Chemotherapy is one of the most used traditional treatments against cancer, followed by surgery and radiotherapy. During chemotherapy treatment, a combination of several drugs is administered to the patient to remove or kill cancer cells. Despite being the most commonly used treatment strategy, chemotherapy has several drawbacks that are hard to overcome, particularly the side effects that prevail for a very long time. The inherent toxicity of the drugs causes a variety of symptoms like weakness, hair loss, and nausea. Therefore, chemotherapy is considered to be far from the ideal approach as it hampers the patients’ quality of life as well.
Scientists continue to hunt for new advancements in cancer treatment strategies. They are trying to improve the efficacy and specificity of chemotherapy by using carriers to deliver drugs only where they are needed, with precision and efficiency.
Carriers based on gold nanostructures are a perfect choice to perform this task because of their excellent stability, absence of toxicity and ease of modification with various chemical agents. Additionally, some gold nanostructures, such as nanoclusters, are fluorescent, which allows them to be used for bio-tracking and imaging purposes.
A team of scientists in the department of NanoBiotechnology at IMDEA Nanociencia, led by Professor Alvaro Somoza, has used gold nanoclusters coated with albumin to fuel the attachment of two active molecules for the treatment of breast cancer, The researchers used doxorubicin (D), a chemotherapeutic agent that breaks into the DNA causing the cell to die. Another chemotherapeutic used in the treatment was camptothecin analog SN38 (S), a potent topoisomerase 1 inhibitor. In molecular biology Type I topoisomerases are enzymes that cut one of the two strands of double-stranded DNA, relax the strand, and reanneal the strand.
Putting nanotherapy to test
The modified nanostructures were tested in an artificial environment against breast cancer cells. Here, the release of chemotherapeutics took place in a regulated manner. The researchers noted that the nanotherapy remarkably reduced the size and number of mammospheres, a cancer cell model. This type of cell shows higher resistance to chemotherapy and is responsible for relapses and chemoresistance. Also, the system by combining both drugs presented remarkable anti-tumor activity in different cancer models, confirming its promising nanotherapeutic potential.
The albumin-stabilized gold nanoclusters have been used for the first time. The nanoclusters were successful in delivering more than one drug with excellent anti-tumor activity. The researchers believe that the bi-functional nanostructure can turn out to be an excellent solution to overcome the solubility and bio-distribution problems of different drugs. These nanomaterials could be a great strategy to get the chemotherapeutics inside the tumor efficiently. The gold nanostructures act as vehicles for carrying the drugs where they are needed and release them on internal stimuli. On the other hand, chemotherapy research is trying to develop new drugs for cancer treatment, but emerging nanotherapies are about bringing advancements in the existing drugs, evolve as a vehicle for targeted drug delivery, reducing cost and improving the efficiency of the treatment.