Protein-Nanoparticle Interactions

In the recent decade, the fabrication of nanoparticles and exploration of their properties have attracted the attention of all branches of science such as physicists, chemists, biologists, engineers, and even medical doctors. Interests for nanoparticles arise from the fact that their mechanical, chemical, electrical, optical, magnetic, electro-optical, and magneto-optical properties of these nanoparticles are completely different from their bulk properties and the predetermined differences are depended on the physicochemical properties of the nanoparticles. There are numerous areas where nanoparticles are of scientific and technological interest, specifically for medical community, where the synthetic and biologic worlds come together and lead to an important concern for design of safe nano-biomaterials. In this chapter, we review and discuss the major biomedical applications of nanoparticles. 1.1 Nanoscience in Medicine Nanomedicine is the application of nanosciences to health and exploits the physical, chemical, and biological properties of nanomaterials. The advent of nanoscience and nanotechnologies is shaping the face of industrial production and economics. As a matter of fact, nano-based products now include electronic components, paint, sports equipment, fabrics, sunscreens, and other cosmetics [1]. However, the most exciting nano-innovations reside in the conception of new medical products such as heart valves, drug-delivery systems, and imaging techniques [1], which will surely obliterate the long-established boundaries amidst chemistry, physics, and biology. It is anticipated that nanotechnology will have substantial economic impacts by encouraging productivity and competitiveness, converging different disciplines of science and technologies, and stimulating education and human development [2]. Experts predict market growth to hundreds of billions of dollars in the next decade. The worldwide market for products exploiting nanotechnology reached M. Rahman et al., Protein-Nanoparticle Interactions, Springer Series in Biophysics 15, DOI 10.1007/978-3-642-37555-2_1, © Springer-Verlag Berlin Heidelberg 2013 1 about US$254 billion in 2009, with nanomedical products accounting for a margin of US$72.8 billion in 2011 [3]. The US government has granted more than US$20 billion to the US National Nanotechnology Initiative for nanotechnology research and development activities, facilities, and workforce training since 2000 [4]. In 2011, the Canadian Institutes of Health Research (CIHR) and the Canadian Space Agency (CSA) have granted US $16 million in funding to seven new research projects on regenerative medicine and nanomedicine [5]. The European Framework Program [6] will invest about 600 million euros per year for nanotechnology research until 2013, with a supplementary, comparable sum provided by individual countries [7]. The economic landscape is thus being dramatically altered by nanotechnology. For instance, in 2004, worldwide corporations spent US$3.8 billion on research and development [8]. More importantly, there is a shift from the discovery stage to applications on nanotechnology, as demonstrated by the ratio increased corporate patent applications to scientific publications from 0.23 in 1999 to 1.2 in 2008 [2]. Additionally, analysts estimate that by 2014, nanotechnology will be responsible for 15 % of all manufactured merchandise, valuing approximately US$2.6 trillion and will create 10 million jobs globally [1]. Physicochemical properties of nanoparticles such as their small size, large surface area, and kinetics of adsorption make them particularly interesting as tools for molecular diagnostics, in vivo imaging, and improved treatment of disease. Metal oxides have been introduced in the early 1960s as ferromagnetic separation moieties and have brought about the use of nanoparticles for magnetic resonance imaging (MRI) in the late 1970s. More recently, application of nanoparticles to medicine has expanded to cellular therapy [9], tissue repair [10], drug delivery [11], hyperthermia [12], (MRI) [13], magnetic resonance spectroscopy [14], magnetic separation [15], and as sensors for metabolites and other biomolecule [16]. Moreover, the unique magnetic properties and small size of magnetic nanoparticles (MNPs) make them appealing for biomolecule labeling in bioassays, as well as MRI contrast agents [17]. Superparamagnetic iron oxide (SPIO) can also be used as magnetic gradients for cell sorting in bioreactors [18], as well as absorbing material in radio-frequency hyperthermia. Moreover, the exceptional physical, mechanical, and electronic properties of carbon nanotubes (CNTs) allow them to be used as biosensors, probes, actuators, nanoelectronic devices, drug-delivery systems, and tissue-repair scaffolds within biomedical applications [19–21]. Recent research has focused on conjugating nanocarriers to specific ligands such as peptides, antibodies, and small molecules and subsequently directing them to sites of interest [22]. These techniques can prove to be appealing alternatives for current cancer and cardiovascular applications. Thus, a vast array of nanotechnologies can be applied to medical devices, materials, and processes that will affect the prevention, early diagnosis, and treatment of diseases. However, the risk–benefit balance for these materials, with regard to their toxicological profile and any potential adverse pathogenic reactions from exposure, will ultimately define their clinical outcome. 2 1 The Biological Significance of “Nano”-interactions