Adhesion Potential Research Articles

Functionalized chitosan/spherical nanocellulose-based hydrogel with superior antibacterial efficiency for wound healing

Cellulose nanomaterials have received significant interest due to their superior physicochemical properties and biocompatibility. The nanomaterials-based hydrogel patches are widely explored for skin regeneration. However, the injectability and adhesiveness of the hydrogels are crucial challenges for tissue engineering applications. To overcome these, we synthesized an injectable and adhesive hydrogel of spherical nanocellulose (s-NC) reinforced carboxymethyl chitosan for rapid skin regeneration. The s-NC exhibited improved cellular activity than cellulose nanocrystals. The hydrogels exhibited adhesive and injectability potentials and were molded in the desired configurations. An enhanced conductivity was observed in s-NC added hydrogels than the pure polymer hydrogel. The skin regeneration potential of the hydrogel scaffolds was also examined in the rats using the wound healing model. The composite scaffolds also showed improved antibacterial potential. Taken together, the developed hydrogels have the potential and can be explored as a promising biomaterial for enhanced skin regeneration applications.

Erianin Controls Collagen-Mediated Retinal Angiogenesis via the RhoA/ROCK1 Signaling Pathway Induced by the alpha2/beta1 Integrin-Collagen Interaction.

PurposeErianin has been reported to inhibit tumor activity by suppressing the expression of integrins. It is hypothesized that erianin can inhibit retinal neovascularization in collagen by suppressing the expression of integrins. With an aim to test this hypothesis, the regulation of erianin on collagen-mediated retinal angiogenesis via the Ras homolog gene family member A (RhoA)/Rho-associated coiled-coil containing protein kinase 1 (ROCK1) signaling pathway induced by α2 and β1 integrin-collagen interactions was investigated.MethodsThe effects of erianin on human retinal vascular endothelial cells (HRVECs) were assessed in vitro using a hypoxia model in a three-dimensional cell culture induced by cobalt (II) chloride (CoCl2). A hypoxia-induced retinopathy model in adult zebrafish and zebrafish embryos was established to assess the antiangiogenic effect of erianin with and without vitreous collagen in vivo. The expression of α2 and β1 integrin and RhoA/ROCK1 pathway in HRVECs and zebrafish retinas were analyzed.ResultsIn vitro, collagen improved the angiogenic potential of HRVECs, including migration, adhesion, and tube formation, in a three-dimensional cell culture model. Erianin suppressed the angiogenic processes of the CoCl2-induced hypoxia HRVEC model in a concentration-dependent manner. In vivo, erianin reduced retinal angiogenesis in the hypoxia-induced retinopathy model in adult and embryo zebrafish. Erianin inhibited the expression of α2 and β1 integrin and RhoA/ROCK1 in a hypoxia-induced model in vitro in three-dimensional cell culture and in vivo in adult zebrafish.ConclusionsCollagen-mediated retinal angiogenesis may be regulated by erianin via the RhoA/ROCK1 signaling pathway induced by α2 and β1 integrin-collagen interactions. These findings suggest that erianin has the therapeutic potential on intraocular collagen-mediated retinal angiogenesis.

In Vitro Study of the Recruitment and Expansion of Mesenchymal Stem Cells at the Interface of a Cu-Doped PCL-Bioglass Scaffold.

Developing new barrier membranes with improved biomechanical characteristics has acquired much interest owing to their crucial role in the field of periodontal tissue regeneration. In this regard, we enriched the electrospun polycaprolactone (PCL)/gelatin (Gel) membranes by adding bioglass (BG) or Cu-doped bioglass (CuBG) and examined their cellular adhesion and proliferation potential in the presence of alveolar bone marrow-derived mesenchymal stem cells (aBMSCs). The membranes were fabricated and characterized using mechanical strength, SEM, FTIR, EDX, and ICP assay. Besides, aBMSCs were isolated, characterized, and seeded with a density of 35,000 cells in each experimental group. Next, the cellular morphology, cell adhesion capacity, proliferation rate, and membrane antibacterial activity were assessed. The results displayed a significant improvement in the wettability, pore size, and Young’s modulus of the PCL membrane following the incorporation of gelatin and CuBG particles. Moreover, all scaffolds exhibited reasonable biocompatibility and bioactivity in physiological conditions. Although the PCL/Gel/CuBG membrane revealed the lowest primary cell attachment, cells were grown properly and reached the confluent state after seven days. In conclusion, we found a reasonable level of attachment and proliferation of aBMSCs on all modified membranes. Meanwhile, a trace amount of Cu provided superiority for PCL/Gel/CuBG in periodontal tissue regeneration.

