Malmö University Publications
Change search
Link to record
Permanent link

Direct link
Alternative names
Publications (10 of 81) Show all publications
Cretella, M., Fazilati, M., Krcic, N., Argatov, I. & Kocherbitov, V. (2024). Determination of Density of Starch Hydrogel Microspheres from Sedimentation Experiments Using Non-Stokes Drag Coefficient. Gels, 10(4), Article ID 277.
Open this publication in new window or tab >>Determination of Density of Starch Hydrogel Microspheres from Sedimentation Experiments Using Non-Stokes Drag Coefficient
Show others...
2024 (English)In: Gels, E-ISSN 2310-2861, Vol. 10, no 4, article id 277Article in journal (Refereed) Published
Abstract [en]

Sedimentation is an important property of colloidal systems that should be considered when designing pharmaceutical formulations. In pharmaceutical applications, sedimentation is normally described using Stokes' law, which assumes laminar flow of fluid. In this work we studied swelling and hydration of spherical cross-linked amorphous starch microspheres in pure water, solutions of sodium chloride, and in pH-adjusted aqueous solutions. We demonstrated that Reynolds numbers obtained in these experiments correspond to the transition regime between the laminar flow and the turbulent flow and, hence, expressions based on the non-Stokes drag coefficient should be used for calculations of sedimentation velocity from known density or for assessment of density from observed sedimentation velocity. The density of starch microparticles hydrated in water was about 1050 kg/m3, while densities obtained from experiment with other liquids were dependent on the liquids' densities. The data indicate that the swelling of the cross-linked starch microparticles as characterized by their densities is not sensitive to pH and salt concentration in the studied range of these parameters.

Keywords
starch microparticles, cross-linked starch hydrogel, sedimentation, non-Stokes drag
National Category
Chemical Sciences
Identifiers
urn:nbn:se:mau:diva-67292 (URN)10.3390/gels10040277 (DOI)001209889100001 ()38667696 (PubMedID)2-s2.0-85191717484 (Scopus ID)
Available from: 2024-05-20 Created: 2024-05-20 Last updated: 2024-05-20Bibliographically approved
Kocherbitov, V., Music, D. & Veryazov, V. (2024). Hydrogen bonding in glassy trehalose-water system: Insights from density functional theory and molecular dynamics simulations.. Journal of Chemical Physics, 160(8), Article ID 084504.
Open this publication in new window or tab >>Hydrogen bonding in glassy trehalose-water system: Insights from density functional theory and molecular dynamics simulations.
2024 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 160, no 8, article id 084504Article in journal (Refereed) Published
Abstract [en]

We report a detailed density functional theory and molecular dynamics study of hydrogen bonding between trehalose and water, with a special emphasis on interactions in the amorphous solid state. For comparison, water-water interactions in water dimers and tetramers are evaluated using quantum calculations. The results show that the hydrogen bonding energy is dependent not only on the geometry (bond length and angle) but also on the local environment of the hydrogen bond. This is seen in quantum calculations of complexes in vacuum as well as in amorphous solid states with periodic boundary conditions. The temperature-induced glass transition in the trehalose-water system was studied using molecular dynamics simulations with varying cooling and heating rates. The obtained parameters of the glass transition are in good agreement with the experiments. Moreover, the dehydration of trehalose in the glassy state was investigated through a gradual dehydration with multiple small steps under isothermal conditions. From these simulations, the values of water sorption energy at different temperatures were obtained. The partial molar enthalpy of mixing of water value of -18 kJ/mol found in calorimetric experiments was accurately reproduced in these simulations. These findings are discussed in light of the hydrogen bonding data in the system. We conclude that the observed exothermic effect is due to different responses of liquid and glassy matrices to perturbations associated with the addition or removal of water molecules.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2024
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-66691 (URN)10.1063/5.0194537 (DOI)001177451000005 ()38411233 (PubMedID)2-s2.0-85186274717 (Scopus ID)
Available from: 2024-04-11 Created: 2024-04-11 Last updated: 2024-04-25Bibliographically approved
Kelly, S. J., Genevskiy, V., Björklund, S., Gonzalez-Martinez, J. F., Poeschke, L., Schröder, M., . . . Kocherbitov, V. (2024). Water Sorption and Structural Properties of Human Airway Mucus in Health and Muco-Obstructive Diseases.. Biomacromolecules, 25(3), 1578-1591
Open this publication in new window or tab >>Water Sorption and Structural Properties of Human Airway Mucus in Health and Muco-Obstructive Diseases.
Show others...
2024 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 25, no 3, p. 1578-1591Article in journal (Refereed) Published
Abstract [en]

