Tamás Bozó - Academia.edu (original) (raw)

Papers by Tamás Bozó

Research paper thumbnail of Determination of the Main Phase Transition Temperature of Phospholipids by Oscillatory Rheology

Molecules, Jun 29, 2023

Knowledge of the physical and chemical properties of phospholipids, such as phase transition temp... more Knowledge of the physical and chemical properties of phospholipids, such as phase transition temperatures (Tc), is of great importance in order to reveal the functionalities of biological and artificial membranes. Our research group developed an oscillatory rheological method for the simple and rapid determination of phase transition temperatures (Tc). The phospholipids constructing the membranes undergo conformational changes at their Tc, which cause alterations of viscoelastic properties of the molecules. The oscillatory technique recommended by us proved to be appropriate to reveal the altered molecular properties of phospholipids as tracking the slightest changes in the viscoelasticity. Our study demonstrates the abrupt changes in rheological properties at Tc for the following phospholipids: 1,2-Dimyristoyl-sn-glycero-3-Phosphocholine (DMPC), 1,2-Dipalmitoylsn-glycero-3-Phosphatidylcholine (DPPC), and 1,2-Distearoyl-sn-glycero-3-Phosphocholine (DSPC), proving that the applied methodology is adequate for determining the Tc of phospholipids.

Research paper thumbnail of A myosin II nanomachine mimicking the striated muscle

Nature Communications, Aug 30, 2018

The contraction of striated muscle (skeletal and cardiac muscle) is generated by ATPdependent int... more The contraction of striated muscle (skeletal and cardiac muscle) is generated by ATPdependent interactions between the molecular motor myosin II and the actin filament. The myosin motors are mechanically coupled along the thick filament in a geometry not achievable by single-molecule experiments. Here we show that a synthetic one-dimensional nanomachine, comprising fewer than ten myosin II dimers purified from rabbit psoas, performs isometric and isotonic contractions at 2 mM ATP, delivering a maximum power of 5 aW. The results are explained with a kinetic model fitted to the performance of mammalian skeletal muscle, showing that the condition for the motor coordination that maximises the efficiency in striated muscle is a minimum of 32 myosin heads sharing a common mechanical ground. The nanomachine offers a powerful tool for investigating muscle contractile-protein physiology, pathology and pharmacology without the potentially disturbing effects of the cytoskeletal-and regulatory-protein environment.

Research paper thumbnail of <scp>BRAF</scp> increases endothelial cell stiffness through reorganization of the actin cytoskeleton

The FASEB Journal, Aug 2, 2022

The dynamics of the actin cytoskeleton and its connection to endothelial cellcell junctions deter... more The dynamics of the actin cytoskeleton and its connection to endothelial cellcell junctions determine the barrier function of endothelial cells. The proper regulation of barrier opening/closing is necessary for the normal function of vessels, and its dysregulation can result in chronic and acute inflammation leading to edema formation. By using atomic force microscopy, we show here that thrombin-induced permeability of human umbilical vein endothelial cells, associated with actin stress fiber formation, stiffens the cell center. The depletion of the MEK/ERK kinase BRAF reduces thrombin-induced permeability prevents stress fiber formation and cell stiffening. The peripheral actin ring becomes stabilized by phosphorylated myosin light chain, while cofilin is excluded from the cell periphery. All these changes can be reverted by the inhibition of ROCK, but not of the MEK/ERK module. We propose that the balance between the binding of cofilin and myosin to F-actin in the cell periphery, which is regulated by the activity of ROCK, determines the local dynamics of actin reorganization, ultimately driving or preventing stress fiber formation.