Bioconjugation Strategy for Ceramic Membranes Decorated with Candida Antarctica Lipase B-Impact of Immobilization Process on Material Features.

A strategy for the bioconjugation of the enzyme Candida antarctica lipase B onto titania ceramic membranes with varied pore sizes (15, 50, 150, and 300 kDa) was successfully performed. The relationship between the membrane morphology, i.e.,the pore size of the ceramic support, and bioconjugation performance was considered. Owing to the dimension of the enzyme (~33 kDa), the morphology of the ceramics allowed (50, 150, and 300 kDa) or did not allow (15 kDa) the entrance of the enzyme molecules into the porous structure. Such a strategy made it possible to better understand the changes in the material (morphology) and physicochemical features (wettability, adhesiveness, and surface charge) of the samples, which were systematically examined. The silane functionalization and enzyme immobilization were accomplished via the covalent route. The samples were characterized after each stage of the modification, which was very informative from the material point of view. As a consequence of the modification, significant changes in the contact angle, roughness, adhesion, and zeta potential were observed. For instance, for the 50 kDa membrane, the contact angle increased from 29.1 ± 1.5° for the pristine sample to 72.3 ± 1.5° after silane attachment; subsequently, it was reduced to 57.2 ± 1.5° after the enzyme immobilization. Finally, the contact angle of the bioconjugated membrane used in the enzymatic process rose to 92.9 ± 1.5°. By roughness (Sq) controlling, the following amendments were noticed: for the pristine 50 kDa membrane, Sq = 1.87 ± 0.21 µm; after silanization, Sq = 2.33 ± 0.30 µm; after enzyme immobilization, Sq = 2.74 ± 0.26 µm; and eventually, after the enzymatic process, Sq = 2.37 ± 0.27 µm. The adhesion work of the 50 kDa samples was equal to 136.41 ± 2.20 mN m−1 (pristine membrane), 94.93 ± 2.00 mN m−1 (with silane), 112.24 ± 1.90 mN m−1 (with silane and enzyme), and finally, 69.12 ± 1.40 mN m−1 (after the enzymatic process). The materials and physicochemical features changed substantially, particularly after the application of the membrane in the enzymatic process. Moreover, the impact of ceramic material morphology on the zeta potential value is here presented for the first time. With an increase in the ceramic support cut-off, the amount of immobilized lipase rose, but the specific productivity was higher for membranes possessing smaller pores, owing to the higher grafting density. For the enzymatic process, two modes of accomplishment were selected, i.e., stirred-tank and cross-flow. The latter method was characterized by a much higher effectiveness, with a resulting productivity equal to 99.7 and 60.3 µmol h−1 for the 300 and 15 kD membranes, respectively.

Mussel-inspired fabrication of superior superhydrophobic cellulose-based composite membrane for efficient oil emulsions separation, excellent anti-microbial property and simultaneous photocatalytic dye degradation

Flexible multiple functional cellulose-based membrane (CM) for oil/water separation, anti-microbial and photodegradation are in great demand in marine wastewater treatment due to its’ effective and ecologically benign. Based on this requirement, MnO2 micro/nanoparticles were in situ deposited on CM sample surface followed by decoration of stearic acid (STA) for very effective oil/water separation, anti-fouling, and dye photodegradation triggered by visible light. The results demonstrated that this as-prepared CM sample showed superhydrophobicity with a water contact angle of 162 ± 2° and superoleophilicity with an oil contact angle of 0°. It also demonstrated exceptional high stability in hostile environments (acid and alkali solution, high temperature, wear resistance, underwater writing, self-cleaning) and a 2.6% increase in tensile strength. In addition, it can successfully separate emulsified oils from typical oil-in-water emulsions with good separation efficiency all over 98% and comparatively high flux (145.8 L·m−2·h−1). After 8 cycles, the separation efficiency of the n-hexane/water emulsion is still over 98%. Moreover, over 98% of MB was degraded by using superhydrophobic CM sample, indicating strong photocatalytic activity. Meanwhile, in the maritime environment, this biomimetic sample decreased the adherence of green algae by more than 95%, demonstrating strong anti-biofouling adhesion potential. It indicates that this cost-effective, scalable, environmental friendly, and efficient methodology presented superhydrophobic CM sample has the potential to promote the widespread development of multipurpose superwetting materials, with enticing potential for the treatment of complex oily wastewater.

