Strong Adhesion Ability Research Articles

Adhesion Ability and Cytotoxic Evaluation of Lactobacillus Strains Isolated from Malaysian Fermented Fish (Pekasam) on HT-29 and CCD-18CO Intestinal Cells

Bacterial adhesion to host cells is the most important probiotic character. However, the adhesion of probiotic should not affect the viability of the host cells. In this study, Lactobacillus plantarum strain L8, Lactobacillus plantarum strain L20 and Lactobacillus pentosus strain S1 were tested for their cytotoxic effects through MTT assay and their ability to adhere and colonize on HT-29 and CCD-18Co intestinal cells as detected microscopically using light microscopy and Scanning Electron Microscopy (SEM). No cytotoxicity effects were observed on both intestinal cells following 24 h treatment with all Lactobacillus strains. Additionally, all strains demonstrated strong adhesive activity where more than 100 bacteria adhered to both intestinal cells although differences in the adhesion scores observed among different strains. The adhesion as observed via SEM showed an autoagreggative pattern and adhered as clusters on the surface of both intestinal cells. In conclusion, all three Lactobacillus strains are non-cytotoxic to both cells with strong adhesion ability on intestinal cells and this study also proved that Malaysian fermented fish are good source of probiotic bacteria.

Pollen-inspired microparticles with strong adhesion for drug delivery

Microparticles with strong adhesion property was presented as efficacious drug delivery systems. Here, inspired by natural pollen, polymer microparticles with surface textures and homogeneous size were fabricated through evaporation-induced interfacial instability of microfluidic droplets templates. The resultant particles exhibited controllable surface roughness and thus strong adhesion ability to the intestinal mucosa. Such particles were employed as novel drug carriers, which contributed to enhanced loading efficacy and controllable release kinetics, and were proved to increase therapeutic effectiveness through in vivo and in vitro tests, thus playing a potential role in sustained drug delivery, bioimaging, diagnostics, etc.

Polydopamine Based Colloidal Materials: Synthesis and Applications.

Polydopamine is a synthetic analogue of natural melanin (eumelanin) produced from oxidative polymerization of dopamine. Owing to its strong adhesion ability, versatile chemical reactivity, biocompatibility and biodegradation, polydopamine is commonly applied as a versatile linker to synthesize colloidal materials with diverse structures, unique physicochemical properties and tunable functions, which allow for a broad scope of applications including biomedicine, sensing, catalysis, environment and energy. In this personal account, we discuss first about the different synthetic approaches of polydopamine, as well as its polymerization mechanism, and then with a comprehensive overview of recent progress in the synthesis and applications of polydopamine-based colloidal materials. Finally, we summarize this personal account with future perspectives.

Molecular and virulence characterization of highly prevalent Streptococcus agalactiae circulated in bovine dairy herds

Bovine mastitis caused by Streptococcus agalactiae continues to be one of the major veterinary and economic issues in certain areas of the world. The more prevalent S. agalactiae strains that cause bovine mastitis in China dairy farms belong to a number of bovine-adapted sequence types (STs) ST67, ST103 and ST568. However, it is unknown why these STs can emerge as highly prevalent clones in bovine dairy farms. Here, to determine if a variety of virulence characteristics were associated with these highly prevalent STs, the molecular and virulence characterization of 116 strains isolated from bovine, human, fish and environment were analyzed. Our data showed that all bovine-adapted strains could be assigned to capsular genotype Ia or II, and carried pilus island 2b, and lactose operon. Importantly, we demonstrated that the growth ability in milk, biofilm formation ability and adhesion ability to bovine mammary epithelial cells (BMECs) were significantly higher for all bovine-adapted strains compared to strains from other origins. Additionally, ST103 and ST568 strains exhibited significantly higher hemolytic activity and cytotoxicity than ST67 strains. In conclusion, our study provides substantial evidence for the hypothesis that the virulence characteristics including efficient growth in milk, elevated biofilm formation ability, together with strong adhesion ability might have favored the high prevalence of the STs in the bovine environment, whereas the hemolytic activity and cytotoxicity were not the crucial characteristics.

