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Falk, Yana Znamenskaya
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Publications (8 of 8) Show all publications
Falk, Y. Z., Runnsjö, A., Pettigrew, A., Scherer, D., Engblom, J. & Kocherbitov, V. (2020). Interactions of Perfluorohexyloctane With Polyethylene and Polypropylene Pharmaceutical Packaging Materials.. Journal of Pharmaceutical Sciences, 109(7), 2180-2188, Article ID S0022-3549(20)30185-4.
Open this publication in new window or tab >>Interactions of Perfluorohexyloctane With Polyethylene and Polypropylene Pharmaceutical Packaging Materials.
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2020 (English)In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 109, no 7, p. 2180-2188, article id S0022-3549(20)30185-4Article in journal (Refereed) Published
Abstract [en]

Semifluorinated alkanes (SFAs) are aprotic solvents, which may be used as drug solvents for topical ocular applications, for instance, in dry eye syndrome. Their physical properties suggest that they might be prone to interaction with plastic materials, such as, polyethylene (PE) and polypropylene (PP), which are commonly used as packaging materials for pharmaceutical products. In this study, we investigate interactions of PE and PP with a liquid SFA perfluorohexyloctane (PFHO) using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and cross-polarized light microscopy. Binary phase diagrams of PFHO-PE and PFHO-PP systems demonstrating interactions of PFHO with the polymeric materials were constructed based on DSC data. According to this data, PFHO tends to lower the melting temperatures of PE and PP. The equilibrium values of solubilities of the polymers in PFHO and PFHO in the polymers were obtained by extrapolation of melting enthalpy data. Absorption of PFHO by PE and PP materials at ambient conditions after four weeks of equilibration was also studied by TGA. From the presented results, it may be concluded that thorough studies of interactions of PE or PP with SFAs are required when these materials are used as packaging components in SFA-based formulations.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Extractables, Leachables, Phase diagram, Polyethylene, Polypropylene, Semifluorinated alkanes, Thermal analysis
National Category
Pharmaceutical Sciences
Identifiers
urn:nbn:se:mau:diva-17145 (URN)10.1016/j.xphs.2020.03.026 (DOI)000542548300008 ()32240694 (PubMedID)2-s2.0-85083463223 (Scopus ID)
Available from: 2020-04-30 Created: 2020-04-30 Last updated: 2024-02-05Bibliographically approved
Falk, Y. Z., Engblom, J., Pedersen, J. S., Arnebrant, T. & Kocherbitov, V. (2018). Effects of Hydration on Structure and Phase Behavior of Pig Gastric Mucin Elucidated by SAXS (ed.). Journal of Physical Chemistry B, 122(30), 7539-7546
Open this publication in new window or tab >>Effects of Hydration on Structure and Phase Behavior of Pig Gastric Mucin Elucidated by SAXS
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2018 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 122, no 30, p. 7539-7546Article in journal (Refereed) Published
Abstract [en]