The effect of rigid cells on blood viscosity: linking rheology and sickle cell anemia.

Sickle cell anemia (SCA) is a disease that affects red blood cells (RBCs). Healthy RBCs are highly deformable objects that under flow can penetrate blood capillaries smaller than their typical size. In SCA there is an impaired deformability of some cells, which are much stiffer and with a different shape than healthy cells, and thereby affect regular blood flow. It is known that blood from patients with SCA has a higher viscosity than normal blood. However, it is unclear how the rigidity of cells is related to the viscosity of blood, in part because SCA patients are often treated with transfusions of variable amounts of normal RBCs and only a fraction of cells will be stiff. Here, we report systematic experimental measurements of the viscosity of a suspension varying the fraction of rigid particles within a suspension of healthy cells. We also perform systematic numerical simulations of a similar mixed suspension of soft RBCs, rigid particles, and their hydrodynamic interactions. Our results show that there is a rheological signature within blood viscosity to clearly identify the fraction of rigidified cells among healthy deformable cells down to a 5% volume fraction of rigidified cells. Although aggregation of RBCs is known to affect blood rheology at low shear rates, and our simulations mimic this effect via an adhesion potential, we show that such adhesion, or aggregation, is unlikely to provide a physical rationalization for the viscosity increase observed in the experiments at moderate shear rates due to rigidified cells. Through numerical simulations, we also highlight that most of the viscosity increase of the suspension is due to the rigidity of the particles rather than their sickled or spherical shape. Our results are relevant to better characterize SCA, provide useful insights relevant to rheological consequences of blood transfusions, and, more generally, extend to the rheology of mixed suspensions having particles with different rigidities, as well as offering possibilities for developments in the field of soft material composites.

Probiotic characterisation of Enterococcus faecalis strain isolated from a household dahi sample of Wayanad district, Kerala

Household dahi sample with good organoleptic properties from Wayanad district of Kerala was screened for lactic acid bacteria. Gram positive cocci exhibiting potential to ferment lactose was further characterised biochemically and later identified by 16srRNA sequencing as Enterococcus faecalis. The isolate was evaluated for its physiological and probiotic properties like temperature tolerance, salt tolerance and proteolytic activity. Probiotic properties like acid tolerance, bile tolerance, adhesion potential and antimicrobial activity against clinical isolate of E. coli were evaluated. Virulence based on haemolysis in blood agar was also done. The isolate was able to survive both 4o C and 45o C as well as salt concentration of 2 to 8 per cent. This remarkably proteolytic isolate was able to survive at pH 2 and 3 for 3 h and could tolerate bile concentration of 0.3 per cent for 3 h and 0.6 per cent for 1 h. Cell surface hydrophobicity was found to be 19.6 per cent and auto aggregation 80.39 per cent. The isolate could inhibit the growth of pathogenic E.coli by producing a zone of clearance of 19mm. Antibiogram revealed resistance to Ceftriaxone, Cefotaxime, Cefazolin and Vancomycin. The isolate produced alpha haemolysis in blood agar. Study revealed that detail biochemical and molecular level characterization is required for assessing probiotic potential of lactic acid bacteria from naturally fermented products.

An overview of different types and potential of bio-based adhesives used for wood products

Bio-based adhesives have shown promise in the engineered wood products industry, and there is a substantial growth of research on bio-based bonding agents. Wood is a renewable resource, and most of the engineered wood products are synthetic adhesive-bonded composites and laminates. Environmental concerns exist for the use of adhesives made from fossil fuels lowering the bio-content of the bonded wood products. Bio-based adhesives are getting more attention since they are environmentally friendly green products without any adverse effects on the environment. However, there is a remaining challenge for the industry to make them more effective than synthetic ones in terms of their mechanical properties and long-term durability. These adhesives, with different components such as cellulose, proteins, lignins, and tannins are adhesives which exhibit great potential for the bonding of specially engineered wood products. The modification of bio-based adhesives with different dispersing agents and cross-linkers can improve their strength and water resistance properties to compete with synthetic adhesives. The blending of proteins and carbohydrates can yield good bio-adhesives with acceptable adhesive properties. All these improvements of bio-based adhesives help us move towards ‘sustainable’ products where clean synthesis, biomass and water-based processing are highly desirable. Based on studies conducted in recent decades, the objective of this article is to review the production processes of adhesives from different bio-resources, their necessary modification for improving properties and their utilization in the wood-based industries. Finding the research gaps would also help to hasten the research activities for applying these bio-based adhesives at the industrial scale.

