1
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Bai G, Niu C, Liang X, Li L, Wei Z, Chen K, Bohinc K, Guo X. Dextran-based antibacterial hydrogel-derived fluorescent sensors for the visual monitoring of AgNPs. Int J Biol Macromol 2024; 267:131288. [PMID: 38565365 DOI: 10.1016/j.ijbiomac.2024.131288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/16/2024] [Accepted: 03/29/2024] [Indexed: 04/04/2024]
Abstract
The unpredictable release behavior of metal nanoparticles/metal ions from metal nanoparticle-loaded hydrogels, without a suitable in situ detection method, is resulting in serious cytotoxicity. To optimize the preparation and design of antibacterial hydrogels for in situ detection of metal nanoparticles, an in-situ detection platform based on the fluorescence signal change caused by the potential surface energy transfer of silver nanoparticles (AgNPs) and carbon dots (CD) through silver mirror reaction and Schiff base reaction was established. The antimicrobial test results show that the composite antimicrobial hydrogel, with lower dosages of AgNPs and CD, exhibited a higher inhibition rate of 99.1 % against E. coli and 99.8 % against S. aureus compared to the single antimicrobial component. This suggests a potential synergistic antimicrobial activity. Furthermore, the fluorescence detection platform was established with a difference of <3 μg between detected values and actual values over a period of 72 h. This demonstrates the excellent in situ detection capability of the hydrogel in antimicrobial-related applications.
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Affiliation(s)
- Ge Bai
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China
| | - Chunhua Niu
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China
| | - Xuexue Liang
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China
| | - Lan Li
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China
| | - Zhong Wei
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China
| | - Kai Chen
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China.
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
| | - Xuhong Guo
- State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, PR China; State Key Laboratory of Chemical Engineering and International Joint Research Center of Green Energy Chemical Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
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2
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Matijaković Mlinarić N, Wawrzaszek B, Kowalska K, Selmani A, Učakar A, Vidmar J, Kušter M, Van de Velde N, Trebše P, Sever Škapin A, Jerman I, Abram A, Zore A, Roblegg E, Bohinc K. Poly(Allylamine Hydrochloride) and ZnO Nanohybrid Coating for the Development of Hydrophobic, Antibacterial, and Biocompatible Textiles. Nanomaterials (Basel) 2024; 14:570. [PMID: 38607105 PMCID: PMC11013899 DOI: 10.3390/nano14070570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/13/2024]
Abstract
In healthcare facilities, infections caused by Staphylococcus aureus (S. aureus) from textile materials are a cause for concern, and nanomaterials are one of the solutions; however, their impact on safety and biocompatibility with the human body must not be neglected. This study aimed to develop a novel multilayer coating with poly(allylamine hydrochloride) (PAH) and immobilized ZnO nanoparticles (ZnO NPs) to make efficient antibacterial and biocompatible cotton, polyester, and nylon textiles. For this purpose, the coated textiles were characterized with profilometry, contact angles, and electrokinetic analyzer measurements. The ZnO NPs on the textiles were analyzed by scanning electron microscopy and inductively coupled plasma mass spectrometry. The antibacterial tests were conducted with S. aureus and biocompatibility with immortalized human keratinocyte cells. The results demonstrated successful PAH/ZnO coating formation on the textiles, demonstrating weak hydrophobic properties. Furthermore, PAH multilayers caused complete ZnO NP immobilization on the coated textiles. All coated textiles showed strong growth inhibition (2-3-log reduction) in planktonic and adhered S. aureus cells. The bacterial viability was reduced by more than 99%. Cotton, due to its better ZnO NP adherence, demonstrated a slightly higher antibacterial performance than polyester and nylon. The coating procedure enables the binding of ZnO NPs in an amount (<30 µg cm-2) that, after complete dissolution, is significantly below the concentration causing cytotoxicity (10 µg mL-1).
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Affiliation(s)
- Nives Matijaković Mlinarić
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena Pot 5, 1000 Ljubljana, Slovenia; (N.M.M.); (P.T.); (A.Z.)
| | - Barbara Wawrzaszek
- Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, Pl. Maria Curie-Skłodowska 3, 20-031 Lublin, Poland; (B.W.); (K.K.)
| | - Klaudia Kowalska
- Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, Pl. Maria Curie-Skłodowska 3, 20-031 Lublin, Poland; (B.W.); (K.K.)
| | - Atiđa Selmani
- Pharmaceutical Technology and Biopharmacy, Institute of Pharmaceutical Sciences, University of Graz, Universitätsplatz 1, 8010 Graz, Austria; (A.S.); (E.R.)
| | - Aleksander Učakar
- Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (A.U.); (J.V.); (M.K.); (A.A.)
| | - Janja Vidmar
- Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (A.U.); (J.V.); (M.K.); (A.A.)
| | - Monika Kušter
- Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (A.U.); (J.V.); (M.K.); (A.A.)
| | - Nigel Van de Velde
- National Institute of Chemistry, Hajdrihova Ulica 19, 1000 Ljubljana, Slovenia; (N.V.d.V.); (I.J.)
| | - Polonca Trebše
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena Pot 5, 1000 Ljubljana, Slovenia; (N.M.M.); (P.T.); (A.Z.)
| | - Andrijana Sever Škapin
- Slovenian National Building and Civil Engineering Institute, Dimčeva Ulica 12, 1000 Ljubljana, Slovenia;
- Faculty of Polymer Technology—FTPO, Ozare 19, 2380 Slovenj Gradec, Slovenia
| | - Ivan Jerman
- National Institute of Chemistry, Hajdrihova Ulica 19, 1000 Ljubljana, Slovenia; (N.V.d.V.); (I.J.)
| | - Anže Abram
- Jožef Stefan Institute, Jamova Cesta 39, 1000 Ljubljana, Slovenia; (A.U.); (J.V.); (M.K.); (A.A.)
| | - Anamarija Zore
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena Pot 5, 1000 Ljubljana, Slovenia; (N.M.M.); (P.T.); (A.Z.)
| | - Eva Roblegg
- Pharmaceutical Technology and Biopharmacy, Institute of Pharmaceutical Sciences, University of Graz, Universitätsplatz 1, 8010 Graz, Austria; (A.S.); (E.R.)
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena Pot 5, 1000 Ljubljana, Slovenia; (N.M.M.); (P.T.); (A.Z.)
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3
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Najmi Z, Mlinarić NM, Scalia AC, Cochis A, Selmani A, Učakar A, Abram A, Zore A, Delač I, Jerman I, Van de Velde N, Vidmar J, Bohinc K, Rimondini L. Antibacterial evaluation of different prosthetic liner textiles coated by CuO nanoparticles. Heliyon 2024; 10:e23849. [PMID: 38192822 PMCID: PMC10772625 DOI: 10.1016/j.heliyon.2023.e23849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 12/03/2023] [Accepted: 12/13/2023] [Indexed: 01/10/2024] Open
Abstract
Prosthetic liners are mainly used as an interface between residual limbs and prosthetic sockets to minimize physical and biological damage to soft tissue. However, the closed and moist conditions within liners and the amputee's skin provide a suitable environment for bacterial growth to cause infections. This study aimed to coat a comprehensive variant material with copper oxide nanoparticles (CuO NPs) and compare their surface analysis and antibacterial properties. These materials were covered with CuO NPs solution at a concentration of 70 μg mL-1 to achieve this purpose. After drying, their surface characteristics were analyzed by measuring zeta potential, contact angle, surface roughness, and fiber arrangement. Cu-released concentration from the coatings into the acetate buffer solution by inductively coupled plasma mass spectrometry indicated that lycra and nylon quickly released Cu ions to concentrations up to ∼0.2 μg mL-1 after 24 h, causing low metabolic activity of human bone-marrow mesenchymal stem cells (bMSC) in the indirect assay. Antibacterial activity of the coated specimens was evaluated by infecting their surfaces with the Gram-positive bacteria Staphylococcus epidermidis, reporting a significant ∼40 % reduction of metabolic activity for x-dry after 24 h; in addition, the number of viable bacterial colonies adhered to the surface of this material was reduced by ∼23 times in comparison with non-treated x-dry that were visually confirmed by scanning electron microscope. In conclusion, CuO NPs x-dry shows optimistic results to pursue further experiments due to its slow speed of Cu release and prolonged antibacterial activity, as well as its compatibility with human cells.