Research paper thumbnail of Protomer polymorphism in mechanically stretched von Willebrand factor

Biophysical Journal, Feb 1, 2022

Research paper thumbnail of BRAF increases endothelial cell stiffness through reorganization of the actin cytoskeleton

The FASEB Journal

The dynamics of the actin cytoskeleton and its connection to endothelial cellcell junctions deter... more The dynamics of the actin cytoskeleton and its connection to endothelial cellcell junctions determine the barrier function of endothelial cells. The proper regulation of barrier opening/closing is necessary for the normal function of vessels, and its dysregulation can result in chronic and acute inflammation leading to edema formation. By using atomic force microscopy, we show here that thrombin-induced permeability of human umbilical vein endothelial cells, associated with actin stress fiber formation, stiffens the cell center. The depletion of the MEK/ERK kinase BRAF reduces thrombin-induced permeability prevents stress fiber formation and cell stiffening. The peripheral actin ring becomes stabilized by phosphorylated myosin light chain, while cofilin is excluded from the cell periphery. All these changes can be reverted by the inhibition of ROCK, but not of the MEK/ERK module. We propose that the balance between the binding of cofilin and myosin to F-actin in the cell periphery, which is regulated by the activity of ROCK, determines the local dynamics of actin reorganization, ultimately driving or preventing stress fiber formation.

Research paper thumbnail of Insights into the Structure of Comirnaty Covid-19 Vaccine: A Theory on Soft, Partially Bilayer-Covered Nanoparticles with Hydrogen Bond-Stabilized mRNA–Lipid Complexes

Research paper thumbnail of Structural hierarchy of mechanical extensibility in human von Willebrand factor multimers

Protein Science

The von Willebrand factor (VWF) is a multimeric glycoprotein composed of 80‐ to 120‐nm‐long proto... more The von Willebrand factor (VWF) is a multimeric glycoprotein composed of 80‐ to 120‐nm‐long protomeric units and plays a fundamental role in mediating platelet function at high shear. The exact nature of the shear‐induced structural transitions have remained elusive; uncovering them requires the high‐resolution quantitative analysis of gradually extended VWF. Here, we stretched human blood‐plasma‐derived VWF with molecular combing and analyzed the axial structure of the elongated multimers with atomic force microscopy. Protomers extended through structural intermediates that could be grouped into seven distinct topographical classes. Protomer extension thus progresses through the uncoiling of the C1–6 domain segment, rearrangements among the N‐terminal VWF domains, and unfolding and elastic extension of the A2 domain. The least and most extended protomer conformations were localized at the ends and the middle of the multimer, respectively, revealing an apparent necking phenomenon ch...

Research paper thumbnail of New insights into the structure of Comirnaty Covid-19 vaccine: A theory on soft nanoparticles with mRNA-lipid supercoils stabilized by hydrogen bonds

Despite the worldwide success of mRNA-LNP Covid-19 vaccines, the nanoscale structure of these for... more Despite the worldwide success of mRNA-LNP Covid-19 vaccines, the nanoscale structure of these formulations is still poorly understood. To fill this gap, we used a combination of atomic force microscopy (AFM), dynamic light scattering (DLS), transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM) and the determination of LNP pH gradient to analyze the nanoparticles (NPs) in BNT162b2 (Comirnaty), comparing it with the well characterized pegylated liposomal doxorubicin (Doxil). Comirnaty NPs had similar size to Doxil, however, unlike Doxil liposomes, wherein the stable ammonium and pH gradient enables accumulation of14C-methylamine in the intraliposomal aqueous phase, Comirnaty LNPs lack such pH gradient in spite of the fact that the pH 4, at which LNPs are prepared, is raised to pH 7.2 after loading of the mRNA. Mechanical manipulation of Comirnaty NPs with AFM revealed soft, compliant structures. The sawtooth-like force transitions seen during ca...

Research paper thumbnail of Protomer polymorphism in mechanically stretched von Willebrand factor

Biophysical Journal, 2022

Research paper thumbnail of Structural and nanomechanical assessment of photosensitization induced membrane disruption

Biophysical Journal, 2022

Research paper thumbnail of Effect of hypercholesterolemia on circulating and cardiomyocyte-derived extracellular vesicles