In this work small-angle X-ray scattering (SAXS) was used to study hydration and temperature-induced changes of pig gastric mucin (PGM) within the entire concentration range. The scattering is interpreted as originating from PGM fiber-like structures that adopt rod-like bottle-brush conformation in dilute solutions. On the basis of the knowledge about molecular structure of mucins and SAXS data for dilute solutions, we propose a theoretical model for predicting mucin conformation in solution and calculate the corresponding scattering profile. This bottle-brush model comprises a protein backbone with carbohydrate side chains and corresponding structural parameters, such as grafting distance and lengths of the backbone and side chains. It describes the experimental PGM data from dilute solutions in the full q range very well. It furthermore suggests that the carbohydrate side chains are grafted with a regular separation of around 5 nm and a length of 14 nm. The cross-section size with a radius of about 1 nm is also in accordance with the size of the carbohydrate units. Structuring of PGM solutions at higher concentrations was investigated by analyzing semidilute and concentrated PGM samples. Starting at about 20 wt %, Bragg peaks become clearly visible indicating a more ordered mucin system. In very dehydrated and fully dry mucin samples these peaks are not present indicating lack of long-range order. The SAXS data show that the structural change occurring at about 80 wt % mucin and 25 degrees C corresponds to a glass transition in agreement with our previous calorimetric results. Temperature also has an effect on the phase behavior of mucin. At intermediate levels of hydration, a phase transition is observed at about 60-70 degrees C. The main Bragg peak appears to split in two, indicating formation of a different structure at elevated temperatures. These findings are used to improve the PGM water phase diagram.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
Chemistry, Physical
National Category
Natural Sciences
Identifiers
urn:nbn:se:mau:diva-5260 (URN)10.1021/acs.jpcb.8b05496 (DOI)000440956300009 ()29989815 (PubMedID)2-s2.0-85049844913 (Scopus ID)26637 (Local ID)26637 (Archive number)26637 (OAI)
Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-02-05Bibliographically approved
Gonzalez-Martinez, J. F., Falk, Y. Z., Björklund, S., Erkselius, S., Rehnberg, N. & Sotres, J. (2018). Humidity-induced phase transitions of surfactants embedded in latex coatings can drastically alter their water barrier and mechanical properties (ed.). Polymers, 10, Article ID 284.
Open this publication in new window or tab >>Humidity-induced phase transitions of surfactants embedded in latex coatings can drastically alter their water barrier and mechanical properties
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2018 (English)In: Polymers, E-ISSN 2073-4360, Vol. 10, article id 284Article in journal (Refereed) Published
Abstract [en]

Latex coatings are environmentally friendly i.e., they are formed from aqueous polymer dispersions, are cheap to produce and provide exceptional mechanical properties. Therefore, they are ubiquitous and can be found in a wide range of different applications such as paints and varnishes, pressure-sensitive adhesives, textiles, construction materials, paper coatings and inks. However, they also have weaknesses and their surfactant content is among them. Surfactants are often needed to stabilize polymer particles in the aqueous latex dispersions. These surfactants also form part of the coatings formed from these dispersions, and it is well-known that they can lower their performance. This work further explores this aspect and focuses on the role that embedded surfactant domains play in the response of latex coatings to humid environments. For this purpose, we made use of several experimental techniques where humidity control was implemented: quartz crystal microbalance with dissipation, atomic force microscopy and differential scanning calorimetry. By means of this multimethodological approach, we report that surfactants embedded in latex coatings can undergo humidity-induced transitions towards more hydrated and softer phases, and that this results in a drastic decrease of the mechanical and water barrier properties of the whole coatings. Subsequently, this work highlights the potential of taking into account the phase behavior of surfactants when choosing which ones to use in the synthesis of latex dispersions as this would help in predicting their performance under different environmental conditions.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
latex, surfactant, coating, relative humidity, QCM-D, AFM
National Category
Natural Sciences
Identifiers
urn:nbn:se:mau:diva-4057 (URN)10.3390/polym10030284 (DOI)000428388200058 ()30966319 (PubMedID)2-s2.0-85043317145 (Scopus ID)25286 (Local ID)25286 (Archive number)25286 (OAI)
Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-02-05Bibliographically approved
Falk, Y. Z., Schmitt, J. & Alfredsson, V. (2018). Langmuir - Blodgett monolayers of SBA-15 particles with different morphologies (ed.). Microporous and Mesoporous Materials, 256, 32-38
Open this publication in new window or tab >>Langmuir - Blodgett monolayers of SBA-15 particles with different morphologies
2018 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 256, p. 32-38Article in journal (Refereed) Published
Abstract [en]