Comparative evaluation of incorporation calcium silicate and calcium phosphate nanoparticles on biomimetic dentin remineralization and bioactivity in an etch-and-rinse adhesive system.

This study aimed to evaluate the remineralization potential and bioactivity of adhesives, containing amorphous calcium phosphate (ACP) and calcium silicate (CS) nanoparticles (NPs). In this study, dentin slices (n=60) were prepared and etched with phosphoric acid. Next, they were divided into two groups: pre- and post-immersion in a simulated body fluid (SBF) for three weeks. The two groups were also divided into five subgroups (n=6 per subgroup), including the control (0 wt.% NPs); adhesives containing 1 wt.% and 2.5 wt.% (CS) nanoparticles; and adhesives containing 1 wt.% and 2.5 wt.% ACP nanoparticles. The remineralization potential and bioactivity of the adhesives were evaluated. The shear bond strength of the samples (n=18) was also assessed using a universal testing machine. The present results revealed that the adhesive containing ACP and CS nanoparticles showed bioactivity and remineralization potential without any reduction in the bond strength. The outcomes revealed that Cs and ACP nanoparticles induced mineralization in the dentin and incorporation of these nanoparticles to dentin bonding agents could improve the bio-functionalization of dentin bond. Key words:Calcium phosphate, calcium silicate, fourier transform infrared spectroscopy, scanning electron microscopy, tooth remineralization.

Bio-Inspired Gelatin-Based Adhesive Modified with Waterborne Polyurethane on Click Chemistry

As a non-toxic, highly reactive biomass material, gelatin is wildly used as the component of biomass-based adhesive. However, like most aqueous adhesives, gelatin-based adhesives suffer from long solidifying time or high solidifying temperature due to the low volatility of water, which highly limits the application potential of gelatinbased adhesives. Inspired by the fast adhesion of marine organisms through the formation of chemical crosslinks, herein, a kind of low temperature curable eco-friendly gelatin-based adhesive with good adhesive properties and fast curing at low temperature is developed by introducing clicking chemical Diels-Alder (DA) reaction between blocked waterborne polyurethane (MWPU) and gelatin. The furfuryl glycidyl ether (FGE) and 4-Maleimidophenol (4-HPM) for the DA reaction are grafted on gelatin, and the end-capping of MWPU, respectively. With the addition of MWPU and FGE, the cross-linking degree of gelatin increased, and the adhesion properties of the adhesive were improved. The shear strength and T-peel strength of the modified adhesive reached 0.95 MPa and 1.42 N/mm, respectively, after the curing time of 8 min at 40°C, which can meet the application requirements as adhesive for bio-medical use.

In Vitro Probiotic Characteristics and Whole Genome Sequence Analysis of Lactobacillus Strains Isolated from Cattle-Yak Milk.

Simple SummaryCattle-yak milk is rich in numerous bioactive substances that function beyond their nutritive value. Given the high content of conjugated linoleic acid (CLA), this exponent suggests a potential role for cattle-yak milk in preventing cancer, heart disease, and metabolic disorders, such as diabetes. It is expected to isolate probiotic strains with natural and excellent characteristics in optimizing human health. However, little research data and much fewer studies on probiotics from cattle-yak milk are reported. Therefore, in the present study, the beneficial strains from cattle-yak milk were identified to evaluate probiotic characteristics of potential strains, and to screen potential probiotics with an emphasis on making better use of milk in such extreme climatic environments. These findings support the potential application of cattle-yak milk in human health, animal food processing, and drug production in the future as a potential candidate for probiotics.Cattle-yak milk is an important raw material and an indispensable source of high-quality food for local farmers and herdsmen to produce ghee, milk residue, yogurt, and other dairy products. In this study, Lactobacillus strains were isolated from cattle-yak milk for potential probiotic candidates using a series of in vitro tests, including probiotic characterization and safety evaluation (antibiotic susceptibility and hemolytic ability). The results found that the Lactobacillus rhamnosus CY12 strain showed a high survival rate in bile salts, under acid conditions, and in the gastrointestinal juice environment, as well as showing high antimicrobial activity and adhesive potential. The safety evaluation showed that all strains were considered non-hemolytic. In addition, the whole-genome sequencing indicated that the strain CY12 spanned 2,506,167 bp, with an average length of 881 bp; the GC content in the gene region (%) was 47.35, contained 1347 protein-coding sequences, and accounted for 85.72% of the genome. The genome annotation showed that genes mainly focused on the immune system process, metabolic process, carbohydrate utilization, carbon metabolism, galactose metabolism, and biological adhesion, etc. This study revealed that the Lactobacillus rhamnosus CY12 strain might be an excellent potential probiotic in the development of feed additives for animals and has the ability to promote health.

