Tag Archives: uniqprobes

Monitoring SARS-CoV-2 Surrogate TGEV Individual Virions Structure Survival under Harsh Physicochemical Environments

Successful airborne transmission of coronaviruses through fluid microdroplets requires a virion structure that must withstand harsh natural conditions. *

Because of the strict biosafety requirements for the study of human respiratory viruses, it is important to develop surrogate models to facilitate their investigation. *

In the article “Monitoring SARS-CoV-2 Surrogate TGEV Individual Virions Structure Survival under Harsh Physicochemical Environments” Miguel Cantero, Diego Carlero, Francisco Javier Chichón, Jaime Martín-Benito and Pedro José De Pablo explore the mechanical properties and nanostructure of transmissible gastroenteritis virus (TGEV) virions in liquid milieu and their response to different chemical agents commonly used as biocides in their quest for a SARS-CoV2 surrogate for dynamic nanoscale structure studies that can alleviate the use of BSL3 labs that are highly demanded for biomedical and biotechnological research. *

In past few years, atomic force microscopy (AFM) has been used to thoroughly characterize the physical properties, structure and stability of many viruses. *

It is possible to scan individual viruses, obtaining their topography and a variety of physical properties such as mechanics or electrostatics in controlled liquid milieu. Atomic Force Microscopy has provided biophysical information on all kinds of viruses, including bacteriophages and eukaryotic viruses. *

For the research described in their article the authors used AFM to explore in real time the stability of individual TGEV particles as a surrogate model for SARS-CoV-2 in order to elucidate its structural stability under a range of physicochemical assaults, including mechanical stress, desiccation-rehydration cycles and treatment with chemical agents commonly used as biocides, such as detergents and ethanol. *

They also aimed to show that some structural research can be performed with non-hazardous CoV strains. *

All the described AFM experiments were carried out with NANOSENSORS™ uniqprobe qp-BioAC AFM probes. *

The data collected by Miguel Cantero  et al. for the article provide two-fold results on virus stability:

First, while particles with larger size and lower packing fraction kept their morphology intact after successive mechanical aggressions, smaller viruses with higher packing fraction showed conspicuous evidence of structural damage and content release.

Second, monitoring the structure of single TGEV particles in the presence of detergent and alcohol in real time revealed the stages of gradual degradation of the virus structure in situ. *

These data suggest that detergent is three orders of magnitude more efficient than alcohol in destabilizing TGEV virus particles, paving the way for optimizing hygienic protocols for viruses with similar structure, such as SARS-CoV-2. *

Figure 3 from “Monitoring SARS-CoV-2 Surrogate TGEV Individual Virions Structure Survival under Harsh Physicochemical Environments” by Miguel Cantero et al.: Treatment of TGEV with IGEPAL 0.2% (A). Topographical images before (left) and after (right) IGEPAL treatment (B). Profiles traced over the particles before (black) and after (blue) the treatment. The time interval between images was ~30 s (C). Height distribution of TGEV particles before (black) and after (blue) treatment (n = 103). Counts taken from the distribution curve were normalized for comparison. The peak shifts from the value of the intact particle height to the height of the cores. NANOSENSORS uniqprobe qp-BioAC AFM probes were used for the atomic force microscopy measurements.
Figure 3 from “Monitoring SARS-CoV-2 Surrogate TGEV Individual Virions Structure Survival under Harsh Physicochemical Environments” by Miguel Cantero et al.:
Treatment of TGEV with IGEPAL 0.2% (A). Topographical images before (left) and after (right) IGEPAL treatment (B). Profiles traced over the particles before (black) and after (blue) the treatment. The time interval between images was ~30 s (C). Height distribution of TGEV particles before (black) and after (blue) treatment (n = 103). Counts taken from the distribution curve were normalized for comparison. The peak shifts from the value of the intact particle height to the height of the cores.

*Miguel Cantero, Diego Carlero, Francisco Javier Chichón, Jaime Martín-Benito and Pedro José De Pablo
Monitoring SARS-CoV-2 Surrogate TGEV Individual Virions Structure Survival under Harsh Physicochemical Environments
Cells 2022, 11(11), 1759
DOI: https://doi.org/10.3390/cells11111759

Open Access: The article “Monitoring SARS-CoV-2 Surrogate TGEV Individual Virions Structure Survival under Harsh Physicochemical Environments” by Miguel Cantero, Diego Carlero, Francisco Javier Chichón, Jaime Martín-Benito and Pedro José De Pablo is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Cerosomes as skin repairing agent: Mode of action studies with a model stratum corneum layer at liquid/air and liquid/solid interfaces

