Written by Keshav Suresh
Nearly 14.5 million Americans are reported to have been affected by cancer as of January 1st, 2014, with an estimated 1.7 million more cases to be diagnosed in 2016. Out of these cases about 595,000 are expected to be fatal. To put this into perspective that is nearly 5% of the U.S. population with cancer, with a death rate of about 1,630 people per day [1].There is no doubt that cancer is a big problem in the United States—a thriving First World country—and the rest of the world, and is therefore the focus of many different research projects. One of the most promising solutions for this overwhelmingly large problem is surprisingly small: nanogels.
Despite its simple name, nanogels are extremely complex structures that have just recently become viable in the laboratory. They are essentially polymers made by placing modified macromolecules in a solution of oil and water. The addition of extra functional groups in polymers (like polysaccharides) and the differences in hydrophilic/phobic properties in the oil-in-water solution lead to the polymers self assembling into a gel through the process of cross-linking. Cross-links are bonds between macromolecules in which at least four chains connect to certain regions on each macromolecule. These special cross-link bonds allow for a flexible structure which enables the macromolecules to sit in them while simultaneously preventing the entire complex from dissolving in any solution [2].
Nanogels are of special interest as a method for drug delivery due to the unique properties their size can bring about. They are small enough to interact with actual cell receptors, and are able to directly enter into the cytoplasm of the target cell which increases the effectiveness of the drug while limiting exposure to other cells [3]. In a clinical setting this means less of the drug would be needed to achieve the same result, and any possible resulting side effects would be greatly reduced.For all the research done on cancer, there have been a surprisingly large number of potential solutions found. However, one of the biggest deterrents in using some of these compounds has to do with how they perform in the human body. Many of these are highly soluble and therefore dissociate far before they have the chance to have any meaningful impact on a patient. An example of such a compound is Paclitaxel (PTX), a very versatile drug used to treat a wide range of cancers from ovarian to pancreatic. While doctors are currently using this drug around the world, it is highly soluble, and so most of it is not even properly utilized by the body. Worse, because an immense amount of the drug has to be used to gain any meaningful effect, there are many harmful side effects that may result, such as hair loss and muscle and joint pains [4]. In contrast, by using nanogels as a way to deliver this drug in a lab, researchers were able to use it more efficiently while cutting down on the side effects, improving the quality of cancer treatment for patients overall.
Nanogels have shown promising results in a laboratory setting and the next step for this technology involves actual human trials. Cancer has been an enormous issue indefinitely that it seems as if there is no hope of ever beating it, but much like the Biblical story of David and Goliath, perhaps all we need is faith in the little guy to help us all.
References:
1.: American Cancer Society. 2016. Cancer Facts & Figures 2016. Atlanta: American Cancer Society; 2016: 1-66.
2.Rigogliuso, Salvatrice, Maria A. Sabatino, Giorgia Adamo, Natascia Grimaldi, Clelia Dispenza, Giulio Ghersi. 2012. “Polymeric Nanogels: Nanocarriers For Drug Delivery Application.” Chemical Engineering Transactions 27 : 247-252.
3. Toita, Sayaka, Shin-Ichi Sawada, Kazunari Akiyoshi. 2010 “Polysaccharide Nanogel Gene Delivery System with Endosome-escaping Function: Co-delivery of Plasmid DNA and Phospholipase A2.” Journal of Controlled Release 155.1: 54-59.
4. Li, Na, Jinli Wang, Xingguo Yang, Lingbing Li. 2010,”Novel Nanogels as Drug Delivery Systems for Poorly Soluble Anticancer Drugs.”Colloids and Surfaces B: Biointerfaces 83: 237-44.