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Affiliation(s)
- Ziba Najmi
- Department of Health Sciences, Center for Translational Research on Autoimmune and Allergic Diseases-CAAD, Università Del Piemonte Orientale UPO, Corso Trieste 15/A, 28100, Novara, NO, Italy
| | | | - Alessandro Calogero Scalia
- Department of Health Sciences, Center for Translational Research on Autoimmune and Allergic Diseases-CAAD, Università Del Piemonte Orientale UPO, Corso Trieste 15/A, 28100, Novara, NO, Italy
| | - Andrea Cochis
- Department of Health Sciences, Center for Translational Research on Autoimmune and Allergic Diseases-CAAD, Università Del Piemonte Orientale UPO, Corso Trieste 15/A, 28100, Novara, NO, Italy
| | - Atiđa Selmani
- Pharmaceutical Technology and Biopharmacy, Institute of Pharmaceutical Sciences, University of Graz, Universitätsplatz 1, 8010, Graz, Austria
| | | | - Anže Abram
- Institut Jožef Stefan, Jamova Cesta 39, 1000, Ljubljana, Slovenia
| | - Anamarija Zore
- University of Ljubljana, Zdravstvena Pot, 1000, Ljubljana, Slovenia
| | - Ida Delač
- Institute of Physics, Bijenička Cesta 46, 10000, Zagreb, Croatia
| | - Ivan Jerman
- National Institute of Chemistry, Hajdrihova Ulica 19, 1000, Ljubljana, Slovenia
| | - Nigel Van de Velde
- National Institute of Chemistry, Hajdrihova Ulica 19, 1000, Ljubljana, Slovenia
| | - Janja Vidmar
- Department of Environmental Sciences, Jožef Stefan Institute, Jamova Cesta 39, 1000, Ljubljana, Slovenia
| | - Klemen Bohinc
- University of Ljubljana, Zdravstvena Pot, 1000, Ljubljana, Slovenia
| | - Lia Rimondini
- Department of Health Sciences, Center for Translational Research on Autoimmune and Allergic Diseases-CAAD, Università Del Piemonte Orientale UPO, Corso Trieste 15/A, 28100, Novara, NO, Italy
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4
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Selmani A, Siboulet B, Špadina M, Foucaud Y, Dražić G, Radatović B, Korade K, Nemet I, Kovačević D, Dufrêche JF, Bohinc K. Cation Adsorption in TiO 2 Nanotubes: Implication for Water Decontamination. ACS Appl Nano Mater 2023; 6:12711-12725. [PMID: 37533543 PMCID: PMC10391741 DOI: 10.1021/acsanm.3c00916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/13/2023] [Indexed: 08/04/2023]
Abstract
TiO2 nanotubes constitute very promising nanomaterials for water decontamination by the removal of cations. We combined a range of experimental techniques from structural analyses to measurements of the properties of aqueous suspensions of nanotubes, with (i) continuous solvent modeling and (ii) quantum DFT-based simulations to assess the adsorption of Cs+ on TiO2 nanotubes and to predict the separation of metal ions. The methodology is set to be operable under realistic conditions, which, in this case, include the presence of CO2 that needs to be treated as a substantial contaminant, both in experiments and in models. The mesoscopic model, based on the Poisson-Boltzmann equation and surface adsorption equilibrium, predicts that H+ ions are the charge-determining species, while Cs+ ions are in the diffuse layer of the outer surface with a significant contribution only at high concentrations and high pH. The effect of the size of nanotubes in terms of the polydispersity and the distribution of the inner and outer radii is shown to be a third-order effect that is very small when the nanotube layer is not very thick (ranging from 1 to 2 nm). Besides, DFT-based molecular dynamics simulations demonstrate that, for protonation, the one-site and successive association assumption is correct, while, for Cs+ adsorption, the size of the cation is important and the adsorption sites should be carefully defined.
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Affiliation(s)
- Atiđa Selmani
- Division
of Physical Chemistry, Ruđer Bošković
Institute, Bijenička
Cesta 54, 10000 Zagreb, Croatia
- Pharmaceutical
Technology & Biopharmacy, Institute
of Pharmaceutical Sciences, University of Graz, A-8010, Graz, Austria
| | - Bertrand Siboulet
- ICSM,
Université Montpellier, CEA, CNRS, ENSCM, 30207 Bagnols-sur-Ceze, France
| | - Mario Špadina
- Division
of Physical Chemistry, Ruđer Bošković
Institute, Bijenička
Cesta 54, 10000 Zagreb, Croatia
- Faculty
of Health Sciences, University of Ljubljana, Zdravstvena 5, SI-1000 Ljubljana, Slovenia
| | - Yann Foucaud
- ICSM,
Université Montpellier, CEA, CNRS, ENSCM, 30207 Bagnols-sur-Ceze, France
| | - Goran Dražić
- Laboratory
for Materials Chemistry, National Institute
of Chemistry, Hajdrihova ulica 19, SI-1000 Ljubljana, Slovenia
| | | | - Karla Korade
- Faculty of
Science, University of Zagreb, Horvatovac 102A, 10 000 Zagreb, Croatia
| | - Ivan Nemet
- Faculty of
Science, University of Zagreb, Horvatovac 102A, 10 000 Zagreb, Croatia
| | - Davor Kovačević
- Faculty of
Science, University of Zagreb, Horvatovac 102A, 10 000 Zagreb, Croatia
| | | | - Klemen Bohinc
- Faculty
of Health Sciences, University of Ljubljana, Zdravstvena 5, SI-1000 Ljubljana, Slovenia
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5
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Marić I, Zore A, Rojko F, Škapin AS, Štukelj R, Učakar A, Vidrih R, Veselinović V, Gotić M, Bohinc K. Antifungal Effect of Polymethyl Methacrylate Resin Base with Embedded Au Nanoparticles. Nanomaterials (Basel) 2023; 13:2128. [PMID: 37513139 PMCID: PMC10383817 DOI: 10.3390/nano13142128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 07/11/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023]
Abstract
Full and partial restorations in dentistry must replicate the characteristics of the patient's natural teeth. Materials must have good mechanical properties and be non-toxic and biocompatible. Microbes, which can form biofilms, are constantly in contact with restorations. In this study, we investigate how well Candida albicans adheres to a polymethyl methacrylate (PMMA) resin base with gold (Au) nanoparticles. We synthesized Au nanoparticles and characterized them. The average size of Au nanoparticles embedded in PMMA was 11 nm. The color difference ΔE between PMMA and PMMA/Au composites was 2.7 and was still esthetically acceptable to patients. PMMA/Au surfaces are smoother and more hydrophilic than pure PMMA surfaces, and the isoelectric point of both types of surfaces was 4.3. Above the isoelectric point, PMMA/Au surfaces are more negatively charged than PMMA surfaces. The added Au nanoparticles decreased the tensile strength, while the hardness did not change significantly. Adhesion measurements showed that PMMA surfaces modified with Au nanoparticles reduced the extent of microbial adhesion of Candida albicans.
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Affiliation(s)
- Ivan Marić
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
- Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Anamarija Zore
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Franc Rojko
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Andrijana Sever Škapin
- Slovenian National Building and Civil Engineering Institute, 1000 Ljubljana, Slovenia
- Faculty of Polymer Technology-FTPO, Ozare 19, 2380 Slovenj Gradec, Slovenia
| | - Roman Štukelj
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
| | | | - Rajko Vidrih
- Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Valentina Veselinović
- Faculty of Medicine, University of Banja Luka, 78000 Banja Luka, Bosnia and Herzegovina
| | | | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
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6
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Higuchi Y, Bohinc K, Reščič J, Shimokawa N, Ito H. Coarse-grained molecular dynamics simulation of cation distribution profiles on negatively charged lipid membranes during phase separation. Soft Matter 2023; 19:3640-3651. [PMID: 37162535 DOI: 10.1039/d3sm00222e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Revealing the ion distributions on a charged lipid membrane in aqueous solution under the influence of long-range interactions is essential for understanding the origin of the stability of the bilayer structure and the interaction between biomembranes and various electrolytes. However, the ion distributions and their dynamics associated with the phase separation process of the lipid bilayer membrane are still unclear. We perform coarse-grained molecular dynamics simulations to reveal the Na+ and Cl- distributions on charged phospholipid bilayer membranes during phase separation. During the phase separation, cations closely follow the position of negatively charged lipids on a microsecond timescale and are rapidly redistributed parallel to the lipid bilayer. In the homogenous mixture of zwitterionic and negatively charged lipids, cations weakly follow negatively charged lipids, indicating the strong interaction between cations and negatively charged lipids. We also compare cation concentrations as a function of surface charge density obtained by our simulation with those obtained by a modified Poisson-Boltzmann theory. Including the ion finite size makes the statistical results consistent, suggesting the importance of the ion-ion interactions in aqueous solution. Our simulation results advance our understanding of ion distribution during phase separation.
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Affiliation(s)
- Yuji Higuchi
- Research Institute for Information Technology, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena 5, SI 1000 Ljubljana, Slovenia
| | - Jurij Reščič
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Vecna pot 113, 1000 Ljubljana, Slovenia
| | - Naofumi Shimokawa
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Hiroaki Ito
- Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
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7
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Klačić T, Bohinc K, Kovačević D. Suppressing the Hofmeister Anion Effect by Thermal Annealing of Thin-Film Multilayers Made of Weak Polyelectrolytes. Macromolecules 2022; 55:9571-9582. [PMID: 36397937 PMCID: PMC9661731 DOI: 10.1021/acs.macromol.2c01517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/16/2022] [Indexed: 11/30/2022]
Abstract
![]()
Thin films made of
weak polyelectrolytes poly(allylamine hydrochloride)
(PAH) and poly(acrylic acid) (PAA) have been fabricated on silicon
wafers using the layer-by-layer (LbL) method. To study the influence
of counteranion type on the growth and properties of PAH/PAA multilayers,
the nature of the supporting sodium salt was varied from cosmotropic
to chaotropic anions (F–, Cl–,
and ClO4–). Results of ellipsometry and
AFM measurements indicate that the film thickness and surface roughness
systematically increase on the order F– < Cl– < ClO4–. Furthermore,
we found that the hydrophobicity of the PAH/PAA multilayer also follows
the described trend when a polycation is the terminating layer. However,
the heating of PAH/PAA multilayers to 60 °C during the LbL assembly
suppressed the influence of background anions on the multilayer formation
and properties. On the basis of the obtained results, it could be
concluded that thermal annealing induces changes at the polymer–air
interface in the sense of reorientation and migration of polymer chains.
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Affiliation(s)
- Tin Klačić
- Division of Physical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia
| | - Davor Kovačević
- Division of Physical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
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8
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Selmani A, Kovačević D, Bohinc K. Nanoparticles: From synthesis to applications and beyond. Adv Colloid Interface Sci 2022; 303:102640. [PMID: 35358806 DOI: 10.1016/j.cis.2022.102640] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/04/2022] [Accepted: 03/06/2022] [Indexed: 12/18/2022]
Abstract
In modern-day research, nanoparticles (size < 100nm) are an indispensable tool for various applications, especially in the field of biomedicine. Although enormous efforts have been made to understand the properties and specificities of nanoparticles, many questions are still not answered and the new ones arise. In this review we summarize current trends in the nanoparticle synthesis and characterization and interpret the stability of nanoparticles in various media from aqueous solutions to biological milieu important for the in vitro and in vivo studies. To get more detailed insight into nanoparticle charging properties and interactions of nanoparticles with interfaces the theoretical models are presented. Finally, the overview of nanoparticle applications is given and the future prospects are discussed.
