Biology - Page 6

Researchers developed a new way to detect protein-protein interactions using graphene. This kind of detection is used to monitor how a disease-related protein interacts with libraries of small peptides. The idea is to mix a tagged peptide with Graphene Oxide, which quenches the fluorescent signal from the pyrene-bound peptide when pyrene stacks onto its flat surface. Then, when adding the protein that needs to be tested you can find out whether it binds to the peptide by seeing whether the tagged peptide leaves the graphene oxide and the fluorescent signal returns.

Researchers managed to fabricate electrochemical actuators based on flexible graphene paper. These kinds of devices can convert electrical energy into mechanical energy through stretching or contraction, behaving like artificial muscles. This has all sorts of potential applications - in healthcare and nanotechnology...

The graphene-paper actuators lengthen in response to applied voltage, due to changes in the carboncarbon bond length. The team managed to increase the response by magnetizing the paper using Fe₃O₄ nanoparticles.

Researchers from Korea report that graphene is better than glass for human neural stem cells (hNSCs) growth - exhibiting a greater ratio of neurons to glial cells. When using graphene as a substrate, cells grew well and stuck well on the graphene, and the substrate could deliver currents to the neural cells, which may be useful for neural stimulation.

Mark Ming-Cheng Cheng, an assistant professor from Wayne State University received a five-year, $475,000 grant from the National Science Foundation to study the potential of graphene for neural implants that can be used to treat disorders and diseases such as blindness, deafness, epilepsy, spinal cord injury, and Alzheimer's and Parkinson's. He hopes to check out whether graphene can be used to make reliable, high-performance, long-term implantable electrode systems.

Currently electrodes are used to stimulate connections between brain parts, but these typically stop working after a few weeks because scar tissue forms around the electrode, and the materials that comprise the electrode can't carry enough charge through the scar tissue. Cheng suggested that graphene might be better suited to long-term treatment than platinum and iridium oxide, two of the most popular materials now used to make implantable electrodes.

Rigoberto Gobet Advincula, a polymer chemist from the University of Houston has developed two different materials that are both equally effective against E. coli. One of them is graphene based - which is proving to be an effective antimicrobial.

This is not the first time we hear that Graphene can be used against E. coli - back in 2010, researchers from Shanghai University has developed two water-based dispersible graphene derivatives (graphene oxide and reduced graphene oxide) that can effectively inhibit the growth of E.coli and have minimal toxic effects on harming cells (cytotoxicity).

Researchers from Asia demonstrated that graphene provides a promising biocompatible scaffold that does not hamper the proliferation of human mesenchymal stem cells (hMSCs) and accelerates their specific differentiation into bone cells. The differentiation rate is comparable to the one achieved with common growth factors, demonstrating graphene's potential for stem cell research.

Oxford Nanopore has reached an agreement with Harvard University to develop technology that uses graphene for DNA and RNA sequencing. This technology was developed in the Harvard laboratories of Professors Jene Golovchenko, Daniel Branton, and Charles Lieber and Oxford Nanopore now has exclusive rights to develop and commercialize it.

The Harvard team used graphene to separate two chambers containing ionic solutions, and created a hole - a nanopore in the graphene. The group demonstrated that the graphene nanopore could be used as a trans-electrode, measuring a current flowing through the nanopore between two chambers. The trans-electrode was used to measure variations in the current as a single molecule of DNA was passed through the nanopore. This resulted in a characteristic electrical signal that reflected the size and conformation of the DNA molecule.

Researchers from the Nankai University in china have developed a new drug delivery system that uses Graphene Oxide as the drug carrier. Graphene oxide has a very high surface area, enabling it to transport a large amount of the drug.

The team attached superparamagnetic Fe3O4 nanoparticles to the graphene oxide, which allows allows the carrier to be targeted to the tumor site by an external magnetic field.

Researchers in China and Japan have developed a graphene oxide based fluorescence assay for fast, ultra-sensitive, and selective detection of protein and demonstrated its use for detection of a prognostic indicator in early-stage cancer, cyclin A₂.

Although the researchers have managed to detect cyclin A₂ in their lab set-up with high sensitivity and specificity, this method still can not be applied to detect cyclin A₂ in clinical samples due to the trace amount of cyclin A₂ in the cell total protein. The team is trying to incorporate a signal amplification step to increase the output signal and detection sensitivity to solve this issue.

Researchers from Shanghai University has developed two water-based dispersible graphene derivatives that can effectively inhibit the growth of E.coli and have minimal toxic effects on harming cells (cytotoxicity). The two derivatives are based on graphene oxide (GO) and reduced graphene oxide (rGO).

The group tested the antibacterial properties of the GO sheets with E.coli DH5 cells via a luciferase-based ATP assay kit. After two hours incubation with the GO sheets of 20 µg/mL at 37C, the cell metabolic activity of the bacteria fell to around 70 per cent. With a GO concentration of 85 µg/mL, the activity of the E.coli cells fell to just 13 per cent suggesting a strong inhibition ability of GO nanosheets to E.coli, said the researchers.