The human skin is the second largest organ of the human body. The stratum corneum (SC) is the outmost layer of the human skin and performs various protective and adaptive physiological functions such as protecting against physical, chemical and biological damages.*

The homeostasis of the lipid matrix of the stratum corneum is essential for the correct functioning of the SC. If the composition of this lipid matrix is changed or disturbed skin ailments such as atopic dermatitis or psoriasis can be the result. According to various studies direct replenishment of the SC lipids on damaged skin has positive effects on the recovery of its barrier properties.*

Cerosomes or stratum corneum liposomes are a relatively new class of liposomes which are being investigated for the application as skin barrier repairing agents in chronical skin diseases.*

In the article “Cerosomes as skin repairing agent: Mode of action studies with a model stratum corneum layer at liquid/air and liquid/solid interfaces” Fabio Strati, Tetiana Mukhina, Reinhard H. H. Neubert, Lukas Opalka, Gerd Hause, Christian E. H. Schmelzer, Matthias Menzel, Gerald Brezesinski describe how they prepared cerosomes, i.E. liposomes composed of SC lipids in order to investigate the mechanism of interaction with a 2D model of the SC lipid matrix.*

After a first step of characterizing the used SC model monolayer in detail they carried out the development of stable SC liposomes, the so-called cerosomes, in a second step.*

Once the cerosome formulations were developed and characterized, the interaction between these and monolayers of the SC lipid matrix model was investigated.*

The interaction was probed by means of adsorption isotherms after subphase injection, and after the transfer to a solid support by atomic force microscopy (AFM) measurements.*

The AFM experiments were performed to gain information about the structures of the formed assemblies. This technique allows to resolve the lateral organization and to visualize the presence of lipid domains and/or adsorbed vesicles be performing topographic surface measurements of the sample deposited onto a solid support with an Angstrom resolution in transversal direction.*

Topographical images were recorded in liquid state using NANOSENSORS uniqprobe qp-BioT AFM probes in a standard liquid cell containing the needed buffer.*

The results obtained with the application of AFM showed that the liposomes were able to both penetrate into empty spaces and lower domains present in the SC model monolayer and get adsorbed at the monolayer forming localized multilayers.*

The results presented in the article indicate that a strong interaction occurred between SC monolayers and the cerosomes.*

The study proves for the first time the mode of action by which cerosomes exploit their function as skin barrier repairing agents on the SC.*

The use of such formulations might not only be limited to restore the damaged skin but they could be also used to deliver active pharmaceutical ingredients encapsulated in the cerosomes. This might open new and interesting scenarios for treating skin conditions such as inflammations caused by atopic dermatitis and/or psoriasis.*

Fig. 7 from “Cerosomes as skin repairing agent: Mode of action studies with a model stratum corneum layer at liquid/air and liquid/solid interfaces” by F. Strati et al: AFM scans of a) SC model monolayer transferred via LB method onto mica support, b) SC model monolayer after injection of cerosomes, c) SC model monolayer after injection of cerosome + S75-3 formulation, and d) SC model monolayer after injection of S75-3 liposomal formulation. All samples were transferred via the LS method onto glass substrate. Each experiment was performed at 20°C and the subphase used for a) was Millipore water while for b), c), and d) the same aqueous solutions have been used as for the formulation of the liposomes. Topographical images were recorded in liquid state using NANOSENSORS uniqprobe qp-BioT AFM probes in a standard liquid cell containing the needed buffer.
Fig. 7 from “Cerosomes as skin repairing agent: Mode of action studies with a model stratum corneum layer at liquid/air and liquid/solid interfaces” by F. Strati et al: AFM scans of a) SC model monolayer transferred via LB method onto mica support, b) SC model monolayer after injection of cerosomes, c) SC model monolayer after injection of cerosome + S75-3 formulation, and d) SC model monolayer after injection of S75-3 liposomal formulation. All samples were transferred via the LS method onto glass substrate. Each experiment was performed at 20°C and the subphase used for a) was Millipore water while for b), c), and d) the same aqueous solutions have been used as for the formulation of the liposomes.