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Affiliation(s)
- Atiđa Selmani
- Department of Pharmaceutical Technology and Biopharmacy, Institute of Pharmaceutical Sciences, University of Graz, 8010 Graz, Austria.
| | - Davor Kovačević
- Division of Physical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, SI-1000 Ljubljana, Slovenia.
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9
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Bohinc K, Špadina M, Reščič J, Shimokawa N, Spada S. Influence of Charge Lipid Head Group Structures on Electric Double Layer Properties. J Chem Theory Comput 2021; 18:448-460. [PMID: 34937343 PMCID: PMC8757465 DOI: 10.1021/acs.jctc.1c00800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
In this study we
derived a model for a multicomponent lipid monolayer
in contact with an aqueous solution by means of a generalized classical
density functional theory and Monte Carlo simulations. Some of the
important biological lipid systems were studied as monolayers composed
of head groups with different shapes and charge distributions. Starting
from the free energy of the system, which includes the electrostatic
interactions, additional internal degrees of freedom are included
as positional and orientational entropic contributions to the free
energy functional. The calculus of variation was used to derive Euler–Lagrange
equations, which were solved numerically by the finite element method.
The theory and Monte Carlo simulations predict that there are mainly
two distinct regions of the electric double layer: (1) the interfacial
region, with thickness less than or equal to the length of the fully
stretched conformation of the lipid head group, and (2) the outside
region, which follows the usual screening of the interface. In the
interfacial region, the electric double layer is strongly perturbed,
and electrostatic profiles and ion distributions have functionality
distinct to classical mean-field theories. Based purely on Coulomb
interactions, the theory suggests that the dominant effect on the
lipid head group conformation is from the charge density of the interface
and the structured lipid mole fraction in the monolayer, rather than
the salt concentration in the system.
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Affiliation(s)
- Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Mario Špadina
- Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Jurij Reščič
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Naofumi Shimokawa
- Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Simone Spada
- National Institute of Oceanography and Applied Geophysics - OGS, 34010 Trieste, Italy
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10
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Domingues B, Pacheco M, Cruz JE, Carmagnola I, Teixeira‐Santos R, Laurenti M, Can F, Bohinc K, Moutinho F, Silva JM, Aroso IM, Lima E, Reis RL, Ciardelli G, Cauda V, Mergulhão FJ, Gálvez FS, Barros AA. Future Directions for Ureteral Stent Technology: From Bench to the Market. Advanced Therapeutics 2021. [DOI: 10.1002/adtp.202100158] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Beatriz Domingues
- 3B's Research Group‐Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine Avepark‐Parque Barco Guimarães 4805‐017 Portugal
- ICVS/3B's‐PT Government Associate Laboratory Braga/Guimarães 4805‐017 Portugal
| | - Margarida Pacheco
- 3B's Research Group‐Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine Avepark‐Parque Barco Guimarães 4805‐017 Portugal
- ICVS/3B's‐PT Government Associate Laboratory Braga/Guimarães 4805‐017 Portugal
| | - Julia E. Cruz
- Endourology‐Endoscopy Department Minimally Invasive Surgery Centre Jesús Usón Cáceres 10071 Spain
| | - Irene Carmagnola
- Department of Mechanical and Aerospace Engineering Politecnico di Torino Turin 10129 Italy
- Polito BIOMedLAB Politecnico di Torino Turin 10129 Italy
| | - Rita Teixeira‐Santos
- LEPABE–Laboratory for Process Engineering Environment Biotechnology and Energy Faculty of Engineering University of Porto Porto 4200‐465 Portugal
| | - Marco Laurenti
- Department of Applied Science and Technology Politecnico di Torino Turin 10129 Italy
| | - Fusun Can
- Department of Medical Microbiology School of Medicine Koc University Istanbul 34450 Turkey
| | - Klemen Bohinc
- Faculty of Health Sciences University of Ljubljana Ljubljana 1000 Slovenia
| | - Fabíola Moutinho
- i3S‐Instituto de Investigação e Inovação em Saúde Universidade do Porto Porto 4200‐135 Portugal
- INEB‐Instituto de Engenharia Biomédica Universidade do Porto Porto 4200‐135 Portugal
| | - Joana M. Silva
- 3B's Research Group‐Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine Avepark‐Parque Barco Guimarães 4805‐017 Portugal
- ICVS/3B's‐PT Government Associate Laboratory Braga/Guimarães 4805‐017 Portugal
| | - Ivo M. Aroso
- 3B's Research Group‐Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine Avepark‐Parque Barco Guimarães 4805‐017 Portugal
- ICVS/3B's‐PT Government Associate Laboratory Braga/Guimarães 4805‐017 Portugal
| | - Estêvão Lima
- School of Health Sciences Life and Health Sciences Research Institute (ICVS) University of Minho Braga 4710‐057 Portugal
| | - Rui L. Reis
- 3B's Research Group‐Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine Avepark‐Parque Barco Guimarães 4805‐017 Portugal
- ICVS/3B's‐PT Government Associate Laboratory Braga/Guimarães 4805‐017 Portugal
| | - Gianluca Ciardelli
- Department of Mechanical and Aerospace Engineering Politecnico di Torino Turin 10129 Italy
- Polito BIOMedLAB Politecnico di Torino Turin 10129 Italy
| | - Valentina Cauda
- Department of Applied Science and Technology Politecnico di Torino Turin 10129 Italy
| | - Filipe J. Mergulhão
- LEPABE–Laboratory for Process Engineering Environment Biotechnology and Energy Faculty of Engineering University of Porto Porto 4200‐465 Portugal
| | - Federico S. Gálvez
- Endourology‐Endoscopy Department Minimally Invasive Surgery Centre Jesús Usón Cáceres 10071 Spain
| | - Alexandre A. Barros
- 3B's Research Group‐Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine Avepark‐Parque Barco Guimarães 4805‐017 Portugal
- ICVS/3B's‐PT Government Associate Laboratory Braga/Guimarães 4805‐017 Portugal
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11
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Bohinc K, Abram A, Zore A, Štukelj R, Lenarčič A, Vidrih R, Škapin AS. Biophysical Properties of Foamed and Solid Polymers Used in Orthotics and Prosthetics. Materials (Basel) 2021; 14:6877. [PMID: 34832279 PMCID: PMC8619838 DOI: 10.3390/ma14226877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/24/2021] [Accepted: 10/27/2021] [Indexed: 12/02/2022]
Abstract
Orthotic and prosthetic materials should have good mechanical and antibacterial properties. Therefore, in our study, we consider four common foamed closed-cells and two solid polymeric materials regarding their mechanical behaviour and tendency for bacterial adhesion. For all materials, the surface roughness, hydrophobicity, zeta potential, tensile properties, hardness and CIE color parameters were measured. We found that foamed polymeric materials have higher roughness, higher hydrophobicity, lower Young's modulus, lower maximum tensile strength and lower hardness than solid materials. Bacterial adhesion test measurements based on observation by scanning electron microscopy show much a lower adhesion extent of S. aureus on solid materials than on foamed materials. The measured biophysical properties could be the key data for users to select the optimal materials.
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Affiliation(s)
- Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia; (A.Z.); (R.Š.); (A.L.)
| | - Anže Abram
- Department for Nanostructured Materials, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia;
| | - Anamarija Zore
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia; (A.Z.); (R.Š.); (A.L.)
| | - Roman Štukelj
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia; (A.Z.); (R.Š.); (A.L.)
| | - Ana Lenarčič
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000 Ljubljana, Slovenia; (A.Z.); (R.Š.); (A.L.)
| | - Rajko Vidrih
- Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia;
| | - Andrijana Sever Škapin
- Slovenian National Building and Civil Engineering Institute, Dimičeva ulica 12, 1000 Ljubljana, Slovenia;
- Faculty of Polymer Technology-FTPO, Ozare 19, 2380 Slovenj Gradec, Slovenia
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12
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Guo J, Ito H, Higuchi Y, Bohinc K, Shimokawa N, Takagi M. Three-Phase Coexistence in Binary Charged Lipid Membranes in a Hypotonic Solution. Langmuir 2021; 37:9683-9693. [PMID: 34288679 DOI: 10.1021/acs.langmuir.1c00967] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We investigated the phase separation of dioleoylphosphatidylserine (DOPS) and dipalmitoylphosphatidylcholine (DPPC) in giant unilamellar vesicles in a hypotonic solution using fluorescence and confocal laser scanning microscopy. Although phase separation in charged lipid membranes is generally suppressed by the electrostatic repulsion between the charged headgroups, osmotic stress can promote the formation of charged lipid domains. Interestingly, we observed a three-phase coexistence even in the DOPS/DPPC binary lipid mixtures. The three phases were DPPC-rich, dissociated DOPS-rich, and nondissociated DOPS-rich phases. The two forms of DOPS were found to coexist owing to the ionization of the DOPS headgroup, such that the system could be regarded as quasi-ternary. The three formed phases with differently ionized DOPS domains were successfully identified experimentally by monitoring the adsorption of positively charged particles. In addition, coarse-grained molecular dynamics simulations confirmed the stability of the three-phase coexistence. Attraction mediated by hydrogen bonding between protonated DOPS molecules and reduction of the electrostatic interactions at the domain boundaries stabilized the three-phase coexistence.
