Tag Archives: AFMカンチレバー

Development of a Lidocaine-Loaded Alginate/CMC/PEO Electrospun Nanofiber Film and Application as an Anti-Adhesion Barrier

Surgery, particularly open surgery, is known to cause tissue/organ adhesion during healing. These adhesions occur through contact between the surgical treatment site and other organ, bone, or abdominal sites. Fibrous bands can form in unnecessary contact areas and cause various complications. Consequently, film- and gel-type anti-adhesion agents have been developed. The development of sustained drug delivery systems is very important for disease treatment and prevention.*

In “Development of a Lidocaine-Loaded Alginate/CMC/PEO Electrospun Nanofiber Film and Application as an Anti-Adhesion Barrier” Seungho Baek, Heekyung Park, Youngah Park, Hyun Kang and Donghyun Lee describe how the drug release behavior was controlled by crosslinking lidocaine-loaded alginate/carboxymethyl cellulose (CMC)/polyethylene oxide (PEO) nanofiber films prepared by electrospinning.*

Lidocaine is mainly used as an anesthetic and is known to have anti-adhesion effects.*

Based on the results presented in the article, this study shows that the drug release behavior can be controlled by using CaCl2 as a nontoxic crosslinking agent to produce a good anti-adhesion barrier that can prevent unnecessary tissue adhesion at a surgical site.*

The authors selected atomic force microscopy (AFM) using NANOSENSORS™ PointProbe® Plus PPP-NCHR AFM cantilevers to analyze the electrospun films.*

Figure 3 from “Development of a Lidocaine-Loaded Alginate/CMC/PEO Electrospun Nanofiber Film and Application as an Anti-Adhesion Barrier” by Seungho Baek et al.:
Morphological and surface characterization of the 9% (w/v) alginate/CMC/PEO nanofiber film. Analyses used the noncontact mode of atomic microscopy. (a–c) are the same films at different scales (scale bars 40 µm, 15 µm, and 5 µm).
Figure 3 from “Development of a Lidocaine-Loaded Alginate/CMC/PEO Electrospun Nanofiber Film and Application as an Anti-Adhesion Barrier” by Seungho Baek et al.:
Morphological and surface characterization of the 9% (w/v) alginate/CMC/PEO nanofiber film. Analyses used the noncontact mode of atomic microscopy. (a–c) are the same films at different scales (scale bars 40 µm, 15 µm, and 5 µm).

*Seungho Baek, Heekyung Park, Youngah Park, Hyun Kang and Donghyun Lee
Development of a Lidocaine-Loaded Alginate/CMC/PEO Electrospun Nanofiber Film and Application as an Anti-Adhesion Barrier
Polymers 2020, 12(3), 618
DOI: https://doi.org/10.3390/polym12030618

Please follow this external link to read the full article: https://www.mdpi.com/2073-4360/12/3/618/htm

Open Access: The article “Development of a Lidocaine-Loaded Alginate/CMC/PEO Electrospun Nanofiber Film and Application as an Anti-Adhesion Barrier” by Seungho Baek, Heekyung Park, Youngah Park, Hyun Kang and Donghyun Lee 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 license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license 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 license, visit http://creativecommons.org/licenses/by/4.0/.

Simultaneous co-localized super-resolution fluorescence microscopy and atomic force microscopy: combined SIM and AFM platform for the life sciences

Correlating data from different microscopy techniques holds the potential to discover new facets of signalling events in cellular biology.*

In the article “Simultaneous co-localized super-resolution fluorescence microscopy and atomic force microscopy: combined SIM and AFM platform for the life sciences” Ana I. Gómez-Varela, Dimitar R. Stamov, Adelaide Miranda, Rosana Alves, Cláudia Barata-Antunes, Daphné Dambournet, David G. Drubin, Sandra Paiva and Pieter A. A. De Beule report for the first time a hardware set-up capable of achieving simultaneous co-localized imaging of spatially correlated far-field super-resolution fluorescence microscopy and atomic force microscopy, a feat only obtained until now by fluorescence microscopy set-ups with spatial resolution restricted by the Abbe diffraction limit.*

