Nanotherapy: Small Particles for a Big Issue

by Aviram Nessim, April 8, 2022

The incidence and mortality rates of cancer remain at an unreasonably high rate despite the existence of cancer therapies. In 2018, nearly 10 million lives were lost as a consequence of some form of cancer (NIH, 2020). That same year, almost 20 million novel cases of the pernicious disease arose (NIH, 2020). While anticancer treatments, such as chemotherapy and radiation therapy, are credited with increasing survival rates of cancer patients in the last 50 years, these anticancer therapeutics are coupled with unintended consequences. More often than not, survivors are free from malignant cells, but are left to manage chronic, adverse side effects. Maladies caused by the central treatment often require further medical care. Additional ailments arise because these anticancer agents are nonspecific in their targeting, leading to an inability to distinguish between healthy cells and their rapidly dividing, malignant counterparts. This has led to the development and engineering of drugs with the ability to identify healthy tissues while destroying the cancer, furthermore diminishing side effects. 

Over the past decades, nanotherapy has emerged at the forefront of cancer treatment by offering the means to target tumors in a safer and more effective manner through its accuracy and selective delivery. This report will argue for the utilization and prioritization of nanotherapy by explaining how it works, how it has displayed significant benefits in early trials, and why it has the potential to be the superior option for cancer treatment.

The prefix “nano” describes one-billionth of a unit. Nanotechnology is the science that deals with a range of a few nanometers (nm) to several hundred nm, depending on its intended use. A “nanoparticle” is a suitable name as its sheer size can fit one-thousand particles end-to-end within the diameter of a single human hair. Other molecules quantified as nanoparticles include viruses and DNA. Nanoparticles fall under the umbrella of nanotechnology, expressed on an atomic, molecular, and supramolecular scale. Nanoparticles are applied as a cancer treatment, with precise, minimal side effects made possible by nanotechnology. When used to treat ill humans and animals, the nanomedical term for this manipulation of matter on a near-atomic scale becomes known as nanotherapy. 

Three categories of nanoparticles exist: metal, non-metal, and composite. The ideal nanoparticle is based on conditions such as size and shape of the cancerous cells. Once the precise nanoparticle is determined, it is prepared using two delivery methods. Yu et. al state:

All the preparation methods of nanoparticles can be classified into two methods: bottom-up approaches and top-down approaches. The bottom-up approach is essentially through basic units (atoms, molecules and even smaller particles can be used as the basis for assembling the required nanostructures) stacked on each other to form nanoparticles, while the top-down approach is essentially where a whole solid material begins to decompose into nanoparticles (Yu et. al, 2021, 2).   

Nanotherapy adopts a complex and unique ideology that begins with the loading of the nanoparticle to the patient. The different nanoparticle sizes and modes of delivery hit their greatest success rate once the patient’s needs are determined. The approach for nanoparticle synthesis calls for the optimum loading of either a drug, gene, or targeting ligand, which is “fired” at the cancer cell. The most common and aggressive nanomedicines include Abraxane (albumin nanospheres) and Doxil (PEGylated doxorubicin) which prevent cancer from dividing in the lungs, breasts, and ovaries. However, because each patient’s treatment is tailored to his or her diagnosis, nanomedicines and their dosage are unique to each patient. This is the essence of nanotechnology’s engineering: making anticancer agents that specialize in targeting the tumor while mitigating harmful side effects.

Nanotherapy has opened the door for a new era of cancer treatment thanks to numerous studies that demonstrate its great potential for combating cancer. Magnetic nanoparticles to treat mice with brain tumors revealed remarkable and promising findings. First, researchers discovered that the cancerous brain cells were eliminated with a 100 percent success rate, a result current therapies have never achieved. Second and most astonishing, the nanotherapy did not cause any adverse side effects in any of the mice. This outcome was reached through proper antibody loading, correct particle usage, and appropriate preparation methods (Northwestern, 2016). Employing this method also allows the receptors to be recognized and destroyed, thus eliminating threats to healthy cells and reducing side effects. The researchers’ work was praised, namely by lead scientist Dr. Maciej Leśniak. Dr. Leśniak suggested that nanotherapy could possibly be a panacea for a range of cancers. Leśniak stated, “I think this has applications to many types of cancers, from brain tumors to breast cancer. As long as there’s a specific target, you can take advantage of the nanoparticle’s mechanical properties” (Northwestern, 2016). Regardless of the anatomical location, tumors possess unique receptors which can be destroyed with the correct treatment. The research proved that when nanoparticles are properly chosen, loaded, and prepared, the cancer cells are specifically targeted, and unwanted side effects are slim. 

Nanotherapy has also been shown to prevent specific cancerous outcomes from occurring. Researchers created a table showcasing positive outcomes of nanotherapy in malignant tumor patients. In the study, by adhering to the proper nanoparticle guidelines, loading, and preparation, the researchers discovered that nanoparticles in the subject cancer patient were found to have high enhancements of drug accumulation in the tumor (Sutradhar & Amin, 2014). In another patient where the cancer had metastasized, the secondary tumor was successfully destroyed with effective nanotherapy. The research clearly demonstrates the great potential for nanotechnology to be used to defeat cancer varieties.