An in situ photocrosslinkable platelet rich plasma - Complexed hydrogel glue with growth factor controlled release ability to promote cartilage defect repair.

In this study, we have developed a photocrosslinkable platelet rich plasma (PRP) - complexed hydrogel glue (HNPRP) for cartilage regeneration. The in situ formed HNPRP hydrogel glue showed not only the controlled release ability of growth factors, but also strong tissue adhesiveness, which could resolve the current problems in clinical application of PRP. Furthermore, HNPRP hydrogel glue could promote integrative hyaline cartilage regeneration, and its reparative efficacy for cartilage defect was better than thrombin activated PRP gel. This study provided not only an effective repair material for cartilage regeneration, but also developed an advanced method for PRP application.

Facile fabrication approach for a novel multifunctional superamphiphobic coating based on chemically grafted montmorillonite/Al2O3-polydimethylsiloxane binary nanocomposite

In this paper, a novel multifunctional superamphiphobic coating for anticorrosion was successfully prepared on aluminum substrate via a simple spraying technique. Al2O3 nanoparticles were chemically grafted onto montmorillonite (MMT) nanosheets via coupling effect of NH2-C3H6-Si(OC2H5)3 (KH-550) and then modified by low surface energy material polydimethylsiloxane (PDMS). The ethylene tetrafluoroethylene (ETFE) composite coating with 25 wt% MMT/Al2O3-PDMS binary nanocomposite exhibited well-designed nano/μ structures and possessed superamphiphobicity with high contact angles towards water (164°), glycerol (158°) and ethylene glycol (155°). This coating demonstrated outstanding self-cleaning ability and strong adhesive ability (Grade 1 according to the GB/T 9286). The superhydrophobicity could be maintained after 8000 times abrasion or annealing treatment for 2 h under 350 °C. The coating still retained high water-repellence after immersion in 1 mol/L HCl (146°), 1 mol/L NaOH (144°) and 3.5 wt% NaCl (151°) solutions for 30 d. It should be noted that this superamphiphobic coating revealed excellent long-term corrosion protection with extremely low corrosion rate (4.3 × 10−3 μm/year) and high protection performance (99.999%) after 30 d immersion in 3.5 wt% NaCl solutions based on electrochemical corrosion measurements. It is believed that such integrated functional coating could pave new way for self-cleaning and anticorrosion applications under corrosive/abrasive environment.

Improvement of Interfacial Adhesion by Bio-Inspired Catechol-Functionalized Soy Protein with Versatile Reactivity: Preparation of Fully Utilizable Soy-Based Film.

The development of materials based on renewable resources with enhanced mechanical and physicochemical properties is hampered by the abundance of hydrophilic groups because of their structural instability. Bio-inspired from the strong adhesion ability of mussel proteins, renewable and robust soy-based composite films were fabricated from two soybean-derived industrial materials: soluble soybean polysaccharide (SSPS) and catechol-functionalized soy protein isolate (SPI-CH). The conjugation of SPI with multiple catechol moieties as a versatile adhesive component for SSPS matrix efficiently improved the interfacial adhesion between each segment of biopolymer. The biomimetic adherent catechol moieties were successfully bonded in the polymeric network based on catechol crosslinking chemistry through simple oxidative coupling and/or coordinative interaction. A combination of H-bonding, strong adhesion between the SPI-CH conjugation and SSPS matrix resulted in remarkable enhancements for mechanical properties. It was found that the tensile strength and Young’s modulus was improved from 2.80 and 17.24 MPa of unmodified SP film to 4.04 and 97.22 MPa of modified one, respectively. More importantly, the resultant films exhibited favorable water resistance and gas (water vapor) barrier performances. The results suggested that the promising way improved the phase adhesion of graft copolymers using catechol-functionalized polymers as versatile adhesive components.