The authors detail system integration and demonstrate system performance using sub-resolution fluorescent beads and applied to a test sample consisting of human bone osteosarcoma epithelial cells, with plasma membrane transporter 1 (MCT1) tagged with an enhanced green fluorescent protein (EGFP) at the N-terminal.*

The simultaneous operation of AFM and super-resolution fluorescence microscopy technique provides a powerful observational tool on the nanoscale, albeit data acquisition is typically obstructed by a series of integration problems. The authors of the above-mentioned article believe that the combination of SR-SIM with AFM presents one of the most promising schemes enabling simultaneous co-localized imaging, allowing the recording of nanomechanical data and cellular dynamics visualization at the same time.*

For measurements on cells in liquid NANOSENSORS™ uniqprobe qp-BioAC-CI AFM probes ( CB1 ) with a nominal resonance frequency of 90 kHz (in air), spring constant of 0.3 Nm−1, partial gold coating on the detector side, and quartz-like circular symmetric hyperbolic (double-concaved) tips with ROC of 30 nm were used. The corresponding AFM areas for the cell images were acquired with a Z-cantilever velocity of 250 μms−1 at a max Z-length of 1.5 μm, resulting in an acquisition time (based on the number of pixels) for Figs. 2, 3, 4 of ca. 13, 8 and 15 min respectively.*

Figure 4 a and b from Ana I. Gómez-Varela et al “Simultaneous co-localized super-resolution fluorescence microscopy and atomic force microscopy: combined SIM and AFM platform for the life sciences :  Simultaneous SR-SIM/AFM acquisition. The AFM measurements were carried out on fixed U2OS cells in medium/buffer with (a) and without N-SIM illumination (b). For convenience and enhanced feature/noise contrast, both AFM topography images in the SR-SIM/AFM overlays are displayed with an edge detection algorithm using a pixel difference operator in X. The topography images from Petri dish surface on three positions (labelled in the figures) were planefit (1st order polynomial function) to compensate for tilts in the sample surface, and subjected to surface roughness analysis Please have a look at the full article to view the full figure. https://rdcu.be/b4Iot
Figure 4 a and b from Ana I. Gómez-Varela et al “Simultaneous co-localized super-resolution fluorescence microscopy and atomic force microscopy: combined SIM and AFM platform for the life sciences : Simultaneous SR-SIM/AFM acquisition. The AFM measurements were carried out on fixed U2OS cells in medium/buffer with (a) and without N-SIM illumination (b). For convenience and enhanced feature/noise contrast, both AFM topography images in the SR-SIM/AFM overlays are displayed with an edge detection algorithm using a pixel difference operator in X. The topography images from Petri dish surface on three positions (labelled in the figures) were planefit (1st order polynomial function) to compensate for tilts in the sample surface, and subjected to surface roughness analysis. Please have a look at the full article to view the full figure. https://rdcu.be/b4Iot

*Ana I. Gómez-Varela, Dimitar R. Stamov, Adelaide Miranda, Rosana Alves, Cláudia Barata-Antunes, Daphné Dambournet, David G. Drubin, Sandra Paiva and Pieter A. A. De Beule
Simultaneous co-localized super-resolution fluorescence microscopy and atomic force microscopy: combined SIM and AFM platform for the life sciences
Nature Scientific Reports volume 10, Article number: 1122 (2020)
DOI: https://doi.org/10.1038/s41598-020-57885-z

Please follow this external link to read the full article https://rdcu.be/b4Iot

Open Access: The article “Simultaneous co-localized super-resolution fluorescence microscopy and atomic force microscopy: combined SIM and AFM platform for the life sciences” by Ana I. Gómez-Varela, Dimitar R. Stamov, Adelaide Miranda, Rosana Alves, Cláudia Barata-Antunes, Daphné Dambournet, David G. Drubin, Sandra Paiva and Pieter A. A. De Beule 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 license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license 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 license, visit http://creativecommons.org/licenses/by/4.0/.

