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  • 1.
    Bastardo Zambrano, Luis Alejandro
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Iruthayaraj, Joseph
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Dédinaité, Andra
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Vareikis, Aušvydas
    Department of Polymer Chemistry, Vilnius University.
    Makuška, Ričardas
    Department of Polymer Chemistry, Vilnius University.
    van der Wal, Albert
    Lever Faberage Europe Global Technology Centre, Unilever R and D.
    Furó, István
    KTH, Skolan för kemivetenskap (CHE), Kemi, Fysikalisk kemi.
    Garamus, Vasil M.
    GKSS Research Centre.
    Claesson, Per M.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Soluble complexes in aqueous mixtures of low charge density comb polyelectrolyte and oppositely charged surfactant probed by scattering and NMR2007Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 312, nr 1, s. 21-33Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A low charge density polyelectrolyte with a high graft density of 45 units long poly(ethylene oxide) side-chains has been synthesized. In this comb polymer, denoted PEO(45)MEMA:METAC-2, 2 mol% of the repeating methacrylate units in the polymer backbone carry a permanent positive charge and the remaining 98 mol% a 45 unit long PEO side-chain. Here we describe the solution conformation of this polymer and its association with an anionic surfactant, sodium dodecylsulfate, SDS. It will be shown that the polymer can be viewed as a stiff rod with a cross-section radius of gyration of 29 A. The cross section of the rod contracts with increasing temperature due to decreased solvency of the PEO side-chains. The anionic surfactant associates to a significant degree with PE045MEMA:METAC-2 to form soluble complexes at all stoichiometries. A cooperative association is observed as the free SDS concentration approaches 7 mM. At saturation the number of SDS molecules associated with the polymer amounts to 10 for each PEO side-chain. Two distinct populations of associated surfactants are observed, one is suggested to be molecularly distributed over the comb polymer and the other constitutes small micellar-like structures at the periphery of the aggregate. These conclusions are reached based on results from small-angle neutron scattering, static light scattering, NMR, and surface tension measurements.

  • 2.
    Blomberg, Eva
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Kärnkemi.
    Layer-by-Layer Assembly of Biomacromolecules2011Inngår i: Encyclopedia of Surface and Colloid Science, SecondEdition / [ed] P. Somasundaran, London: Taylor & Francis, 2011, 1, s. 1-14Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The ability to construct thin films with controlled thickness on almost any type of surface is of great interestin many research fields. For biomedical applications, thin films on medical devices have been found toimprove the biocompatibility, reduce the immunological response, and deliver medical drugs locally. Thelayer structure is closely related to the function and efficiency of such films. During the last decades, it hasbeen shown that the layer-by-layer (LbL) assembly of charged macromolecules has created an inexpensiveroute to the formation of thin multilayer films, and the interest in using biomacromolecules (e.g., polysaccharidesand proteins) has emerged in recent years. The LbL technique offers unique opportunities forcontrolling the physical properties of thin surface layers, such as film thickness, chemical and elasticproperties, and stability. In this entry, we will focus on recent advances in the multilayer film area usingbiomacromolecules. We will discuss how different physicochemical properties of biomacromolecules andof the deposition solution affect the formation and structure of LbL-assembled multilayer. Finally, we willaddress some suggested applications for these biopolymer film coatings.

  • 3.
    Feldötö, Zsombor
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Braesch-Andersen, Sten
    Mabtech AB, Sweden.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. Institute for Surface Chemistry, Sweden.
    Adsorption of IgG on/in a PAH/PSS Multilayer Film: Layer Structure and Cell Response2011Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 354, nr 1, s. 31-37Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The binding of immunogloblulins (IgG) (mouse monoclonal recognizing IFN gamma) on precoated polystyrene or silica surfaces by the layer-by-layer technique has been investigated with QCM-D and DPI. The aim of the work was to increase the sensitivity of the conventional enzyme-linked immunosorbent spot (ELISpot) assay. The polyelectrolytes used to build the multilayers were poly(allylamine hydrochloride) (PAH)/poly(sodium 4-styrenesulfonate) (PSS) alternately adsorbed from 150 mM NaCl. The multilayer build up is linear and the internal structure of the PAH/PSS multilayer is compact and rigid as observed by low relative water content (20-25%) and high layer refractive index (n similar to 1.5) after the formation of five bilayers. Incorporation of IgG within the PAH/PSS multilayer did not give rise to overcharging and did not affect the linear build up. ELISpot test on PAH/PSS multilayer modified polystyrene wells showed that the cytokine response was significantly smaller than on the regular PVDF backed polystyrene wells. This may be due to the compact and rigid nature of the PAH/PSS multilayer, which does not allow formation of the kind of three dimensional support needed to achieve bioactive IgG binding to the surface. Immunological tests of the polyelectrolyte multilayers in the absence of IgG showed that PSS terminated PAH/PSS multilayer did not induce any cytokine response whereas PAH terminated did, which suggests that PSS totally covers the surface from the cells point of view.