Scientific reports, May 26, 2024

Hypercholesterolemia (HC) induces, propagates and exacerbates cardiovascular diseases via various... more Hypercholesterolemia (HC) induces, propagates and exacerbates cardiovascular diseases via various mechanisms that are yet not properly understood. Extracellular vesicles (EVs) are involved in the pathomechanism of these diseases. To understand how circulating or cardiac-derived EVs could affect myocardial functions, we analyzed the metabolomic profile of circulating EVs, and we performed an in-depth analysis of cardiomyocyte (CM)-derived EVs in HC. Circulating EVs were isolated with Vezics technology from male Wistar rats fed with high-cholesterol or control chow. AC16 human CMs were treated with Remembrane HC supplement and EVs were isolated from cell culture supernatant. The biophysical properties and the protein composition of CM EVs were analyzed. THP1-ASC-GFP cells were treated with CM EVs, and monocyte activation was measured. HC diet reduced the amount of certain phosphatidylcholines in circulating EVs, independently of their plasma level. HC treatment significantly increased EV secretion of CMs and greatly modified CM EV proteome, enriching several proteins involved in tissue remodeling. Regardless of the treatment, CM EVs did not induce the activation of THP1 monocytes. In conclusion, HC strongly affects the metabolome of circulating EVs and dysregulates CM EVs, which might contribute to HC-induced cardiac derangements.

Research paper thumbnail of Development, structure and mechanics of a synthetic E. coli outer membrane model

Nanoscale Advances, 2021

The outer membrane (OM) of Gram-negative bacteria is a complex asymmetric bilayer containing lipi... more The outer membrane (OM) of Gram-negative bacteria is a complex asymmetric bilayer containing lipids, lipopolysaccharides (LPS) and proteins.

Research paper thumbnail of Kohleát nanorészecskék biofizikai jellemzése

Research paper thumbnail of Live cell confocal fluorescence and TIRF imaging of membrane nanotube networks between B lymphocytes: Studies on the conditions and mechanism of their growth

Research paper thumbnail of Optimization of Quality Attributes and Atomic Force Microscopy Imaging of Reconstituted Nanodroplets in Baicalin Loaded Self-Nanoemulsifying Formulations

Pharmaceutics, 2018

The objective of the study was to develop baicalin loaded liquid self-nanoemulsifying drug delive... more The objective of the study was to develop baicalin loaded liquid self-nanoemulsifying drug delivery systems (BSNEDDS) and to characterize them by physicochemical methods in order to optimize the composition and quality attributes. Atomic force microscopy (AFM) was utilized to evaluate the morphological characteristics and size distribution of reconstituted nanoemulsion droplets with a new sample preparation method for the elucidation of individual nanodroplets without any signs of coalescence. Response surface methodology and desirability approach was used to select the optimized composition related to droplet size, zeta-potential, polydispersity index (PDI), and turbidity characteristics. Droplet size distribution measured by dynamic light scattering method was highly desirable with 52.87 ± 0.5322 nm, which was confirmed by AFM imaging. The optimized formula contains Peceol® (14.29%, w/w), Kolliphor® EL (57.14%, w/w), and Transcutol® P (28.57%, w/w). Long-term stability analysis di...

Research paper thumbnail of A Myosin II Nanomachine Mimicking the Striated Muscle

Biophysical Journal, 2019

Research paper thumbnail of The Power of a Synthetic Machine Based on the Fast Myosin Isoform of Skeletal Muscle

Biophysical Journal, 2018

Research paper thumbnail of Microstructural Distinction of Electrospun Nanofibrous Drug Delivery Systems Formulated with Different Excipients

Molecular pharmaceutics, 2018

The electrospun nanofiber-based orally dissolving webs are promising candidates for rapid drug re... more The electrospun nanofiber-based orally dissolving webs are promising candidates for rapid drug release, which is due to the high surface area to volume ratio of the fibers and the high amorphization efficacy of the fiber formation process. Although the latter is responsible for the physical and/or chemical instability of these systems. The primary aim of the present study was to elucidate how the addition of polysorbate 80 (PS80) and hydroxypropyl-β-cyclodextrin (HP-β-CD) influenced the electrospinning process, the properties, and the behavior of the obtained nanofibers. In order to reveal any subtle changes attributable to the applied excipients, the prepared samples were subjected to several state of the art imaging and solid state characterization techniques at both macroscopic and microscopic levels. Atomic force microscopy (AFM) revealed the viscoelastic nature of the fibrous samples. At relatively low forces mostly elastic deformation was observed, while at higher loads plasti...

