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  • 1. Badell, Maria Valldeperas
    et al.
    Dabkowska, Aleksandra
    Naidjonoka, Polina
    Welbourn, Rebecca
    Palsson, Gunnar K.
    Barauskas, Justas
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Nylander, Tommy
    Lipid Sponge-Phase Nanoparticles as Carriers for Enzymes2018In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 114, no 3, suppl 1, p. 15A-15AArticle in journal (Other academic)
    Abstract [en]

    Immobilization of enzymes into different support materials has been widely studied as means to control their activity and stability. Here we will consider lipid liquid crystalline phases as enzyme carriers, as they have been demonstrated to have a high potential in a range of applications such as drug delivery, protein encapsulation or crystallization thanks to the wide range of self-assembly structures they can form, which have cavities of nano-scale dimensions. Furthermore, such structures have also been observed in a range of living organisms. Although, reverse cubic or hexagonal lipid aqueous phase can be used to entrap smaller biomolecules, it is still challenging to encapsulate bioactive macromolecules, such as proteins. Here, we will present a novel lipid system able to form highly swollen sponge phases (L3), with aqueous pores up to 13 nm of diameter. We will show that this structure is preserved even in excess aqueous solution, where they form sponge-like nanoparticles (L3 NPs) in which two enzymes of different sizes, Aspartic protease and beta-galactosidase (34 KDa and 460 KDa, respectively), could be included. To reveal the nature of the interaction between the enzymes and the lipid matrix, we studied the adsorption of both proteins on the lipid layers formed by the L3 NPs. The results will be discussed in terms of the ability of these nanoparticles to encapsulate and release of the proteins in the lipid matrix.

  • 2.
    Barauskas, Justas
    et al.
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Anderberg, Hanna
    Svendsen, Allan
    Nylander, Tommy
    Thermomyces lanuginosus lipase-catalyzed hydrolysis of the lipid cubic liquid crystalline nanoparticles2016In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 137, p. 50-59Article in journal (Refereed)
    Abstract [en]

    In this study well-ordered glycerol monooleate (GMO)-based cubic liquid crystalline nanoparticles (LCNPs) have been used as substrates for Thermomyces lanuginosus lipase in order to establish the relation between the catalytic activity, measured by pH-stat titration, and the change in morphology and nano-structure determined by cryogenic transmission electron microscopy and synchrotron small angle X-ray diffraction. The initial lipase catalyzed LCNP hydrolysis rate is approximately 25% higher for large 350 nm nanoparticles compared to the small 190 nm particles, which is attributed to the increased number of structural defects on the particle surface. At pH 8.0 and 8.4 bicontinuous Im3m cubic LCNPs transform into "sponge"-like assemblies and disordered multilamellar onion-like structures upon exposure to lipase. At pH 6.5 and 7.5 lipolysis induced phase transitions of the inner core of the particles, following the sequence Im3m cubic -> reversed hexagonal -> reversed micellar Fd3m cubic -> reversed micelles. These transitions to the liquid crystalline phases with higher negative curvature of the lipid/water interface were found to trigger protonation of the oleic acid produced during lipase catalyzed reaction. The increase curvature of the reversed discrete micellar cubic phase was suggested to cause an increase in the oleic acid pK(a) to a larger value observed by pH-stat titration. (C) 2015 Elsevier B.V. All rights reserved.

  • 3.
    Barauskas, Justas
    et al.
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Christerson, Lars
    Wadsater, Maria
    Lindström, Fredrick
    Lindqvist, Anna-Karin
    Tiberg, Fredrik
    Bioadhesive Lipid Compositions: Self-Assembly Structures, Functionality, and Medical Applications2014In: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392, Vol. 11, no 3, p. 895-903Article in journal (Refereed)
    Abstract [en]

    Lipid-based liquid crystalline compositions of phospholipids and diglycerides have unique bioadhesive properties with several medical applications, as exemplified by a lipid-based medical device indicated for management and relief of intraoral pain. The present paper describes the relation between self-assembly properties of phosphatidyl choline (PC) and glycerol dioleate (GDO) mixtures in the presence of aqueous fluids and functional attributes of the system, including: film formation and bioadhesion, intraoral coverage, acceptance by patients, and potential as a drug delivery system. The phase behavior of PC/GDO was characterized using synchrotron small-angle X-ray scattering. Functional properties, including the presence of study formulations at intraoral surfaces, ease of attachment, taste, and degree of and intraoral pain, were assessed in a crossover clinical pilot study in head and neck cancer patients. An optimum in functional properties was indicated for formulations with a PC/GDO weight ratio of about 35/65, where the lipids form a reversed cubic liquid crystalline micellar phase structure (Fd3m space group) over the relevant temperature range (25-40 degrees C).