Bioinspired polydopamine deposition and silane grafting modification of bamboo fiber for improved interface compatibility of poly (lactic acid) composites

The surface of bamboo fiber (BF) has poor interface compatibility with the surface of the poly (lactic acid) (PLA), which compromises composite performance. In this study, a bioinspired polydopamine (PDA) function coating was constructed on a BF surface to act as a bridge to introduce an epoxy-functionalized silane layer (KH560). The results of the test confirmed that KH560 was successfully grafted onto the surface of the BF. Therefore, the flexural, tensile, and impact strength of the modified composites increased by 37.22%, 49.64%, and 26.66%, respectively, compared with that of the untreated composites. Furthermore, the PDA-KH560-modified BF enhanced the PLA composites’ thermal stability. This strategy is assumed to provide a simple and green method for improving interface adhesion strength and potentials for future manufacturing of high-performance composites.

Peritoneal endometriosis and infertility

Peritoneal endometriosis and infertility in most of patients (in 80%) are pathogenetically conjugated. Both peritoneal endometriosis and infertility are based in ovarian failure. These women have a low endometrial receptivity for blastocysts implantation (retardation development of glands, vessels, and stroma; changes in the microrelief of the epithelium). Even at the beginning of the menstruation patients with peritoneal endometriosis and infertility have cells with a great adhesive and proliferative potential in the endometrium. This kind of cells have an ability for long autonomous existence. Ovarian failure in these women is a promotion factor for development of the retrograde menstruation. In these conditions the endometrial cells with adhesive potential are frequently bringing in the abdominal cavity. Active endometrium heterotopias support the ovarian failure and create conditions for uterine infertility (implantation disorders).

Characteristics of surface layer protein from Lactobacillus kefiri HBA20 and the role in mediating interactions with Saccharomyces cerevisiae Y8

In this study, the surface layer protein (SLP) from Lactobacillus kefiri HBA20 was characterized. The SLP was extracted by 5M LiCl. The molecular mass of the SLP was approximately 64 kDa as analyzed via SDS-PAGE. The surface morphology and the adhesion potential of L. kefiri HBA20 in the absence and presence of SLP were measured by AFM. Moreover, the protein secondary structure was evaluated by using circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR), respectively. SLP had high β-sheet contents and low content of α-helix. Thermal analysis of SLP of Lactobacillus kefiri HBA20 exhibited one transition peak at 129.64 °C. Furthermore, SEM measurements were showed that after the SLP were removed from the cell surface, the coaggregation ability with Saccharomyces cerevisiae Y8 of the strain was significantly reduced. In conclusion, the SLP of Lactobacillus kefiri HBA20 has a stable structure and the ability of adhesion to yeast. Molecular docking study revealed that mannan bind with the hydrophobic residues of SLP. Our results will help further understanding of the new surface layer protein and the interaction between L. kefiri and S. cerevisiae.