Effect of polydopamine coating on improving photostability of polyphenylene sulfide fiber

The effect of polydopamine coating on improving photostability of polyphenylene sulfide (PPS) fiber was investigated in detail. Due to strong adhesion ability and self-polymerization of dopamine in alkaline solution, the polydopamine could be easily coated on polyphenylene sulfide fiber under mild conditions. XPS, ATR-FTIR and SEM, which indicated the polydopamine coating was homogeneous, confirmed the polydopamine coating on PPS fiber. The UV-spectra analysis of polydopamine coating showed that it had a strong absorbance in ultraviolet wavelength and was very stable to it, which implied that the polydopamine was a potential photoprotection agent. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) experiment further revealed that the PDA could quench free radicals, suggesting PDA was a good antioxidant. This scavenging ability of PDA might contribute to improving photostability of PPS fiber. Compared to pristine PPS fiber, the PPS fiber coated by polydopamine obviously had better photostability after ultraviolet irradiation according to mechanical test, which proved that polydopamine coating did improve the photostability of PPS fiber.

Single‐Molecule Force Spectroscopy Reveals Multiple Binding Modes between DOPA and Different Rutile Surfaces

Inspired by marine mussel adhesive systems, numerous 3,4-dihydroxyphenylalanine (DOPA)-containing surface coating materials have been recently designed. It is well known that DOPA has a strong adhesion ability to different kinds of wet surfaces. However, the molecular mechanism of DOPA adhesion remains elusive. Recent biophysical studies of DOPA adhesion by both surface force apparatus (SFA) and atomic force microscopy (AFM) suggest that DOPA can bind to a wide range of surfaces exhibiting diverse chemical properties through different binding mechanisms. Here, using AFM-based single-molecule force spectroscopy, we show that even for chemically well-defined crystal surfaces, DOPA can bind to them by multiple binding modes. The binding forces between DOPA and different rutile TiO2 surfaces can vary within a broad range from 40-800 pN at a pulling speed of 1000 nm s-1 and are largely dependent on the surface properties. Our findings indicate that the local chemical environment can greatly affect DOPA adhesion, and that single-molecule force spectroscopy is a unique tool to reveal the heterogeneity of DOPA adhesion to the same surface.

Superamphiphobic and Electroactive Nanocomposite toward Self-Cleaning, Antiwear, and Anticorrosion Coatings.

Multifunctional coatings are in urgent demand in emerging fields. In this work, nanocomposite coatings with extraordinary self-cleaning, antiwear, and anticorrosion properties were prepared on aluminum substrate by a facile spraying technique. Core-shell structured polyaniline/functionalized carbon nanotubes (PANI/fCNTs) composite and nanosized silica were synergistically integrated into ethylene tetrafluoroethylene (ETFE) matrix to construct lotus-leaf-like structures, and 1H,1H,2H,2H- perfluorooctyltriethoxysilane (POTS) was used to decrease the surface energy. The composite coating with 6 wt % PANI/fCNTs possesses superamphiphobic property, with contact angles of 167°, 163°, and 159° toward water, glycerol, and ethylene glycol, respectively. This coating demonstrates stable nonwetting performance over a wide temperature range (<400 °C), as well as outstanding self-cleaning ability to prevent contamination by sludge, concentrated H2SO4, and ethylene glycol. Superamphiphobic surface property could be maintained even after 45 000 times abrasion or bending test for 30 times. The coating displayed strong adhesive ability (grade 1 according to the GB/T9286) on the etched aluminum plate. The superamphiphobic surface could be retained after immersion in 1 mol/L HCl and 3.5 wt % NaCl solutions for 60 and 90 d, respectively. It should be noted that this coating reveals significantly improved anticorrosion performance as compared to the bare ETFE coating and ETFE composite coating without PANI/fCNTs. Such coatings with integrated functionalities offer promising self-cleaning and anticorrosion applications under erosive/abrasive environment.

