The Stanly News and Press (Albemarle, NC)

State & National News

July 29, 2013

NCSU Study -- Injectable ‘Smart Sponge’ Holds Promise for Controlled Drug Delivery

Monday, July 29, 2013 —             Researchers have developed a drug delivery technique for diabetes treatment in which a sponge-like material surrounds an insulin core. The sponge expands and contracts in response to blood sugar levels to release insulin as needed. The technique could also be used for targeted drug delivery to cancer cells.

            “We wanted to mimic the function of health beta-cells, which produce insulin and control its release in a healthy body,” says Dr. Zhen Gu, lead author of a paper describing the work and an assistant professor in the joint biomedical engineering program at North Carolina State University and the University of North Carolina at Chapel Hill. “But what we’ve found also holds promise for smart drug delivery targeting cancer or other diseases.” The research team includes Daniel Anderson, the senior author and an associate professor of chemical engineering and member of the Koch Institute for Integrative Cancer Research at MIT, and researchers from the Department of Anesthesiology at Boston Children’s Hospital.

            The researchers created a spherical, sponge-like matrix out of chitosan, a material found in shrimp and crab shells. Scattered throughout this matrix are smaller nanocapsules made of a porous polymer that contain glucose oxidase or catalase enzymes. The sponge-like matrix surrounds a reservoir that contains insulin. The entire matrix sphere is approximately 250 micrometers in diameter and can be injected into a patient.

            When a diabetic patient’s blood sugar rises, the glucose triggers a reaction that causes the nanocapsules’ enzymes to release hydrogen ions. Those ions bind to the molecular strands of the chitosan sponge, giving them a positive charge. The positively charged chitosan strands then push away from each other, creating larger gaps in the sponge’s pores that allow the insulin to escape into the bloodstream. In type 1 and advanced type 2 diabetes, the body needs injections of insulin, a hormone that transports glucose – or blood sugar – from the bloodstream into the body’s cells.

            As the insulin is released, the body’s glucose levels begin to drop. This causes the chitosan to lose its positive charge, and the strands begin to come back together. This shrinks the size of the pores in the sponge, trapping the remaining insulin.

            While this work created hydrogen ions by using enzymes that are responsive to glucose, the technique could be simplified to target cancers by eliminating the enzymes altogether. Tumors are acidic environments that have high concentrations of hydrogen ions. If the sponge reservoir were filled with anticancer drugs, the drugs would be released when the chitosan came into contact with the hydrogen ions in tumor tissues or cancer cells.

            “We can also adjust the size of the overall ‘sponge’ matrix as needed, as small as 100 nanometers,” Gu says.

Text Only
State & National News
  • linda-ronstadt.jpg Obama had crush on First Lady of Rock

    Linda Ronstadt remained composed as she walked up to claim her National Medal of Arts at a White House ceremony Monday afternoon.

    July 29, 2014 1 Photo

  • Brother sues W.Va. senator over business loan

    FAIRMONT, W. Va. - U.S. Sen. Joe Manchin's brother claims he's owed $1.7 million that he loaned to keep a family carpet out of bankruptcy in the 1980s.

    July 28, 2014

  • CATS-DOGS281.jpg Where cats are more popular than dogs in the U.S.-and all over the world

    We all know there are only two types of people in the world: cat people and dog people. But data from market research firm Euromonitor suggest that these differences extend beyond individual preferences and to the realm of geopolitics: it turns out there are cat countries and dog countries, too.

    July 28, 2014 1 Photo

  • WORLD NEWS: Fast food comes to standstill in China

    BEIJING - The shortage of meat is the result of China's latest food scandal, in which a Shanghai supplier allegedly tackled the problem of expired meat by putting it in new packaging and shipping it to fast-food restaurants around the country

    July 28, 2014

  • Facebook continues moneymaking trend

    WASHINGTON - Facebook seems to have figured out - for now at least - the holy grail for all media right now: how to make money selling mobile ads.

    July 25, 2014

  • Arizona's prolonged lethal injection is fourth in U.S. this year

    NEW YORK - Arizona's execution of double-murderer Joseph Wood marked the fourth time this year that a state failed to dispatch a convict efficiently, according to the Constitution Project, a bipartisan legal group.

    July 25, 2014

  • N.C. Energy Policy Council Long Range Energy Generation and Renewable Energy Committee to meet

    RALEIGH – The North Carolina Energy Policy Council’s Long Range Energy Generation and Renewable Energy Committee will meet via conference call at 9 a.m. July 31.

    July 24, 2014

  • N.C. State University Turfgrass Field Day set for Aug. 13

    N.C. State University’s annual Turfgrass Field Day will be held in Raleigh at the Lake Wheeler Turfgrass Research Lab, Aug. 13, 8:30 a.m. - 2 p.m. One of the largest events of its kind in the country, the field day offers the industry and general public a chance to view the Turfgrass Program’s ongoing research trials and speak directly with N.C. State faculty and staff.

    July 24, 2014

  • NCSU Study: Urban Heat Boosts Some Pest Populations 200-Fold, Killing Red Maples

                New research from North Carolina State University shows that urban “heat islands” are slowly killing red maples in the southeastern United States. One factor is that researchers have found warmer temperatures increase the number of young produced by the gloomy scale insect – a significant tree pest – by 300 percent, which in turn leads to 200 times more adult gloomy scales on urban trees.

    July 23, 2014

  • An oncologist uses scorpion venom to locate cancer cells

    Olson, a pediatric oncologist and research scientist in Seattle, has developed a compound he calls Tumor Paint. When injected into a cancer patient, it seems to light up all the malignant cells so surgeons can easily locate and excise them.

    July 22, 2014

House Ads
Seasonal Content