This study presents an optimized protocol for the deposition of mesoporous SBA-15 particles with platelet-like and rod-like morphologies on different types of supporting substrates using LangmuirBlodgett methodology, resulting in the formation of monolayers with porosity orientation controlled by the type, i. e. the morphology, of particles used over large areas. The morphology of the SBA-15 particles and specifically their aspect ratio are essential for the orientation of the particles and, hence, the orientation of the intrinsic porosity. Deposition on a surface, establishes a layer of SBA-15 platelets with pores oriented perpendicular to the substrate, or a layer of SBA-15 rods with pores oriented parallel to the substrate. In both cases, the oriented SBA-15 particles can be deposited onto areas that are larger than square centimeter using Langmuir-Blodgett technique. SEM characterization demonstrates formation of uniform close-packed layer of oriented mesoporous SBA-15 silica particles. Additionally, the particles coverage of the surface is independent and unaffected by the type of supporting substrate, which allows convenient experimental performance without requiring surface or particle modifications. In conclusion, Langmuir Blodgett is a convenient technique for deposition of mesoporous SBA-15 particles with different morphology types in order to obtain a close-packed layer. The methodology is suitable to create large area sensors, used in; for instance, bio-sensing applications. (C) 2017 Elsevier Inc. All rights reserved.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Mesoporous silica, Deposition, Pore orientation, Langmuir-Blodgett, Monolayer
National Category
Natural Sciences
Identifiers
urn:nbn:se:mau:diva-5048 (URN)10.1016/j.micromeso.2017.07.049 (DOI)000415781200005 ()2-s2.0-85026462054 (Scopus ID)26549 (Local ID)26549 (Archive number)26549 (OAI)
Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-02-05Bibliographically approved
Znamenskaya, Y., Björklund, S., Kocherbitov, V. & Alfredsson, V. (2016). Effect of hydration and dehydration on the properties of SBA-15 layer studied by humidity scanning QCM-D (ed.). Microporous and Mesoporous Materials, 230, 58-65
Open this publication in new window or tab >>Effect of hydration and dehydration on the properties of SBA-15 layer studied by humidity scanning QCM-D
2016 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 230, p. 58-65Article in journal (Refereed) Published
Abstract [en]