Effect of polydopamine coating on improving photostability of poly(1,3,4-oxadiazole)s fiber

Effect of polydopamine coating on improving photostability of poly(1,3,4-oxadiazole)s (POD) fiber was studied in detail. Due to strong adhesion ability of polydopamine, the POD fiber could be coated easily by dopamine in Tris–HCl (pH = 8.5) solution at room temperature with exist of oxygen. The polydopamine coating was characterized by SEM, XPS and ATR-FTIR. It was proved by UV-spectra analysis that the polydopamine coating had a strong absorbance in ultraviolet wavelength and was very stable to ultraviolet. Additionally, it was found by pyrogallol autoxidation method that the polydopamine could efficiently capture superoxide anion radical, which was an important factor that resulted in photodegradation of POD fiber, due to its catechol structure. These two findings implied that polydopamine coating was a potential photoprotection agent. Finally, compared to POD fiber, the tensile test of POD fiber coated by polydopamine further proved that the polydopamine did improve the photostability of POD fiber. And the FTIR analysis of POD coated by polydopamine also confirmed that there was almost no macromolecular change after UV exposure.

Simple but Strong: A Mussel-Inspired Hot Curing Adhesive Based on Polyvinyl Alcohol Backbone.

The strong adhesion ability of mussel foot-byssal proteins (Mfps) has inspired scientists to develop novel materials for strong and reversible adhesion, coating, antifouling, and many other applications. However, in many cases, the high costs and the tedious preparation steps of such bioinspired materials hamper the process to push them into practical application. Here a simple but effective way (one step) is presented to synthesize a mussel-inspired glue from two cheap commercially available materials: polyvinyl alcohol (PVA) and 3,4-dihydroxybenzaldehyde (DBA). This bioinspired hot curing adhesive exhibits a strong bonding ability as high as 17.3 MPa on stainless steel surfaces, which surpasses most of the commercially available adhesives.

A functional binder–sulfonated poly(ether ether ketone) for sulfur cathode of Li–S batteries

Sulfonated poly(ether ether ketone) (SPEEK) with strong electronegativity and adhesion ability of S/C compounds was prepared by a homogeneous reaction as the binder for the sulfur cathode of Li–S batteries compared to the conventional polyvinylidene fluoride (PVDF) binder.

Effects of SOX2 on Proliferation, Migration and Adhesion of Human Dental Pulp Stem Cells.

As a key factor for cell pluripotent and self-renewing phenotypes, SOX2 has attracted scientists’ attention gradually in recent years. However, its exact effects in dental pulp stem cells (DPSCs) are still unclear. In this study, we mainly investigated whether SOX2 could affect some biological functions of DPSCs. DPSCs were isolated from the dental pulp of human impacted third molar. SOX2 overexpressing DPSCs (DPSCs-SOX2) were established through retroviral infection. The effect of SOX2 on cell proliferation, migration and adhesion ability was evaluated with CCK-8, trans-well system and fibronectin-induced cell attachment experiment respectively. Whole genome expression of DPSCs-SOX2 was analyzed with RNA microarray. Furthermore, a rescue experiment was performed with SOX2-siRNA in DPSC-SOX2 to confirm the effect of SOX2 overexpression in DPSCs. We found that SOX2 overexpression could result in the enhancement of cell proliferation, migration, and adhesion in DPSCs obviously. RNA microarray analysis indicated that some key genes in the signal pathways associated with cell cycle, migration and adhesion were upregulated in different degree, and the results were further confirmed with qPCR and western-blot. Finally, DPSC-SOX2 transfected with SOX2-siRNA showed a decrease of cell proliferation, migration and adhesion ability, which further confirmed the biological effect of SOX2 in human DPSCs. This study indicated that SOX2 could improve the cell proliferation, migration and adhesion ability of DPSCs through regulating gene expression about cell cycle, migration and adhesion, and provided a novel strategy to develop seed cells with strong proliferation, migration and adhesion ability for tissue engineering.

