Do Nanomedicines Require Novel Safety Assessments to Ensure their Safety for Long-Term Human Use?

Abstract

Nanomaterials have different chemical, physical and biological characteristics than larger materials of the same chemical composition. These differences give nanotechnology a double identity: their use implies novel and interesting medical and/or industrial applications but also potential danger for human and environmental health. Here, we briefly review the most important types of nanomaterials, the difficulties in assessing safety or toxicity, and describe existing test protocols used in nanomaterial safety evaluation. In general, the big challenge of nanotechnology, particularly for nanomedicine (nano-bioengineering), is to understand which nano-specific characteristics interact with particular biological systems and functions in order to optimize the therapeutic potential and reduce the undesired responses. The evaluation of the safety of medicinal nanomaterials, especially for long-term application, is an important challenge for the near future. At present, it is still too early to predict, on the basis of the characteristics of the nanomaterial, a possible biological response because no reliable database exists. Therefore, a case-by-case approach for hazard identification is still required, so it is difficult to establish a risk assessment framework.

Toxicity studies of coumarin 6-encapsulated polystyrene nanospheres conjugated with peanut agglutinin and poly(N-vinylacetamide) as a colonoscopic imaging agent in rats

“…However, regulatory agencies exercise considerable cautions before approving the human use of novel nano-sized biomaterials due to their potential toxicity. 26–28 The present study was performed in facilities of the third party in accordance with Good Laboratory Practice (GLP) regulations with the aim of investigating toxicities of the nanobeacon after its repeated oral and single intrarectal administrations in rats.…”

Study on Controllable Preparation of Silica Nanoparticles with Multi-sizes and Their Size-dependent Cytotoxicity in Pheochromocytoma Cells and Human Embryonic Kidney Cells

“…6) The increasing production has led to calls for more information regarding the potential impacts that releases of these materials may have on human and environmental health. 7) More and more researchers began to pay attention to the safety issue of the nanomaterials, 8,9) but the overwhelming majorities of such studies are related to the risk of nanomaterials themselves. The harm resulted from nanomaterials with different sizes were seldom reported Only the cytotoxicity induced by nano and fine-sized particles were investigated and compared.…”

Designing oversight for nanomedicine research in human subjects: systematic analysis of exceptional oversight for emerging technologies

“…Now another emerging domain of human subjects research—nanomedicine--is prompting calls for extra oversight (Lenk and Biller-Adorno 2007; Resnik and Tinkle 2007; Bawa and Johnson 2008; DeVille 2008; Fadeel and Garcia-Bennett 2009; Harris 2009; Hoet et al 2009; Hansen 2010). (See Table 1 for a list of recent proposals.)…”

“…Researchers are working to develop nanodiagnostics and nanotherapeutics, including nonviral nanovectors for gene therapy, nano drug-delivery mechanisms, and nanomaterials that differentially bind to cancerous micrometastases and facilitate imaging for early detection (Wagner et al 2006; Virdi 2008). However, characteristics of nanoparticles and nanomaterials, including size and surface reactivity, have contributed to emergent physico-chemical properties that allow the particles and materials to interact with the body in new ways (Chan 2006; Hoet et al 2009). Some of these novel properties are therapeutically advantageous, such as the ability to cross the blood-brain barrier.…”

“…Some of these novel properties are therapeutically advantageous, such as the ability to cross the blood-brain barrier. However, these novel properties can also lead to risk through bioaccumulation (accumulation of particles in organs of the body), translocation (as when crossing the blood-brain barrier is not intended), infiltration and interaction with the immune system, bioreactivity, DNA toxicity, persistence, and agglomeration (formation of larger nano-structures) (Chan 2006; Faunce and Shats 2007; Fadeel and Garcia-Bennett 2009; Hoet et al 2009; Staggers 2009).…”