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Affiliation(s)
- Jingyu Guo
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Hiroaki Ito
- Department of Physics, Chiba University, Chiba 263-8522, Japan
| | - Yuji Higuchi
- Institute for Solid State Physics, The University of Tokyo, Chiba 227-8581, Japan
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Ljubljana SI-1000, Slovenia
| | - Naofumi Shimokawa
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Masahiro Takagi
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
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13
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Špadina M, Dourdain S, Rey J, Bohinc K, Pellet-Rostaing S, Dufrêche JF, Zemb T. How acidity rules synergism and antagonism in liquid–liquid extraction by lipophilic extractants—Part II: application of the ienaic modelling. Solvent Extraction and Ion Exchange 2021. [DOI: 10.1080/07366299.2021.1899614] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- M. Špadina
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France
- Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
| | - S. Dourdain
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France
| | - J. Rey
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France
| | - K. Bohinc
- Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
| | | | | | - T. Zemb
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France
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14
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Dourdain S, Špadina M, Rey J, Bohinc K, Pellet-Rostaing S, Dufrêche JF, Zemb T. How Acidity Rules Synergism and Antagonism in Liquid–Liquid Extraction by Lipophilic Extractants—Part I: Determination of Nanostructures and Free Energies of Transfer. Solvent Extraction and Ion Exchange 2021. [DOI: 10.1080/07366299.2021.1899606] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- S. Dourdain
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France
| | - M. Špadina
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France
- Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
| | - J. Rey
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France
| | - K. Bohinc
- Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia
| | | | | | - T. Zemb
- ICSM, Univ Montpellier, CEA, CNRS, ENSCM, Marcoule, France
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15
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Zore A, Bezek K, Jevšnik M, Abram A, Runko V, Slišković I, Raspor P, Kovačević D, Bohinc K. Bacterial adhesion rate on food grade ceramics and Teflon as kitchen worktop surfaces. Int J Food Microbiol 2020; 332:108764. [PMID: 32585372 DOI: 10.1016/j.ijfoodmicro.2020.108764] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/20/2022]
Abstract
Here we present a research of bacterial adhesion to two most often used materials in modern kitchens, namely food grade ceramics and Teflon. To test the bacterial adhesion on kitchen worktops Escherichia coli, Pseudomonas aeruginosa and Campylobacter jejuni were used as the most common foodborne contaminants. Contact angle, roughness and streaming potential measurements were used for surface characterization. Crystal violet staining and scanning electron microscopy were applied for bacterial adhesion analysis. We showed that the adhesion of tested bacteria strains was lower on the Teflon surface compared to the ceramics. The hydrophobicity of the surface substantially contributed to the bacterial adhesion rate. On the other hand, the surface roughness and charge did not play a crucial role in the adhesion process.
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Affiliation(s)
- Anamarija Zore
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Katja Bezek
- Faculty of Health Sciences, University of Primorska, 6310 Izola, Slovenia
| | - Mojca Jevšnik
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Anže Abram
- Department for Nanostructured Materials, Jožef Stefan Institute, 1000 Ljubljana, Slovenia
| | - Valentina Runko
- Department of Chemistry, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia
| | - Irena Slišković
- Department of Chemistry, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia
| | - Peter Raspor
- University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Davor Kovačević
- Department of Chemistry, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia.
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16
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Filipović U, Dahmane RG, Ghannouchi S, Zore A, Bohinc K. Bacterial adhesion on orthopedic implants. Adv Colloid Interface Sci 2020; 283:102228. [PMID: 32858407 DOI: 10.1016/j.cis.2020.102228] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 01/19/2023]
Abstract
Orthopedic implants are routinely used for fixation of fractures, correction of deformities, joint replacements, and soft tissue anchorage. Different biomaterials have been engineered for orthopedic implants. Previously, they were designed merely as mechanical devices, now new strategies to enhance bone healing and implant osteointegration via local delivery of molecules and via implant coatings are being developed. These biological coatings should enhance osteointegration and reduce foreign body response or infection. This article reviews current and future orthopedic implants, materials and surface characteristics, biocompatibility, and mechanisms of bacterial adhesion. Additionally, the review is addressing implant-related infection, the main strategies to prevent it and suggest possible future research that may control implant related-infection.
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Affiliation(s)
- Urška Filipović
- University Clinical Center of Ljubljana, Department of Traumatology, Zaloska 7, 1000 Ljubljana, Slovenia
| | - Raja Gošnak Dahmane
- University of Ljubljana, Faculty of Health Sciences, Zdravstvena pot 5, 1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Medicine, Institute of Anatomy, Korytkova 2, 1000 Ljubljana, Slovenia
| | | | - Anamarija Zore
- University of Ljubljana, Faculty of Health Sciences, Zdravstvena pot 5, 1000 Ljubljana, Slovenia
| | - Klemen Bohinc
- University of Ljubljana, Faculty of Health Sciences, Zdravstvena pot 5, 1000 Ljubljana, Slovenia.
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17
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Yang Q, Li L, Zhao F, Wang Y, Ye Z, Hua C, Liu Z, Bohinc K, Guo X. Spherical Polyelectrolyte Brushes as Templates to Prepare Hollow Silica Spheres Encapsulating Metal Nanoparticles. Nanomaterials (Basel) 2020; 10:nano10040799. [PMID: 32326263 PMCID: PMC7221898 DOI: 10.3390/nano10040799] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/13/2020] [Accepted: 04/13/2020] [Indexed: 01/30/2023]
Abstract
Integrating hollow silica spheres with metal nanoparticles to fabricate multifunctional hybrid materials has attracted increasing attention in catalysis, detection, and drug delivery. Here, we report a simple and general method to prepare hollow silica spheres encapsulating silver nanoparticles (Ag@SiO2) based on spherical polyelectrolyte brushes (SPB), which consist of a polystyrene core and densely grafted poly (acrylic acid) (PAA) chains. SPB were firstly used as nanoreactors to generate silver nanoparticles in situ and then used as sacrificial templates to prepare hybrid hollow silica spheres. The resulted Ag@SiO2 composites exhibit high catalytic activity and good reusability for the reduction of 4-nitrophenol to 4-aminophenol by NaBH4. More importantly, this developed approach can be extended to the encapsulation of other metal nanoparticles such as gold nanoparticles into the hollow silica spheres. This work demonstrates that SPB are promising candidates for the preparation of hollow spheres with encapsulated metal nanoparticles and the resulted hybrid spheres show great potential applications in catalysis.
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Affiliation(s)
- Qingsong Yang
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.Y.); (F.Z.); (Y.W.); (Z.Y.); (C.H.)
| | - Li Li
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.Y.); (F.Z.); (Y.W.); (Z.Y.); (C.H.)
- Correspondence: (L.L.); (X.G.); Tel.: +86-21-6425-3789 (L.L.); +86-21-6425-3491 (X.G.)
| | - Fang Zhao
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.Y.); (F.Z.); (Y.W.); (Z.Y.); (C.H.)
| | - Yunwei Wang
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.Y.); (F.Z.); (Y.W.); (Z.Y.); (C.H.)
| | - Zhishuang Ye
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.Y.); (F.Z.); (Y.W.); (Z.Y.); (C.H.)
| | - Chen Hua
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.Y.); (F.Z.); (Y.W.); (Z.Y.); (C.H.)
| | - Zhiyong Liu
- Engineering Research Center of Materials Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832000, Xinjiang, China;
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Xuhong Guo
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.Y.); (F.Z.); (Y.W.); (Z.Y.); (C.H.)
- Engineering Research Center of Materials Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832000, Xinjiang, China;
- Correspondence: (L.L.); (X.G.); Tel.: +86-21-6425-3789 (L.L.); +86-21-6425-3491 (X.G.)
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18
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Špadina M, Bohinc K. Multiscale modeling of solvent extraction and the choice of reference state: Mesoscopic modeling as a bridge between nanoscale and chemical engineering. Curr Opin Colloid Interface Sci 2020. [DOI: 10.1016/j.cocis.2020.03.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
In solvent extraction, the self-assembly of amphiphilic molecules into an organized structure is the phenomenon responsible for the transfer of the metal ion from the aqueous phase to the organic solvent. Despite their significance for chemical engineering and separation science, the forces driving the solute transfer are not fully understood. Instead of assuming the simple complexation reaction with predefined stoichiometry, we model synergistic extraction systems by a colloidal approach that explicitly takes into account the self-assembly resulting from the amphiphilic nature of the extractants. Contrary to the current paradigm of simple stoichiometry behind liquid-liquid extraction, there is a severe polydispersity of aggregates completely different in compositions, but similar in the free energy. This variety of structures on the nanoscale is responsible for the synergistic transfer of ions to the organic phase. Synergy can be understood as a reciprocal effect of chelation: it enhances extraction because it increases the configurational entropy of an extracted ion. The global overview of the complex nature of a synergistic mixture shows different regimes in self-assembly, and thus in the extraction efficiency, which can be tuned with respect to the green chemistry aspect.
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Affiliation(s)
- Mario Špadina
- ICSM , CEA, CNRS, ENSCM, Univ Montpellier, Marcoule F-30207 , France
| | - Klemen Bohinc
- Faculty of Health Sciences , University of Ljubljana , 1000 Ljubljana , Slovenia
| | - Thomas Zemb
- ICSM , CEA, CNRS, ENSCM, Univ Montpellier, Marcoule F-30207 , France
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Bohinc K, Reščič J, Spada S, May S, Maset S. Influence of added salt on the surface induced ordering of nanoparticles with discretely distributed charges. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111134] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Martín-Molina A, Lue L, Quesada-Pérez M, Bohinc K. Interaction between charged lipid vesicles and point- or rod-like trivalent ions. Colloids Surf B Biointerfaces 2019; 178:525-529. [PMID: 31004839 DOI: 10.1016/j.colsurfb.2019.02.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 01/30/2019] [Accepted: 02/05/2019] [Indexed: 10/27/2022]
Abstract
This work examines the influence of the charge distribution of trivalent cations on their interaction with soft anionic particles, using a combination of experimental measurements and theoretical modelling. In particular, we perform electrophoresis measurements to determine the zeta-potential of anionic liposomes in the presence of spermidine and lanthanum cations. We work in a range of electrolyte concentration where a reversal in the electrophoretic mobility of the liposomes is expected; however, unlike the case of lanthanum cations, spermidine does not induce mobility reversal of liposomes. As a result, the charge distribution within the counterion appears to be a key factor. This conclusion is supported by a theory that accounts for intra-ionic correlations, which has previously been successfully used to describe the colloidal electric double layer. It allows us to model spermidine as rod-like ions and lanthanum cations as point-like ions in order to test the importance of the ionic geometry in the interactions with soft particles such as lipid vesicles.