Surface deposited layers of mesoporous silica particles could function as support for bio-sensing or drug release applications. It is crucial to control the surface deposition process and employ relevant techniques to characterize the properties of the particles on the surface. Here, we deposit SBA-15 particles on native silica or cationic surfaces and characterize the hydration and dehydration by employing a novel method based on humidity scanning quartz crystal microbalance with dissipation (HS QCM-D). SBA-15 platelets are deposited with mesopores oriented parallel to the surface normal using drop deposition. SEM shows a monolayer on the surface, which is established as stable. Water sorption-desorption isotherms of the SBA-15 layer from HS QCM-D are compared with isotherms from water sorption calorimetry and nitrogen sorption on bulk material. We demonstrate that HS QCM-D provides results in good agreement with results obtained with the reference methods. The properties of SBA-15 particles are retained during the deposition process and unaffected by the presence of the surface. In addition, HS QCM-D is a fast technique that requires significantly lower amount of material (∼5000 times) compared to experiments on bulk material. HS QCM-D provides complete characterization of the pore size distribution of SBA-15.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Hydration, Mesoporous silica, HS QCM-D, Humidity scanning
National Category
Natural Sciences
Identifiers
urn:nbn:se:mau:diva-14854 (URN)10.1016/j.micromeso.2016.04.034 (DOI)000378661100008 ()2-s2.0-84965129116 (Scopus ID)21839 (Local ID)21839 (Archive number)21839 (OAI)
Available from: 2020-03-30 Created: 2020-03-30 Last updated: 2024-04-08Bibliographically approved
Znamenskaya, Y. (2013). Effect of hydration on thermodynamic, rheological and structural properties of mucin (ed.). (Doctoral dissertation). Malmö University, Faculty of Health and Society
Open this publication in new window or tab >>Effect of hydration on thermodynamic, rheological and structural properties of mucin
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Mucus, an adherent hydrated layer covering the epithelium, is found in all internal tracts of the body and plays an important role in animal and human life. One of the essential functions of mucus is protection of tissues against dehydration. A major component of mucus, forming the macromolecular matrix and also being responsible for its viscoelastic properties, is the glycoprotein mucin. Mucin is a complex molecule owing to the high molar mass, its polydispersity and high degree of glycosylation. This thesis is aimed to investigate how thermodynamic, structural and rheological properties of mucin are affected by hydration. The effect of hydration on thermodynamic properties of pig gastric mucin (PGM) and bovine submaxillary mucin (BSM) has been studied using sorption calorimetry and differential scanning calorimetry (DSC). The analysis of sorption isotherms shows higher water sorption capacity of PGM compared to BSM at relative humidity (RH) levels lower than about 78%. The value of the hydration enthalpy at zero water content at 25ºC for both biopolymers is close to -20 kJ/ mol. RH levels at which glass transition of both mucins occurs are shown to be between 60 and 70%. The RH at which glass transition occurs is weakly dependent on the temperature and mucin type. The phase diagram of PGM demonstrates two different glass transition regions: dependent and independent on hydration levels, respectively. In particular at mucin concentrations from 0 to 67 wt%, the glass transition occurs at a constant temperature of about –15ºC. At higher concentrations of mucin, the glass transition temperature (Tg) increases with increasing mucin concentrations. It is also demonstrated that the QCM-D technique can be used to obtain the water sorption isotherms of mucin films in particular and in general to monitor glass transitions in biopolymers. Hydration-induced changes of rheological properties of mucin films are investigated using a model-free approach. The ratio of G’/G’’ is evaluated as a function of relative humidity. Observed transitions from solid-like behaviour to liquid-like behaviour in mucin system occur in the same humidity range as that found in sorption calorimetric experiments. The structural properties of mucin have been studied using atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS). AFM indicates the presence of dumbbell as well as fiber-like structures in PGM samples. In the case of BSM samples, only fiber-like structures are observed. SAXS studies show three ranges of scattering vector q corresponding to different fractal dimensions in dilute PGM and BSM solutions. Dehydration-induced structural changes in PGM are demonstrated by a distinct appearance of peaks on scattering curves starting from 20 wt% of mucin. Structural changes at about 80 wt% obtained in SAXS at 25°C, correspond to mucin glass transition, and are in agreement with sorption calorimetry and DSC studies. Temperature-induced phase behaviour changes occur around 60-70°C at intermediate levels of hydration. A comparison between water sorption isotherms of BSM/chitosan multilayers and those of individual biopolymers shows that the water sorption capacity of BSM/chitosan multilayers is similar compared to that of individual biopolymers, although some differences exist. In particular, at low RH levels the water sorption capacity of multilayers is slightly higher compared to each biopolymer, however at high RH the multilayer films are less hydrated than individual biopolymers.

Place, publisher, year, edition, pages
Malmö University, Faculty of Health and Society, 2013. p. 69
Series
Malmö University Health and Society Dissertations, ISSN 1653-5383 ; 2
Keywords
mucous gel, mucus, mucin, PGM, BSM, BSM/chitosan multilayers, hydration, water sorption isotherm, relative humidity, water activity, bound water, enthalpy of hydration of biopolymer, glass transition, rheology, phase diagram, fiber-like structure, dumbbell-like structure, sorption calorimetry, DSC, QCM-D, SAXS, AFM
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:mau:diva-7330 (URN)15514 (Local ID)978-91-7104-513-3 (ISBN)978-91-7104-514-0 (ISBN)15514 (Archive number)15514 (OAI)
Note

Note: the papers are not included in the fulltext online.

