The scientists have solved this challenge with their tiny globules - 1, 000 of them together would be as wide as a human hair. They have a core with tissue structure in which the drug molecules are separated from each other, and a soft, gel-like shell. This also gives the nanolipo gels their name. All materials of the NLG are, comparable to self-dissolving threads in surgery, so biodegradable and seem to be well tolerated. In the experiment with mice, no side effects were observed. However, whether the NLGs are actually safe and suitable for humans must be determined in further studies.
For the also problematic addressing of the drug packages, the researchers took advantage of a special feature of cancer tissue: The vascular system of a tumor is more disordered and more branched than the normal bloodstreams in the body. Although small enough to travel across the body, NLGs remain stuck in the labyrinth of narrow and intersecting cancer vessels. Thus, they accumulate in the blood vessels of the tumor, even if they were not injected there. After a few days, the outer skin of the beads dissolves and the drugs work directly where they are needed: in the middle of the heart of the tumor.
The drugs that the researchers delivered in this double pack have completely different areas of work: One is an inhibitor for the so-called transforming growth factor β, or TGF-β. It is a signaling molecule of the tumor that confuses the immune system and slows down the body's defenses. The second drug that helped the team with NLGs is the cytokine interleukin-2 (IL-2). This protein alerts the immune system and thus strengthens the body's defense. Thus, the active substance double pack prevents, on the one hand, the tumor from suppressing the immune system and, on the other hand, improves the effectiveness of body defense. display
The double-stroke method has already proven its worth, at least in the laboratory: The researchers gave their NLGs to mice that were suffering from one of the most vicious cancers, black skin cancer. The results showed impressive results, the team reports: In comparison to mice that did not receive any or only one of the two drugs, the animals developed smaller and fewer tumors. All animals treated with both drugs in the NLGs survived, and at forty percent the tumor completely receded. Tarek Fahmy and his colleagues now hope their system will soon benefit human patients. They are also sure that in addition to the two active ingredients tested, other medicines can also be transported in the NLGs.Tarek Fahmy (Yale University) et al .: Nature Materials, doi: 10.1038 / nmat3355 © science.de? Sabine Short