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Affiliation(s)
- Alberto Martín-Molina
- Departamento de Fisica Aplicada and Instituto Carlos I de Fisica Teorica y Computacional, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Leo Lue
- Department of Chemical and Process Engineering, University of Strathclyde, Glasgow G1 1XJ, UK
| | - Manuel Quesada-Pérez
- Departamento de Fisica, Escuela Politecnica Superior de Linares, Universidad de Jaen, 23700 Linares, Jaen, Spain
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena 5, SI-1000 Ljubljana, Slovenia.
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22
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Bezek K, Nipič D, Torkar KG, Oder M, Dražić G, Abram A, Žibert J, Raspor P, Bohinc K. Biofouling of stainless steel surfaces by four common pathogens: the effects of glucose concentration, temperature and surface roughness. Biofouling 2019; 35:273-283. [PMID: 31025585 DOI: 10.1080/08927014.2019.1575959] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Revised: 01/18/2019] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
There is a wide range of factors affecting bacterial adhesion and biofilm formation. However, in both food processing and medical settings, it is very hard to obtain suitably controlled conditions so that the factors that reduce surface colonisation and biofouling can be studied. The aim of this study was to evaluate the effect of glucose concentration, temperature and stainless steel (SS) surface roughness on biofouling by four common pathogens (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and L. monocytogenes). Among the tested variables, the untreated SS surface (3C) was shown to be fouled more than 3D polished, brushed or electropolished SS surfaces. Although an array of parameters influenced biofouling, the most promising control measure was the influence of low temperature (4 °C) that reduced biofouling even in the case of the psychrophilic Listeria monocytogenes. The study findings could significantly contribute to the prevention of SS surface contamination and consequential biofouling by food and healthcare associated pathogens.
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Affiliation(s)
- Katja Bezek
- a Faculty of Health Sciences , University of Primorska , Izola , Slovenia
| | - Damjan Nipič
- b Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Karmen Godič Torkar
- b Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Martina Oder
- b Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Goran Dražić
- c Department of materials chemistry, National Institute of Chemistry , Ljubljana , Slovenia
| | - Anže Abram
- d Department for nanostructured materials, Jozef Stefan Institute , Ljubljana , Slovenia
| | - Janez Žibert
- b Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Peter Raspor
- e Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana , Ljubljana , Slovenia
| | - Klemen Bohinc
- b Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
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Špadina M, Bohinc K, Zemb T, Dufrêche JF. Colloidal Model for the Prediction of the Extraction of Rare Earths Assisted by the Acidic Extractant. Langmuir 2019; 35:3215-3230. [PMID: 30673246 PMCID: PMC6488188 DOI: 10.1021/acs.langmuir.8b03846] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/19/2019] [Indexed: 05/28/2023]
Abstract
We propose the statistical thermodynamic model for the prediction of the liquid-liquid extraction efficiency in the case of rare-earth metal cations using the common bis(2-ethyl-hexyl)phosphoric acid (HDEHP) extractant. In this soft matter-based approach, the solutes are modeled as colloids. The leading terms in free-energy representation account for: the complexation, the formation of a highly curved extractant film, lateral interactions between the different extractant head groups in the film, configurational entropy of ions and water molecules, the dimerization, and the acidity of the HDEHP extractant. We provided a full framework for the multicomponent study of extraction systems. By taking into account these different contributions, we are able to establish the relation between the extraction and general complexation at any pH in the system. This further allowed us to rationalize the well-defined optimum in the extraction engineering design. Calculations show that there are multiple extraction regimes even in the case of lanthanide/acid system only. Each of these regimes is controlled by the formation of different species in the solvent phase, ranging from multiple metal cation-filled aggregates (at the low acid concentrations in the aqueous phase), to the pure acid-filled aggregates (at the high acid concentrations in the aqueous phase). These results are contrary to a long-standing opinion that liquid-liquid extraction can be modeled with only a few species. Therefore, a traditional multiple equilibria approach is abandoned in favor of polydisperse spherical aggregate formations, which are in dynamic equilibrium.
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Affiliation(s)
- Mario Špadina
- ICSM,
CEA, CNRS, ENSCM, University of Montpellier, 34199 Marcoule, France
| | - Klemen Bohinc
- Faculty
of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Thomas Zemb
- ICSM,
CEA, CNRS, ENSCM, University of Montpellier, 34199 Marcoule, France
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Abstract
Charged lipids in cell membranes and subcellular organelles are arranged in the form of a bilayer with the hydrocarbon tails sequestered away from the water and the polar head groups exposed to the aqueous environment. Most of them bear net negative charges leading to the negatively charged cell membranes. Charged lipid-lipid and lipid-protein interactions are generally dynamic and heavily depend on their local molecular concentrations. To examine the electrostatic properties of charged lipid layers in contact with an electrolyte solution, we incorporate the single chain mean field theory with Poisson-Boltzmann theory to explore the equilibrium structure of charged phospholipid membranes. Using the three bead coarse-grained model we reproduced the essential equilibrium properties of the charged phospholipid bilayer. We also investigate the influence of the mobile ions on the thickness of the layer, the area per lipid (APL), and the electrostatic potential of the membrane. Then we investigate the attraction-repulsion property of two charged nanoparticles which are stuck on the charged lipid molecules surrounded with mobile ions. After that we simulated the interaction between the Pleckstrin homology domain (PH domain) of Akt and the cytoplasmic membrane. Taking into account the electrostatic interaction, we observe the structure changes of the membrane at different concentrations of mobile ions in its equilibrium state. Also we discuss the influence of mobile ions on the size of the pore opened in the membrane by the charged protein. Such an observation may shed light on the activation of oncogenic Akt (or protein kinase B) around the membrane at the molecular level.
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Affiliation(s)
- Beibei Huang
- Intelligent Molecular Discovery Laboratory, Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, 1901 East Road, Houston, TX 77054, USA.
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Bossa GV, Caetano DLZ, de Carvalho SJ, Bohinc K, May S. Modeling the camel-to-bell shape transition of the differential capacitance using mean-field theory and Monte Carlo simulations. Eur Phys J E Soft Matter 2018; 41:113. [PMID: 30259300 DOI: 10.1140/epje/i2018-11723-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 08/30/2018] [Indexed: 06/08/2023]
Abstract
Mean-field electrostatics is used to calculate the differential capacitance of an electric double layer formed at a planar electrode in a symmetric 1:1 electrolyte. Assuming the electrolyte is also ion-size symmetric, we derive analytic expressions for the differential capacitance valid up to fourth order in the surface charge density or surface potential. Our mean-field model accounts exclusively for electrostatic interactions but includes an arbitrary non-ideality in the mixing entropy of the mobile ions. The ensuing criterion for the camel-to-bell shape transition of the differential capacitance is analyzed using commonly used mixing models (one based on a lattice gas and the other based on the Carnahan-Starling equation of state) and compared with Monte Carlo simulations. We observe a reasonable agreement between all our mean-field models and the simulation data for the camel-to-bell shape transition. The absolute value of the differential capacitance for an uncharged (or weakly charged) electrode is, however, not reproduced by our mean-field approaches, not even upon introducing a Stern layer with a thickness equal of the ion radius. We show that, if a Stern layer is introduced, its thickness dependence on the ion size is non-monotonic or, depending on the salt concentration, even inversely proportional.
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Affiliation(s)
- Guilherme V Bossa
- Department of Physics, North Dakota State University, 58108-6050, Fargo, ND, USA
- Department of Physics, São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences, 15054-000, São José do Rio Preto, SP, Brazil
| | - Daniel L Z Caetano
- Department of Physics, São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences, 15054-000, São José do Rio Preto, SP, Brazil
| | - Sidney J de Carvalho
- Department of Physics, São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences, 15054-000, São José do Rio Preto, SP, Brazil
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Poljanska 26a, 1000, Ljubljana, Slovenia
| | - Sylvio May
- Department of Physics, North Dakota State University, 58108-6050, Fargo, ND, USA.
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Špadina M, Bohinc K, Zemb T, Dufrêche JF. Multicomponent Model for the Prediction of Nuclear Waste/Rare-Earth Extraction Processes. Langmuir 2018; 34:10434-10447. [PMID: 30081639 PMCID: PMC6197759 DOI: 10.1021/acs.langmuir.8b01759] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 07/18/2018] [Indexed: 05/28/2023]
Abstract
We develop a minimal model for the prediction of solvent extraction. We consider a rare earth extraction system for which the solvent phase is similar to water-poor microemulsions. All physical molecular quantities used in the calculation can be measured separately. The model takes into account competition complexation, mixing entropy of complexed species, differences of salt concentrations between the two phases, and the surfactant nature of extractant molecules. We consider the practical case where rare earths are extracted from iron nitrates in the presence of acids with a common neutral complexing extractant. The solvent wetting of the reverse aggregates is taken into account via the spontaneous packing. All the water-in-oil reverse aggregates are supposed to be spherical on average. The minimal model captures several features observed in practice: reverse aggregates with different water and extractant content coexist dynamically with monomeric extractant molecules at and above a critical aggregate concentration (CAC). The CAC decreases upon the addition of electrolytes in the aqueous phase. The free energy of transfer of an ion to the organic phase is lower than the driving complexation. The commonly observed log-log relation used to determine the apparent stoichiometry of complexation is valid as a guideline but should be used with care. The results point to the fact that stoichiometry, as well as the probabilities of a particular aggregate, is dependent on the composition of the entire system, namely the extractant and the target solutes' concentrations. Moreover, the experimentally observed dependence of the extraction efficiency on branching of the extractant chains in a given solvent can be quantified. The evolution of the distribution coefficient of particular rare earth, acid, or other different metallic cations can be studied as a function of initial extractant concentration through the whole region that is typically used by chemical engineers. For every chemical species involved in the calculation, the model is able to predict the exact equilibrium concentration in both the aqueous and the solvent phases at a given thermodynamic temperature.