 

*Fabio Strati, Tetiana Mukhina, Reinhard H. H. Neubert, Lukas Opalka, Gerd Hause, Christian E. H. Schmelzer, Matthias Menzel, Gerald Brezesinski
Cerosomes as skin repairing agent: Mode of action studies with a model stratum corneum layer at liquid/air and liquid/solid interfaces
BBA Advances, Volume 2, 2022, 100039
DOI: https://doi.org/10.1016/j.bbadva.2021.100039

Please follow this external link to read the full article:  https://doi.org/10.1016/j.bbadva.2021.100039

Open Access: The article “Cerosomes as skin repairing agent: Mode of action studies with a model stratum corneum layer at liquid/air and liquid/solid interfaces” by Fabio Strati, Tetiana Mukhina, Reinhard H. H. Neubert, Lukas Opalka, Gerd Hause, Christian E. H. Schmelzer, Matthias Menzel, Gerald Brezesinski is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Supercritical carbon dioxide decellularization of plant material to generate 3D biocompatible scaffolds

Biocompatible scaffolds that can be repopulated with human cells have many uses such serving as replacement organs and tissues. Therefore there is an increasing interest in plant-based biomaterials for tissue engineering.*

As the above mentioned scaffolds should mimic the in vivo tissue environment closely they need to provide a fitting structural and biomechanical support to the cells while at the same time promoting cell behaviour and tissue development. *

Currently the standard method to prepare plant tissue to serve as a biocompatible scaffold is to decellularize it with serial chemical treatment.*

In their article “Supercritical carbon dioxide decellularization of plant material to generate 3D biocompatible scaffolds” Ashlee F. Harris, Jerome Lacombe, Sumedha Liyanage, Margaret Y. Han, Emily Wallace, Sophia Karsunky, Noureddine Abidi and Frederic Zenhausern explore another method to produce biocompatible scaffolds.*

They use supercritical carbon dioxide (scCO2) together with 2% peracetic acid to decellularize plant material.*

Their subsequent investigations show that the process of decellularization, scaffold structure preservation and recellularization with human cells is less time consuming than with the standard chemical method.

In a further step the authors of the article describe how they use various scientific methods to evaluate the scaffolds they decellularized by the described scCO2 method.*

Ashlee F. Harris et al. use Atomic Force Microscopy (AFM) in order to find out if the scCO2 treatment had an impact on the mechanical properties of the scaffolds produced with this method.*

With AFM topography measurements they are able to establish that structures such as plant vasculature were preserved.*

The following determination of the Young’s Modulus calculated from multiple force curves of a homogeneous surface section of the produced scaffold shows it to be slightly lower than the one from a chemically decellularized scaffold.*

NANOSENSORS™ uniqprobe qp-BioAC AFM probes ( CB3 nominal values: 80 μm length, 30 μm mean width, 400 nm thickness, force constant 0.06 N/m, resonance frequency 30 kHz) were used for the scaffold measurements with Atomic Force Microscopy.

Figure 3 from “Supercritical carbon dioxide decellularization of plant material to generate 3D biocompatible scaffolds AFM imaging and spectrometry measurement” by Ashlee F. Harris et al.: 
They used AFM surface topography measurements to confirm that the structures such as plant vasculature were preserved after the scSO2 process and used  AFM force curves to calculate the  Young’s Modulus (YM) of the scCO2 decellularized scaffold. NANOSENSORS uniqprobe qp-BioAC AFM probes were used for the described AFM measurments. 
(a) Representative false colored three-dimensional surface mapping images and (b) Young’s modulus of scCO2 and chemically decellularized scaffolds (data as mean ± SEM; n = 5).
Figure 3 from “Supercritical carbon dioxide decellularization of plant material to generate 3D biocompatible scaffolds AFM imaging and spectrometry measurement” by Ashlee F. Harris et al.: (a) Representative false colored three-dimensional surface mapping images and (b) Young’s modulus of scCO2 and chemically decellularized scaffolds (data as mean ± SEM; n = 5).

While the scCo2 method promises to be a faster way to decellularize plant material and produce sterile and biocompatible scaffolds further research will be necessary to determine whether the differences the authors detected between the scaffolds produced with the scCO2 approach and the scaffolds produced with the chemical approach have a major influence on how repopulated cells behave in the achieved scaffolds.*

*Ashlee F. Harris, Jerome Lacombe, Sumedha Liyanage, Margaret Y. Han, Emily Wallace, Sophia Karsunky, Noureddine Abidi and Frederic Zenhausern
Supercritical carbon dioxide decellularization of plant material to generate 3D biocompatible scaffolds
Nature Scientific Reports 11, 3643 (2021)
DOI: https://doi.org/10.1038/s41598-021-83250-9

Please follow this external link to read the full article: https://rdcu.be/cAqW3

Open Access The article “Supercritical carbon dioxide decellularization of plant material to generate 3D biocompatible scaffolds” by Ashlee F. Harris, Jerome Lacombe, Sumedha Liyanage, Margaret Y. Han, Emily Wallace, Sophia Karsunky, Noureddine Abidi and Frederic Zenhausern is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.