The protein albumin is already responsible for many vital processes in the human body. Now chemists at Martin Luther University Halle-Wittenberg (MLU) in Germany have developed a method for producing various albumin-based gels, which they say could find use as innovative drug carrier systems that more easily reach the bloodstream. They report their work in a paper in Biomaterials Science.
Albumin is a protein found in large quantities in the blood of all mammals: human blood contains up to 60 grams per liter. "Albumin is responsible for many important processes in the body. It can penetrate cell membranes and is thus able to transport essential substances into the cells. It also helps to detoxify cells," says Dariush Hinderberger, a chemist at MLU. He has been investigating albumin for more than 10 years, studying the protein's structure, dynamics and transport properties. Albumin is already being used by the pharmaceutical industry to produce vaccines and medicines, but not in gel form.
"Until now albumin gels have been a somewhat annoying by-product of normal lab work," says Hinderberger. However, in future the gels could be used to produce so-called drug-delivery implants. These would be injected into the patient and then slowly broken down by the body, releasing their drug cargo over a long period of time and thus saving patients from having to undergo repeated injections. "But in order to see whether potential albumin-based drug carrier systems can be developed, it is first necessary to understand how and why the gels form," says Hinderberger, summarising the idea behind his new study.
"In order to see whether potential albumin-based drug carrier systems can be developed, it is first necessary to understand how and why the gels form."Dariush Hinderberger, Martin Luther University Halle-Wittenberg
In response, the chemists at MLU investigated various albumin solutions. "We wanted to find out what exactly happens to the protein particles and their structure when we modify certain properties," says Hinderberger. First, the researchers tested how the solution's pH value affects gel formation; then they heated up the liquid and analyzed what changes occurred and at what stage.
With the aid of infrared spectroscopy, the group was able to demonstrate how the structure of albumin changes when exposed to heat. This causes the protein tangle to open up, allowing it to more easily clump together with other substances to produce the gel. Based on these findings the research group was able to produce a different, much softer, gel by slowing down the gel formation process, which they did by lowering the temperature and choosing a solution with a relatively neutral pH value. "Under these conditions there was little change to the structure of the individual albumin molecules from which the other basic mechanical properties of the gel stem," explains Hinderberger.
Finally, the researchers pursued the question of whether albumin gels are principally suited to act as drug carriers. In initial investigations they were able to show that fatty acids bind well to the gel. However, follow-up studies will be needed to find out whether the albumin gels are also suitable for transporting pharmaceutical agents in the human body.
This story is adapted from material from Martin Luther University Halle-Wittenberg, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.