Muco-obstructive diseases change airway mucus properties, impairing mucociliary transport and increasing the likelihood of infections. To investigate the sorption properties and nanostructures of mucus in health and disease, we investigated mucus samples from patients and cell cultures (cc) from healthy, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) airways. Atomic force microscopy (AFM) revealed mucin monomers with typical barbell structures, where the globule to spacer volume ratio was the highest for CF mucin. Accordingly, synchrotron small-angle X-ray scattering (SAXS) revealed more pronounced scattering from CF mucin globules and suggested shorter carbohydrate side chains in CF mucin and longer side chains in COPD mucin. Quartz crystal microbalance with dissipation (QCM-D) analysis presented water sorption isotherms of the three types of human airway mucus, where, at high relative humidity, COPD mucus had the highest water content compared to cc-CF and healthy airway mucus (HAM). The higher hydration of the COPD mucus is consistent with the observation of longer side chains of the COPD mucins. At low humidity, no dehydration-induced glass transition was observed in healthy and diseased mucus, suggesting mucus remained in a rubbery state. However, in dialyzed cc-HAM, a sorption-desorption hysteresis (typically observed in the glassy state) appeared, suggesting that small molecules present in mucus suppress the glass transition.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:mau:diva-66269 (URN)10.1021/acs.biomac.3c01170 (DOI)001166555000001 ()38333985 (PubMedID)2-s2.0-85187249840 (Scopus ID)
Available from: 2024-03-08 Created: 2024-03-08 Last updated: 2024-04-11Bibliographically approved
Kocherbitov, V. (2023). A model for water sorption isotherms and hydration forces in sugar surfactants. Journal of Colloid and Interface Science, 633, 343-351
Open this publication in new window or tab >>A model for water sorption isotherms and hydration forces in sugar surfactants
2023 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 633, p. 343-351Article in journal (Refereed) Published
Abstract [en]

HYPOTHESIS: Hydration forces between surfactant bilayers can be assessed using water sorption isotherms of surfactants. For a quantitative description, a water sorption model that relates water activity to water content in surfactant-based systems should be proposed.

THEORY AND SIMULATIONS: A water sorption model for nonionic surfactant systems based on the idea on partial solvent accessibility is proposed. The model contains only two parameters: one describes the strength of interactions, the other describes the fraction of surfactant available for water. For comparison, molecular dynamics simulations of bilayers of n-octyl β-d-glucoside with different water contents are presented.

