Tag Archives: force mapping

Plant-Based Scaffolds Modify Cellular Response to Drug and Radiation Exposure Compared to Standard Cell Culture Models

Plant-based scaffolds present many advantages over a variety of biomaterials.*

Recent studies explored their potential to be repopulated with human cells and thus highlight a growing interest for their use in tissue engineering or for biomedical applications. However, it is still unclear if these in vitro plant-based scaffolds can modify cell phenotype or affect cellular response to external stimuli.

In the research article “Plant-Based Scaffolds Modify Cellular Response to Drug and Radiation Exposure Compared to Standard Cell Culture Models “ Jerome Lacombe, Ashlee F. Harris, Ryan Zenhausern, Sophia Karsunsky and Frederic Zenhausern report the characterization of the mechano-regulation of melanoma SK-MEL-28 and prostate PC3 cells seeded on decellularized spinach leaves scaffolds, compared to cells deposited on standard rigid cell culture substrate, as well as their response to drug and radiation treatment.*

In their study the authors show that plant decellularization provide soft scaffolds that match the stiffness range of most of the human tissue and modify cell behavior, including drug and radiation response, compared to standard cell culture models. Because of their distinguished features (natural vasculature, low immunogenicity, low cost, relative ease, etc.) and their wide variations in the shape and structures, these scaffolds offer a multi-controllable model with multiple biochemical and biophysical interactions. However, additional studies are required to determine if they could address important architectural and physical challenges of the in vivo tissue environment.

For force measurement, the Young’s Modulus (YM) of the leaf scaffolds were determined using force spectroscopy mode at liquid interface with NANOSENSORS uniqprobe qp-BioAC AFM probes for leaves measurement.*

NANOSENSORS uniqprobe qp-BioAC AFM probe top view (SEM image
NANOSENSORS uniqprobe qp-BioAC AFM probe top view (SEM image)

*Jerome Lacombe, Ashlee F. Harris, Ryan Zenhausern, Sophia Karsunsky and Frederic Zenhausern
Plant-Based Scaffolds Modify Cellular Response to Drug and Radiation Exposure Compared to Standard Cell Culture Models
Frontiers in Bioengineering and Biotechnology (2020) 8:932.
DOI: 10.3389/fbioe.2020.00932

Please follow this external link to read the full article: https://www.frontiersin.org/articles/10.3389/fbioe.2020.00932/full#B27

Open Access: The article “Plant-Based Scaffolds Modify Cellular Response to Drug and Radiation Exposure Compared to Standard Cell Culture Models” by Jerome Lacombe, Ashlee F. Harris, Ryan Zenhausern, Sophia Karsunsky 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 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/.

Single layer graphene induces load-bearing molecular layering at the hexadecane-steel interface

Carbon-based layers play an important role in boundary lubrication, from graphite as commercial solid lubricant in a spray can over diamond-like carbon coatings in automotive industries all the way to graphitic layers found in metal-metal hip implants. With increasing availability of graphene, the two-dimensional building block of graphite, its possible role in lubrication is being explored. *

After the discovery of friction and wear reduction on steel surfaces by graphene in a variety of environments, graphene is now emerging as new lubricant. Polymer composites with graphene exhibit improved tribological properties due to wear reduction by efficient transfer layers. The composite approach has been successfully extended to multilayers of polymer and graphene. The use of graphene as additive in formulated lubricant oils is also promising after functionalization to improve solubility. *

In their letter “Single layer graphene induces load-bearing molecular layering at the hexadecane-steel interface” G. Krämer, C. Kim, K-S. Kim and R. Bennewitz report experimental results for fundamental lubrication properties of the interface between a hexadecane model lubricant and a steel surface modified by a single layer graphene. Using high-resolution force microscopy, they quantify that the reduction of friction on graphene is connected to an ordered layer of adsorbed hexadecane molecules and that the graphene induces an ordering in molecular layers in the confined liquid above graphene patches. *

A single layer of graphene on steel surfaces causes a change in the near-surface structure of the model lubricant hexadecane. Hexadecane adsorbs in an ordered layer aligned straight molecules, and this layer is stable under scanning in contact with the tip of an atomic force microscope, while no such layer is observed on the steel substrate. Graphene and hexadecane layer reduce friction at the nanoscale by a factor of three compared to the bare steel in hexadecane. *

All AFM measurements described in this letter were performed using a NANOSENSORS™ PointProbe® Plus PPP-CONTR AFM probe at room temperature with a home-built fluid cell where the cantilever was fully immersed in hexadecane.*

 Figure 3 from “Single layer graphene induces load-bearing molecular layering at the hexadecane-steel interface” by G Krämer et al.:
 High-resolution lateral force maps recorded in hexadecane with a normal force of 3 nN. (a) On graphene, the adsorbed hexadecane molecules arrange in form of lamellae with a width of 2.1 nm. The cross-section was taken along the line indicated. The schematic depiction of the orientation of one hexadecane molecule is informed by the results in [21]. (b) On the steel substrate, an irregular stick-slip pattern with a characteristic slip length of about 1 nm is observed. The two cross-sections are taken the along the lines indicated in the respective color.
Figure 3 from “Single layer graphene induces load-bearing molecular layering at the hexadecane-steel interface” by G Krämer et al.:
High-resolution lateral force maps recorded in hexadecane with a normal force of 3 nN. (a) On graphene, the adsorbed hexadecane molecules arrange in form of lamellae with a width of 2.1 nm. The cross-section was taken along the line indicated. The schematic depiction of the orientation of one hexadecane molecule is informed by the results in [21]. (b) On the steel substrate, an irregular stick-slip pattern with a characteristic slip length of about 1 nm is observed. The two cross-sections are taken the along the lines indicated in the respective color.

*G. Krämer, C. Kim, K-S. Kim and R. Bennewitz
Single layer graphene induces load-bearing molecular layering at the hexadecane-steel interface
Nanotechnology, Volume 30, Number 46, 2019, 46LT01
DOI: https://doi.org/10.1088/1361-6528/ab3cab

Please follow this external link to read the full article: https://iopscience.iop.org/article/10.1088/1361-6528/ab3cab

Open Access: The letter “Single layer graphene induces load-bearing molecular layering at the hexadecane-steel interface” by G Krämer, C Kim, K-S Kim and R Bennewitz 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/.