstrated that the GLEPS with higher carbohydrate and uronic acid contents exhibited strong in vitro antioxidant activities via radical scavenging, reductive capacity, and chelation of transition metal catalysis. These findings indicated that RSM is an efficient tool to predict the composition of culture medium required for maximizing GLEPS yield, and GLEPS had potent antioxidant activities and could be explored as a novel natural antioxidant in functional food or medicine.

Binding of the periodontitis associated bacterium Porphyromonas gingivalis to glycoproteins from human epithelial cells.

INTRODUCTION: In the present study we examined the ability of the periodontal pathogen Porphyromonas gingivalis to adhere to glycoconjugates on intact cells and to protein preparations of epithelial cells (KB cells). METHODS: The KB cell protein preparation was separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes by Western blotting. The membranes were used in overlay assays with labeled P. gingivalis. Flow cytometry was used to analyze attachment of bacteria to intact KB cells. RESULTS: Glycoconjugate expression on the KB cells and in the protein preparation was confirmed. Binding was detected to several bands on the Western blots. Flow cytometry showed a distinct increase in fluorescence for strain FDC 381. Preincubation of the bacteria with mannose, fucose, N-acetylglucosamine and N-acetylgalactosamine inhibited the binding to KB cells by approximately 30% whereas preincubation with N-acetylneuraminic acid reduced the binding by 60%. CONCLUSION: These results indicate that carbohydrate structures are involved in the binding process of P. gingivalis to oral epithelial cells and that neuraminic acid plays a significant role in the adhesion process.

Functionalization promotes pathogen-mimicking characteristics of polyanhydride nanoparticle adjuvants.

Rational design of adjuvants and delivery systems will promote development of next-generation vaccines to control emerging and re-emerging diseases. To accomplish this, understanding the immune-enhancing properties of new adjuvants relative to those induced by natural infections can help with the development of pathogen-mimicking materials that will effectively initiate innate immune signaling cascades. In this work, the surfaces of polyanhydride nanoparticles composed of sebacic acid (SA) and 1,6-bis(p-carboxyphenoxy) hexane were decorated with an ethylene diamine spacer partially modified with either a glycolic acid linker or an α-1,2-linked di-mannopyranoside (di-mannose) to confer "pathogen-like" properties and enhance adjuvanticity. Co-incubation of linker-modified nanoparticles with dendritic cells (DCs) elicited significant increases in surface expression of MHC I, MHC II, CD86, and CD40, and enhanced secretion of IL-6, IL-12p40, and TNF-α. An 800% increase in uptake of ethylene-diamine-spaced, linker and di-mannose functionalized polyanhydride nanoparticles was also observed. Together, our data showed that linker-functionalized polyanhydride nanoparticles demonstrate similar patterns of uptake, intracellular trafficking, particle persistence, and innate activation as did DCs exposed to Yersinia pestis or Escherichia coli. These results set the stage for rational selection of adjuvant chemistries to induce pathogen-mimicking immune responses. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2762-2771, 2017.

Characterization of biofilm-forming abilities of antibiotic-resistant Salmonella typhimurium DT104 on hydrophobic abiotic surfaces.

BACKGROUND AND PURPOSE: Salmonella typhimurium DT104 strain has emerged as a global human and veterinary public health concern because of its antibiotic resistance and extensive host range. Although it is thought to be more virulent, to date, factors relevant to its virulence have not been fully elucidated. Thus, understanding how this strain forms biofilms on hydrophobic surfaces will add to current knowledge on its possible virulence mechanism. METHODS: Biofilm-forming abilities of clinical isolates of S. typhimurium DT104 from human and animal sources on hydrophobic inanimate surfaces were assessed by absorbance at 600 nm of crystal violet-bound cells recovered from 96-well tissue culture plates after growth in a nutrient-rich growth medium and various adjusted media; and scanning electron microscopy based on standard procedures. RESULTS: In the nutrient-rich growth medium, Luria-Bertani (LB), biofilms were formed in small quantities, preferentially on polystyrene (p<0.05), and followed different time courses. Significantly lower amounts of biofilms were formed on polystyrene when a nutrient-deficient growth medium (adherence test medium) was used. Inclusion of D-(+)-mannose in LB at a concentration of 100 mM significantly (p<0.05) inhibited biofilm formation on polystyrene. D-(+)-glucose relatively enhanced biofilm formation but D-(-)-mannitol only insignificantly influenced the process. The action of mannose on polyvinly chloride (PVC) was insignificant, suggesting that its action may be surface-dependent. Additionally, glucose significantly reduced biofilm growths of 2 of the isolates and only that of the PVC-loving strain T980021 on polystyrene and PVC, respectively. At the concentration tested, unlike xylose, both D-mannose and D-glucose significantly (p<0.05) inhibited bacterial growth, providing a possible mechanism for their inhibitory action on biofilm formation by S. typhimurium. While stress of starvation resulted in significant reduction in biofilm formation on polystyrene in all but the PVC-loving strain T980021, high osmolarity had little effect on the quantity of biofilm formed on polystyrene. The extent of primary attachment to polystyrene as well as their capacity to form biofilm did not correlate with their cell surface hydrophobicity and exopolysaccharide production. CONCLUSIONS: D-(+)-mannose inhibits biofilm formation by S. typhimurium DT104 on polystyrene but not on PVC. There was also a general lack of correlation between the ability of S. typhimurium DT104 to form biofilm and its physicochemical surface characteristics.