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Affiliation(s)
- Mario Špadina
- Institut
de Chimie Séparative de Marcoule, Ecole Nationale Supérieure
de Chimie de Montpellier, CEA/CNRS, Université
de Montpellier, F-30207 Bagnols sur Ceze Cedex, France
| | - Klemen Bohinc
- Faculty
of Health Sciences, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Thomas Zemb
- Institut
de Chimie Séparative de Marcoule, Ecole Nationale Supérieure
de Chimie de Montpellier, CEA/CNRS, Université
de Montpellier, F-30207 Bagnols sur Ceze Cedex, France
| | - Jean-François Dufrêche
- Institut
de Chimie Séparative de Marcoule, Ecole Nationale Supérieure
de Chimie de Montpellier, CEA/CNRS, Université
de Montpellier, F-30207 Bagnols sur Ceze Cedex, France
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Špadina M, Gourdin-Bertin S, Dražić G, Selmani A, Dufrêche JF, Bohinc K. Charge Properties of TiO 2 Nanotubes in NaNO 3 Aqueous Solution. ACS Appl Mater Interfaces 2018; 10:13130-13142. [PMID: 29620855 DOI: 10.1021/acsami.7b18737] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Charging of material surfaces in aqueous electrolyte solutions is one of the most important processes in the interactions between biomaterials and surrounding tissue. Other than a biomaterial, titania nanotubes (TiO2 NTs) represent a versatile material for numerous applications such as heavy metal adsorption or photocatalysis. In this article, the surface charge properties of titania NTs in NaNO3 solution were investigated through electrophoretic mobility and polyelectrolyte colloid titration measuring techniques. In addition, we used high-resolution transmission electron microscopy imaging to determine the morphology of TiO2 NTs. A theoretical model based on the classical density functional theory coupled with the charge regulation method in terms of mass action law was developed to understand the experimental data and to provide insights into charge properties at different physical conditions, namely, pH and NaNO3 concentration. Two intrinsic protonation constants and surface site density have been obtained. The electrostatic properties of the system in terms of electrostatic potentials and ion distributions were calculated and discussed for various pH values. The model can quantitatively describe the titration curve as a function of pH for higher bulk salt concentrations and the difference in the equilibrium amount of charges between the inner and outer surfaces of TiO2 NTs. Calculated counterion (NO3-) distributions show a pronounced decrease of NO3- ions for high bulk pH (both inside and outside TiO2 NT) because of the strong electric field. With the decrease of bulk pH or the increase of the salt concentration, NO3- is able to accumulate near the TiO2 NTs surfaces.
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Affiliation(s)
- Mario Špadina
- Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257, CEA, Université de Montpellier, CNRS, ENSCM, BP 17171, F-30207 Bagnols-sur-Ceze , France
| | - Simon Gourdin-Bertin
- Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257, CEA, Université de Montpellier, CNRS, ENSCM, BP 17171, F-30207 Bagnols-sur-Ceze , France
| | - Goran Dražić
- Laboratory for Materials Chemistry , National Institute of Chemistry , SI-1000 Ljubljana , Slovenia
| | - Atiđa Selmani
- Division of Physical Chemistry , Ruđer Boškovic Institute , 10000 Zagreb , Croatia
| | - Jean-François Dufrêche
- Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257, CEA, Université de Montpellier, CNRS, ENSCM, BP 17171, F-30207 Bagnols-sur-Ceze , France
| | - Klemen Bohinc
- Faculty of Health Sciences , University of Ljubljana , Zdravstvena 5 , SI-1000 Ljubljana , Slovenia
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Oder M, Arlič M, Bohinc K, Fink R. Escherichia coli biofilm formation and dispersion under hydrodynamic conditions on metal surfaces. Int J Environ Health Res 2018; 28:55-63. [PMID: 29232959 DOI: 10.1080/09603123.2017.1415309] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The aim of this study was to analyze the impact of hydrodynamic forces on the multiplication of E. coli, and biofilm formation and dispersion. The experiments were provided in a flow chamber simulating a cleaning-in-place system. Biofilm biomass was measured using a crystal violet dye method. The results show that hydrodynamic forces affect not only biofilm formation and dispersion but the multiplication of E. coli in the first place. We found more biofilm biomass on the rough surface than on the smooth one. The results of the biofilm formation test show that laminar flow promotes the biofilm growth over 72 h, meanwhile turbulent flow after 48 h causes decrease in biomass. The results of the biofilm dispersion test, in contrast, show that laminar flow removed less biofilm from both materials that turbulent flow did. Therefore, taking into account these findings in cleaning-in-place technology can substantially reduce E. coli multiplication and biofilm formation.
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Affiliation(s)
- Martina Oder
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Mateja Arlič
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Klemen Bohinc
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Rok Fink
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
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Bohinc K, Bossa GV, May S. Incorporation of ion and solvent structure into mean-field modeling of the electric double layer. Adv Colloid Interface Sci 2017; 249:220-233. [PMID: 28571611 DOI: 10.1016/j.cis.2017.05.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 04/28/2017] [Accepted: 05/02/2017] [Indexed: 01/13/2023]
Abstract
An electric double layer forms when the small mobile ions of an electrolyte interact with an extended charged object, a macroion. The competition between electrostatic attraction and translational entropy loss of the small ions results in a diffuse layer of partially immobilized ions in the vicinity of the macroion. Modeling structure and energy of the electric double layer has a long history that has lead to the classical Poisson-Boltzmann theory and numerous extensions that account for ion-ion correlations and structural ion and solvent properties. The present review focuses on approaches that instead of going beyond the mean-field character of Poisson-Boltzmann theory introduce structural details of the ions and the solvent into the Poisson-Boltzmann modeling framework. The former include not only excluded volume effects but also the presence of charge distributions on individual ions, spatially extended ions, and internal ionic degrees of freedom. The latter treat the solvent either explicitly as interacting Langevin dipoles or in the form of effective non-electrostatic interactions, in particular Yukawa interactions, that are added to the Coulomb potential. We discuss how various theoretical models predict structural properties of the electric double layer such as the differential capacitance and compare some of these predictions with computer simulations.
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Affiliation(s)
- Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Ljubljana SI-1000, Slovenia.
| | | | - Sylvio May
- Department of Physics, North Dakota State University, Fargo, ND 58108-6050, USA
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Abstract
Electrostatic interactions govern the physical properties of charged cylindrical structures in electrolyte solutions. Besides the surface charge on the cylinders, another factor influencing the electrostatic interactions are the mobile ions. The finite size of the mobile ions is included by the excluded volume effect within the lattice statistics, while the electrostatic interactions are considered by means of the mean electrostatic field. In this article we consider charged parallel cylinders embedded into an electrolyte solution of mobile monovalent ions. A modified nonlinear Poisson-Boltzmann equation is proposed via variational procedure, and we implement the finite element method to solve it numerically. Excluded volume effect of the system containing two and multiple charged parallel cylinders are taken into account. Numerical results show that the excluded volume effect decreases the concentration of counterion and increases the electrostatic potential near the charged cylinders. The angular distribution of counterion around the particular cylinder is asymmetric. The study of the electrostatic interaction between two parallel equally charged cylinders reveals that an increase in the free energy is seen when the ionic strength is decreased. The free energy decreases as a function of the cylinders separation distance. On the contrary for two oppositely charged cylinders, the free energy increases with increasing cylinder separation distance, while for two cylinders with different charged density it shows nonmonotonic variation with the increasing cylinders separation distance.
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Affiliation(s)
- Beibei Huang
- Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center , 1901 East Road, Houston, Texas 77054, United States
| | - Stefano Maset
- Dipartimento di Scienze Matematiche Universita' di Trieste , 34100 Trieste, Italy
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana , 1000 Ljubljana, Slovenia
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Oder M, Fink R, Bohinc K, Torkar KG. The influence of shear stress on the adhesion capacity of Legionella pneumophila. Arh Hig Rada Toksikol 2017; 68:109-115. [DOI: 10.1515/aiht-2017-68-2904] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 05/01/2017] [Indexed: 12/16/2022] Open
Abstract
Abstract
Bacterial adhesion is a complex process influenced by many factors, including hydrodynamic conditions. They affect the transfer of oxygen, nutrients, and bacterial cells in a water supply and cooling systems. The aim of this study was to identify hydrodynamic effects on bacterial adhesion to and detachment from stainless steel surfaces. For this purpose we observed the behaviour of bacterium L. pneumophila in no-flow and laminar and turbulent flow conditions simulated in a fluid flow chamber. The bacterial growth in no-flow and laminar flow conditions was almost identical in the first 24 h, while at 48 and 72 h of incubation, the laminar flow stimulated bacterial growth. In the second part of this study we found that laminar flow accelerated bacterial adhesion in the first 48 h, but after 72 h the amount of bacterial cells exposed to the flow dropped, probably due to detachment. In the third part we found that the turbulent flow detached more bacterial cells than the laminar, which indicates that the strength of shear forces determines the rate of bacterial removal.
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Affiliation(s)
- Martina Oder
- Faculty of Health Sciences, University of Ljubljana, Ljubljana , Slovenia
| | - Rok Fink
- Faculty of Health Sciences, University of Ljubljana, Ljubljana , Slovenia
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, Ljubljana , Slovenia
| | - Karmen Godič Torkar
- University of Ljubljana, Faculty of Health Sciences, Department for Sanitary Engineering, Zdravstvena pot 5, 1000 Ljubljana , Slovenia
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Fink R, Okanovič D, Dražič G, Abram A, Oder M, Jevšnik M, Bohinc K. Bacterial adhesion capacity on food service contact surfaces. Int J Environ Health Res 2017; 27:169-178. [PMID: 28347157 DOI: 10.1080/09603123.2017.1310188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The aim of this study was to analyse the adhesion of E. coli, P. aeruginosa and S. aureus on food contact materials, such as polyethylene terephthalate, silicone, aluminium, Teflon and glass. Surface roughness, streaming potential and contact angle were measured. Bacterial properties by contact angle and specific charge density were characterised. The bacterial adhesion analysis using staining method and scanning electron microscopy showed the lowest adhesion on smooth aluminium and hydrophobic Teflon for most of the bacteria. However, our study indicates that hydrophobic bacteria with high specific charge density attach to those surfaces more intensively. In food services, safety could be increased by selecting material with low adhesion to prevent cross contamination.