Degradation Behaviors of Two Epoxy Coatings After Dry/Wet-Accelerated Fog Exposure of Different Solutions

Applying organic coating is an important and effective approach for the protection of metal from corrosion. Weathering degradation and under-film corrosion are the two major important factors that cause the failure of organic coatings. In this work, the degradation investigation of two epoxy coatings (clear and pigmented coatings) was carried out under the dry–wet circulation of three different water fog solutions (deionized water, 0.5 wt% NaCl, 0.05 wt% NaCl + 0.35 wt% (NH4)2SO4) in 35 days. The apparent performance (pull-off adhesion and surface potentials) and electrochemical features [electrochemical noise and electrochemical impedance spectroscopy (EIS)] of the coating samples were monitored after dry–wet fog exposure. In our three accelerating systems of the fog atmosphere, the time that the detectable defects appeared on the surface of coating samples was far ahead in the mixed salt solution than that in the deionized water or 0.5 wt% NaCl solution. For a defective or damaged coating surface, the derived results by using the standard deviation method (SDM) or Fourier power spectrum (FPS) were rather higher than those obtained from EIS as a whole, while for the same coating, the degradation trend with time derived from EIS, SDM, FPS, and scanning Kelvin probe was consistent with each other.

Dental Composite Restorations Repair: A Systematic Review and Meta-analysis

Background: Controversy exists in the literature regarding the most optimal repair procedure for improving the adhesion between the repair resin and the existing resin composite materials. Hence the aim of the present study was to do a systematic review and to analyze the adhesion potential of resin-based composites to similar and dissimilar composites and aimed to determine the possible dominant factors affecting the bond strength results.
 Materials & Methods: Randomized clinical trials (RCTs) and prospective cohort design were searched through electronic databases including MEDLINE, PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for randomized clinical trials (RCTs) until July 2020 that compared different methods of composite restoration repair and a minimum mean follow-up time of 1 year. There were no restrictions on a particular treatment indication or outcome measures. Two authors independently conducted screening, risk of bias assessment, and data extraction of eligible trials in duplicate. We applied the Cochrane risk of bias assessment tool to consider the risk of bias.
 Results: We identified 10 articles; two of them were RCTs, and eight prospective cohort studies. There were 530 participants, with 990 teeth, dealing with resin-based composite (RBC) restorations. The intervention of defective restorations ranged from minimal intervention to total restoration replacement. The evaluation criteria were also varied with different evaluation protocols. The low number and heterogeneity of RCTs did not allow for meta-analyses.
 Conclusions: Although different repair protocols are mentioned in the literature according to the included studies, an appropriate and definitive conclusion can't be drawn. However, it seems repairs versus replacements should be considered as the first line of treatment when all factors lead to repair rather than replacement. Further randomized controlled trials with high methodological quality need to be conducted in order to establish evidence-based recommendations, particularly for RBC repair.

Chlorine-resistant bacteria (CRB) in the reverse osmosis system for wastewater reclamation: Isolation, identification and membrane fouling mechanisms

Chlorine disinfection is often used as a pretreatment technology to control biofouling of reverse osmosis (RO) membranes. However, previous studies showed that biofouling of the RO system was aggravated after chlorine disinfection. Chlorine-resistant bacteria (CRB) were presumed to be closely related to the aggravation of fouling caused by chlorine disinfection. In order to analyze the membrane fouling mechanisms of CRB, 5 CRB strains were isolated from the surface of fouled RO membranes for wastewater reclamation, and 3 reference bacterial strains, Sphingopyxis soli BM1–1, Pseudomonas aeruginosa PAO1 and Escherichia coli CGMCC1.3373, were selected for comparative study. The chlorine resistance, membrane fouling potential, secretion and adhesion characteristics of these strains were evaluated. Among these isolated strains, 3 strains showed much higher chlorine resistance than PAO1 under the condition of 0.5, 2, 5 mg/L-Cl2, especially Bacillus CR19 and Bacillus CR2. Furthermore, a significant positive correlation was found between membrane fouling potential and chlorine resistance of all the strains in this study. The membrane fouling potential of the above 8 strains increased monotonically with the increase of chlorine resistance (under the condition of 0.5 mg/L-Cl2). Serious fouling caused by extracellular substances was observed in biofouling layers of the strains with high chlorine resistance, which lead to more severe flux decline. Extracellular polymeric substances (EPS) amount per cell was found to be the main factor related to the chlorine resistance as well as the fouling potential. Computational fluid dynamics (CFD) simulation was used to demonstrate the filtration resistance induced by the secretion of EPS. However, CRB with higher EPS amount may not show higher membrane adhesion potential, and thus may not be the dominant strain on the RO membranes before chlorine disinfection. These CRB with high fouling potential but low membrane adhesion potential, such as Bacillus CR19 and Bacillus CR2, may become the dominant bacteria on the membrane surface after chlorine disinfection and thus aggravate membrane fouling significantly.