  • 4. Chang, Debby P.
    et al.
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Dabkowska, Aleksandra P.
    Wadsäter, Maria
    Tiberg, Fredrik
    Nylander, Tommy
    Non-lamellar lipid liquid crystalline structures at interfaces2015In: Advances in Colloid and Interface Science, ISSN 0001-8686, E-ISSN 1873-3727, Vol. 222, p. 135-147Article, review/survey (Refereed)
    Abstract [en]

    The self-assembly of lipids leads to the formation of a rich variety of nano-structures, not only restricted to lipid bilayers, but also encompassing non-lamellar liquid crystalline structures, such as cubic, hexagonal, and sponge phases. These non-lamellar phases have been increasingly recognized as important for living systems, both in terms of providing compartmentalization and as regulators of biological activity. Consequently, they are of great interest for their potential as delivery systems in pharmaceutical, food and cosmetic applications. The compartmentalizing nature of these phases features mono- or bicontinuous networks of both hydrophilic and hydrophobic domains. To utilize these non-lamellar liquid crystalline structures in biomedical devices for analyses and drug delivery, it is crucial to understand how they interact with and respond to different types of interfaces. Such non-lamellar interfacial layers can be used to entrap functional biomolecules that respond to lipid curvature as well as the confinement. It is also important to understand the structural changes of deposited lipid in relation to the corresponding bulk dispersions. They can be controlled by changing the lipid composition or by introducing components that can alter the curvature or by deposition on nano-structured surface, e.g. vertical nano-wire arrays. Progress in the area of liquid crystalline lipid based nanoparticles opens up new possibilities for the preparation of well-defined surface films with well-defined nano-structures. This review will focus on recent progress in the formation of non-lamellar dispersions and their interfacial properties at the solid/liquid and biologically relevant interfaces.

  • 5. Chang, Debby P.
    et al.
    Dabkowska, Aleksandra P.
    Campbell, Richard A.
    Wadsater, Maria
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Tiberg, Fredrik
    Nylander, Tommy
    Interfacial properties of POPC/GDO liquid crystalline nanoparticles deposited on anionic and cationic silica surfaces2016In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, no 38, p. 26630-26642Article in journal (Refereed)
    Abstract [en]

    Reversed lipid liquid crystalline nanoparticles (LCNPs) of the cubic micellar (I-2) phase have high potential in drug delivery applications due to their ability to encapsulate both hydrophobic and hydrophilic drug molecules. Their interactions with various interfaces, and the consequences for the particle structure and integrity, are essential considerations in their effectiveness as drug delivery vehicles. Here, we have studied LCNPs formed of equal fractions of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and glycerol dioleate in the presence of different fractions of the stabilizer Polysorbate 80. We have used a combination of ellipsometry, quartz crystal microbalance with dissipation monitoring and neutron reflectometry to reveal the structure and composition of the adsorbed layer on both anionic silica and cationic (aminopropyltriethoxysilane) silanized surfaces. For both types of surfaces, there is a spread near-surface layer comprising lipid and polymer as well as a sparse coverage of intact particles. The composition of the near-surface layer is very close to that of the particles, in contrast to the lipid bilayer observed with related systems. The interaction is stronger for cationic than anionic surfaces, which is rationalized in terms of the negative zeta potential of the LCNPs. The work shows that the attachment of and spreading from LCNPs is influenced by the properties of the surface, the internal structure, composition and stability of the particles as well as the nature of the stabilizer.