  • 4.
    Hedberg, Jonas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lowe, Troy
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Wold, Susanna
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Interactions between surfactants and silver nanoparticles of varying charge2012Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 369, nr 1, s. 193-201Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The interaction between silvernanoparticles (Ag NPs) of different surface charge and surfactants relevant to the laundry cycle has been investigated to understand changes in speciation, both in and during transport from the washing machine. Ag NPs were synthesized to exhibit either a positive or a negative surface charge in solution conditions relevant for the laundry cycle (pH 10 and pH 7). These particles were characterized in terms of size and surface charge and compared to commercially laser ablated Ag NPs. The surfactants included anionic sodium dodecylbenzenesulfonate (LAS), cationic dodecyltrimethylammoniumchloride (DTAC) and nonionic Berol 266 (Berol). Surfactant–Ag NP interactions were studied by means of dynamic light scattering, Raman spectroscopy, zeta potential, and Quartz Crystal Microbalance. Mixed bilayers of CTAB and LAS were formed through a co-operative adsorption process on positively charged Ag NPs with pre-adsorbed CTAB, resulting in charge reversal from positive to negative zeta potentials. Adsorption of DTAC on negatively charged synthesized Ag NPs and negatively charged commercial Ag NPs resulted in bilayer formation and charge reversal. Weak interactions were observed for nonionic Berol with all Ag NPs via hydrophobic interactions, which resulted in decreased zeta potentials for Berol concentrations above its critical micelle concentration. Differences in particle size were essentially not affected by surfactant adsorption, as the surfactant layer thicknesses did not exceed more than a few nanometers. The surfactant interaction with the Ag NP surface was shown to be reversible, an observation of particular importance for hazard and environmental risk assessments.

  • 5.
    Hedberg, Yolanda
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Jacksén, Johan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Analytisk kemi.
    Emmer, Åsa
    KTH, Skolan för kemivetenskap (CHE), Kemi, Analytisk kemi.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Wallinder, Inger Odnevall
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Chromium-protein complexation studies by adsorptive cathodic stripping voltammetry and MALDI-TOF-MS2012Inngår i: Journal of Applied Electrochemistry, ISSN 0021-891X, E-ISSN 1572-8838, Vol. 42, nr 5, s. 349-358Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A methodology using stripping voltammetry has been elaborated to enable sensitive and reliable protein-chromium complexation measurements. Disturbing effects caused by adsorption of proteins on the mercury electrode were addressed. At low concentrations of proteins (< 60-85 nM), chromium-protein complexation measurements were possible. Chromium(VI) complexation was quantitatively determined using differently sized, charged, and structured proteins: serum albumin (human and bovine), lysozyme, and mucin. Generated results showed a strong relation between complexation and protein size, concentration, and the number of amino acids per protein mass. Complexation increased nonlinearly with increasing protein concentrations. The nature of this complexation was based on weak interactions judged from combined results with MALDI-TOF-MS and adsorptive cathodic stripping voltammetry.

  • 6.
    Hedberg, Yolanda
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Wang, Xin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Hedberg, Jonas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Surface-protein interactions on different stainless steel grades: effects of protein adsorption, surface changes and metal release2013Inngår i: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 24, nr 4, s. 1015-1033Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Implantation using stainless steels (SS) is an example where an understanding of protein-induced metal release from SS is important when assessing potential toxicological risks. Here, the protein-induced metal release was investigated for austenitic (AISI 304, 310, and 316L), ferritic (AISI 430), and duplex (AISI 2205) grades in a phosphate buffered saline (PBS, pH 7.4) solution containing either bovine serum albumin (BSA) or lysozyme (LSZ). The results show that both BSA and LSZ induce a significant enrichment of chromium in the surface oxide of all stainless steel grades. Both proteins induced an enhanced extent of released iron, chromium, nickel and manganese, very significant in the case of BSA (up to 40-fold increase), whereas both proteins reduced the corrosion resistance of SS, with the reverse situation for iron metal (reduced corrosion rates and reduced metal release in the presence of proteins). A full monolayer coverage is necessary to induce the effects observed.