Paper IV published in dissertation as manuscript with title "Effects of Dehydration on Structural Properties and Phase Behaviour of Pig Gastric Mucin Evaluated by SAXS"

Available from: 2020-02-28 Created: 2020-02-28 Last updated: 2024-03-07Bibliographically approved
Znamenskaya, Y., Sotres, J., Gavryushov, S., Engblom, J., Arnebrant, T. & Kocherbitov, V. (2013). Water Sorption and Glass Transition of Pig Gastric Mucin Studied by QCM-D (ed.). Journal of Physical Chemistry B, 117(8), 2554-2563
Open this publication in new window or tab >>Water Sorption and Glass Transition of Pig Gastric Mucin Studied by QCM-D
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2013 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 117, no 8, p. 2554-2563Article in journal (Refereed)
Abstract [en]

Hydration of films of pig gastric mucin was studied using a quartz crystal microbalance with dissipation monitoring (QCM-D) equipped with a humidity module. As a prerequisite, the water adsorption isotherm of a clean silica surface was determined. Atomic force microscopy was used to characterize the changes occurring on the silica surface after repeated sorption/desorption and cleaning cycles. The water sorption isotherms of several hundreds of nanometers thick mucin films were obtained in QCM-D experiments using analysis of overtone behavior. The results show that the sorption isotherms are not dependent on the film thicknesses and are in good agreement with sorption calorimetric data on mucin in the bulk phase. Moreover, hydration-induced changes of rheological properties of mucin films were investigated using a model-free approach. The ratio of G′/G″ was evaluated as a function of relative humidity. The transition from solidlike behavior to liquidlike behavior was observed in the same humidity range as in sorption calorimetric experiments. Thus, ability of QCM-D to monitor glass transition in biopolymers was demonstrated.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2013
Keywords
Hydration, Glass transition, Sorption Calorimetry, Mucin
National Category
Natural Sciences
Identifiers
urn:nbn:se:mau:diva-14549 (URN)10.1021/jp311968b (DOI)000315707900037 ()23369097 (PubMedID)2-s2.0-84874604458 (Scopus ID)16488 (Local ID)16488 (Archive number)16488 (OAI)
Available from: 2020-03-30 Created: 2020-03-30 Last updated: 2024-02-05Bibliographically approved
Znamenskaya, Y., Sotres, J., Engblom, J., Arnebrant, T. & Kocherbitov, V. (2012). Effect of hydration on structural and thermodynamic properties of pig gastric and bovine submaxillary gland mucins (ed.). Journal of Physical Chemistry B, 116(16), 5047-5055
Open this publication in new window or tab >>Effect of hydration on structural and thermodynamic properties of pig gastric and bovine submaxillary gland mucins
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2012 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 116, no 16, p. 5047-5055Article in journal (Refereed)
Abstract [en]

One of the essential functions of mucous gel is protection of tissues against dehydration. The effect of hydration on the structural and thermodynamic properties of pig gastric mucin (PGM) and bovine submaxillary gland mucin (BSM) have been studied using atomic force microscopy (AFM), sorption, and differential scanning calorimetry (DSC). The analysis of sorption isotherms shows the higher water sorption capacity of PGM compared to BSM at RH levels lower than about 78%. The value of the hydration enthalpy at zero water content at 25 °C for both biopolymers is about −20 kJ/mol. Glass transitions of BSM and PGM occur at RH levels between 60 and 70% for both mucins. AFM indicates the presence of a dumbbell structure as well as a fiber-like structure in PGM samples. The experimental volume of the dry dumbbell molecule obtained by AFM is 3140 ± 340 nm3. Using DSC data, the amount of nonfreezing water was calculated to be about 0.51 g/g of PGM. The phase diagram of PGM demonstrates two regions of different Tg: dependent and independent of hydration levels. In particular, at mucin concentrations from 0 to 67 wt %, the glass transition occurs at a constant temperature of about −15 °C. At higher concentrations of mucin, Tg is increasing with increasing mucin concentrations.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2012
Keywords
Hydration, Mucin, DSC, Sorption calorimetry, Glass transition, water activity, Enthalpy
National Category
Natural Sciences
Identifiers
urn:nbn:se:mau:diva-14889 (URN)10.1021/jp212495t (DOI)000303173800033 ()22455728 (PubMedID)2-s2.0-84860276215 (Scopus ID)14292 (Local ID)14292 (Archive number)14292 (OAI)
Available from: 2020-03-30 Created: 2020-03-30 Last updated: 2024-02-05Bibliographically approved
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