Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Injectable sponge delivers drugs, cells, and structure

14.11.2012
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 (see video).

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.

Supplemental videos are available, via PNAS, here:
http://www.pnas.org/content/suppl/2012/11/08/1211516109.DCSupplemental

PRESS CONTACTS:

Harvard School of Engineering and Applied Sciences
Caroline Perry, (617) 496-1351

Wyss Institute for Biologically Inspired Engineering at Harvard
Kristen Kusek, (617) 432-8266

Caroline Perry | EurekAlert!
Further information:
http://www.seas.harvard.edu

More articles from Life Sciences:

nachricht One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie

nachricht The dark side of cichlid fish: from cannibal to caregiver
20.04.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>