Nanoparticles in Medicine and Environment: Benefits and Cytotoxicity

Medical Applications: Iron Oxide Nanoparticles in Pancreatic Cancer

Today, cancer represents the third-leading cause of death, after heart disease and stroke (Malekigorji, Anthony, Hoskins & Hoskins, 2014). The problem is global in scope. According to Malekigorji and her colleagues, "Studies have demonstrated that there were 10 million new instances, about 6 million deaths and 22 million patients living with cancer worldwide in the year 2000" (2014, p. 1). Of all cancer types, pancreatic cancer is especially deadly. In this regard, Malekigorji et al. emphasize that pancreatic cancer "is still the fourth most common cause of cancer-related death in the Western world" (2014, p. 1).

Although significant progress has been made in treating certain cancers such as leukemia and breast cancer, far fewer advances have been achieved with pancreatic cancer for several reasons, including its resistance to conventional chemotherapeutic interventions and inefficient drug delivery systems (Malekigorji et al., 2014). Pancreatic adenocarcinomas typically create a barrier that inhibits efficient drug penetration. While it is possible to overcome these constraints by increasing the dosage of chemotherapeutic agents, this alternative introduces numerous serious side effects due to the non-selectivity of these drugs in targeting tumor cells (Malekigorji et al., 2014).

Environmental Toxicity: Silver Nanoparticles and Aquatic Life

Because they have easily modified surfaces, magnetic nanoparticles have been viewed as a viable alternative for treating pancreatic cancer through improved drug delivery mechanisms, magnetic resonance imaging applications, and magnetic fluid hyperthermia, which is used for both diagnosis and treatment (Malekigorji et al., 2014).

The same attributes that are making nanoparticles more popular for biomedical applications are generating increasing attention from researchers concerned about the cytotoxicity of these materials on the natural environment when they are purposely or inadvertently released. Johari (2014) reports that "the number of consuming products by human beings in which nanomaterials are used has increased from 54 in 2005 to 1,628 in 2013 and it is predicted that this number would be rapidly increasing in future years too" (p. 1). Although this issue remains understudied, Johari (2014) emphasizes that it is inevitable that nanoparticles will find their way into the ecosystem, and his experiments with rainbow trout suggest there is indeed cause for concern.

Therapeutic Mechanisms and Drug Delivery

Consequently, Johari advises that "understanding the potential effects of this nanomaterial on aquatic organisms is very important" (2014, p. 2). Based on his analysis of differences in rainbow trout exposed to colloidal silver nanoparticles and a control group, Johari determined that while there was no substantive difference identified 24 hours post-fertilization, there were significant differences identified thereafter, including reduced hatching and survival rates. These findings indicate that silver nanoparticles can harm the aquatic environment and the fish populations that depend on it.

The utility of iron oxide nanoparticles in cancer therapy stems from their unique properties and the problems they solve in conventional treatment. Traditional chemotherapy drugs are distributed nonselectively throughout the body, damaging both cancerous and healthy cells and resulting in severe side effects. Iron oxide nanoparticles address this limitation by serving as targeted drug carriers. Their easily modified surfaces allow them to be conjugated with chemotherapeutic agents and directed to tumor sites using external magnetic fields. Additionally, nanoparticles can cross the dense stromal barrier that pancreatic adenocarcinomas create, delivering therapeutic payloads more efficiently than free drug molecules. Beyond drug delivery, these same nanoparticles function as contrast agents in magnetic resonance imaging, enabling improved visualization of tumors for diagnostic and treatment monitoring purposes. Magnetic fluid hyperthermia represents a third application, whereby externally applied magnetic fields cause the nanoparticles to generate heat, selectively destroying cancer cells while minimizing damage to surrounding tissues.