  • 7.
    Lowe, Troy A.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Hedberg, Jonas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Wold, Susanna
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Chemical Speciation Measurements of Silver Ions in Alkaline Carbonate Electrolytes Using Differential Pulse Stripping Voltammetry on Glassy Carbon Compared With Ion Selective Electrode Measurements2013Inngår i: International Journal of Electrochemical Science, ISSN 1452-3981, E-ISSN 1452-3981, Vol. 8, nr 3, s. 3851-3865Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Given the increasing incorporation of silver nanoparticles as an antibacterial additive in washing machines and textiles, sensitive methods for accurate determination of Ag+ ions in laundry relevant electrolytes (alkaline carbonate) are required. The most widely reported method, the silver ion selective electrode (ISE), lacked sensitivity and accuracy and was affected by the concentration of Na2CO3 in solution. Differential pulse stripping voltammetry (DPSV) on glassy carbon electrodes (GCE) was therefore investigated as an alternative technique. Surface preparation of the GCE surface was essential and a suitable procedure was developed. A linear response was observed from 0 to 180 mg L-1 with a lower detection limit of 500 ng L-1 (5 nM). DPSV was shown to be significantly more sensitive and accurate in determining the Ag+ activity than the silver ISE technique, particularly below 200 nM.

  • 8.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Adsorption of biopolymers and their layer-by-layer assemblies on hydrophilic surfaces2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    It is widely known that surfaces play an important role in numerous biological processes and technological applications. Thus, being able to modify surface properties provides an opportunity to control many phenomena occurring at interfaces. One way of controlling surface properties is to adsorb a polymer film onto the surface, for example through layer-by-layer (LbL) deposition of polyelectrolytes. This simple but versatile technique enables various polymers, proteins, colloidal particles etc. to be incorporated into the film, resulting in a multifunctional coating. Due to recent legislations and a consumer demand for more environmentally friendly products, we have chosen to use natural polymers (biopolymers) from renewable resources. The focus of this thesis has been on the adsorption of biopolymers and their layer-by-layer formation at solid-liquid interfaces; these processes have been studied by a wide range of techniques. The main method was the quartz crystal microbalance with dissipation monitoring (QCM-D), which measures the adsorbed mass, including trapped solvent and the viscoelastic properties of an adsorbed film. This technique was often complemented with an optical method, such as ellipsometry or dual polarization interferometry (DPI), which provided information about the “dry” polymer or protein adsorbed mass. From this combination, the solvent content and density of the layers was evaluated. In addition, the surface force apparatus (SFA), X-ray photoelectron spectroscopy (XPS), total internal reflection fluorescence (TIRF), and fluorescence resonance energy transfer (FRET) were utilized, providing further information about the film structure, chemical composition, and polymer inter-layer diffusion. Adsorption studies of the glycoprotein mucin, which has a key role in the mucousal function, showed that despite the net negative charge of mucin, it adsorbed on negatively charged substrates. The adsorbed layer was highly hydrated and the segment density on the substrate was low. We showed the importance of characterizing the mucin used, since differences in purity, such as the presence of albumin, gave rise to different adsorption behaviours in terms of both adsorbed amount and structure. The adsorbed mucin layer was to a large extent desorbed upon exposure to the anionic surfactant sodium dodecyl sulfate (SDS). In order to prevent desorption, we demonstrated that a protective layer of the cationic polysaccharide chitosan could be adsorbed onto the mucin layer and that the mucin-chitosan complexes resisted the desorption normally induced by association with SDS. Moreover, the association between chitosan and SDS was examined at the solid-liquid interface, in the bulk, and at the air-water interface. In all these environments chitosan-SDS complexes were formed and a net charge reversal of the complexes from positive to negative was observed when the concentration of SDS was increased. Furthermore, the LbL deposition method could be used to form a multilayer-like film by alternate adsorption of mucin and chitosan on silica substrates. The LbL technique was also applied to two proteins, lysozyme and β-casein with the aim of building a multilayer film consisting entirely of proteins. These proteins formed complexes at the solid-liquid interface, resulting in a proteinaceous layer, but the build-up was highly irregular with an increase in adsorbed amount per protein deposition cycle that was far less than a monolayer.Continuing with chitosan, known to have antibacterial properties we assembled multilayers with an anti-adhesive biopolymer, heparin, to evaluate the potential of this system as a coating for medical implants. Multilayers were assembled under various solution deposition conditions and the film structure and dynamics were studied in detail. The chitosan-heparin film was highly hydrated, in the range 60-80 wt-% depending on the deposition conditions. The adsorbed amount and thickness of the film increased exponential-like with the number of deposition steps, which was explained by inter-diffusion of chitosan molecules in the film during the build-up. In a novel approach, we used the distant dependent FRET technique to prove the inter-layer diffusion of fluorescent-labelled chitosan molecules within the film. The diffusion coefficient was insignificantly dependent on the deposition pH and ionic strength, and hence on the film structure. With the use of a pH sensitive dye buried under seven chitosan-heparin bilayers, we showed that the dye remained highly sensitive to the charge of the outermost layer. From complementary QCM-D data, we suggested that an increase in the energy dissipation does not necessarily indicate that the layer structure becomes less rigid.