FINDINGS: The model provides an excellent fit of experimental data on water sorption isotherms of two sugar surfactants. The results of the fitting are compared with molecular dynamics simulations and show a good correlation between simulations and the theory proposed. Analysis of interaction energies shows weakly endothermic hydration both in the simulations and in the sorption model, which agrees with calorimetric data on hydration. The model also shows a non-exponential decay of hydration forces with respect to the distance between bilayers; an expression for the decay length is derived.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Enthalpy, Entropy, Hydration forces, Liquid crystalline phase, Non-ionic surfactants, Solvent accessibility, Water activity, Water sorption isotherm
National Category
Materials Chemistry
Identifiers
urn:nbn:se:mau:diva-56629 (URN)10.1016/j.jcis.2022.11.088 (DOI)000908352700013 ()36459939 (PubMedID)2-s2.0-85145492618 (Scopus ID)
Available from: 2022-12-13 Created: 2022-12-13 Last updated: 2024-02-05Bibliographically approved
Hernandez, A. R., Bogdanova, E., Campos Pacheco, J. E., Kocherbitov, V., Feiler, A., Pilkington, G., . . . Valetti, S. (2023). Disordered mesoporous silica particles as emerging platform to deliver biologic molecules to the lungs. Journal of Aerosol Medicine, 36(6), Article ID A32.
Open this publication in new window or tab >>Disordered mesoporous silica particles as emerging platform to deliver biologic molecules to the lungs
Show others...
2023 (English)In: Journal of Aerosol Medicine, ISSN 1941-2711, E-ISSN 1941-2703, Vol. 36, no 6, article id A32Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
Mary Ann Liebert, 2023
National Category
Biomedical Laboratory Science/Technology
Identifiers
urn:nbn:se:mau:diva-66241 (URN)001126390700109 ()
Available from: 2024-03-07 Created: 2024-03-07 Last updated: 2024-03-07Bibliographically approved
Bogdanova, E., Lages, S., Phan-Xuan, T., Kamal, M. A., Terry, A., Millqvist Fureby, A. & Kocherbitov, V. (2023). Lysozyme-Sucrose Interactions in the Solid State: Glass Transition, Denaturation, and the Effect of Residual Water.. Molecular Pharmaceutics, 20(9), 4664-4675
Open this publication in new window or tab >>Lysozyme-Sucrose Interactions in the Solid State: Glass Transition, Denaturation, and the Effect of Residual Water.
Show others...
2023 (English)In: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392, Vol. 20, no 9, p. 4664-4675Article in journal (Refereed) Published
Abstract [en]

The freeze-drying of proteins, along with excipients, offers a solution for increasing the shelf-life of protein pharmaceuticals. Using differential scanning calorimetry, thermogravimetric analysis, sorption calorimetry, and synchrotron small-angle X-ray scattering (SAXS), we have characterized the properties at low (re)hydration levels of the protein lysozyme, which was freeze-dried together with the excipient sucrose. We observe that the residual moisture content in these samples increases with the addition of lysozyme. This results from an increase in equilibrium water content with lysozyme concentration at constant water activity. Furthermore, we also observed an increase in the glass transition temperature (Tg) of the mixtures with increasing lysozyme concentration. Analysis of the heat capacity step of the mixtures indicates that lysozyme does not participate in the glass transition of the sucrose matrix; as a result, the observed increase in the Tg of the mixtures is the consequence of the confinement of the amorphous sucrose domains in the interstitial space between the lysozyme molecules. Sorption calorimetry experiments demonstrate that the hydration behavior of this formulation is similar to that of the pure amorphous sucrose, while the presence of lysozyme only shifts the sucrose transitions. SAXS analysis of amorphous lysozyme–sucrose mixtures and unfolding of lysozyme in this environment show that prior to unfolding, the size and shape of lysozyme in a solid sucrose matrix are consistent with its native state in an aqueous solution. The results obtained from our study will provide a better understanding of the low hydration behavior of protein–excipient mixtures and support the improved formulation of biologics.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
Keywords
differential scanning calorimetry, glass transition, hydration, proteins, small-angle X-ray scattering, solid-state formulations
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-62084 (URN)10.1021/acs.molpharmaceut.3c00403 (DOI)001044988400001 ()37555640 (PubMedID)2-s2.0-85168498460 (Scopus ID)
Available from: 2023-08-23 Created: 2023-08-23 Last updated: 2023-09-19Bibliographically approved
Slaninova, E., Obruca, S., Kocherbitov, V. & Sedlacek, P. (2023). On the bioprotective effects of 3-hydroxybutyrate: Thermodynamic study of binary 3HB-water systems.. Biophysical Journal, 122(3), 460-469, Article ID S0006-3495(23)00004-8.
Open this publication in new window or tab >>On the bioprotective effects of 3-hydroxybutyrate: Thermodynamic study of binary 3HB-water systems.
2023 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 122, no 3, p. 460-469, article id S0006-3495(23)00004-8Article in journal (Refereed) Published
Abstract [en]

