Home
 »  News
 »  Controlled insulin delivery via injectable 'smart sponge'
Diabetes1 Headlines

Controlled insulin delivery via injectable 'smart sponge'

Printer Friendly Version     Email this Article     Links/Reprints

sponge

Controlled insulin delivery via injectable 'smart sponge'

August 08, 2013

Source: North Carolina State University

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. "And the chitosan itself can be absorbed by the body, so there are no long term health effects."

In tests using diabetic laboratory mice, the researchers found the sponge matrix was effective at reducing blood sugar for up to 48 hours. However, the researchers published a separate "smart system" for insulin delivery in May that maintained normal blood sugar levels for 10 days.

"But we learned a lot from the promising 'sponge' research and will further optimize it. Meanwhile, we are already exploring applications to combat cancer," Gu says.

Discuss in the Diabetes1 forums

Photo: Gregory Moine

Previous Stories

Timing of First Exposure To Solid Food Appears Associated With Development Of Type 1 Diabetes

Scientist Working To Break Vicious Cycle Causing Vision Loss In Diabetes

Air Pollution Increases Risk Of Insulin Resistance In Children

more Feature Stories

Comments

  • Add Comment

  • RSS
    From the BLOGS
    My Third Left "Nipple"
    Comment By FatCatAnna
    more
    Comment
    more Blogs
    Medication
    By FatCatAnna

    Posted: Mar 17, 2017
     Thanks for that Andre77 ... though in this area where you've posted "Type 1 Diabetes" - we already know we've got diabetes (50+ years for me).   DiabetesUK has a pretty good description of ...

    more more Forums Create a Topic
    Your Treat Medication Part 6
    Hypoglycemia And Glucagon-Treatment Plan: Diabetes Medications
    Guide to preparing for insulin injection using a pen ...
    more more Featured Videos
    Cost Savings Tool
    Do you know the annual cost of managing your diabetes? Would you like to find ways to reduce your costs? Calculate your total budget and identify ways to save money. You can do this in just a few minutes by entering facts about the products you use. This quick analysis will provide you with a comprehensive overview of both spending and potential savings.

    Cost Savings Tool
    Monitor Comparison Tools
    Blood glucose monitors offer an easy way to test your blood sugar at home or on the go. Use this comparison tool as a guide to learn more about the features and benefits of your current monitor or to find a new one.
    Handheld Monitor Comparison
    Continuous Glucose Monitor Comparison
    Advanced BMI Calculator
    Ever wonder if you are at a healthy weight? Then enter your height and weight in our advanced Body Mass Index (BMI) calculator. This tool provides you with two important numbers reflecting the estimated impact of your present body weight and shape upon your overall health.
    Advanced BMI Calculator
    more Care Tools
     
    Dr. Wayne Caputo

    Dr. Wayne Caputo:

    Simplifying Treatment of Diabetic Ulcers
      more
      more Heroes
      nominate a Hero
      Hero policy
    Home | About Us | Press | Make a Suggestion | Content Syndication | Terms of Service | Editorial Policy | Privacy Policy
    Last updated: Aug 20, 2017  © 2017 Body1 All rights reserved.