Corporate Banner
Satellite Banner
Stem Cells, Cellular Therapy & Biobanking
Scientific Community
Become a Member | Sign in
Home>News>This Article

Injectable Sponge Delivers Drugs, Cells, and Structure

Published: Monday, November 19, 2012
Last Updated: Monday, November 19, 2012
Bookmark and Share
Compressible bioscaffold pops back to its molded shape once inside the body.

Bioengineers at Harvard have developed a gel-based sponge that can be molded to any shape, loaded with drugs or stem cells, compressed to a fraction of its size, and delivered via injection. Once inside the body, it pops back to its original shape and gradually releases its cargo, before safely degrading.
The biocompatible technology, revealed this week in the Proceedings of the National Academy of Sciences, amounts to a prefabricated healing kit for a range of minimally invasive therapeutic applications, including regenerative medicine.

“What we’ve created is a three-dimensional structure that you could use to influence the cells in the tissue surrounding it and perhaps promote tissue formation,” explains principal investigator David J. Mooney, Robert P. Pinkas Family Professor of Bioengineering at the Harvard School of Engineering and Applied Sciences (SEAS) and a Core Faculty Member at the Wyss Institute for Biologically Inspired Engineering at Harvard.

“The simplest application is when you want bulking,” Mooney explains. “If you want to introduce some material into the body to replace tissue that’s been lost or that is deficient, this would be ideal. In other situations, you could use it to transplant stem cells if you’re trying to promote tissue regeneration, or you might want to transplant immune cells, if you’re looking at immunotherapy.”

Consisting primarily of alginate, a seaweed-based jelly, the injectable sponge contains networks of large pores, which allow liquids and large molecules to easily flow through it. Mooney and his research team demonstrated that live cells can be attached to the walls of this network and delivered intact along with the sponge, through a small-bore needle. Mooney’s team also demonstrated that the sponge can hold large and small proteins and drugs within the alginate jelly itself, which are gradually released as the biocompatible matrix starts to break down inside the body.

Normally, a scaffold like this would have to be implanted surgically. Gels can also be injected, but until now those gels would not have carried any inherent structure; they would simply flow to fill whatever space was available.

“Our scaffolds can be designed in any size and shape, and injected in situ as a safe, preformed, fully characterized, sterile, and controlled delivery device for cells and drugs,” says lead author Sidi Bencherif, a postdoctoral research associate in Mooney’s lab at SEAS and at the Wyss Institute.
Bencherif and his colleagues pushed pink squares, hearts, and stars through a syringe to demonstrate the versatility and robustness of their gel.

The spongelike gel is formed through a freezing process called cryogelation. As the water in the alginate solution starts to freeze, pure ice crystals form, which makes the surrounding gel more concentrated as it sets. Later on, the ice crystals melt, leaving behind a network of pores. By carefully calibrating this mixture and the timing of the freezing process, Mooney, Bencherif, and their colleagues found that they could produce a gel that is extremely strong and compressible, unlike most alginate gels, which are brittle.

The resulting “cryogel” fills a gap that has previously been unmet in biomedical engineering.
“These injectable cryogels will be especially useful for a number of clinical applications including cell therapy, tissue engineering, dermal filler in cosmetics, drug delivery, and scaffold-based immunotherapy,” says Bencherif. “Furthermore, the ability of these materials to reassume specific, pre-defined shapes after injection is likely to be useful in applications such as tissue patches where one desires a patch of a specific size and shape, and when one desires to fill a large defect site with multiple smaller objects. These could pack in such a manner to leave voids that enhance diffusional transport to and from the objects and the host, and promote vascularization around each object.”

The next step in the team’s research is to perfect the degradation rate of the scaffold so that it breaks down at the same rate at which newly grown tissue replaces it. Harvard’s Office of Technology Development has filed patent applications on the invention and is actively pursuing licensing and commercialization opportunities.

Coauthors included R. Warren Sands, Deen Bhatta, and Catia S. Verbeke at SEAS; Praveen Arany at SEAS and the Wyss Institute; and David Edwards, who is Gordon McKay Professor of the Practice of Bioengineering at SEAS and a Core Faculty Member at the Wyss Institute.

The research was supported by the Wyss Institute for Biologically Inspired Engineering at Harvard, the National Institutes of Health, and the Juvenile Diabetes Research Foundation.

Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,600+ scientific posters on ePosters
  • More than 3,800+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Scientific News
Snapshot Turns T Cell Immunology on its Head
New research may have implications for 1 diabetes sufferers.
Developing a Gel that Mimics Human Breast for Cancer Research
Scientists at the Universities of Manchester and Nottingham have been funded to develop a gel that will match many of the biological structures of human breast tissue, to advance cancer research and reduce animal testing.
Lung Repair and Regeneration Gene Discovered
New role for hedgehog gene offers better understanding of lung disease.
Restoring Vision with Stem Cells
Age-related macular degeneration (AMRD) could be treated by transplanting photoreceptors produced by the directed differentiation of stem cells, thanks to findings published today by Professor Gilbert Bernier of the University of Montreal and its affiliated Maisonneuve-Rosemont Hospital.
The Age of Humans Controlling Microbes
Engineered bacteria could soon be used to detect environmental toxins, treat diseases, and sustainably produce chemicals and fuels.
Gene Expression: A Snapshot of Stem Cell Development
New genes found that regulate development of stem cells.
Tissue-Engineered Colon from Human Cells
A study by scientists at Children’s Hospital Los Angeles has shown that tissue-engineered colon derived from human cells is able to develop the many specialized nerves required for function, mimicking the neuronal population found in native colon.
Tension Helps Heart Cells Develop Normally in the Lab
Stanford engineers have uncovered the important role tension plays in growing heart cells out of the body.
Urine Excretion From Stem Cell-Derived Kidneys
Researchers report a strategy for enabling urine excretion from kidneys grown from stem cells.
Stem Cell Research Hints at Evolution of Human Brain
Researchers at UC San Francisco have succeeded in mapping the genetic signature of a unique group of stem cells in the human brain that seem to generate most of the neurons in our massive cerebral cortex.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,600+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,800+ scientific videos