Friday, October 21, 2016

A Combined Therapy Technique for Treating Cancer


Many people are diagnosed with cancer every day or have loved ones who have suffered from all different types of cancer. With so many people battling cancer, effective treatment strategies are crucial. Chemotherapy is one type of current cancer treatment that is widely used. However, it has its drawbacks. Patients experience many harmful side effects because the drugs target both cancerous and healthy cells. Photothermal therapy (PTT) is an emerging technique that has shown to be effective in killing cancer cells. It uses electromagnetic energy (usually in near infrared wavelength) to excite light sensitizers (such as noble metals, carbon materials, or organic polymers and molecules). When excited, they release vibrational energy in the form of heat, which kills the cancer cells. This technique is especially favorable because it is selective, targeting the cancer cells and leaving healthy cells alone. Therefore, it is noninvasive and much safer. Adverse side effects are severely diminished. However, PTT does not always destroy all the cancer cells, which can result in relapses.
            The limitations of these treatments lead researchers to consider a combined treatment therapy that involves chemotherapy and PTT. Studies have shown that heat can improve the effectiveness of chemotherapy, so researchers have focused on the cancer treatments that combine chemotherapy and PTT. Tu et. al developed carbon nanoparticles (CNPs)/doxorubicin@SiO2 nanocomposites via reverse microemulsion, while also controlling the size and high drug loading ratio, to deliver the drugs using the combined methodology. The nanocomposites are a good platform for delivery due to their ability to generate high heat, perform pH responsive drug delivery, and release a high amount of drugs when induced by heat. Mice were injected with 4T1 tumor cells. They were treated using each therapy separately and combined. For the single therapy, the tumors continually grew throughout 14 days of treatment. When the treatment techniques were combined, the tumors were completely eradicated six days after the treatment. These results exhibit the effectiveness of a combined therapy approach for cancer treatment.

Figure 1. Schematic diagram showing the strategy for the synthesis and combined photothermal and chemo-therapy of CNPs/Dox@SiO2 NCs.
This research is very important given the prevalence of cancer throughout the world. In the United States alone, approximately 1,685,210 cancer cases will be diagnosed and 595,690 deaths from cancer will occur in 2016 (American Cancer Society). With the large incidence of cancer diagnoses and cancer deaths, the demand for newer, safer, and more effective treatments is great. This study introduces an alternative technique for cancer treatment that combines chemotherapy and photothermal therapy with the use of carbon nanoparticles (CNPs)/doxorubicin@SiO2 nanocomposites to deliver the drugs. This is a more effective technique due to the selective targeting of cancer cites. This therapy would produce significantly fewer side effects for patients. Additionally, the method’s ability to eradicate the entire tumor severely decreases the chances that the patient will have a recurrence of the cancer. This methodology also has such a huge impact because it can be used on all types of cancer.

References:
Xiaolong Tu, Lina Wang, Yuhua Cao, Yufei Ma, He Shen, Mengxin Zhang, and Zhijun Zhang. "Efficient cancer ablation by combined photothermal and enhanced chemo-therapy based on carbon nanoparticles/doxorubicin@SiO2 nanocomposites." Carbon. Volume 97, 35-44, February 2016. http://www.sciencedirect.com.ezproxy.shsu.edu/science/article/pii/S0008622315004406

5 comments:

  1. Super cool! How does the PTT only target cancer cells? Do you know if this has been tested on humans yet?

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    1. From my understanding, the nanoparticles can be designed so that they select against the cancer cells and therefore target those cells. I am not sure if this technique has been tested on humans yet. I have not found any articles indicating that it has.

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    2. I think it has something to do with growth rate? The faster the cells grow the quicker these particles are taken up?

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  2. I have not heard of this treatment yet. Do you know what stage of testing they are in? If they have already been doing human trials, do you think this would become a more widely used and recommended source of treatment? To me, it sounds like this method would be much more advantageous than chemotherapy alone.

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  3. I am not sure how close they are to testing this technique on humans or if they have already started. The main articles I have found on the topic used mice to study the effectiveness of the technique. Once it gets to the point where this treatment is being used on humans, I think it would definitely become a more widely used and recommended treatment because it is more selective and less invasive.

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