  • 9.
    Lundin, Maria
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Tilton, Robert D
    Carnegie Mellon University, Pittsburgh, USA.
    Polymer Dynamics in Layer-by-Layer Assemblies of Chitosan and Heparin2010Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 26, nr 5, s. 3242-3251Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The layer-by-layer deposition method has been used to build a multilayer thin film with two polysaccharides, chitosan CH (weak polycation) and heparin HEP (strong polyanion), on planar quartz surfaces. The film structure and dynamics in aqueous Solution were studied with fluorescence resonance energy transfer (FRET) and total internal reflection fluorescence (TIRF). Particular emphasis was placed on the effect of deposition conditions, i.e.. pH and salt concentration, on the out-of-plane (vertical) diffusion of fluorescence labeled chitosan in the chitosan/heparin (CH/HEP) film. FRET analysis showed that CH molecules diffused within the film with a diffusion coefficient that was not significantly sensitive to the deposition pH and Solution ionic strength. A pH-sensitive label bound to CH embedded within the CH/HEP Film wits sensitive to the charge of the outermost polymer layer even when buried under 14 alternate layers of CH and HER A consideration of the results obtained with both fluorescence techniques showed that the structure of the CH/HEP thin film wits highly interpenetrated without clear boundaries between each layer. These results are consistent with the hypothesis that the previously observed exponential-like film growth of CH and HEP in terms of, layer thickness and deposited amount versus deposition cycle can be attributed to out-of-plane diffusion of CH molecules in the multilayer.

  • 10.
    Lundin, Maria
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Elofsson, Ulla
    YKI, Institute for Surface Chemistry, Stockholm.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Rutland, Mark
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Adsorption of lysozyme, beta-casein and their layer-by-layer formation on hydrophilic surfaces: Effect of ionic strength2010Inngår i: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 77, nr 1, s. 1-11Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The adsorbed amount and layer structure of lysozyme, beta-casein and mixed layers of the two proteins were studied on hydrophilic silica and quartz surfaces using the following techniques: ellipsometry, quartz crystal microbalance with dissipation monitoring (QCM-D) and total internal reflection fluorescence (TIRF). Particular emphasis was put on the effect of solution ionic strength on the layer formation. Both lysozyme and beta-casein showed a higher affinity for the silica surface when adsorbed from a solution of low ionic strength even though beta-casein and silica are negatively charged at the pH used. No beta-casein remained adsorbed after rinsing with a 150 mM buffer solution. The adsorbed amount of lysozyme on silica exceeded a monolayer coverage irrespective of the solution conditions and displayed a rigid structure. beta-Casein forms more than a single layer on pre-adsorbed lysozyme; an inner flat layer and an outer layer with an extended structure, which largely desorbs on rinsing. The build-up through sequential adsorption of lysozyme and beta-casein is favoured at intermediate and high ionic strength. The total adsorbed amount increased slightly with each deposition cycle and the mixed lysozyme/beta-casein layers contain higher amounts of protein compared to those of pure lysozyme or beta-casein. Sequential adsorption gives rise to a proteinaceous layer consisting of both lysozyme and beta-casein. The protein layers are probably highly interpenetrated with no clear separation between them.