Research paper thumbnail of Study on the dissolution improvement of albendazole using reconstitutable dry nanosuspension formulation

European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, Jan 18, 2018

The aim of the study was to improve the solubility and dissolution rate of the poorly water solub... more The aim of the study was to improve the solubility and dissolution rate of the poorly water soluble drug albendazole via surfactant assisted media milling process. Preparation of a nanosuspension and then post-processing with a solidification technique applied to improve the applicability of nanosuspension in a solid dosage forms carrier. The dry nanosuspension was obtained using microcrystalline cellulose as solid carrier after tray drying at 40 °C. Both reconstitution from the solid carrier and dissolution profile studies were investigated in biorelevant Artificial Rumen Fluid (ARF) at pH = 6.50 and dissolution media at pH = 1.20 and pH = 6.80. Reconstitution studies have demonstrated that the mean hydrodynamic diameter values of albendazole crystals released from the dry suspension were nanosized (intensity weighted hydrodynamic diameter values: 200.40 ± 2.318 nm in ARF at pH = 6.50, 197.17 ± 0.208 nm in dissolution medium at pH = 6.80). Thermodynamic solubility studies have indi...

Research paper thumbnail of Thallium Labeled Citrate-Coated Prussian Blue Nanoparticles as Potential Imaging Agent

Contrast media & molecular imaging, 2018

The aim of this study was to develop and characterize a nanoparticle-based image-contrast platfor... more The aim of this study was to develop and characterize a nanoparticle-based image-contrast platform which is biocompatible, chemically stable, and accessible for radiolabeling with Tl. We explored whether this nanoparticle enhanced the T1 signal which might make it an MRI contrast agent as well. The physical properties of citrate-coated Prussian blue nanoparticles (PBNPs) (iron(II);iron(III);octadecacyanide) doped with Tl isotope were characterized with atomic force microscopy, dynamic light scattering, and zeta potential measurement. PBNP biodistribution was determined by using SPECT and MRI following intravenous administration into C57BL6 mice. Activity concentrations (MBq/cm) were calculated from the SPECT scans for each dedicated volume of interest (VOI) of liver, kidneys, salivary glands, heart, lungs, and brain. PBNP accumulation peaked at 2 hours after injection predominantly in the kidneys and the liver followed by a gradual decrease in activity in later time points. We synth...

Research paper thumbnail of Determination of the Main Phase Transition Temperature of Phospholipids by Oscillatory Rheology

Molecules, Jun 29, 2023

Knowledge of the physical and chemical properties of phospholipids, such as phase transition temp... more Knowledge of the physical and chemical properties of phospholipids, such as phase transition temperatures (Tc), is of great importance in order to reveal the functionalities of biological and artificial membranes. Our research group developed an oscillatory rheological method for the simple and rapid determination of phase transition temperatures (Tc). The phospholipids constructing the membranes undergo conformational changes at their Tc, which cause alterations of viscoelastic properties of the molecules. The oscillatory technique recommended by us proved to be appropriate to reveal the altered molecular properties of phospholipids as tracking the slightest changes in the viscoelasticity. Our study demonstrates the abrupt changes in rheological properties at Tc for the following phospholipids: 1,2-Dimyristoyl-sn-glycero-3-Phosphocholine (DMPC), 1,2-Dipalmitoylsn-glycero-3-Phosphatidylcholine (DPPC), and 1,2-Distearoyl-sn-glycero-3-Phosphocholine (DSPC), proving that the applied methodology is adequate for determining the Tc of phospholipids.

Research paper thumbnail of A myosin II nanomachine mimicking the striated muscle

Nature Communications, Aug 30, 2018

The contraction of striated muscle (skeletal and cardiac muscle) is generated by ATPdependent int... more The contraction of striated muscle (skeletal and cardiac muscle) is generated by ATPdependent interactions between the molecular motor myosin II and the actin filament. The myosin motors are mechanically coupled along the thick filament in a geometry not achievable by single-molecule experiments. Here we show that a synthetic one-dimensional nanomachine, comprising fewer than ten myosin II dimers purified from rabbit psoas, performs isometric and isotonic contractions at 2 mM ATP, delivering a maximum power of 5 aW. The results are explained with a kinetic model fitted to the performance of mammalian skeletal muscle, showing that the condition for the motor coordination that maximises the efficiency in striated muscle is a minimum of 32 myosin heads sharing a common mechanical ground. The nanomachine offers a powerful tool for investigating muscle contractile-protein physiology, pathology and pharmacology without the potentially disturbing effects of the cytoskeletal-and regulatory-protein environment.

