Graphene and painkiller receptor combined into scalable chemical sensor

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Almost every biological process involves sensing the presence of a certain chemical. Finely tuned over millions of years of evolution, the body's different receptors are shaped to accept certain target chemicals. When they bind, the receptors tell their host cells to produce nerve impulses, regulate metabolism, defend the body against invaders or myriad other actions depending on the cell, receptor and chemical type.

Now, researchers from the University of Pennsylvania have led an effort to create an artificial chemical sensor based on one of the human body's most important receptors, one that is critical in the action of painkillers and anesthetics. In these devices, the receptors' activation produces an electrical response rather than a biochemical one, allowing that response to be read out by a computer.

By attaching a modified version of this mu-opioid receptor to strips of graphene, they have shown a way to mass produce devices that could be useful in drug development and a variety of diagnostic tests. And because the mu-opioid receptor belongs to the most common class of such chemical sensors, the findings suggest that the same technique could be applied to detect a wide range of biologically relevant chemicals.

The study, published in the journal Nano Letters, was led by A.T. Charlie Johnson, director of Penn's Nano/Bio Interface Center and professor of physics in Penn's School of Arts & Sciences; Renyu Liu, assistant professor of anesthesiology in Penn's Perelman School of Medicine; and Mitchell Lerner, then a graduate student in Johnson's lab. It was made possible through a collaboration with Jeffery Saven, professor of chemistry in Penn Arts & Sciences. The Penn team also worked with researchers from the Seoul National University in South Korea.

Their study combines recent advances from several disciplines.

Johnson's group has extensive experience attaching biological components to nanomaterials for use in chemical detectors. Previous studies have involved wrapping carbon nanotubes with single-stranded DNA to detect odors related to cancer andattaching antibodies to nanotubes to detect the presence of the bacteria associated with Lyme disease.

The groups of Saven and Liu have used computational techniques toredesign the mu-opioid receptor to make it easier to use in research. In its natural state, the receptor is not water soluble, making many common experimental techniques impossible. Worse, proteins like this receptor would normally be grown in genetically engineered bacteria to generate the quantity necessary for extensive study, but parts of the natural mu-opioid receptor are toxic to the E. coli used in this method.

After Saven and Liu addressed these problems with the redesigned receptor, they saw that it might be useful to Johnson, who had previously published a study onattaching a similar receptor protein to carbon nanotubes. In that case, the protein was difficult to grow genetically, and Johnson and his colleagues also needed to include additional biological structures from the receptors' natural membranes in order to keep them stable.

In contrast, the computationally redesigned protein could be readily grown and attached directly to graphene, opening up the possibility of mass producing biosensor devices that utilize these receptors.

"Due to the challenges associated with isolating these receptors from their membrane environment without losing functionality," Liu said, "the traditional methods of studying them involved indirectly investigating the interactions between opioid and the receptor via radioactive or fluorescent labeled ligands, for example. This multi-disciplinary effort overcame those difficulties, enabling us to investigate these interactions directly in a cell free system without the need to label any ligands."

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Graphene and painkiller receptor combined into scalable chemical sensor

Medical Technology Breaking News Aethlon Medical (OTCQB AEMD) CEO Note Cancer Therapy Publication References Aethlon …

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Medical Technology Breaking News: Aethlon Medical (OTCQB: AEMD) CEO Note: Cancer Therapy Publication References Aethlon Medical

Visit this company: http://www.aethlonmedical.com

SAN DIEGO - April 22, 2014 (Investorideas.com newswire) Aethlon Medical, Inc. (OTCBB:AEMD), today released the following note authored by its Chairman and CEO, Jim Joyce.

When we initiated our first exosome research program, the medical community generally viewed these particles as nothing more than cellular debris with no biological function. In contrast, we believed that exosomes, also known as microvesicles or extracellular vesicles, suppressed the immune system of cancer patients and that stage of cancer progression correlated directly with quantity of exosomes in circulation. We envisioned the possibility that a medical device could eliminate circulating exosomes and combine to improve the benefit of established cancer therapies without adding drug toxicity.

Today, I am pleased to inform you that a team of researchers from Harvard Medical School, Massachusetts General Hospital and University of Oxford have published a review article that validates the original rationale of our exosome research and further reinforces our future plan to submit an investigational device exemption (IDE) to the U.S. Food and Drug Administration (FDA) that requests permission to initiate Hemopurifier studies in cancer patients.

The article entitled: "Extracellular Vesicles: Emerging Targets for Cancer Therapy" is published in the current issue of the journal "Trends in Molecular Medicine".

The article reviews recent discoveries that have increased the understanding of extracellular vesicles (EV's) role in tumor development and progression, including immune suppression, angiogenesis, and metastasis. On the basis of this understanding, EV's have emerged to be targets for anticancer therapy. The article then discusses novel therapeutic strategies to target EVs to prevent tumor growth and spread. In this regard, Aethlon Medical is the only organization referenced based on our extracorporeal device strategy to target the elimination of exosomes from circulation of cancer patients.

The authors presented the following knowledge of EV's role is cancer progression:

The abstract of the article can be found online at: http://www.ncbi.nlm.nih.gov/pubmed/24703619

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Medical Technology Breaking News Aethlon Medical (OTCQB AEMD) CEO Note Cancer Therapy Publication References Aethlon ...