Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Antigen-Encapsulated Chitosan Particles Improve Immune Response

06.03.2013
Biomaterial enhances activation of cells critical for immunity

Biomedical engineering researchers at the University of Arkansas have encapsulated two types of protein antigens in chitosan and demonstrated that the combined material enables or improves three important immune responses.

The researchers – Bhanu Koppolu, a doctoral student and senior research assistant, and David Zaharoff, assistant professor of biomedical engineering – have worked with chitosan for many years and continue to demonstrate its effectiveness as potential biomaterial for the targeted delivery of vaccines and immunotherapy.

“A great deal of effort has been spent developing delivery systems capable of enhancing vaccine responses with specific antigens,” Koppolu said. “We believe we have developed a system that will accomplish this. In all tests, our material outperformed soluble antigen. The encapsulation of antigens in chitosan particles enhanced uptake, activation and presentation by antigen-presenting cells.”

The researchers’ study was published in the journal Biomaterials.

Vaccine development over the past several decades has shifted toward antigens, which are toxins or other foreign substances that induce an immune response, specifically the production of antibodies. Before this shift, vaccine development had focused on developing whole pathogens, which are bacteria and viruses that cause minor versions of diseases for the purpose of immune response.

With this goal, medical researchers have focused on encapsulating polypeptide antigens in nano- and micro-particles as a strategy to enhance immune response. Packaging antigens in these particles has several advantages. The particles prevent antigen degradation, facilitate ingestion of chemical agents into antigen-presenting cells and can be engineered to carry adjuvants, which are substances in addition to the primary antigen or drug.

One particle material that Zaharoff and other researchers have focused on is chitosan, which is a natural polysaccharide derived primarily from the exoskeletons of crustaceans. Chitosan-based vaccine delivery systems have many advantages, Zaharoff said. The particles are easy to produce, and polypeptides can be encapsulated during particle formation or absorbed into particle surfaces after formation.

Most importantly, chitosan’s muco-adhesiveness and ability to loosen gaps between layers of tissue make it an excellent vehicle for delivering vaccine agents.

For their study, Koppolu and Zaharoff focused solely on the function of so-called antigen-presenting cells –macrophages and dendritic cells – which play a critical role in the production of antibodies that fight bacteria, viruses and other foreign substances.

Macrophage cells are phagocytic, meaning they are capable of engulfing and absorbing bacteria and other small cells and particles. Macrophage cells exist in stationary form in tissues or as a mobile white blood cell, especially at sites of infection. Dendritic cells are other types of immune cells that process antigen material. They are short, branch-like extensions of nerve cells.

The researchers’ in vitro experiments demonstrated that antigens encapsulated in chitosan enhanced activation of antigen-presenting cells. The combined material also increased the release of cytokines – proteins that produce an immune response – and caused a proliferation of antigen-specific T cells, or lymphocytes, which also actively participate in immune response. The researchers discovered that uptake of antigen encapsulated in chitosan by dendritic cells and macrophages depended on particle size, antigen concentration and exposure time.

Zaharoff has investigated chitosan for several years, going back to his time (2004-2008) at the National Cancer Institute’s Laboratory of Tumor Immunology and Biology. In 2009, after coming to the University of Arkansas and setting up the Laboratory of Vaccine and Immunotherapy Delivery, Zaharoff presented results of a major study of the effects of chitosan combined with Interleukin-12, a powerful cytokine.

The combined material eradicated bladder tumors in mice. Zaharoff is currently in discussions with clinical investigators at the University of Arkansas for Medical Sciences to translate the bladder cancer immunotherapy into human trials.

Zaharoff is holder of the Twenty-First Century Professorship in Biomedical Engineering in the College of Engineering.

CONTACTS:
Bhanu Koppolu, doctoral student/senior research assistant, biomedical engineering
College of Engineering
479-575-3964, bhanu.koppolu@gmail.com
David Zaharoff, assistant professor, biomedical engineering
College of Engineering
479-575-2005, zaharoff@uark.edu
Matt McGowan, science and research communications officer
University Relations
479-575-4246, dmcgowa@uark.edu
Follow University of Arkansas research on Twitter @UArkResearch

Matt McGowan | Newswise
Further information:
http://www.uark.edu

More articles from Life Sciences:

nachricht Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society

nachricht New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>