  • 6. Chang, Debby P.
    et al.
    Jankunec, Marija
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Tiberg, Fredrik
    Nylander, Tommy
    Adsorption of lipid liquid crystalline nanoparticles: effects of particle composition, internal structure, and phase behavior2012In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 28, no 29, p. 10688-10696Article in journal (Refereed)
    Abstract [en]

    Controlling the interfacial behavior and properties of lipid liquid crystalline nanoparticles (LCNPs) at surfaces is essential for their application for preparing functional surface coatings as well as understanding some aspects of their properties as drug delivery vehicles. Here we have studied a LCNP system formed by mixing soy phosphatidylcholine (SPC), forming liquid crystalline lamellar structures in excess water, and glycerol dioleate (GDO), forming reversed structures, dispersed into nanoparticle with the surfactant polysorbate 80 (P80) as stabilizer. LCNP particle properties were controlled by using different ratios of the lipid building blocks as well as different concentrations of the surfactant P80. The LCNP size, internal structure, morphology, and charge were characterized by dynamic light scattering (DLS), synchrotron small-ange X-ray scattering (SAXS), cryo-transmission electron microscopy (cryo-TEM), and zeta potential measurements, respectively. With increasing SPC to GDO ratio in the interval from 35:65 to 60:40, the bulk lipid phase structure goes from reversed cubic micellar phase with Fd3m space group to reversed hexagonal phase. Adding P80 results in a successive shift toward more disorganized lamellar type of structures. This is also seen from cryo-TEM images for the LCNPs, where higher P80 ratios results in more extended lamellar layers surrounding the inner, more dense, lipid-rich particle core with nonlamellar structure. When put in contact with a solid silica surface, the LCNPs adsorb to form multilayer structures with a surface excess and thickness values that increase strongly with the content of P80 and decreases with increasing SPC:GDO ratio. This is reflected in both the adsorption rate and steady-state values, indicating that the driving force for adsorption is largely governed by attractive interactions between poly(ethylene oxide) (PEO) units of the P80 stabilizer and the silica surface. On cationic surface, i.e., silica modified with 3-aminopropltriethoxysilane (APTES), the slightly negatively charged LCNPs give rise to a very significant adsorption, which is relatively independent of LCNP composition. Finally, the dynamic thickness measurements indicate that direct adsorption of intact particles occurred on the cationic surface, while a slow buildup of the layer thickness with time is seen for the weakly interacting systems.

  • 7. Chang, Debby P.
    et al.
    Jankunec, Marija
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Tiberg, Fredrik
    Nylander, Tommy
    Adsorption of lipid liquid crystalline nanoparticles on cationic, hydrophilic, and hydrophobic surfaces2012In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 4, no 5, p. 2643-2651Article in journal (Refereed)
    Abstract [en]

    Investigation of nonlamellar nanoparticles formed by dispersion of self-assembled lipid liquid crystalline phases is stimulated by their many potential applications in science and technology; resulting from their unique solubilizing, encapsulating, and space-dividing nature. Understanding the interfacial behavior of lipid liquid crystalline nanoparticles (LCNPs) at surfaces can facilitate the exploitation of such systems for a number of potentially interesting uses, including preparation of functional surface coatings and uses as carriers of biologically active substances. We have studied the adsorption of LCNP, based on phosphatidylcholine/glycerol dioleate and Polysorbate 80 as stabilizers, at different model surfaces by use of in situ ellipsometry. The technique allows time-resolved monitoring of the layer thickness and the amount adsorbed, thereby providing insights into the restructuring of the lipid nanoparticle upon adsorption. The effects of solvent condition, electrolyte concentration, particle size, and surface chemistry on adsorbed layer properties were investigated. Furthermore, the internal structures of the particles were investigated by cryo-transmission electron microscopy and small angle X-ray diffraction on the corresponding liquid crystalline phases in excess water. LCNPs are shown to form well-defined layers at the solid–liquid interface with a structure and coverage that are determined by the interplay between the self-assembly properties of the lipids and lipid surface interactions, respectively. At the hydrophobic surface, hydrophobic interaction results in a structural transition from the original LCNP morphology to a monolayer structure at the interface. In contrast, at cationic and hydrophilic surfaces, relaxation is a relatively slow process, resulting in much thicker adsorbed layers, with thickness and adsorption behavior that to a greater extent reflect the original bulk LCNP properties.