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Affiliation(s)
- Rok Fink
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Denis Okanovič
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Goran Dražič
- b Department for Materials Chemistry , National Institute of Chemistry Slovenia , Ljubljana , Slovenia
| | - Anže Abram
- c Department for Nanostructured Materials , Jozef Stefan Institute , Ljubljana , Slovenia
| | - Martina Oder
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Mojca Jevšnik
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Klemen Bohinc
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
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Bohinc K, Vantur N, Torkar D, Lampe T, Hribernik M, Jakovljević M. Knee stiffness and viscosity: New implementation and perspectives in prosthesis development. Bosn J Basic Med Sci 2017; 17:164-171. [PMID: 28422623 PMCID: PMC5474111 DOI: 10.17305/bjbms.2017.1765] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 01/24/2017] [Accepted: 01/25/2017] [Indexed: 11/16/2022] Open
Abstract
The pendulum test is a method applied to measure passive resistance of the knee. A new and simple pendulum test with instrumentation based on infrared camera was used to evaluate knee stiffness and viscosity on a female human cadaver. The stiffness and viscosity were calculated based on the kinetic data. During the measurements, the periarticular and intraarticular soft tissue of the knee was gradually removed to determine the stiffness and viscosity as a function of the tissue removal rate. The measurements showed that the removal of tissue around the joint reduces the damping of leg oscillation, and therefore decreases the stiffness and viscosity. The contribution to knee joint damping was 10% for the skin, 20% for ligaments, and 40% for muscles and tendons. Tissue removal has a very large impact on the knee stiffness and viscosity.
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Affiliation(s)
- Klemen Bohinc
- Prosthetics Department, Faculty of Health Sciences, University of Ljubljana, Ljubljana, Slovenia.
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Bohinc K, Volpe Bossa G, Gavryushov S, May S. Poisson-Boltzmann model of electrolytes containing uniformly charged spherical nanoparticles. J Chem Phys 2016; 145:234901. [DOI: 10.1063/1.4968210] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Guilherme Volpe Bossa
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050, USA
| | - Sergei Gavryushov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, IMB RAS, Vavilova St. 32,119991 Moscow, Russia
| | - Sylvio May
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050, USA
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Kovačević D, Pratnekar R, Godič Torkar K, Salopek J, Dražić G, Abram A, Bohinc K. Influence of Polyelectrolyte Multilayer Properties on Bacterial Adhesion Capacity. Polymers (Basel) 2016; 8:E345. [PMID: 30974625 PMCID: PMC6432465 DOI: 10.3390/polym8100345] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 09/11/2016] [Accepted: 09/14/2016] [Indexed: 01/07/2023] Open
Abstract
Bacterial adhesion can be controlled by different material surface properties, such as surface charge, on which we concentrate in our study. We use a silica surface on which poly(allylamine hydrochloride)/sodium poly(4-styrenesulfonate) (PAH/PSS) polyelectrolyte multilayers were formed. The corresponding surface roughness and hydrophobicity were determined by atomic force microscopy and tensiometry. The surface charge was examined by the zeta potential measurements of silica particles covered with polyelectrolyte multilayers, whereby ionic strength and polyelectrolyte concentrations significantly influenced the build-up process. For adhesion experiments, we used the bacterium Pseudomonas aeruginosa. The extent of adhered bacteria on the surface was determined by scanning electron microscopy. The results showed that the extent of adhered bacteria mostly depends on the type of terminating polyelectrolyte layer, since relatively low differences in surface roughness and hydrophobicity were obtained. In the case of polyelectrolyte multilayers terminating with a positively charged layer, bacterial adhesion was more pronounced than in the case when the polyelectrolyte layer was negatively charged.
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Affiliation(s)
- Davor Kovačević
- Department of Chemistry, Faculty of Science, University of Zagreb, Zagreb 10000, Croatia.
| | - Rok Pratnekar
- Faculty of Health Sciences, Ljubljana 1000, Slovenia.
| | | | - Jasmina Salopek
- Department of Chemistry, Faculty of Science, University of Zagreb, Zagreb 10000, Croatia.
| | - Goran Dražić
- Jožef Stefan Institute, Ljubljana 1000, Slovenia.
- National Institute of Chemistry, Ljubljana 1000, Slovenia.
- Jožef Stefan International Postgraduate School, Ljubljana 1000, Slovenia.
| | - Anže Abram
- Jožef Stefan Institute, Ljubljana 1000, Slovenia.
- National Institute of Chemistry, Ljubljana 1000, Slovenia.
- Jožef Stefan International Postgraduate School, Ljubljana 1000, Slovenia.
| | - Klemen Bohinc
- Faculty of Health Sciences, Ljubljana 1000, Slovenia.
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Abstract
Charged spherical nanoparticles trapped at the interface between water and air or water and oil exhibit repulsive electrostatic forces that contain a long-ranged dipolar and a short-ranged exponentially decaying component. The former are induced by the unscreened electrostatic field through the non-polar low-permittivity medium, and the latter result from the overlap of the diffuse ion clouds that form in the aqueous phase close to the nanoparticles. The magnitude of the long-ranged dipolar interaction is largely determined by the residual charges that remain attached to the air- (or oil-) exposed region of the nanoparticle. In the present work we address the question to what extent the charges on the water-immersed part of the nanoparticle provide an additional contribution to the dipolar interaction. To this end, we model the electrostatic properties of a spherical particle - a nanoparticle or a colloid - that partitions equatorially to the air-water interface, thereby employing nonlinear Poisson-Boltzmann theory in the aqueous solution and accounting for the propagation of the electric field through the interior of the particle. We demonstrate that the apparent charge density on the air-exposed region of the particle, which determines the dipole potential, is influenced by the electrostatic properties in the aqueous solution. We also show that this electrostatic coupling through the particle can be reproduced qualitatively by a simple analytic planar capacitor model. Our results help to rationalize the experimentally observed weak but non-vanishing salt dependence of the forces that stabilize ordered two-dimensional arrays of interface-trapped nanoparticles or colloids.
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Bohinc K, Reščič J, Lue L. Interactions between charged surfaces mediated by stiff, multivalent zwitterionic polymers. Soft Matter 2016; 12:4397-4405. [PMID: 27087406 DOI: 10.1039/c6sm00236f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The interaction between like-charged objects in electrolyte solutions can be heavily altered by the presence of multivalent ions which possess a spatially distributed charge. In this work, we examine the influence of stiff, multivalent zwitterionic polymers on the interaction between charged surfaces using a splitting field theory previously shown to be accurate for the weak to the intermediate to the strong electrostatic coupling regimes. The theory is compared to Monte Carlo simulations and good agreement is found between both approaches. For surface separations shorter than the polymer length, the polymers are mainly oriented parallel to the surfaces, and the surface-surface interaction is repulsive. When the surface separation is comparable to the length of polymers, the polymers have two main orientations. The first corresponds to the polymers adsorbed onto the surface with their centers located near to or in contact with the surface; the second corresponds to polymers which are perpendicular to the charged surfaces, bridging both surfaces and leading to an attractive force between them. Increasing the surface charge density leads to more pronounced attraction via bridging. At surface separations greater than the polymer length, the polymers in the center of the system are still mainly perpendicular to the surfaces, due to "chaining" between zwitterions that enable them to bridge the surfaces at larger separations. This leads to an attractive interaction between the surfaces with a range significantly longer than the length of the polymers.
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Affiliation(s)
- Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
| | - Jurij Reščič
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
| | - Leo Lue
- Department of Chemical and Process Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, UK.
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Abstract
The interaction between two charged particles (such as nanoparticles or colloids) trapped at the air-water interface becomes dipolar at large separations. The corresponding dipole moment can be modeled by considering a single point charge located exactly at the interface, but this model fails to correctly predict the dipole moment's dependence on the salt concentration in the aqueous medium. We extend the single point charge model to two point charges that are separated by a fixed distance and are located at the air-water interface, with one charge being immersed in air and the other in the solvent. The two point charges represent the surface charges at the air-exposed and water-exposed regions of an interface-trapped particle. The two point charges also account for the spatial extension of the particle. On the basis of the Debye-Hückel model, we derive mathematical expressions for the interaction between two pairs of charges and discuss the salt concentration dependence of the dipolar moment at large separations. Our results reveal a residual dipole moment in the limit of large salt content that originates from the charge attached to the air-exposed region of the particle. We discuss nonlinear screening effects and compare the predicted dipolar moments with recent experimental results.
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Affiliation(s)
- Guilherme Volpe Bossa
- Department of Physics, North Dakota State University , P.O. Box 6050, Fargo, North Dakota 58108-6050, United States
| | - Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana , Zdravstvena 5, SI-1000 Ljubljana, Slovenia
| | - Matthew A Brown
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zürich , CH-8093 Zurich, Switzerland
| | - Sylvio May
- Department of Physics, North Dakota State University , P.O. Box 6050, Fargo, North Dakota 58108-6050, United States
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Kurinčič M, Jeršek B, Klančnik A, Možina SS, Fink R, Dražić G, Raspor P, Bohinc K. Effects of natural antimicrobials on bacterial cell hydrophobicity, adhesion, and zeta potential. Arh Hig Rada Toksikol 2016; 67:39-45. [PMID: 27092638 DOI: 10.1515/aiht-2016-67-2720] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 03/01/2016] [Indexed: 12/16/2023] Open
Abstract
Interactions between bacterial cells and contact materials play an important role in food safety and technology. As bacterial strains become ever more resistant to antibiotics, the aim of this study was to analyse adhesion of selected foodborne bacterial strains on polystyrene surface and to evaluate the effects of natural antimicrobials on bacterial cell hydrophobicity, adhesion, and zeta potential as strategies of adhesion prevention. The results showed strain-specific adhesion rate on polystyrene. The lowest and the highest adhesion were found for two B. cereus lines. Natural antimicrobials ferulic and rosmarinic acid substantially decreased adhesion, whereas the effect of epigallocatechin gallate was neglectful. Similar results were found for the zeta potential, indicating that natural antimicrobials reduce bacterial adhesion. Targeting bacterial adhesion using natural extracts we can eliminate potential infection at an early stage. Future experimental studies should focus on situations that are as close to industrial conditions as possible.