Enhanced electrochemical performance of sulfur cathodes with a water-soluble binder

The LA132 is a promising binder for Li–S batteries due to its strong adhesion ability and non-swellable property.

Promotion of cell adhesion by low-molecular-weight hydrogel by Lys based amphiphile.

Hydrogels formed by low-molecular hydrogelators have been used as anti-microbial agents and cell-attachment materials. However the biomedical application of low-molecular gelators is slowly progressing compared to the hydrogels formed by polymer hydrogelator that is applied to biomedical application such as tissue engineering and biomedical regions. To obtain a simple molecular model for potent and prospective usage of low-molecular hydrogelators, we designed a Lys-based hydrogelator which was mimic to the poly cationic poly-l-lysine that promotes cells to attach to a plastic plate nonspecifically. The gel-coating led to cause 10-fold cell attachment compared to no-coating well. Also five-time cells were attached to the well compared to the poly-l-lysine coating. From the competitive assay, these hydrogels could interact with cells through electrostatic interaction between positive charge from -NH3(+) in the hydrogelator and negative charge from substances on the cell surface such as glycosaminoglycans. This strong adhesive ability can be useful for the tissue engineering and molecular glue regions using low-molecular hydrogels in the future.

Multilayer encapsulated mesoporous silica nanospheres as an oral sustained drug delivery system for the poorly water-soluble drug felodipine.

We used a combination of mesoporous silica nanospheres (MSN) and layer-by-layer (LBL) self-assembly technology to establish a new oral sustained drug delivery system for the poorly water-soluble drug felodipine. Firstly, the model drug was loaded into MSN, and then the loaded MSN were repeatedly encapsulated by chitosan (CHI) and acacia (ACA) via LBL self-assembly method. The structural features of the samples were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen adsorption. The encapsulating process was monitored by zeta-potential and surface tension measurements. The physical state of the drug in the samples was characterized by differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). The influence of the multilayer with different number of layers on the drug release rate was studied using thermal gravimetric analysis (TGA) and surface tension measurement. The swelling effect and the structure changes of the multilayer were investigated to explore the relationship between the drug release behavior and the state of the multilayer under different pH conditions. The stability and mucosa adhesive ability of the prepared nanoparticles were also explored. After multilayer coating, the drug release rate was effectively controlled. The differences in drug release behavior under different pH conditions could be attributed to the different states of the multilayer. And the nanoparticles possessed good stability and strong mucosa adhesive ability. We believe that this combination offers a simple strategy for regulating the release rate of poorly water-soluble drugs and extends the pharmaceutical applications of inorganic materials and polymers.

Combination of a Novel Photosensitizer DTPP with 650 nm Laser Results in Efficient Apoptosis and Cytoskeleton Collapse in Breast Cancer MCF-7 Cells

Luminal A type breast cancer was suitable for Photodynamic therapy (PDT) as its strong adhesion ability, low malignancy and easily being exposed to laser. To examine the novel photosensitizer agent 5-5-(4-N, N-diacetoxylphenyl-10, 15, 20-tetraphenylporphyrin)(DTPP) mediate PDT in breast cancer cell, Luminal A type breast cancer MCF-7 cells were used in this study, various concentrations of DTPP (0, 2, 4, 6, 8, 10, 12, 15, 20, 25, 30 μg/mL) and different time intervals (0, 0.5, 1, 2, 4, 6, 8 min) of laser exposure at 650 nm wavelength (power of 20 mW) were tested in PDT. The survival rates of MCF-7 cells were measured using a sensitive cell proliferation assay (MTT) to establish optimal semilethal dose and optimal time exposure, a further study of effects on cytoskeleton and apoptosis were also performed. Cell cycle and apoptosis variation were assayed by flow cytometry. Microtubule, microfilament, and nuclei were observed using laser scanning confocal microscopy. Oncoproteins Bcl-2, beta-tubulin, and beta-catenin were detected by means of electrophoresis. The novel DTPP showed an efficient growth inhibition of MCF-7 during PDT, effective combinations in MCF-7 cells were shown to be 4 μg mL(-1) PS irradiated for 8 min at least or 15 μg mL(-1) irradiated for 2 min at least. Microtubule, microfilament, and nucleus staining demonstrated that cytoskeletal collapse occurs at 0.5 h after PDT. Bcl-2 and skeleton adhesion proteins beta-catenin were reduced in the level of expression; whereas, skeleton proteins beta-tubulin and actin maintained similar levels of expression 12 h after PDT. These results provided a better understanding of DTPP-PDT in MCF-7 cells.