Nanotherapy is unlike chemotherapy in that side effects are rare, and when they do occur, they are usually not caused by the nanotechnology itself (Zhang, et. al, 2019). Nanotechnology reduces traditional therapies’ side effects since its tailored style of treatment attacks soley the afflicted cells. Although nanotherapy’s side effects are not as common as its chemotherapy counterpart, patients who have been treated with Abraxane and Doxil, the only approved nanomedicines, have reported post-nanotherapy side effects of weight loss, nausea, and diarrhea. While Abraxane has shown to be efficacious and generally safe, Doxil has had many reports of unwanted adverse effects (Wu, et. al, 2017). “Adverse reactions are common after doxorubicin administration, including fatigue, alopecia, nausea and vomiting, and oral sores…Doxorubicin is also associated with significant cardiac toxicity, which limits the long-term use of the drug” (Johnson-Arbor & Dubey, 2021). However, a valid suspicion is that these problems may be from the chemotherapy drugs they contain. One explanation for chemotherapeutic drugs producing side effects is that cancer cells do not differ greatly from healthy cells. Because of their similarity, chemotherapeutic drugs like Abraxane and Doxil that kill cancer cells may also attack normal cells despite the implementation of a different mode of delivery. Therefore, conventional chemotherapeutic drugs could be phased out by less harmful nanotherapeutic agents to eradicate the causation of such unwelcome side effects.

Many cancer patients are recipients of chemotherapy and the incidental effects caused by the chemotherapeutic agents. Unlike nanotherapy, chemotherapy has little ability to be tailored to the patient’s specifications as it has adopted the proverbial “one size fits all” treatment. Patients generally receive the same prescribed conventional chemotherapy with little to no variation.  Chemotherapy is engineered to be arbitrarily fired into the body and kill rapidly dividing cells, which subsequently results in a high mortality of healthy cells. Chemotherapy is not a guaranteed cure and is often shown to be ineffective in combating certain types of tumors. This is due to chemotherapeutic agents being too weak to reach the core of solid tumors and failing to eliminate any of the cancerous cells. Numerous “cycles” of treatment are performed in an attempt to destroy the cancer cells. Chemotherapy drugs are highly toxic and with each “cycle,” greater doses of radioactive particles enter the patient’s bloodstream. This can reduce life expectancy as well as produce possible deleterious side effects.

While many praise and are grateful for the life saving results of chemotherapy, in the long run, the often undesirable side effects may do more harm than good. I personally have seen the effects of chemotherapy through the experiences of one of my closest childhood friends that went to both my elementary and middle school. Thankfully, chemotherapy cured Jon of aggressive leukemia. While we all celebrated, his parents were mindful of the potential side effects they were advised of prior to their son’s treatment. Shortly after his final chemotherapy treatment, Jon began attending routine appointments, tests, scans, and procedures, the effects of which would remain with him for the rest of his life. Now in his late teens, Jon routinely visits many specialists to ensure his cancer does not return or metastasize, as well as making sure that his chances of reproduction are not being affected. The chemotherapy that was a blessing over a dozen years ago has also caused Jon high levels of anxiety, irrational behavior, mood swings, body image disorder, learning issues, and clinical depression. One cannot help but wonder: had Jon had the benefit of nanotherapy, would he perhaps not be facing these issues today?

Although cancer is one of the most dreaded and lethal diseases, there is a lack of awareness of current treatments for the cancer patient (WHO, 2022). Nanotherapy has strong potential to eliminate the lethal disease and decrease side effects that are produced by conventional therapies. Supported by research, nanotherapy could lead the way to the widespread implementation of the less harmful remedy for cancer patients. As further research and clinical trials are conducted, I am confident that these small particles will develop into safer, more effective life saving solutions.


References

Dunne, N. (2016, February 19). Nanoparticles destroy cancer with mechanical force. Northwestern University Feinberg School of Medicine News Center. https://news.feinberg.northwestern.edu/2016/02/nanoparticles-destroy-cancer-with-mechanical-force/

Johnson-Arbor, K., & Dubey, R. (2021, August 16). Doxorubicin. StatPearls [Internet].  https://www.ncbi.nlm.nih.gov/books/NBK459232/

Miller, Wilkes, Wahab, O’Connell, Legha, Ruddy, & Griffiths. (n.d.). Side effects of cancer treatments. CancerQuest. https://www.cancerquest.org/patients/side-effects

National Cancer Institute. (2020, September 25). Cancer statistics. https://www.cancer.gov/about-cancer/understanding/statistics 

Sutradhar, K. B., & Amin, M. L. (2014, January 16). Nanotechnology in cancer drug delivery and selective targeting. International Scholarly Research Notices, 2014, https://doi.org/10.1155/2014/939378

World Health Organization. (2022, February 3). Cancer. https://www.who.int/news-room/fact-sheets/detail/cancer

Wu, D., Si, M., Xue, H. Y., & Wong, H. L. (2017, August 16). Nanomedicine applications in the treatment of breast cancer: Current state of the art. International Journal of Nanomedicine, 12, 5879–5892. https://doi.org/10.2147/IJN.S123437

Yu, Z., Gao, L., Chen, K., Zhang, W., Zhang, Q., Li, Q., & Hu, K. (2021, May 20). Nanoparticles: A new approach to upgrade cancer diagnosis and treatment. Nanoscale Research Letters, 16(1), 88. https://doi.org/10.1186/s11671-021-03489-z

Zhang, Y., Li, M., Gao, X., Chen, Y., & Liu, T. (2019, December 17). Nanotechnology in cancer diagnosis: Progress, challenges and opportunities. Journal of Hematology & Oncology, 12(1), 137. https://doi.org/10.1186/s13045-019-0833-3

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