The side effects of chemotherapy place it far from the ideal treatment. Spanish scientists work to optimize its effectiveness, using gold nanoparticles as vehicles to administer drugs only where it is needed. Specifically, they have used the combination of two drugs simultaneously that has given good results in the reduction of breast cancer cells.
Chemotherapy is one of the most used cancer treatments, along with surgery and radiotherapy. In it, one or more medications are administered to the patient to eliminate or damage the cancer cells. However, it has several difficult problems to overcome, such as certain side effects. The inherent toxicity causes a variety of symptoms that include weakness, nausea and hair loss, which keeps this therapy from being ideal.
In this regard, scientists are trying to improve the efficacy and specificity of chemotherapy using vehicles to administer medications only where it is needed. Those based on gold nanostructures are excellent candidates due to their excellent stability, absence of toxicity and ease modification with various chemical agents. In addition, some gold nanostructures, such as nanoclusters, are fluorescent, which allows their use simultaneously for biomarking and imaging purposes.
The NanoBiotechnology group at IMDEA Nanoscience, led by Álvaro Somoza, has used gold nanoclusters coated with albumin to facilitate the incorporation of two active molecules for the treatment of breast cancer.
In particular, they have used doxorubicin (D), a chemotherapeutic agent that is sandwiched into the DNA causing cell death; and camptothecin analog SN38 (S), a potent topoisomerase I inhibitor.
The modified nanostructures were tested in vitro with breast cancer cells, where drug release took place in a controlled manner. The nanotherapy was able to reduce the size and quantity of mammospheres, a model of cancer stem cells.
These types of cells have greater resistance to chemotherapy and are responsible for relapse and chemoresistance. In addition, this system that combines two types of drugs exhibits excellent antitumor activity in different cancer models, confirming its promising nanotherapeutic potential.
This is the first time that gold nanoclusters stabilized with albumin have been used to administer more than one drug, with excellent antitumor activity, in different cancer cell models, including cancer stem cells.
“Our bifunctional nanostructure could be an excellent solution to overcome the problems of solubility and biodistribution of drugs with different properties,” says Somoza. These nanomaterials could be the basis of a Trojan horse strategy to effectively release chemotherapy within tumors.
The gold nanoclusters act as vehicles to deliver drugs where needed and release by internal stimuli. While research in chemotherapy is aimed at developing new drugs for the treatment of cancer, emerging nanotherapies try to build smart vehicles for existing drugs, with the consequent cost reduction and improved treatment efficiency.