Tag Archives: PointProbe Plus

articles on the PointProbe Plus AFM probe series

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/.

Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2

Engineering chlorophyll (Chl) pigments that are bound to photosynthetic light-harvesting proteins is one promising strategy to regulate spectral coverage for photon capture and to improve the photosynthetic efficiency of these proteins.*

The in situ oxidation of BChl a in light-harvesting protein LH2 from a purple bacterium Rhodoblastus acidophilus by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone demonstrated in the article “Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2” by Yoshitaka Saga et al. will be useful for engineering photofunctions in natural light-harvesting proteins and for understanding the alteration from BChl pigments in anoxygenic photosynthetic bacteria to Chl pigments in oxygenic organisms in the evolution of photosynthesis.*

The authors observed their sample in 20 mM Tris buffer containing 150 mM NaCl (pH 8.0) using a  home-built frequency modulation AFM ( FM-AFM ) with NANOSENSORS™ PPP-NCHAuD AFM probes.*

Figure 6 from «Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2” by Y. Saga et al.: FM-AFM images of native LH2 (A) and oxidized LH2 (B) adsorbed on mica taken in 20 mM Tris buffer containing 150 mM NaCl (pH 8.0). Left: wide images. Middle: locally enlarged images of single LH2 proteins. Right: overlapped height-profiles of ten proteins. NANOSENSORS PPP-NCHAuD AFM probes were used.
Figure 6 from «Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2” by Y. Saga et al.: FM-AFM images of native LH2 (A) and oxidized LH2 (B) adsorbed on mica taken in 20 mM Tris buffer containing 150 mM NaCl (pH 8.0). Left: wide images. Middle: locally enlarged images of single LH2 proteins. Right: overlapped height-profiles of ten proteins.

*Yoshitaka Saga, Kiyoshiro Kawano, Yuji Otsuka, Michie Imanishi, Yukihiro Kimura, Sayaka Matsui & Hitoshi Asakawa
Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2
Nature, Scientific Reports, volume 9, Article number: 3636 (2019)
DOI: https://doi.org/10.1038/s41598-019-40082-y

Please follow this external link to read the full article: https://www.nature.com/articles/s41598-019-40082-y

Open Access The article “Selective oxidation of B800 bacteriochlorophyll a in photosynthetic light-harvesting protein LH2” by Yoshitaka Saga, Kiyoshiro Kawano, Yuji Otsuka, Michie Imanishi, Yukihiro Kimura, Sayaka Matsui & Hitoshi Asakawa 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/.

5′-(CGA)n sequence-assisted pH-controlled assembly of supramolecular DNA nanostructure

In the research article “5′-(CGA)n sequence-assisted pH-controlled assembly of supramolecular DNA nanostructure” Yuting Yan, Yanwei Cao, Chunsheng Xiao, Yang Li, Xiaoxuan Xiang and Xinhua Guo demonstratethat the connection of duplex-forming sequences with a G-quadruplex-forming sequence (G6) could be used to construct DNA supramolecular nanostructures with alternating B-duplex and G-quadruplex structures. Their results demonstrate that the TT linker between B-duplex and G-quadruplex structures are necessary for the construction of such nanostructures, because the TT linker can provide structural flexibility for the bending of duplexes at the terminal of G-quadruplex.*

The formation of DNA supramolecular nanostructures was directly observed through AFM measurements.  Atomic force microscopy (AFM) was performed using NANOSENSORS™ PointProbe® Plus PPP-NCHR tapping mode AFM probes.

Figure 5. from “5′-(CGA)n sequence-assisted pH-controlled assembly of supramolecular DNA nanostructure” by Yuting Yan et al.: AFM images of the nanostructures formed by DNA G-quadruplexes self-assembly in KOAc buffer solution; (a,b) SG2 at pH 9.0, (c,d) SG2 at pH 4.5, (e,f) a mixture of SG2 and CSG2 at pH 4.5, (g,h) a mixture of SG2 and CSG2 at pH 9.0. The length of side is 2 µm and the scale bar is 500 nm. NANOSENSORS™ PointProbe® Plus PPP-NCHR AFM probes were used for all AFM images.
Figure 5. from “5′-(CGA)n sequence-assisted pH-controlled assembly of supramolecular DNA nanostructure” by Yuting Yan et al.: AFM images of the nanostructures formed by DNA G-quadruplexes self-assembly in KOAc buffer solution; (a,b) SG2 at pH 9.0, (c,d) SG2 at pH 4.5, (e,f) a mixture of SG2 and CSG2 at pH 4.5, (g,h) a mixture of SG2 and CSG2 at pH 9.0. The length of side is 2 µm and the scale bar is 500 nm.

AFM microscopy was performed on the fresh mica surfaces with the help of magnesium ions which can bind negatively charged DNA strands. The DNA samples were annealed at 100 µM in 100 mM K+ solution at 4°C for one week. Then aliquots were diluted with 2 mM MgCl2 aqueous solution to give a 20 µl analyte containing 1.5 µM DNA. The analytes were spread evenly on the mica surface for 5–8 min. Subsequently, the mica surface was washed with Milli-Q water to wipe off the excess salt, and finally dried in the air.*

*Yuting Yan, Yanwei Cao, Chunsheng Xiao, Yang Li, Xiaoxuan Xiang, Xinhua Guo
5′-(CGA)n sequence-assisted pH-controlled assembly of supramolecular DNA nanostructure
Royal Society Open Science, 1 August 2018, Volume 5, Issue 8
DOI: https://doi.org/10.1098/rsos.180123

Open Access: The article “5′-(CGA)n sequence-assisted pH-controlled assembly of supramolecular DNA nanostructure” by  Yuting Yan et al. 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/.