Health and Medical News and Resources

General interest items edited by Janice Flahiff

Seaweed: An Alternative Protein Source

Dulse, edible algae

Dulse, edible algae (Photo credit: Wikipedia)

 

From the 12 October 2012 article at Science News Daily

 

Teagasc researchers are looking to seaweed for proteins with health benefits for use as functional foods. Historically, edible seaweeds were consumed by coastal communities across the world and today seaweed is a habitual diet in many countries, particularly in Asia. Indeed, whole seaweeds have been successfully added to foods in recent times, ranging from sausages and cheese to pizza bases and frozen-meat products.

Source of protein

Researchers have previously shown that protein-rich red seaweeds such as Palmaria palmata (common name Dulse) and Porphyra (common name Sleabhac or Laver) species may potentially be used in the development of low-cost, highly nutritive diets that may compete with current protein crop sources such as soya bean. For example, the protein content of Dulse varies from between 9-25% depending on the season of collection and harvesting. The highest percentage protein per gram of dried whole seaweed is normally found in P. palmatacollected during the winter season (October — January). Valuable amino acids such as leucine, valine and methionine are well represented in Dulse. In Porphyra species, the amino acid profile is similar to those reported for leguminous plants such as peas or beans.

Health benefits of seaweed..

In addition to its use as a protein source, the researchers have found that some of these seaweed proteins may have health benefits beyond those of basic human nutrition — for use in functional foods.

Bioactive peptides are food-derived peptides that exert a physiological, ‘hormone-like’, beneficial health effect. Proteins and peptides from food sources such as dairy, eggs, meat and fish are well documented as agents capable of reducing high blood pressure and are thought to be able to prevent CVD…

 

 

 

 

October 15, 2012 Posted by | Nutrition | , , , , , , | Leave a comment

Microsponges from seaweed may save lives

Microsponges from seaweed may save lives

Rice University scientists refine process at heart of diagnostic bio-nano-chip

From the February 9 2011 Eureka news alert

Microsponges derived from seaweed may help diagnose heart disease, cancers, HIV and other diseases quickly and at far lower cost than current clinical methods. The microsponges are an essential component of Rice University’s Programmable Bio-Nano-Chip (PBNC) and the focus of a new paper in the journal Small.

The paper by John McDevitt, the Brown-Wiess Professor in Bioengineering and Chemistry, and his colleagues at Rice’s BioScience Research Collaborative views the inner workings of PBNCs, which McDevitt envisions as a mainstream medical diagnostic tool.

PBNCs to diagnose a variety of diseases are currently the focus of six human clinical trials. McDevitt will discuss their development at the annual meeting of the American Association for the Advancement of Science (AAAS) in Washington, D.C., Feb. 17-21.

PBNCs capture biomarkers — molecules that offer information about a person’s health — found in blood, saliva and other bodily fluids. The biomarkers are sequestered in tiny sponges set into an array of inverted pyramid-shaped funnels in the microprocessor heart of the credit card-sized PBNC.

When a fluid sample is put into the disposable device, microfluidic channels direct it to the sponges, which are infused with antibodies that detect and capture specific biomarkers. Once captured, they can be analyzed within minutes with a sophisticated microscope and computer built into a portable, toaster-sized reader.

The biomarker capture process is the subject of the Small paper. The microsponges are 280-micrometer beads of agarose, a cheap, common, lab-friendly material derived from seaweed and often used as a matrix for growing live cells or capturing proteins.

The beauty of agarose is its ability to capture a wide range of targets from relatively huge protein biomarkers to tiny drug metabolites. In the lab, agarose starts as a powder, like Jell-O. When mixed with hot water, it can be formed into gels or solids of any size. The size of the pores and channels in agarose can be tuned down to the nanoscale.

The challenge, McDevitt said, was defining a new concept to quickly and efficiently capture and detect biomarkers within a microfluidic circuit. The solution developed at Rice is a network of microsponges with tailored pore sizes and nano-nets of agarose fibers. The sponge-like quality allows a lot of fluid to be processed quickly, while the nano-net provides a huge surface area that can be used to generate optical signals 1,000 times greater than conventional refrigerator-sized devices. The mini-sensor ensembles, he said, pack maximum punch.

The team found that agarose beads with a diameter of about 280 micrometers are ideal for real-world applications and can be mass-produced in a cost-effective way. These agarose beads retain their efficiency at capturing biomarkers, are easy to handle and don’t require specialized optics to see.

McDevitt and his colleagues tested beads with pores up to 620 nanometers and down to 45 nanometers wide. (A sheet of paper is about 100,000 nanometers thick.) Pores near 140 nanometers proved best at letting proteins infuse the beads’ internal nano-nets quickly, a characteristic that enables PBNCs to test for disease in less than 15 minutes…….

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Co-authors of the paper included first author Jesse Jokerst, a National Institutes of Health postdoctoral fellow at Stanford University; postdoctoral students James Camp, Jorge Wong, Alexis Lennart, Amanda Pollard and Yanjie Zhou, all of the departments of Chemistry and Biochemistry at the University of Texas at Austin; Mehnaaz Ali, an assistant professor of chemistry at Xavier University; and from the McDevitt Lab at Rice, Pierre Floriano, director of microfluidics and image and data analysis; Nicolaos Christodoulides, director of assay development; research scientist Glennon Simmons and graduate student Jie Chou.

The National Institutes of Health, through the National Institute of Dental and Craniofacial Research, funded the research.

Read the abstract at http://onlinelibrary.wiley.com/doi/10.1002/smll.201002089/abstract***

*** For suggestions on how to get this article for free or at low cost, click here

 

 

February 13, 2011 Posted by | Medical and Health Research News | , , , , , , | Leave a comment

   

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