Microorganisms must face various inconvenient conditions; therefore, they developed several approaches for protection. Such a strategy also involves the accumulation of compatible solutes, also called osmolytes. It has been proved that the monomer unit 3-hydroxybutyrate (3HB), which is present in sufficient concentration in poly(3-hydroxybutyrate) (PHB)-accumulating cells, serves as a chemical chaperone protecting enzymes against heat and oxidative stress and as a cryoprotectant for enzymes, bacterial cells, and yeast. The stress robustness of the cells is also strongly dependent on the behavior and state of intracellular water, especially during stress exposure. For a better understanding of the protective mechanism and effect of strongly hydrophilic 3HB in solutions at a wide range of temperatures, a binary phase diagram of system sodium 3HB (Na3HB)-water in equilibrium and the state diagrams showing the glass transitions in the system were constructed. To investigate the activity of water in various compositions of the Na3HB/water system, three experimental techniques have been used (dynamic water sorption analysis, water activity measurements, and sorption calorimetry). First, Na3HB proved its hydrophilic nature, which is very comparable with known compatible solutes (trehalose). Results of differential scanning calorimetry demonstrated that Na3HB is also highly effective in depressing the freezing point and generating a large amount of nonfrozen water (1.35 g of water per gram of Na3HB). Therefore, Na3HB represents a very effective cryoprotectant that can be widely used for numerous applications.

Place, publisher, year, edition, pages
Elsevier, 2023
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:mau:diva-58508 (URN)10.1016/j.bpj.2023.01.004 (DOI)000935472000001 ()36617191 (PubMedID)2-s2.0-85147377576 (Scopus ID)
Available from: 2023-03-02 Created: 2023-03-02 Last updated: 2024-02-05Bibliographically approved
Engstedt, J., Barauskas, J. & Kocherbitov, V. (2023). Phase behavior of soybean phosphatidylcholine and glycerol dioleate in hydrated and dehydrated states studied by small-angle X-ray scattering. Soft Matter, 19(43), 8305-8317
Open this publication in new window or tab >>Phase behavior of soybean phosphatidylcholine and glycerol dioleate in hydrated and dehydrated states studied by small-angle X-ray scattering
2023 (English)In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 19, no 43, p. 8305-8317Article in journal (Refereed) Published
Abstract [en]

Soybean phosphatidylcholine (SPC) and glycerol dioleate (GDO) form liquid crystal nanostructures in aqueous environments, and their mixtures can effectively encapsulate active pharmaceutical ingredients (API). When used in a subcutaneous environment, the liquid crystalline matrix gradually hydrates and degrades in the tissue whilst slowly releasing the API. Hydration dependent SPC/GDO phase behavior is complex, non-trivial, and still not fully understood. A deeper understanding of this system is important for controlling its function in drug delivery applications. The phase behavior of the mixture of SPC/GDO/water was studied as a function of hydration and lipid ratio. Small-angle X-ray scattering (SAXS) was used to identify space groups in liquid crystalline phases and to get detailed structural information on the isotropic reverse micellar phase. The reported pseudo ternary phase diagram includes eight different phases and numerous multiphase regions in a thermodynamically consistent way. For mixtures with SPC as the predominant component, the system presents a reverse hexagonal, lamellar and R3m phase. For mixtures with lower SPC concentrations, reverse cubic (Fd3m and Pm3n) as well as intermediate and isotropic micellar phases were identified. By modeling the SAXS data using a core–shell approach, the properties of the isotropic micellar phase were studied in detail as a function of concentration. Moreover, SAXS analysis of other phases revealed new structural features in relation to lipid–water interactions. The new improved ternary phase diagram offers valuable insight into the complex phase behavior of the SPC/GDO system. The detailed structural information is important for understanding what APIs can be incorporated in the liquid crystal structure.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2023
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-63665 (URN)10.1039/d3sm01067h (DOI)001096679900001 ()37819242 (PubMedID)2-s2.0-85175015955 (Scopus ID)
Available from: 2023-11-13 Created: 2023-11-13 Last updated: 2023-12-06Bibliographically approved
Argatov, I., Krcic, N. & Kocherbitov, V. (2023). Sedimentation of a starch microsphere: What is usually missed and why?. Heliyon, 9(10), Article ID e20257.
Open this publication in new window or tab >>Sedimentation of a starch microsphere: What is usually missed and why?
2023 (English)In: Heliyon, E-ISSN 2405-8440, Vol. 9, no 10, article id e20257Article in journal (Refereed) Published
Abstract [en]

