Scientists, including those of Indian-origin, have found a way to stabilise hemoglobin, the oxygen carrier protein in blood, a discovery that could lead to stable vaccines and affordable artificial blood.
The team's novel approach involves wrapping the polymer poly(acrylic acid) around hemoglobin, protecting it from the intense heat used in sterilisation and allowing it to maintain its biological function and structural integrity.
In addition to having potential applications in the stabilisation of vaccines and development of inexpensive artificial blood, the stabilising polymer also allows vaccines and other biomedical products to be stored for longer periods without refrigeration.
It could also have applications in bio-materials, bio-sensors, and bio-fuels.
"Protein stability is a major issue in biotechnology," says Challa V Kumar, the University of Connecticut professor of chemistry and biochemistry and the primary investigator.
"What we've done is taken this protein molecule and wrapped it up in a polymer chain in order to stabilise it," Kumar said.
"This is the very first example of its kind in the literature of all protein science. No one has ever been able to achieve this kind of stability for proteins," said Kumar.
Searching for a viable material to serve as a protein stabiliser, Kumar's team found one that is readily available, inexpensive, and can be modified chemically for further improvements.
The polymer naturally binds to hemoglobin, creating a tight seal that protects the protein molecule and allows it to retain its structural integrity even after heating it to 120C for extended periods of time (steam sterilisation).
The team including Rajeswari Kasi, associate professor of chemistry, an expert in synthetic polymers and hybrid materials, tested various protein-polymer compositions using transmission electron microscopy (TEM) and optical spectroscopy techniques.
Hemoglobin, when extracted from blood, breaks down and is toxic in its pure form.
Since hemoglobin is the critical oxygen carrier protein in blood, Kumar and his team are looking at ways of stabilising hemoglobin in its natural form so that it retains its activity and stays harmless when administered as a transfusion agent.
This could lead to a new substitute for human blood, which is frequently in short supply.
The study was published in the Journal of Materials Chemistry.