  • 11.
    Lundin, Maria
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Kärnkemi (stängd 20110630).
    Hedberg, Yolanda
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Jiang, T.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Herting, Gunilla
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Wang, X.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Thormann, Esben
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Adsorption and protein-induced metal release from chromium metal and stainless steel2012Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 366, nr 1, s. 155-164Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A research effort is undertaken to understand the mechanism of metal release from, e.g., inhaled metal particles or metal implants in the presence of proteins. The effect of protein adsorption on the metal release process from oxidized chromium metal surfaces and stainless steel surfaces was therefore examined by quartz crystal microbalance with energy dissipation monitoring (QCM-D) and graphite furnace atomic absorption spectroscopy (GFAAS). Differently charged and sized proteins, relevant for the inhalation and dermal exposure route were chosen including human and bovine serum albumin (HSA, BSA), mucin (BSM), and lysozyme (LYS). The results show that all proteins have high affinities for chromium and stainless steel (AISI 316) when deposited from solutions at pH 4 and at pH 7.4 where the protein adsorbed amount was very similar. Adsorption of albumin and mucin was substantially higher at pH 4 compared to pH 7.4 with approximately monolayer coverage at pH 7.4, whereas lysozyme adsorbed in multilayers at both investigated pH. The protein-surface interaction was strong since proteins were irreversibly adsorbed with respect to rinsing. Due to the passive nature of chromium and stainless steel (AISI 316) surfaces, very low metal release concentrations from the QCM metal surfaces in the presence of proteins were obtained on the time scale of the adsorption experiment. Therefore, metal release studies from massive metal sheets in contact with protein solutions were carried out in parallel. The presence of proteins increased the extent of metals released for chromium metal and stainless steel grades of different microstructure and alloy content, all with passive chromium(III)-rich surface oxides, such as QCM (AISI 316), ferritic (AISI 430), austentic (AISI 304, 316L), and duplex (LDX 2205).

  • 12.
    Lundin, Maria
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Macakova, Lubica
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Auletta, Tommaso
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Mucin−Chitosan Complexes at the Solid−Liquid Interface:  Multilayer Formation and Stability in Surfactant Solutions2005Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, s. 9502-9509Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The adsorption of a biologically important glycoprotein, mucin, and mucin-chitosan complex layer formation on negatively charged surfaces, silica and mica, have been investigated employing ellipsometry, the interferometric surface apparatus, and atomic force microscopy techniques. Particular attention has been paid to the effect of an anionic surfactant sodium, dodecyl sulfate (SDS), with respect to the stability of the adsorption layers. It has been shown that mucin adsorbs on negatively charged surfaces to form highly hydrated layers. Such mucin layers readily associate with surfactants and are easily removed from the surfaces by rinsing with solutions of SDS at concentrations >= 0.2 cmc (1 cmc SDS in 30 mM NaCl is equal to 3.3 mM). The mucin adsorption layer is negatively charged, and we show how a positively charged polyelectrolyte, chitosan, associates with the preadsorbed mucin to form mucin-chitosan complexes that resist desorption by SDS even at SDS concentrations as high as 1 cmc. Thus, a method of mucin layer protection against removal by surfactants is offered. Further, we show how mucin-chitosan multilayers can be formed.

  • 13.
    Lundin, Maria
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Macakova, L.ubica
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Dedinaite, Andra
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Claesson, Per Martin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Interactions between Chitosan and SDS at a Low-Charged Silica Substrate Compared to Interactions in the Bulk: The Effect of Ionic Strength2008Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 24, nr 8, s. 3814-3827Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effect of ionic strength on association between the cationic polysaccharide chitosan and the anionic surfactant sodium dodecyl sulfate, SDS, has been studied in bulk solution and at the solid/liquid interface. Bulk association was probed by turbidity, clectrophoretic mobility, and surface tension measurements. The critical aggregation concentration, cac, and the saturation binding of surfactants were estimated from surface tension data. The number of associated SDS molecules per chitosan segment exceeded one at both salt concentrations. As a result, a net charge reversal of the polymer-surfactant complexes was observed, between 1.0 and 1.5 mM SDS, independent of ionic strength. Phase separation occurs in the SDS concentration region where low charge density complexes form, whereas at high surfactant concentrations (up to several multiples of cmc SDS) soluble aggregates are formed. Ellipsometry and QCM-D were employed to follow adsorption of chitosan onto low-charged silica substrates, and the interactions between SDS and preadsorbed chitosan layers. A thin (0.5 nm) and rigid chitosan layer was formed when adsorbed from a 0.1 mM NaNO3 solution, whereas thicker (2 nm) chitosan layers with higher dissipation/unit mass were formed from solutions at and above 30 mM NaNO3. The fraction of solvent in the chitosan layers was high independent of the layer thickness and rigidity and ionic strength. In 30 mM NaNO3 Solution, addition of SDS induced a collapse at low concentrations, while at higher SDS concentrations the viscoelastic character of the layer was recovered. Maximum adsorbed mass (chitosan + SDS) was reached at 0.8 times the cmc of SDS, after which surfactant-induced polymer desorption occurred. In 0.1 mM NaNO3. the initial collapse was negligible and further addition of surfactant lead to the formation of a nonrigid, viscoelastic polymer layer until desorption began above a surfactant concentration of 0.4 times the cmc of SDS.