Gravimetric sedimentation is known as a relatively simple method of determining density of spherical particles. When the method is applied to water-swollen starch microparticles of about submillimeter sizes, it becomes evident that a careful selection of the experimental setup parameters is needed for producing accurate testing results. The main reason for this is that the mean particle density is very close to the density of water, and therefore, a dynamic model accounting for the so-called Bassett history force should be employed for describing the unsteady accelerating particle settling. A main novelty of this study consists in deriving a priori estimates for the settling time and distance.

Place, publisher, year, edition, pages
Cell Press, 2023
Keywords
Sedimentation, Starch microspheres, Non-laminar flow, Settling time, Settling distance
National Category
Water Treatment
Identifiers
urn:nbn:se:mau:diva-63506 (URN)10.1016/j.heliyon.2023.e20257 (DOI)001084092700001 ()37810817 (PubMedID)2-s2.0-85172256835 (Scopus ID)
Available from: 2023-11-07 Created: 2023-11-07 Last updated: 2023-11-07Bibliographically approved
Tsompou, A. & Kocherbitov, V. (2023). Surface and bulk mechanisms in repeating treatment of solid surfaces by purified water. Heliyon, 9(6), Article ID e17163.
Open this publication in new window or tab >>Surface and bulk mechanisms in repeating treatment of solid surfaces by purified water
2023 (English)In: Heliyon, E-ISSN 2405-8440, Vol. 9, no 6, article id e17163Article in journal (Refereed) Published
Abstract [en]

To decrease the negative impact of surfactants, the idea of using purified water in washing has been proposed. Previous studies showed that purified water facilitates the roll-up mechanism by promoting electrostatic interactions between the surface and the soil. However, washing mech-anisms can be dependent on the amount of remaining soil.In this work we studied the removal of thin Vaseline films and thicker oil films from hydro-philic surfaces using multiple washing cycles at different temperatures. The Quartz Crystal Mi-crobalance with Dissipation monitoring (QCM-D) and gravimetric analysis were used for thin and thick films respectively. In QCM-D experiments most of the thin film was removed during the first two cycles, while following cycles did not substantially affect washing efficiency; increased temperature facilitated the washing process. Gravimetric analysis showed that the washing of thicker films can be divided into two regimes. During the first, exponential, regime the amount of oil on the surface is high and surface mechanisms, such as roll-up, dominate. Oil droplets are kinetically stabilized in purified water by electrostatic interactions. As the amount of oil on the surface decreases, the second, linear, regime is introduced. The removal of oil occurs by equi-librium bulk mechanisms, where electrostatic interactions are less important.

Place, publisher, year, edition, pages
Cell Press, 2023
Keywords
Washing and cleaning, Water purity, Quartz crystal microbalance with dissipation, monitoring, Temperature, Washing cycles, Mechanisms of washing and cleaning, Emulsification, Olive oil, Surface tension, Entropy, Charge stabilization
National Category
Applied Mechanics
Identifiers
urn:nbn:se:mau:diva-62433 (URN)10.1016/j.heliyon.2023.e17163 (DOI)001042270500001 ()37484311 (PubMedID)2-s2.0-85162160293 (Scopus ID)
Available from: 2023-09-13 Created: 2023-09-13 Last updated: 2023-09-13Bibliographically approved
Projects
Carbohydrate polymer - water interactions: sorption, porosity and rheology; Malmö högskola, Biofilms Research Center for Biointerfaces (Closed down 2017-12-31)Pickering emulsions on skin: Effects of ethanol prior to, during and after application at different ambient conditions; Malmö UniversityNanoporous silica particles for pharmaceutical formulations; Malmö UniversityNon-invasive monitoring of skin disorders progression and healing – a low molecular weight biomarker approach; Malmö UniversityEncapsulation of pharmaceutical proteins in starch microparticles; Malmö University
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9852-5440

Search in DiVA

Show all publications