Preparation and evaluation of heparin-immobilized poly (lactic acid) (PLA) membrane for hemodialysis

Bio-based poly (lactic acid) membrane with asymmetric porous structure was developed for hemodialysis via phase inversion for the first time. Heparin was immobilized to PLA membrane surface through the strong adhesion ability of dopamine, as confirmed by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) respectively. The morphologies variations of PLA membranes induced by dopamine coating and heparin immobilization were analyzed by scanning electron microscope (SEM) and atomic force microscopy (AFM). Hydrophilicity and permeability of PLA membranes before and after modification were characterized. Particularly, platelet adsorption, plasma recalcification time and hemolysis ratio were executed to evaluate the blood compatibility of PLA membranes decorated by heparin. The in vitro results demonstrated that surface heparinization improved the hemocompatibility of PLA membrane, suppressed the adhesion of platelet, extended plasma recalcilication time, and also decreased hemolysis ratio. The dialysis simulation experiments including urea and lysozyme clearance as well as bovine serum albumin (BSA) rejection were implemented to determine the dialysis performances. The results showed that 79% of urea and 18% of lysozyme were cleaned and over 90% of BSA was retained. This study disclosed a window of opportunity to produce novel hemodialysis membranes using bio-based materials.

New Japanese Yogurts Using Functional Probiotic Lactic Acid Bacteria and Future Strategies to Protect Human Gut

In Japan, milk and food companies have recently developed many functional yogurts using selected probiotic lactic acid bacteria (LAB) and Bifidobacterium strains. In 1991, the FOSHU (foods for specified health uses) system began instituted by the Ministry of Health, Labor and Welfare. In 2010, approximately 1,000 commercially available items were labeled as FOSHU products that are specially given brands showing good health effects for humans. Japanese commercial yogurts are classified into three type categories: fermented using selected probiotics, functional components added, and standard types. Many functions are considered in the selection of probiotics including competitive adhesion exclusion of enteritic pathogens, cholesterol lowering effects, and positive immuno-modulatory effects. Adhesion to the human intestine is one of the most important characteristics of probiotic LAB and bifidobacteria. Our new screening system for adhesive activity involves a combination of three methods: the rat colonic mucin-micro plate assay, the Carnoy’s histochemical staining method, and the carbohydrate probe binding assay. Recently, we developed a new screening assay using the BIACORE biosensor chip coated with human colon mucin (HCM). We found new LAB strains that recognize and specifically bind to the human ABO blood type antigens. We named these “blood type LAB”. We identified the molecular LAB binding mechanism occurring in the human intestine through unique adhesin molecules that are expressed on the bacterial cell surface as lectin-like proteins. Bacteria with strong adhesion ability improve gastrointestinal health by continuous proliferation in the intestine; and increase the chance of intake into the Peyer’s patches through M-cells that inhibit allergies because of LAB immune-stimulating activity. The future Japanese food market will contain superior functional yogurts containing adhesive effective probiotic LAB and bifidobacteria that are expected to be developed using our proposed mass screening system shown here.