Engineering work function of graphene oxide from p to n type using a low power atmospheric pressure plasma jet

Graphene, since its discovery in 2004 has attracted enormous interest due to its physical and chemical properties, and wide applications. *

Graphene oxide (GO) has emerged as an attractive alternative to graphene due to low cost, large scale production and solution processability. GO is prepared by oxidative exfoliation of graphite.*

The work function is a fundamental electronic property of a material and can be used to interpret the relative position of the Fermi level.*

For efficient transport of electrons or holes in a heterojunction device, the work function of the materials plays a crucial role, since work function determines how the bands will align at the contacts.*

Recently there has been an increased interest in applications of GO for interfacial layers and transparent electrode materials in optoelectronic devices e.g. liquid crystal displays (LCDs), organic light emitting diodes (OLEDs), touch screens, dye-sensitized solar cells (DSSCs) and as supercapacitor electrodes. Tuning the work function of GO is key to achieving high performance devices. *

In the article “Engineering work function of graphene oxide from p to n type using a low power atmospheric pressure plasma jet” by Avishek Dey, Paheli Ghosh, James Bowen, Nicholas St. J. Braithwaite and Satheesh Krishnamurthy, the authors demonstrate doping graphene oxide (GO) films using a low power atmospheric pressure plasma jet (APPJ) with subsequent tuning of the work function.*

The surface potential of the plasma functionalized GO films could be tuned by 120 ± 10 mV by varying plasma parameters. *

Scanning Kelvin probe microscopy ( SKPM ) also known as Kelvin probe force microscopy ( KPFM ) measurements were carried out to realize changes in work function of the GO films with plasma functionalization.*

NANOSENSORS™ PointProbe® Plus PPP-EFM AFM probes with a platinum iridium coating were used to perform surface potential measurements. *

The Kelvin probe studies showed that the bonding configuration can influence the work function of GO. Pyridinic nitrogen transforms GO to p-type while graphitic nitrogen increases the electron density of GO and transforming it to n type. Pointing to the fact that a low power APPJ can effectively tune the work function of GO and hence the conductivity. *

The findings presented in the article are extremely useful in fabricating heterojunction devices like sensors and optoelectronic devices where band structure alignment is key to device performance when GO is used as a charge transport layer. This technique can be extended to other known 2D systems.*

Fig. 10 (a) from “Engineering work function of graphene oxide from p to n type using a low power atmospheric pressure plasma jet” by Avishek Dey et al.:

a) KPFM surface potential map of reference GO thin film ( please have a look at https://pubs.rsc.org/image/article/2020/CP/c9cp06174f/c9cp06174f-f10_hi-res.gif for the full figure.)
Figure 10 (a) from “Engineering work function of graphene oxide from p to n type using a low power atmospheric pressure plasma jet” by Avishek Dey et al.:

a) KPFM surface potential map of reference GO thin film ( please have a look at https://pubs.rsc.org/image/article/2020/CP/c9cp06174f/c9cp06174f-f10_hi-res.gif for the full figure.)

*Avishek Dey, Paheli Ghosh, James Bowen, Nicholas St. J. Braithwaite and Satheesh Krishnamurthy
Engineering work function of graphene oxide from p to n type using a low power atmospheric pressure plasma jet
Physical Chemistry Chemical Physics, 2020, 22, 7685-7698
DOI: 10.1039/C9CP06174F

Please follow this external link for the full article: https://pubs.rsc.org/en/content/articlehtml/2020/cp/c9cp06174f

Open Access: The article “Engineering work function of graphene oxide from p to n type using a low power atmospheric pressure plasma jet” by Avishek Dey, logoa, Paheli Ghosh, James Bowen, Nicholas St. J. Braithwaite and Satheesh Krishnamurthy is licensed under a Creative Commons Attribution 3.0 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 license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license 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 license, visit http://creativecommons.org/licenses/by/3.0/.