Research paper thumbnail of <scp>BRAF</scp> increases endothelial cell stiffness through reorganization of the actin cytoskeleton

The FASEB Journal, Aug 2, 2022

The dynamics of the actin cytoskeleton and its connection to endothelial cellcell junctions deter... more The dynamics of the actin cytoskeleton and its connection to endothelial cellcell junctions determine the barrier function of endothelial cells. The proper regulation of barrier opening/closing is necessary for the normal function of vessels, and its dysregulation can result in chronic and acute inflammation leading to edema formation. By using atomic force microscopy, we show here that thrombin-induced permeability of human umbilical vein endothelial cells, associated with actin stress fiber formation, stiffens the cell center. The depletion of the MEK/ERK kinase BRAF reduces thrombin-induced permeability prevents stress fiber formation and cell stiffening. The peripheral actin ring becomes stabilized by phosphorylated myosin light chain, while cofilin is excluded from the cell periphery. All these changes can be reverted by the inhibition of ROCK, but not of the MEK/ERK module. We propose that the balance between the binding of cofilin and myosin to F-actin in the cell periphery, which is regulated by the activity of ROCK, determines the local dynamics of actin reorganization, ultimately driving or preventing stress fiber formation.

Research paper thumbnail of Protomer polymorphism in mechanically stretched von Willebrand factor

Biophysical Journal, Feb 1, 2022

Research paper thumbnail of BRAF increases endothelial cell stiffness through reorganization of the actin cytoskeleton

The FASEB Journal

The dynamics of the actin cytoskeleton and its connection to endothelial cellcell junctions deter... more The dynamics of the actin cytoskeleton and its connection to endothelial cellcell junctions determine the barrier function of endothelial cells. The proper regulation of barrier opening/closing is necessary for the normal function of vessels, and its dysregulation can result in chronic and acute inflammation leading to edema formation. By using atomic force microscopy, we show here that thrombin-induced permeability of human umbilical vein endothelial cells, associated with actin stress fiber formation, stiffens the cell center. The depletion of the MEK/ERK kinase BRAF reduces thrombin-induced permeability prevents stress fiber formation and cell stiffening. The peripheral actin ring becomes stabilized by phosphorylated myosin light chain, while cofilin is excluded from the cell periphery. All these changes can be reverted by the inhibition of ROCK, but not of the MEK/ERK module. We propose that the balance between the binding of cofilin and myosin to F-actin in the cell periphery, which is regulated by the activity of ROCK, determines the local dynamics of actin reorganization, ultimately driving or preventing stress fiber formation.

Research paper thumbnail of Insights into the Structure of Comirnaty Covid-19 Vaccine: A Theory on Soft, Partially Bilayer-Covered Nanoparticles with Hydrogen Bond-Stabilized mRNA–Lipid Complexes

Research paper thumbnail of Structural hierarchy of mechanical extensibility in human von Willebrand factor multimers

Protein Science

The von Willebrand factor (VWF) is a multimeric glycoprotein composed of 80‐ to 120‐nm‐long proto... more The von Willebrand factor (VWF) is a multimeric glycoprotein composed of 80‐ to 120‐nm‐long protomeric units and plays a fundamental role in mediating platelet function at high shear. The exact nature of the shear‐induced structural transitions have remained elusive; uncovering them requires the high‐resolution quantitative analysis of gradually extended VWF. Here, we stretched human blood‐plasma‐derived VWF with molecular combing and analyzed the axial structure of the elongated multimers with atomic force microscopy. Protomers extended through structural intermediates that could be grouped into seven distinct topographical classes. Protomer extension thus progresses through the uncoiling of the C1–6 domain segment, rearrangements among the N‐terminal VWF domains, and unfolding and elastic extension of the A2 domain. The least and most extended protomer conformations were localized at the ends and the middle of the multimer, respectively, revealing an apparent necking phenomenon ch...