Relationship Between Increased Fucosylation and Metastatic Potential in Colorectal Cancer.

BACKGROUND: Fucose is utilized for the modification of different molecules involved in blood group determination, immunological reactions, and signal transduction pathways. We have recently reported that enhanced activity of the fucosyltransferase 3 and/or 6 promoted TGF-ß-mediated epithelial mesenchymal transition and was associated with increased metastatic potential of colorectal cancer (CRC), suggesting that fucose is required by CRC cells. With this in mind, we examined requirement of L-fucose in CRC cells and developed fucose-bound nanoparticles as vehicles for delivery of anticancer drugs specific to CRC. METHODS: In this study, we first examined the expression of fucosylated proteins in 50 cases of CRC by immunochistochemical staining with biotinylated Aleuria aurantia lectin (AAL). Then we carried out an L-fucose uptake assay using three CRC cell lines. Finally, we developed fucose-bound nanoparticles as vehicles for the delivery of an anticancer drug, SN38, and examined tumor growth inhibition in mouse xenograft model (n = 6 mice per group). All statistical tests were two-sided. RESULTS: We found a statistically significant relationship between vascular invasion, clinical stage, and intensity score of AAL staining (P ≤ .02). L-fucose uptake assay revealed that L-fucose incorporation, as well as fucosylated protein release, was high in cells rich in fucosylated proteins. L-fucose-bound liposomes effectively delivered Cy5.5 into CRC cells. The excess of L-fucose decreased the efficiency of Cy5.5 uptake through L-fucose-bound liposomes, suggesting an L-fucose receptor dependency. Intravenously injected, L-fucose-bound liposomes carrying SN38 were successfully delivered to CRC cells, mediating efficient tumor growth inhibition (relative tumor growth ratio: no treatment group [NT], 8.29 ± 3.09; SN38-treated group [SN38], 3.53 ± 1.47; liposome-carrying, SN38-treated group [F0], 3.1 ± 1.39; L-fucose-bound, liposome-carrying, SN38-treated group [F50], 0.94 ± 0.89; F50 vs NT, P = .003; F50 vs SN38, P = .02, F50 vs F0, P = .04), as well as prolonging survival of mouse xenograft models (log-rank test, P < .001). CONCLUSIONS: Thus, fucose-bound liposomes carrying anticancer drugs provide a new strategy for the treatment of CRC patients.

Linear biocompatible glyco-polyamidoamines as dual action mode virus infection inhibitors with potential as broad-spectrum microbicides for sexually transmitted diseases.

The initial steps of viral infections are mediated by interactions between viral proteins and cellular receptors. Blocking the latter with high-affinity ligands may inhibit infection. DC-SIGN, a C-type lectin receptor expressed by immature dendritic cells and macrophages, mediates human immunodeficiency virus (HIV) infection by recognizing mannose clusters on the HIV-1 gp120 envelope glycoprotein. Mannosylated glycodendrimers act as HIV entry inhibitors thanks to their ability to block this receptor. Previously, an amphoteric, but prevailingly cationic polyamidoamine named AGMA1 proved effective as infection inhibitor for several heparan sulfate proteoglycan-dependent viruses, such as human papilloma virus HPV-16 and herpes simplex virus HSV-2. An amphoteric, but prevailingly anionic PAA named ISA23 proved inactive. It was speculated that the substitution of mannosylated units for a limited percentage of AGMA1 repeating units, while imparting anti-HIV activity, would preserve the fundamentals of its HPV-16 and HSV-2 infection inhibitory activity. In this work, four biocompatible linear PAAs carrying different amounts of mannosyl-triazolyl pendants, Man-ISA7, Man-ISA14, Man-AGMA6.5 and Man-AGMA14.5, were prepared by reaction of 2-(azidoethyl)-α-D-mannopyranoside and differently propargyl-substituted AGMA1 and ISA23. All mannosylated PAAs inhibited HIV infection. Both Man-AGMA6.5 and Man-AGMA14.5 maintained the HPV-16 and HSV-2 activity of the parent polymer, proving broad-spectrum, dual action mode virus infection inhibitors.