  • 14.
    Lundin, Maria
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Sandberg, Tomas
    BMC, Uppsala University.
    Caldwell, Karin D.
    BMC, Uppsala University.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Comparison of the Adsorption Kinetics and Surface Arrangement of "As Received" and Purified Bovine Submaxillary Gland Mucin(BSM) on Hydrophilic Surfaces2009Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 336, s. 30-39Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effect of bovine serum albumin (BSA) as impurity in a commercial bovine submaxillary gland mucin preparation (BSM; Sigma M3895) on the adsorption of BSM to hydrophilic surfaces (mica and silica) has been Studied in terms of adsorption kinetics, amount and structure of the formed adlayer. The Surface Force Apparatus (SFA) was used to gain information about the extended and compressed structure of adsorbed "as received" BSM, purified BSM, BSA extracted from the "as received" BSM and mixtures of the latter Purified proteins. The adsorbed amount was estimated using a combination of X-ray Photoelectron Spectroscopy (XPS), Enzyme-Linked Immuno Sorbent Assay (ELISA), Enzyme-Linked Lectin Assay (ELLA), Dual Polarization Interferometry (DPI) and Quartz Crystal Microbalance (QCM-D) measurements. Under the used conditions, purified BSM showed very low affinity for silica and only small amounts were found to adsorb on mica. Initially, the BSM molecules adopted an extended conformation on the mica surface with tails extending into the bulk phase. These tails were irreversibly compressed into a very thin (10 A) layer upon applying a high load. "As received" BSM formed considerably thicker Compressed layers (35 A); however, the extended layer structure was qualitatively the same. When Mixtures of purified BSM and BSA were coadsorbed on mica, a 9 wt-% albumin content gave a comparable layer thickness as the "as received" BSM and from XPS data we draw the conclusion that the albumin content in the layer adsorbed from "as received" BSM was approximately 5 wt-%. Adsorption from an equal amount of BSM and BSA revealed that even though the amount of BSM is scarce in the mixed layer, the few BSM molecules have a drastic effect on the adsorbed thickness and Structure. Clearly, this study shows the importance of characterizing the mucin used since differences in purity give rise to different adsorption behaviours in terms of both adsorbed amount and layer Structure.

  • 15.
    Lundin, Maria
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Solaqa, Faten
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Thormann, Esben
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Macakova, Lubica
    Institute for Surface Chemistry, Sweden.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. Institute for Surface Chemistry, Sweden.
    Layer-by-layer assemblies of chitosan and heparin: effect of solution ionic strength and pH2011Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 27, nr 12, s. 7537-7548Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The growth of polysaccharide multilayers consisting of positively charged chitosan (CH) and negatively charged heparin (HEP) was monitored in situ by employing a quartz crystal microbalance (QCM-D) and dual-polarization interferometry (DPI). The main focus was on how the physicochemical properties of the solution affect the growth and structure of the resulting multilayer film These results showed that when increasing the ionic strength of the polysaccharide solutions at a fixed pH, both the "dry" (optical) (DPI) mass and wet (QCM) mass of the adsorbed multilayer film increased. The same effect was found when increasing the pH while keeping the ionic strength constant. Furthermore, the growth of multilayers showed an exponential-like behavior independent of the solution conditions that were used in this study. It was also established that chitosan was the predominant species present in the chitosan heparin multilayer film. We discuss the viscoelastic properties of the adsorbed layers and their variation during the multilayer buildup. Interestingly and contrary to common interpretation of the QCM-D results, we found that under one particular solution condition (pH 4.2 and 30 mM NaCl) the increase in the dissipation of oscillation energy from the adsorbed layer was a consequence of layer stiffening rather than indicating a more hydrated and viscous film. On the basis of the widely used Voigt viscoelastic model for an adsorbed layer, we show that it is the film viscosity and shear that define the layer viscoelasticity (structure) of the film and not the absolute value of energy dissipation, which in fact can be very misleading.

