Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UMass Amherst environmental chemist flashes warning light on new nanoparticle

31.08.2017

In a cover story in Small, Baoshan Xing of UMass Amherst and colleagues report on toxicity for layered BP in three cell lines. They found disruption of cell membrane integrity related to particle size, concentration- and cell-type-dependent cytotoxicity

When environmental and soil chemist Baoshan Xing at the University of Massachusetts Amherst began reading in 2014 that a new, two-dimensional material known as layered black phosphorous (BP) was gaining the attention of biomedical researchers for use in drug delivery systems and tumor photothermal therapy, he was both intrigued and concerned.


A schematic diagram illustrating mechanisms of BP toxicity, which include disruption of cell membrane integrity related to layered BP particle size and generation of reactive oxygen species. Baoshan Xing at UMass Amherst, with colleagues in China, report the findings in a cover story in Small.

Credit: UMass Amherst/Baoshan Xing

"I am not only a soil chemist, but an environmental chemist," he notes. "As agricultural scientists, we are very familiar with phosphorous but I had never heard of two-dimensional black phosphorous. So we read all the nice papers about black phosphorous, and then, as environmental chemists, we started asking about nanoparticle toxicity. You have to be careful where you put such materials in the human body."

In a recent cover story of the journal, Small, his former postdoctoral fellow, Qing Zhao, currently a professor at the Institute of Applied Ecology at the Chinese Academy of Sciences, and Xing report toxicity test results for different thicknesses of layered BP in three cell lines. Briefly, they found disruption of cell membrane integrity related to layered BP particle size, plus concentration- and cell-type-dependent cytotoxicity.

Xing says, "We are among the first ones to work with this material, particularly in regard to its environmental implications." He and colleagues urge that "an in-depth understanding of BP's cytotoxicity is of utmost importance" to provide useful data for risk evaluation and safe biomedical applications.

The researchers acknowledge that the new material, which is collected as thin samples from phosphorous crystals by a technique known as exfoliating, that is, shaving off layers of different thicknesses, does have "unique optical and electrical properties," which might make it "a promising candidate for an efficient drug delivery vehicle and photothermal/photodynamic therapy in treating a variety of cancers."

Xing says, "I remember when single-layer graphene generated great excitement in the research community a decade ago, and I think people are getting excited now about a single layer of black phosphorous, that it might have many exciting applications." But the two materials differ a great deal in their single-layer structure, he adds, where single-layer graphene is perfectly flat, exfoliated BP has a zig-zagged structure.

Zhao, Xing and their colleagues point out that studies of layered BP toxicity conducted to date have used viability reagents, which can interfere with cytotoxicity results. By contrast, they have used a label-free, real-time cell analysis (RTCA) technique that does not need any fluorescent or colorimetric viability reagents.

Assaying layered BP toxicity in three cell types, mouse fibroblast cells (NIH 3T3), human colonic epithelial cells (HCoEpiC) and human embryonic kidney cells (293T), the UMass Amherst and Chinese research team found that layered BP's cytotoxicity is based on the fact that it generates reactive oxygen species (ROS). ROS are among the most potent cell-damaging agents known. Layered BP also disrupts cell membrane integrity in a particle-size-dependent manner. "The larger the BP is, less membrane integrity will be retained," they note.

Further, they say the IC50 values of layered BP can differ by dozens of times depending on particle size and cell type. IC50 values refer to a measure of how effective a material is in inhibiting a specific biological function. Xing and colleagues urge that "special attention should be paid to the size of layered BP and the types of target cell lines for its application in biomedical field."

They add, "Further study is undoubtedly necessary to explore the cytotoxicity mechanisms in depth," and that "given the results from our present study, the mechanisms of BP's cytotoxicity are strikingly complicated and have significant implications for the risk evaluation and safe biomedical applications of BP."

They plan to follow up with further experiments to test their hypothesis that layered BP, with its unusual electrical properties, might prove useful in removing both positively and negatively charged chemicals and organic contaminants from water.

Media Contact

Janet Lathrop
jlathrop@umass.edu
413-545-0444

 @umassscience

http://www.umass.edu 

Janet Lathrop | EurekAlert!

More articles from Life Sciences:

nachricht Polarization of Br2 molecule in vanadium oxide cluster cavity and new alkane bromination
13.07.2020 | Kanazawa University

nachricht Researchers present concept for a new technique to study superheavy elements
13.07.2020 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron cryo-microscopy: Using inexpensive technology to produce high-resolution images

Biochemists at Martin Luther University Halle-Wittenberg (MLU) have used a standard electron cryo-microscope to achieve surprisingly good images that are on par with those taken by far more sophisticated equipment. They have succeeded in determining the structure of ferritin almost at the atomic level. Their results were published in the journal "PLOS ONE".

Electron cryo-microscopy has become increasingly important in recent years, especially in shedding light on protein structures. The developers of the new...

Im Focus: The spin state story: Observation of the quantum spin liquid state in novel material

New insight into the spin behavior in an exotic state of matter puts us closer to next-generation spintronic devices

Aside from the deep understanding of the natural world that quantum physics theory offers, scientists worldwide are working tirelessly to bring forth a...

Im Focus: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

Black phosphorus-based van der Waals heterostructures for mid-infrared light-emission applications

13.07.2020 | Physics and Astronomy

Polarization of Br2 molecule in vanadium oxide cluster cavity and new alkane bromination

13.07.2020 | Life Sciences

Researchers present concept for a new technique to study superheavy elements

13.07.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>