Nanoparticles for cancer therapy

Researchers use nanoparticles for cancer treatment

06/04/2012

Various approaches to support cancer therapy by nanoparticles are currently being explored. Researchers use the nanoparticles to transport drugs directly to the cancer cells and thus increase the efficiency of the treatment.

The US scientists around Jeffrey Hrkach from the biotechnology company BIND Biosciences Inc. in Cambridge describe in the journal „Science Translational Medicine“ the „Development and clinical implementation of polymer nanoparticles containing the chemotherapeutic agent docetaxel for the treatment of patients with solid tumors“ contain. Docetaxel is used, among other things, for the treatment of breast cancer, bronchial carcinoma (lung cancer), prostate cancer, ovarian cancer and gastric carcinoma. With the help of nanoparticles, the drug can be transported directly to the cancer cells and thus significantly increase the chances of success of the treatment, the US scientists report.

Nanoparticles are specifically designed for cancer treatment
Together with researchers from the Karmanos Cancer Institute in Detroit, Harvard Medical School in Boston, Weill Cornell Medical College in New York and the experts from the Institute of Chemical Engineering at the Massachusetts Institute of Technology (MIT) in Cambridge, Jeffrey Hrkach has the options to use Nanoparticles studied in cancer therapy. Her research focused on the use of 50-nanometer capsules to deliver the cancer drugs directly to the tumors. The nanoparticles are specifically designed for the transport of the active ingredients to the cells, which can be influenced in addition to the size of various factors such as the chemical and physical properties of the shell, the solubility of fat and water or other transport parameters. The construction of the tiny transportation vehicles is based on high-tech processes that have only been developed in recent years. The particles processed by biotech companies such as BIND are unimaginably tiny (nanometers = one millionth of a millimeter), but offer promising options for improving cancer therapy, according to the US researchers.

Nanoparticles reduce the risk of side effects
By transporting the cancer drug with the help of nanoparticles directly to the tumors, not only the effectiveness of the drugs could be improved, but also the serious side effects could be largely avoided, said the US scientists. In principle, the nano-transport vehicles can be constructed differently to suit their tasks. The nanoparticles tested in the experiments of Jeffrey Hrkach and colleagues were „from a combinatorial library of more than 100 different nanoparticle formulations“ developed in terms of particle size, surface texture, binding properties, active ingredient contained and its release. The nanoparticles were aligned to transport the drug docetaxel to the cancer cells. For this, the researchers gave the nano-vehicle a surface with which they could dock to specific proteins on the outside of the cancer cells. The docetaxel nanoparticles bind to one „Prostate-specific membrane antigen“ (PSMA), that at „Prostate cancer cells and most solid tumors“ exists, write Hrkach and colleagues.

Successfully tested cancer therapy with nanoparticles
Comparable procedures have already been tested in previous clinical trials and showed significant success there, said the US scientists. The docetaxel nanoparticles themselves have been used successfully in rats, mice and primates (macaques), among others. Thus, suppression of tumor growth using docetaxel nanoparticles has lasted much longer than with conventional solvent-based treatment with docetaxel, Jeffrey Hrkach and colleagues report in the article „Preclinical Development and Clinical Translation of a PSMA-Targeted Docetaxel Nanoparticle with a Differentiated Pharmacological Profile“ in the trade magazine „Science Translational Medicine“. The effectiveness of the docetaxel nanoparticles was significantly higher, since their concentration in the blood plasma after 24 hours at least 100-fold above the docetaxel concentration in the conventional treatment was. However, the risk of side effects was significantly lower for the docetaxel nanoparticles, as they only showed their effect directly on the cancer cells, Hrkach continued.

Cancer drug already has a low concentration due to nanoparticles
According to the US scientists, the new method has now been tested in human clinical trials for the first time. In the Phase I study, 17 patients with multiple pretreated tumors and metastases based on docetaxel nanoparticles were treated. The active ingredient had worked in the subjects already in a much lower concentration, as the docetaxel was delivered directly to the tumors concentrated, report the US researchers. Already 20 percent of the conventional drug concentration would have shown the same effect here. For the researchers, nanoparticles are a promising new approach to cancer therapy that could become an integral part of treating tumors in the future. (Fp)

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Image: TU Braunschweig, Institute of Electrical Measurement Technology and Fundamentals of Electrical Engineering, Nanoparticles.