  • 16. Shi, J.
    et al.
    Hedberg, Yolanda
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Karlsson, H. L.
    Möller, L.
    Hemolytic properties of synthetic nano- and porous silica particles: The effect of surface properties and the protection by the plasma corona2012Inngår i: Acta Biomaterialia, ISSN 1742-7061, E-ISSN 1878-7568, Vol. 8, nr 9, s. 3478-3490Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Novel silica materials incorporating nanotechnology are promising materials for biomedical applications, but their novel properties may also bring unforeseen behavior in biological systems. Micro-size silica is well documented to induce hemolysis, but little is known about the hemolytic activities of nanostructured silica materials. In this study, the hemolytic properties of synthetic amorphous silica nanoparticles with primary sizes of 7-14 nm (hydrophilic vs. hydrophobic), 5-15 nm, 20 nm and 50 nm, and model meso/macroporous silica particles with pore diameters of 40 nm and 170 nm are investigated. A crystalline silica sample (0.5-10 ÎŒm) is included for benchmarking purposes. Special emphasis is given to investigations of how the temperature and solution complexity (solvent, plasma), as well as the physicochemical properties (such as size, surface charge, hydrophobicity and other surface properties), link to the hemolytic activities of these particles. Results suggests the potential importance of small size and large external surface area, as well as surface charge/structure, in the hemolysis of silica particles. Furthermore, a significant correlation is observed between the hemolytic profile of red blood cells and the cytotoxicity profile of human promyelocytic leukemia cells (HL-60) induced by nano- and porous silica particles, suggesting a potential universal mechanism of action. Importantly, the results generated suggest that the protective effect of plasma towards silica nanoparticle-induced hemolysis as well as cytotoxicity is primarily due to the protein/lipid layer shielding the silica particle surface. These results will assist the rational design of hemocompatible silica particles for biomedical applications.

  • 17.
    Shi, Jingwen
    et al.
    Karolinska Inst, Stockholm, Sweden.
    Hedberg, Yolanda
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Karlsson, Hanna
    Karolinska Inst, Stockholm, Sweden.
    Möller, Lennart
    Karolinska Inst, Stockholm, Sweden.
    Hemolysis of silica particles: Importance of surface properties and plasma corona2012Inngår i: Toxicology Letters, ISSN 0378-4274, E-ISSN 1879-3169, Vol. 211, s. S203-S203Artikkel i tidsskrift (Annet vitenskapelig)
  • 18.
    Skoglund, Sara
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Lowe, Troy A.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Hedberg, Jonas
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Blomberg, Eva
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Wold, Susanna
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Lundin, Maria
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Effect of Laundry Surfactants on Surface Charge and Colloidal Stability of Silver Nanoparticles2013Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 29, nr 28, s. 8882-8891Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The stability of silver nanoparticles (Ag NPs) potentially released from clothing during a laundry cycle and their interactions with laundry-relevant surfactants [anionic (LAS), cationic (DTAC), and nonionic (Berol)] have been investigated. Surface interactions between Ag NPs and surfactants influence their speciation and stability. In the absence of surfactants as well as in the presence of LAS, the negatively charged Ag NPs were stable in solution for more than 1 day. At low DTAC concentrations (<= 1 mM), DTAC-Ag NP interactions resulted in charge neutralization and formation of agglomerates. The surface charge of the particles became positive at higher concentrations due to a bilayer type formation of DTAC that prevents from agglomeration due to repulsive electrostatic forces between the positively charged colloids. The adsorption of Berol was enhanced when above its critical micelle concentration (cmc). This resulted in a surface charge dose to zero and subsequent agglomeration. Extended DLVO theory calculations were in compliance with observed findings. The stability of the Ag NPs was shown to depend on the charge and concentration of the adsorbed surfactants. Such knowledge is important as it may influence the subsequent transport of Ag NPs through different chemical transients and thus their potential bioavailability and toxicity.

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