Research paper thumbnail of New insights into the structure of Comirnaty Covid-19 vaccine: A theory on soft nanoparticles with mRNA-lipid supercoils stabilized by hydrogen bonds

Despite the worldwide success of mRNA-LNP Covid-19 vaccines, the nanoscale structure of these for... more Despite the worldwide success of mRNA-LNP Covid-19 vaccines, the nanoscale structure of these formulations is still poorly understood. To fill this gap, we used a combination of atomic force microscopy (AFM), dynamic light scattering (DLS), transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM) and the determination of LNP pH gradient to analyze the nanoparticles (NPs) in BNT162b2 (Comirnaty), comparing it with the well characterized pegylated liposomal doxorubicin (Doxil). Comirnaty NPs had similar size to Doxil, however, unlike Doxil liposomes, wherein the stable ammonium and pH gradient enables accumulation of14C-methylamine in the intraliposomal aqueous phase, Comirnaty LNPs lack such pH gradient in spite of the fact that the pH 4, at which LNPs are prepared, is raised to pH 7.2 after loading of the mRNA. Mechanical manipulation of Comirnaty NPs with AFM revealed soft, compliant structures. The sawtooth-like force transitions seen during ca...

Research paper thumbnail of Protomer polymorphism in mechanically stretched von Willebrand factor

Biophysical Journal, 2022

Research paper thumbnail of Structural and nanomechanical assessment of photosensitization induced membrane disruption

Biophysical Journal, 2022

Research paper thumbnail of Effect of hypercholesterolemia on circulating and cardiomyocyte-derived extracellular vesicles

Scientific reports, May 26, 2024

Hypercholesterolemia (HC) induces, propagates and exacerbates cardiovascular diseases via various... more Hypercholesterolemia (HC) induces, propagates and exacerbates cardiovascular diseases via various mechanisms that are yet not properly understood. Extracellular vesicles (EVs) are involved in the pathomechanism of these diseases. To understand how circulating or cardiac-derived EVs could affect myocardial functions, we analyzed the metabolomic profile of circulating EVs, and we performed an in-depth analysis of cardiomyocyte (CM)-derived EVs in HC. Circulating EVs were isolated with Vezics technology from male Wistar rats fed with high-cholesterol or control chow. AC16 human CMs were treated with Remembrane HC supplement and EVs were isolated from cell culture supernatant. The biophysical properties and the protein composition of CM EVs were analyzed. THP1-ASC-GFP cells were treated with CM EVs, and monocyte activation was measured. HC diet reduced the amount of certain phosphatidylcholines in circulating EVs, independently of their plasma level. HC treatment significantly increased EV secretion of CMs and greatly modified CM EV proteome, enriching several proteins involved in tissue remodeling. Regardless of the treatment, CM EVs did not induce the activation of THP1 monocytes. In conclusion, HC strongly affects the metabolome of circulating EVs and dysregulates CM EVs, which might contribute to HC-induced cardiac derangements.

Research paper thumbnail of Development, structure and mechanics of a synthetic E. coli outer membrane model

Nanoscale Advances, 2021

The outer membrane (OM) of Gram-negative bacteria is a complex asymmetric bilayer containing lipi... more The outer membrane (OM) of Gram-negative bacteria is a complex asymmetric bilayer containing lipids, lipopolysaccharides (LPS) and proteins.

Research paper thumbnail of Kohleát nanorészecskék biofizikai jellemzése

Research paper thumbnail of Live cell confocal fluorescence and TIRF imaging of membrane nanotube networks between B lymphocytes: Studies on the conditions and mechanism of their growth

Research paper thumbnail of Optimization of Quality Attributes and Atomic Force Microscopy Imaging of Reconstituted Nanodroplets in Baicalin Loaded Self-Nanoemulsifying Formulations

Pharmaceutics, 2018

The objective of the study was to develop baicalin loaded liquid self-nanoemulsifying drug delive... more The objective of the study was to develop baicalin loaded liquid self-nanoemulsifying drug delivery systems (BSNEDDS) and to characterize them by physicochemical methods in order to optimize the composition and quality attributes. Atomic force microscopy (AFM) was utilized to evaluate the morphological characteristics and size distribution of reconstituted nanoemulsion droplets with a new sample preparation method for the elucidation of individual nanodroplets without any signs of coalescence. Response surface methodology and desirability approach was used to select the optimized composition related to droplet size, zeta-potential, polydispersity index (PDI), and turbidity characteristics. Droplet size distribution measured by dynamic light scattering method was highly desirable with 52.87 ± 0.5322 nm, which was confirmed by AFM imaging. The optimized formula contains Peceol® (14.29%, w/w), Kolliphor® EL (57.14%, w/w), and Transcutol® P (28.57%, w/w). Long-term stability analysis di...