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Abstract
A coarse-grained model of simple monovalent electrolyte solution in contact with a zwitterionic lipid layer in continuum solvent is studied by canonical Monte Carlo computer simulations and extended Poisson-Boltzmann theory. A structure of zwitterionic layer as well as concentration profiles of positively and negatively charged monovalent ions were obtained from simulations and compared to theoretical predictions. A relatively good agreement between the Monte Carlo computer simulations and theory was observed.
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Abstract
Environmental parameters dictate the conditions for both biofilm formation and deconstruction. The aim of this study is to analyse the impact of hydrodynamic and thermodynamic effects on bacterial detachment. Escherichia coli grown on two stainless steel metal surfaces with different roughness (brushed with roughness of 0.05 μm and electropolished with roughness of 0.29 μm) are exposed to laminar and turbulent (shower) flows of phosphate buffered saline media at temperatures of 8, 20 and 37 °C. Results show that the turbulent flow removes significantly more bacterial cells than laminar flow (p <0.05) on both materials. This indicates that the shear force determines the rate of detached bacteria. It is also observed that detachment of cells is more efficient on brushed than on electropolished contact surfaces because on the latter surface, fewer cells were attached before exposure. Moreover, we demonstrate that the temperature of the washing agent has an impact on bacterial detachment. At the same flow conditions, the exposure to higher temperature results in greater detachment rate.
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Affiliation(s)
- Rok Fink
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | - Martina Oder
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
| | | | - Peter Raspor
- c Faculty of Health Sciences , University of Primorska , Izola , Slovenia
| | - Klemen Bohinc
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
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Oder M, Kompare B, Bohinc K, Torkar KG. The impact of material surface roughness and temperature on the adhesion of Legionella pneumophila to contact surfaces. Int J Environ Health Res 2014; 25:469-479. [PMID: 25307889 DOI: 10.1080/09603123.2014.963035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 08/03/2014] [Indexed: 06/04/2023]
Abstract
The adhesion of bacterial cells to various surfaces is based on physical and chemical interactions between the micro-organisms and the surfaces. The main purpose of this research is to determine the effect of material roughness and incubation temperature on the adhesion of bacteria. To determine the adhesion of the bacterial strain of Legionella pneumophila ATCC 33153 to the glass coupons, a spectrophotometric method of measuring the optical density of crystal violet dye that is released from pre-stained bacterial cells attached to the test surface was used. The intensity of adhesion is in positive correlation to the increase in surface roughness (p < 0.05). The adhesion is the greatest at an optimal temperature of 36 °C, whereas the temperature of 15 °C has a bacteriostatic effect and the temperature of 55 °C a bactericidal effect.
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Affiliation(s)
- Martina Oder
- a Faculty of Health Sciences , University of Ljubljana , Ljubljana , Slovenia
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Reščič J, Kovačević D, Tomšič M, Jamnik A, Ahualli S, Bohinc K. Experimental and theoretical study of the silica particle interactions in the presence of multivalent rod-like ions. Langmuir 2014; 30:9717-9725. [PMID: 25036697 DOI: 10.1021/la501683t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The silica particle interactions in the presence of spermidine were systematically investigated both from experimental and theoretical points of view. The hydrodynamic radii and the corresponding polydispersity indices of the colloidal silica particles were determined by dynamic light scattering (DLS) as a function of spermidine concentration. Whereas the effective size of the silica particles increases with increasing spermidine concentration (pointing to the particle aggregation), the polydispersity index first increases reaches a maximum and then further decreases with the increasing spermidine concentration. From the mobility measurements it was concluded that the increase in spermidine concentration causes less negative values of zeta potential, meaning that the adsorption of spermidine leads to the less negative silica surface. Moreover, Monte Carlo (MC) simulations also confirmed that the addition of spermidine reduces the repulsion between silica particles. The MC concentration profiles of spermidine close to the charged silica particle are in a very good agreement with the results obtained by theory. An important motivation for our study is the effectiveness of multivalent ions to coagulate colloidal suspensions; e.g., the multivalent ions are exploited in the water purification process.
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Affiliation(s)
- Jurij Reščič
- Faculty of Chemistry and Chemical Technology and §Faculty of Health Sciences, University of Ljubljana , Ljubljana, Slovenia
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Preedy E, Perni S, Nipiĉ D, Bohinc K, Prokopovich P. Surface roughness mediated adhesion forces between borosilicate glass and gram-positive bacteria. Langmuir 2014; 30:9466-76. [PMID: 25019516 DOI: 10.1021/la501711t] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
It is well-known that a number of surface characteristics affect the extent of adhesion between two adjacent materials. One of such parameters is the surface roughness as surface asperities at the nanoscale level govern the overall adhesive forces. For example, the extent of bacterial adhesion is determined by the surface topography; also, once a bacteria colonizes a surface, proliferation of that species will take place and a biofilm may form, increasing the resistance of bacterial cells to removal. In this study, borosilicate glass was employed with varying surface roughness and coated with bovine serum albumin (BSA) in order to replicate the protein layer that covers orthopedic devices on implantation. As roughness is a scale-dependent process, relevant scan areas were analyzed using atomic force microscope (AFM) to determine Ra; furthermore, appropriate bacterial species were attached to the tip to measure the adhesion forces between cells and substrates. The bacterial species chosen (Staphylococci and Streptococci) are common pathogens associated with a number of implant related infections that are detrimental to the biomedical devices and patients. Correlation between adhesion forces and surface roughness (Ra) was generally better when the surface roughness was measured through scanned areas with size (2 × 2 μm) comparable to bacteria cells. Furthermore, the BSA coating altered the surface roughness without correlation with the initial values of such parameter; therefore, better correlations were found between adhesion forces and BSA-coated surfaces when actual surface roughness was used instead of the initial (nominal) values. It was also found that BSA induced a more hydrophilic and electron donor characteristic to the surfaces; in agreement with increasing adhesion forces of hydrophilic bacteria (as determined through microbial adhesion to solvents test) on BSA-coated substrates.
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Affiliation(s)
- Emily Preedy
- Cardiff School of Pharmacy and Pharmaceutical Science and ‡Cardiff School of Engineering, Cardiff University , Cardiff CF10 3XQ, UK
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Abstract
The larger permeability of anions than cations through a lipid bilayer can be rationalized by the positive sign of the bilayer's dipole potential. That is, upon crossing the lipid headgroups toward the hydrocarbon chain region, the electrostatic potential increases by several hundred millivolts. We derive an analytic expression for the dipole potential of a single lipid layer using an electrostatic model that is based on an extended version of the linearized Poisson-Boltzmann theory. The model highlights the ability of the lipid headgroups to render the dipole potential positive by inducing an orientational ordering of the solvent molecules. The positive contribution of the solvent overcompensates the negative dipole potential due to the bare lipids. Our theoretical prediction compares accurately with measurements of the dipole potential that we have conducted for mixed anionic-zwitterionic lipid monolayers at the air-water interface.
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Affiliation(s)
- Klemen Bohinc
- Faculty of Health Sciences, University of Ljubljana , Zdravstvena 5, SI-1000 Ljubljana, Slovenia
| | - Juan J Giner-Casares
- BioNanoPlasmonics Lab, CIC biomaGUNE , 20009 Donostia - San Sebastian, Spain.,Department of Physical Chemistry and Applied Thermodynamics, University of Cordoba , Campus de Rabanales, Edificio Marie Curie, Cordoba E-14014, Spain
| | - Sylvio May
- Department of Physics, North Dakota State University , Fargo, North Dakota 58108-6050, United States
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Zhang W, Li N, Bohinc K, Tong P, Chen W. Universal scaling of correlated diffusion in colloidal monolayers. Phys Rev Lett 2013; 111:168304. [PMID: 24182309 DOI: 10.1103/physrevlett.111.168304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 06/29/2013] [Indexed: 06/02/2023]
Abstract
Using the techniques of optical microscopy and particle tracking, we measure the correlated diffusion in a monolayer of uniform silica spheres dispersed at a water-air interface. It is found that the correlated motion of the interfacial particles can be well described by two universal response functions, the normalized longitudinal and transverse diffusion coefficients D(∥)(r/r0) and D(⊥)(r/r0), where r is the interparticle distance and r0=a(λS/a)(3/2) is a new scaling length, which depends on both the Saffman length λS and particle radius a. The obtained response functions characterize the crossover behavior of the colloidal monolayers from the subphase-dominated three-dimensional hydrodynamics at low surface coverage to the monolayer-dominated 2D hydrodynamics at high concentrations. The surface viscosity ηs(2) of the colloidal monolayer obtained by two-particle rheology compares well with the one-particle measurements.
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Affiliation(s)
- Wei Zhang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China and Department of Physics, Jinan University, Guangzhou 510632, China
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Affiliation(s)
- Klemen Bohinc
- Faculty
of Health Sciences, University of Ljubljana, Zdravstvena 5, SI-1000 Ljubljana, Slovenia
| | - Jurij Reščič
- Faculty
of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva
5, SI-1000 Ljubljana, Slovenia
| | - Jean-Francois Dufreche
- Institut
de Chimie Separative de Marcoule, Universite de Montpellier, 30207 Bagnols sur Ceze
Cedex, France
| | - Leo Lue
- Department
of Chemical and Process Engineering, James Weir Building, University of Strathclyde, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom
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