  • 8.
    Cárdenas, Marité
    et al.
    Malmö högskola, Faculty of Health and Society (HS).
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS).
    Schillén, Karin
    Brennan, Jennifer
    Brust, Mattias
    Nylander, Tommy
    Thiol-Specific and Non-Specific Interactions Between DNA and Gold Nanoparticles2006In: Langmuir, Vol. 22, p. 3294-3299Article in journal (Refereed)
    Abstract [en]

    The contribution of nonspecific interactions to the overall interactions of thiol-ssDNA and dsDNA macromolecules with gold nanoparticles was investigated. A systematic investigation utilizing dynamic light scattering and cryogenic transmission electron microscopy has been performed to directly measure and visualize the changes in particle size and appearance during functionalization of gold nanoparticles with thiol-ssDNA and nonthiolated dsDNA. The results show that both thiol-ssDNA and dsDNA do stabilize gold nanoparticle dispersions, but possible nonspecific interactions between the hydrophobic DNA bases and the gold surface promote interparticle interactions and cause aggregation within rather a short period of time. We also discuss the adsorption mechanisms of dsDNA and thiol-ssDNA to gold particles.

  • 9. Dabkowska, A. P.
    et al.
    Hirst, C.
    Valldeperas, M.
    Clifton, L. A.
    Montis, C.
    Nöjd, S.
    Gentile, L.
    Wang, M.
    Pålsson, G. K.
    Lages, S.
    Berti, D.
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Nylander, T.
    Temperature responsive lipid liquid crystal layers with embedded nanogels2017In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 8, p. 1417-1420Article in journal (Refereed)
    Abstract [en]

    Polymer nanogels are embedded within layers consisting of a nonlamellar liquid crystalline lipid phase to act as thermoresponsive controllers of layer compactness and hydration. As the nanogels change from the swollen to the collapsed state via a temperature trigger, they enable on-demand release of water from the mixed polymer-lipid layer while the lipid matrix remains intact. Combining stimuli-responsive polymers with responsive lipid-based mesophase systems opens up new routes in biomedical applications such as functional biomaterials, bioanalysis and drug delivery.

  • 10. Dabkowska, Aleksandra P.
    et al.
    Valldeperas, Maria
    Hirst, Christopher
    Montis, Costanza
    Pálsson, Gunnar K.
    Wang, Meina
    Nöjd, Sofi
    Gentile, Luigi
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Steinke, Nina-Juliane
    Schroeder-Turk, Gerd E.
    George, Sebastian
    Skoda, Maximilian W. A.
    Nylander, Tommy
    Non-lamellar lipid assembly at interfaces: controlling layer structure by responsive nanogel particles2017In: Interface Focus, ISSN 2042-8898, E-ISSN 2042-8901, Vol. 7, no 4Article in journal (Refereed)
    Abstract [en]

    Biological membranes do not only occur as planar bilayer structures, but depending on the lipid composition, can also curve into intriguing three-dimensional structures. In order to fully understand the biological implications as well as to reveal the full potential for applications, e.g. for drug delivery and other biomedical devices, of such structures, well-defined model systems are required. Here, we discuss the formation of lipid non-lamellar liquid crystalline (LC) surface layers spin-coated from the constituting lipids followed by hydration of the lipid layer. We demonstrate that hybrid lipid polymer films can be formed with different properties compared with the neat lipid LC layers. The nanostructure and morphologies of the lipid films formed reflect those in the bulk. Most notably, mixed lipid layers, which are composed of glycerol monooleate and diglycerol monooleate with poly(N-isopropylacrylamide) nanogels, can form films of reverse cubic phases that are capable of responding to temperature stimulus. Owing to the presence of the nanogel particles, changing the temperature not only regulates the hydration of the cubic phase lipid films, but also the lateral organization of the lipid domains within the lipid self-assembled film. This opens up the possibility for new nanostructured materials based on lipid-polymer responsive layers.

  • 11.
    Engstedt, Jenni
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Camurus AB, Ideon Science Park, Lund SE-223 70, Sweden.
    In 't Zandt, René
    Lund University Bioimaging Center, Lund University, Lund SE-221 84, Sweden.
    Barauskas, Justas
    Camurus AB, Ideon Science Park, Lund SE-223 70, Sweden.
    Kocherbitov, Vitaly
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Swelling kinetics of mixtures of soybean phosphatidylcholine and glycerol dioleate2024In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 239, article id 113955Article in journal (Refereed)
    Abstract [en]