Research paper thumbnail of A Myosin II Nanomachine Mimicking the Striated Muscle

Biophysical Journal, 2019

Research paper thumbnail of The Power of a Synthetic Machine Based on the Fast Myosin Isoform of Skeletal Muscle

Biophysical Journal, 2018

Research paper thumbnail of Microstructural Distinction of Electrospun Nanofibrous Drug Delivery Systems Formulated with Different Excipients

Molecular pharmaceutics, 2018

The electrospun nanofiber-based orally dissolving webs are promising candidates for rapid drug re... more The electrospun nanofiber-based orally dissolving webs are promising candidates for rapid drug release, which is due to the high surface area to volume ratio of the fibers and the high amorphization efficacy of the fiber formation process. Although the latter is responsible for the physical and/or chemical instability of these systems. The primary aim of the present study was to elucidate how the addition of polysorbate 80 (PS80) and hydroxypropyl-β-cyclodextrin (HP-β-CD) influenced the electrospinning process, the properties, and the behavior of the obtained nanofibers. In order to reveal any subtle changes attributable to the applied excipients, the prepared samples were subjected to several state of the art imaging and solid state characterization techniques at both macroscopic and microscopic levels. Atomic force microscopy (AFM) revealed the viscoelastic nature of the fibrous samples. At relatively low forces mostly elastic deformation was observed, while at higher loads plasti...

Research paper thumbnail of Study on the dissolution improvement of albendazole using reconstitutable dry nanosuspension formulation

European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, Jan 18, 2018

The aim of the study was to improve the solubility and dissolution rate of the poorly water solub... more The aim of the study was to improve the solubility and dissolution rate of the poorly water soluble drug albendazole via surfactant assisted media milling process. Preparation of a nanosuspension and then post-processing with a solidification technique applied to improve the applicability of nanosuspension in a solid dosage forms carrier. The dry nanosuspension was obtained using microcrystalline cellulose as solid carrier after tray drying at 40 °C. Both reconstitution from the solid carrier and dissolution profile studies were investigated in biorelevant Artificial Rumen Fluid (ARF) at pH = 6.50 and dissolution media at pH = 1.20 and pH = 6.80. Reconstitution studies have demonstrated that the mean hydrodynamic diameter values of albendazole crystals released from the dry suspension were nanosized (intensity weighted hydrodynamic diameter values: 200.40 ± 2.318 nm in ARF at pH = 6.50, 197.17 ± 0.208 nm in dissolution medium at pH = 6.80). Thermodynamic solubility studies have indi...

Research paper thumbnail of Thallium Labeled Citrate-Coated Prussian Blue Nanoparticles as Potential Imaging Agent

Contrast media & molecular imaging, 2018

The aim of this study was to develop and characterize a nanoparticle-based image-contrast platfor... more The aim of this study was to develop and characterize a nanoparticle-based image-contrast platform which is biocompatible, chemically stable, and accessible for radiolabeling with Tl. We explored whether this nanoparticle enhanced the T1 signal which might make it an MRI contrast agent as well. The physical properties of citrate-coated Prussian blue nanoparticles (PBNPs) (iron(II);iron(III);octadecacyanide) doped with Tl isotope were characterized with atomic force microscopy, dynamic light scattering, and zeta potential measurement. PBNP biodistribution was determined by using SPECT and MRI following intravenous administration into C57BL6 mice. Activity concentrations (MBq/cm) were calculated from the SPECT scans for each dedicated volume of interest (VOI) of liver, kidneys, salivary glands, heart, lungs, and brain. PBNP accumulation peaked at 2 hours after injection predominantly in the kidneys and the liver followed by a gradual decrease in activity in later time points. We synth...