Evaluation of the Adhesive Potential of Bacteria Isolated from Meat-Related Sources

Microbial adhesion constitutes the transition of microorganisms from a planktonic mode to a static one. It promotes the formation of biofilm which is responsible for spoilage, foodborne diseases, and corrosion in the food processing industry. In this study, the adhesive potential of fourteen meat-borne bacterial isolates belonging to seven different genera was investigated. All strains were found able to colonize polystyrene surfaces with different levels of firmness. Significant variations were determined in assays of bacterial hydrophobicity and motility. Among the 14 strains, Pseudomonas fragi, Aeromonas salmonicida II, Serratia liquefaciens, Citrobacter braakii, Pseudomonas putida, and Aeromonas veronii had a strong hydrophobic force, while the isolates of Lactobacillus genus showed the most hydrophilic property. In terms of motility, Citrobacter braakii and Escherichia coli exhibited exceptional swarming and swimming abilities, whilst conservatively weak performances were observed in the Lactobacillus strains. Furthermore, the majority of the isolates were predominantly electron donors and weak electron acceptors. Overall, a high level of correlation was observed between biofilm-forming ability with cell surface hydrophobicity and Lewis acid–base properties, whereas the contribution of motility in bacterial adhesion could not be confirmed. Research on the adhesive performance of foodborne bacteria is potentially conducive to developing novel control strategies, such as food processing equipment with specific surfaces, not facilitating attachment.

Surface-initiated ring-opening polymerization of ɛ-caprolactone as a feasible approach to modify flax yarn

Surface-initiated ring-opening (SI-ROP) polymerization of ɛ-caprolactone is known as possible modification method to increase the hydrophobicity of cellulosic substrates. In this study SI-ROP of ɛ-caprolactone is applied on native and mercerized flax yarn. By use of triazabicyclodecene as catalyst, SI-ROP at room temperature was possible and poly-ɛ-caprolactone (PCL) was linked with a weight content of 4–10% to flax yarns. Besides a lower hydrophilicity an increased surface energy was achieved for PCL modified flax yarn. Furthermore, the positive effect of PCL linkage on the fibers surface regarding adhesion potential to an epoxy matrix was shown via conducting fiber-pull-out tests. After SI-ROP of ɛ-caprolactone on flax fiber surface a reduction of fiber pull-out up to 33% was achieved, evoked by physical improvement e.g. better wettability of fiber with epoxy matrix as well as enhanced crosslinking between the hydroxyl groups of the surface grafted PCL and the epoxy resin.

Fabrication of Mesoporous Silica Nanoparticle-Incorporated Coaxial Nanofiber for Evaluating the In Vitro Osteogenic Potential.

The most important role of tissue engineering is to develop a biomaterial with a property that mimics the extracellular matrix (ECM) by enhancing the lineage-specific proliferation and differentiation with favorable regeneration property to aid in new tissue formation. Thus, to develop an ideal scaffold for bone repair, we have fabricated a composite nanofiber by the coaxial electrospinning technique. The coaxial electrospun nanofiber contains the core layer, consisting of polyvinyl alcohol (PVA) blended with oregano extract and mesoporous silica nanoparticles (PVA-OE-MSNPs), and the shell layer, consisting of poly-ε-caprolactone blended with collagen and hydroxyapatite (PCL-collagen-HAP). We evaluated the physicochemical properties of the nanofibers using X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). In vitro biocompatibility, cell adhesion, cell viability, and osteogenic potential were evaluated by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenlytetrazolium bromide (MTT), calcein AM, and alkaline phosphatase (ALP) activity and Alizarin Red staining in NIH 3T3/MG-63 cells. The results showed that the nanoparticle-incorporated coaxial nanofiber was observed with bead-free, continuous, and uniform fiber morphology with a mean diameter in the range of 310 ± 125nm. From the biochemical studies, it is observed that the incorporation of nanofiber with HAP and MSNPs shows good swelling property with ideal porosity, biodegradation, and enhanced biomineralization property. In vitro results showed that the scaffolds with nanoparticles have higher cell adhesion, cell viability, ALP activity, and mineralization potential. Thus, the fabricated nanofiber could be an appropriate implantable biomaterial for bone tissue engineering.