    Lipid-based drug delivery systems offer the potential to enhance bioavailability, reduce dosing frequency, and improve patient adherence. In aqueous environment, initially dry lipid depots take up water and form liquid crystalline phases. Variation of lipid composition, depot size and hydration-induced phase transitions will plausibly affect the diffusion in and out of the depot. Lipid depots of soybean phosphatidylcholine (SPC) and glycerol dioleate (GDO) mixtures were hydrated for varying time durations in a phosphate-buffered saline (PBS) buffer and then analyzed with Karl Fischer titration, magnetic resonance imaging (MRI) and gravimetrically. Mathematical modeling of the swelling process using diffusion equations, was used to estimate the parameters of diffusion. Both composition of lipid mixture and depot size affect swelling kinetics… The diffusion parameters obtained in Karl Fischer titration and MRI (with temporal and spatial resolution respectively) are in good agreement. Remarkably, the MRI results show a gradient of water content within the depot even after the end of diffusion process. Apparently contradicting the first Fick's law in its classical form, these results find an explanation using the generalized Fick's law that considers the gradient of chemical potential rather than concentration as the driving force of diffusion.

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  • 12.
    Kocherbitov, Vitaly
    et al.
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Latynis, Jekaterina
    Misiunas, Audrius
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Nuaura, Gediminas
    Hydration of Lysozyme Studied by Raman Spectroscopy2013In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 117, no 17, p. 4981-4992Article in journal (Refereed)
    Abstract [en]

    Hydration plays a fundamental role in maintaining the three-dimensional structure and function of proteins. In this study, Raman spectroscopy was used to probe the hydration induced structural changes at various sites of lysozyme under isothermal conditions in the range of water contents from 0 to 44 wt %. Raman hydration curves were constructed from detailed analysis of marker bands. Transition inflection points (wm) and onsets determined from the hydration curves have shown that structural changes start at 7–10 and end at about 35 wt % water. The onset of structural changes coincides with the onset of the broad glass transition earlier observed in this system. The increase of α-helix content starts at very low concentrations of water with wm = 12 wt %. Monitoring the development of importance for enzymatic action hydrophobic clusters has revealed wm = 15 wt % and completion of the process at 25 wt %. The parameters of 621 cm–1 (Phe) and 1448 cm–1 (CH2 bending) modes were found to be sensitive to hydration, suggesting changes in organization of water molecules near the protein surface. The native structure of lysozyme was achieved at 35 wt % water where its content is high enough for filling the space between lysozyme molecules.

  • 13. Linkeviciute, Ausra
    et al.
    Budiene, Jurga
    Naujalis, Evaldas
    Katelnikovas, Arturas
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Characterization and stability study of cranberry flavonoids in lipid liquid crystalline systems2017In: European Journal of Lipid Science and Technology, ISSN 1438-7697, E-ISSN 1438-9312, Vol. 119, no 8, article id 1600373Article in journal (Refereed)
    Abstract [en]

    The main objective of the present study was to investigate mixtures of soy phosphatidylcholine (SPC) and glycerol dioleate (GDO) as encapsulation matrices for cranberry flavonoids. The effects of flavonoids loading into non-aqueous formulations, non-lamellar liquid crystalline phases, and their colloidal dispersions were studied by using synchrotron small angle X-ray diffraction, dynamic light scattering. Flavonoids incorporation is discussed with respect to the lipid aggregation behavior, self-assembled nanostructure, and chemical stability by using antioxidant activity assay. The obtained results show that SPC/GDO-based formulations can incorporate relatively high amounts of flavonoids and serve as liquid crystalline delivery vehicles in the form of bulk phases or colloidal dispersions. Practical applications: Our results show that SPC/GDO-based formulations can incorporate relatively high amounts of cranberry flavonoids. The effect flavonoid extracts on the nanostructure of bulk SPC/GDO LC phases are lipid weight ratio-dependent. Flavonoids loaded into SPC/GDO-based formulations and LC phases retain their antioxidant properties. The self-assembled lipid liquid crystalline systems protect bioactive compounds from degradation. These facts are important for the community working in the field of self-assembly of lipid structures, food chemistry, and delivery vehicles of nutraceuticals.

  • 14. Linkeviciute, Ausra
    et al.
    Misiunas, Audrius
    Naujalis, Evaldas
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö högskola, Biofilms Research Center for Biointerfaces.
    Preparation and characterization of quercetin-loaded lipid liquid crystalline systems2015In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 128, p. 296-303Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to investigate mixtures of soy phosphatidylcholine (SPC) and glycerol dioleate (GDO) as encapsulation matrices for antioxidant quercetin. The effects of quercetin loading into non-aqueous formulations, non-lamellar liquid crystalline phases and their colloidal dispersions were studied by using synchrotron small angle X-ray diffraction, dynamic light scattering, cryogenic electron microscopy and high performance liquid chromatography. Quercetin incorporation is discussed in the context of lipid aggregation behavior, self-assembled nanostructure and chemical stability. The obtained results show that SPC/GDO-based formulations can incorporate relatively high amounts of quercetin and serve as liquid crystalline delivery vehicles in the form of bulk phases or colloidal dispersions.

  • 15. Nylander, Tommy
    et al.
    Soltwedel, Olaf
    Ganeva, Marina
    Hirst, Christopher
    Holdaway, James
    Arteta, Marianna Yanez
    Wadsater, Maria
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Frielinghaus, Henrich
    Holderer, Olof
    Lipid non-lamellar phases at the solid/liquid interface - structure and dynamics2017In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 253Article in journal (Other academic)
  • 16. Nylander, Tommy
    et al.
    Soltwedel, Olaf
    Ganeya, Marina
    Hirst, Christopher
    Holdaway, James
    Arteta, Marianna Yanez
    Wadsäter, Maria
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Frielinghaus, Henrich
    Holderer, Olaf
    Relationship between Structure and Fluctuations of Lipid Nonlamellar Phases Deposited at the Solid-Liquid Interface2017In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 121, no 13, p. 2705-2711Article in journal (Refereed)
    Abstract [en]

    The structure and dynamics of nanostructure films formed by mixtures of soy phosphatidylcholine and glycerol dioleate at the silicon aqueous interface were studied by grazing incidence neutron spin echo spectroscopy (GINSES), specular and off-specular neutron, reflectometry, and small-angle X-ray diffraction. Reverse hexagonal (Hr) and micellar cubic phase (Fd3m) layers at: the solid liquid interface have been identified with neutron reflectometry measurements. A preferred orientation of the liquid crystalline (LC) domains was observed only for the anisotropic,H-II phase. The size of the LC domains was found to be about 1 micrometer as estimated from the width of the diffraction peaks. GINSES revealed that the cubic phase forms rather rigid films. In comparison, the HE film was more flexible, appearing as a modified undulation spectrum of the cylinders due to the interaction with the substrate.

  • 17. Tiberg, Fredrik
    et al.
    Johnsson, Markus
    Jankunec, Marija
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Phase behavior, functions, and medical applications of soy phosphatidylcholine and diglyceride lipid compositions2012In: Chemistry Letters, ISSN 0366-7022, E-ISSN 1348-0715, Vol. 41, no 10, p. 1090-1092Article in journal (Refereed)
    Abstract [en]

    Lipid compositions with the ability to self-assemble into biocompatible nano- and mesostructured functional materials have many potential uses in modern medicine. By using twocomponent lipid systems, it is possible to tune the structure formation and related functional properties, e.g., the encapsulation and extended release of small molecules and peptides, by simply varying the ratio of the lipid building blocks. This is shown in detail for the binary phosphatidylcholine and diglyceride lipid systems, which are currently being used in multiple programs for the development of novel pharmaceuticals and marketed products.

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  • 18. Valldeperas, Maria
    et al.
    Salis, Andrea
    Barauskas, Justas
    Tiberg, Fredrik
    Arnebrant, Thomas
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Razumas, Valdemaras
    Monduzzi, Maura
    Nylandert, Tommy
    Enzyme encapsulation in nanostructured self-assembled structures: Toward biofunctional supramolecular assemblies2019In: Current Opinion in Colloid & Interface Science, ISSN 1359-0294, E-ISSN 1879-0399, Vol. 44, p. 130-142Article, review/survey (Refereed)
    Abstract [en]

    Enzymes have come into use for many new applications outside their natural biological environment, taking advantage of their high efficiency and selectivity as biocatalysts. Such new application often requires encapsulation to preserve the structure and activity of the enzyme, but also to regulate and control the activity. Here, we will discuss two types of encapsulation, soft matrices consisting of polar lipid liquid crystals and hard ordered mesoporous silica matrices. For both types of matrices, the challenge is to control the pore size of the matrices and the interaction with the matrix interface. Here, the polar lipid liquid crystals offer larger flexibility than silica, but on the other hand, it is considerably more sensitive to the environment.

  • 19. Valldeperas, Maria
    et al.
    Wisniewska, Malgorzata
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Ram-On, Maor
    Kesselman, Ellina
    Danino, Dganit
    Nylander, Tommy
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Sponge Phases and Nanoparticle Dispersions in Aqueous Mixtures of Mono- and Diglycerides2016In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 32, no 34, p. 8650-8659Article in journal (Refereed)
    Abstract [en]

    The lipid liquid crystalline sponge phase (1,3) has the advantages that it is a nanoscopically bicontinuous bilayer network able to accommodate large amounts of water and it is easy to Manipulate due to its fluidity. This paper reports on the detailed characterization of L3 phases with water channels large enough to encapsulate bioactive macromolecules such as proteins. The aqueous phase behavior of a novel lipid mixture system, consisting of diglycerol monooleate (DGMO), and a mixture of mono-, di- and triglycerides (Capmul GMO50) was studied. In addition, sponge -like nanoparticles (NPs) stabilized by Polysorbate 80 (P80) were prepared based on the DGMO/GMO-50 system, and their structure was correlated with the phase behavior of the corresponding bulk system. These NPs were characterized by dynamic light scattering (DLS), angle X-ray scattering (SAXS) cryo-transmission electron microscopy (Cryo-TEM) and small angle X-ray scattering (SAXS) to determine their size, shape, and DGMO/GMO-50 ratio. In addition, the effect of P80 as stabilizer was investigated. We found that the NPs have aqueous pores with diameters up to 13 nm, similar to the ones in the bulk phase.

  • 20. Wadsaeter, Maria
    et al.
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Rogers, Sarah
    Skoda, Maximilian W. A.
    Thomas, Robert K.
    Tiberg, Fredrik
    Nylander, Tommy
    Structural effects of the dispersing agent polysorbate 80 on liquid crystalline nanoparticles of soy phosphatidylcholine and glycerol dioleate2015In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 11, no 6, p. 1140-1150Article in journal (Refereed)
    Abstract [en]

    Well-defined, stable and highly structured I-2 (Fd (3) over barm) liquid crystalline nanoparticles (LCNP) of 50/50 (wt/wt) soy phosphatidylcholine (SPC)/glycerol dioleate (GDO), can be formed by using a low fraction (5-10 wt%) of the dispersing polymeric surfactant polyoxyethylene (20) sorbitan monooleate (polysorbate 80 or P80). In the present study we used small angle neutron scattering (SANS) and deuterated P80 (d-P80) to determine the location and concentration of P80 within the LCNP and small angle X-ray scattering (SAXS) to reveal the internal structure. SANS data suggests that some d-P80 already penetrates the particle core at 5%. However, the content of d-P80 is still low enough not to significantly change the internal Fd (3) over barm structure of the LCNP. At higher fractions of P80 a phase separation occurs, in which a SPC and P80 rich phase is formed at the particle surface. The surface layer becomes gradually richer in both solvent and d-P80 when the surfactant concentration is increased from 5 to 15%, while the core of the particle is enriched by GDO, resulting in loss of internal structure and reduced hydration. We have used neutron reflectometry to reveal the location of the stabiliser within the adsorbed layer on an anionic silica and cationic (aminopropyltriethoxysilane (APTES) silanized) surface. d-P80 is enriched closest to the supporting surface and slightly more so for the cationic APTES surface. The results are relevant not only for the capability of LCNPs as drug delivery vehicles but also as means of preparing functional surface coatings.

  • 21. Wadsater, Maria
    et al.
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Nylander, Tommy
    Tiberg, Fredrik
    Formation of Highly Structured Cubic Micellar Lipid Nanoparticles of Soy Phosphatidylcholine and Glycerol Dioleate and Their Degradation by Triacylglycerol Lipase2014In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, no 10, p. 7063-7069Article in journal (Refereed)
    Abstract [en]

    Lipid nanoparticles of reversed internal phase structures, such as cubic micellar (I-2) structure show good drug loading ability of peptides and proteins as well as some small molecules. Due to their controllable small size and inner morphology, such nanoparticles are suitable for drug delivery using several different administration routes, including intravenous, intramuscular, and subcutaneous injection. A very interesting system in this regard, is the two component soy phosphatidylcholine (SPC)/glycerol dioleate (GDO) system, which depending on the ratio of the lipid components form a range of reversed liquid crystalline phases. For a 50/50 (w/w) ratio in excess water, these lipids have been shown to form a reversed cubic micellar (I-2) phase of the Fd3m structure. Here, we demonstrate that this SPC/GDO phase, in the presence of small quantities (5-10 wt %) of Polysorbate 80 (P80), can be dispersed into nanoparticles, still with well-defined Fd3m structure. The resulting nanoparticle dispersion has a narrow size distribution and exhibit good long-term stability. In pharmaceutical applications, biodegradation pathways of the drug delivery vehicles and their components are important considerations. In the second part of the study we show how the structure of the particles evolves during exposure to a triacylglycerol lipase (TGL) under physiological-like temperature and pH. TGL catalyzes the lipolytic degradation of acylglycerides, such as GDO, to monoglycerides, glycerol, and free fatty acids. During the degradation, the interior phase of the particles is shown to undergo continuous phase transitions from the reversed 12 structure to structures of less negative curvature (2D hexagonal, bicontinuous cubic, and sponge), ultimately resulting in the formation of multilamellar vesicles.

  • 22. Wadsateri, Maria
    et al.
    Barauskas, Justas
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Tiberg, Fredrik
    Nylander, Tommy
    Non-lameller Lipid Liquid Crystalline Phases: Controlling the Formed Structure using Lipolytic Enzymes with Different Specificity2018In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 114, no 3 Suppl 1, p. 447A-447AArticle in journal (Other academic)
  • 23. Wadsäter, Maria
    et al.
    Barauskas, Justas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Nylander, Tommy
    Tiberg, Fredrik
    Nonlamellar lipid liquid crystalline model surfaces for biofunctional studies2013In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 9, no 37, p. 8815-8819Article in journal (Refereed)
    Abstract [en]

    Nonlamellar lipid liquid crystalline (LC) bulk phases and dispersions show promise as functional nanostructured materials for potential use as controlled release matrices e. g. in pharmaceuticals. Herein, methods for preparing and characterizing thin films of lipid liquid crystalline phases on solid surfaces are presented. The thickness, hydration phase structure and surface topography of spin-coated films of mixtures of soy phosphatidylcholine and glycerol dioleate are characterized by means of spectroscopic ellipsometry, small angle X-ray diffraction and atomic force microscopy. Besides being useful as bioadhesive drug delivery systems, the lipid nonlamellar LC films produced may also be exploited as model surfaces for studying properties such as bioadhesion and biodegradation.

  • 24. Wadsäter, Maria
    et al.
    Barauskas, Justas
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Tiberg, Fredrik
    Nylander, Tommy
    The lipolytic degradation of highly structured cubic micellar nanoparticles of soy phosphatidylcholine and glycerol dioleate by phospholipase A and triacylglycerol lipase.2018In: Chemistry and Physics of Lipids, ISSN 0009-3084, E-ISSN 1873-2941, Vol. 211, p. 86-92Article in journal (Refereed)
    Abstract [en]

    The effects of different lipolytic enzymes on the structure of lipid liquid crystalline nano-particles (LCNP) have been investigated by cryogenic transmission electron microscopy (cryo-TEM) and synchrotron small angle X-ray diffraction (SAXD). Here we used highly structured cubic micellar (Fd3m) nanoparticles of 50/50 (wt%/wt%) soy phosphatidyl choline (SPC)/glycerol dioleate (GDO) as substrate. Two types of lipolytic enzymes were used, phospholipase A (PLA) that catalyses degradation of the phospholipid component, SPC, and porcine pancreatic triacylglycerol lipase (TGL) that facilitate the hydrolysis of the diglyceride, GDO. Evolution of the structure was found to be very different and linked to specificity of the two types of enzymes. PLA, which hydrolyses the lamellar forming component, SPC, induces a reversed micellar lipid phase, while TGL which hydrolysis the reverse phase forming compound, GDO, induces a lamellar phase.

1 - 24 of 24
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