Introduction

Nanotechnology is an exciting multidisciplinary field that involves designing and engineering of materials and systems whose structures and components are less than 100 nm in at least one dimension (Ferrari 2005). In this nanometer scale, the properties of objects (such as electrical, optical, mechanical, etc.) significantly differ from those at larger scales, such as the micrometer scale (Klabunde et al. 1996; Wu et al. 1996; Baraton et al. 1997; Siegel and Fougere 1995). Nanotechnology, thus, can be defined as designing, manipulating, and utilizing novel functional structures, devices, and systems on the order of less than 100 nm.

Having the ability to create new products with new characteristics and properties which did not exist before, nanotechnology has shown great potential in a wide range of applications (such as information and communication technology (Heath et al. 1998; Akyildiz et al. 2008), biology and biotechnology (Giaever 2006; Saini et al. 2006), medicine and medical technology (Silva 2004; Jain 2003; West and Halas 2003), etc.). One of the most exciting contributions nanotechnology has made is in medicine and medical research to improve human health. Novel nanometer scale drug delivery systems and nano tools have been developed to aid in disease detection of higher accuracy at earlier stages to simultaneously treat such diseases more effectively (Park 2007, Orive et al. 2005; Kong and Goldschmidt-Clermont 2005; Jain 2003; Shantesh and Nagraj 2006).

Of the tools that nanotechnology has created, nanoparticles have emerged over the last decade as the most promising for disease sensing, treatment, and management, especially for diagnosing and treating cancer. The term cancer nanotechnol-ogy refers to the use of nanotechnology to diagnose and treat cancer to increase the survival rate and prolong the lifetime of cancer patients. Nanoparticles have been shown to have unique properties that allow them to deeply penetrate tumors with a high level of specificity. In addition, some nanoparticles also have superior imaging capabilities allowing for a highly sensitive diagnosis of cancer (Shantesh and Nagraj 2006; Brannon-Peppas and Blanchette 2004; Brigger et al. 2002) (see Table 1 for a summary of the advantages and disadvantages of the nanoparticles used in cancer diagnostics and treatment that will be discussed in the chapter). Among many kinds of cancer, bone cancer has been the subject of numerous studies due to its complexity.

It was estimated that 2,380 individuals (1,270 men and 1,110 women) would be diagnosed with bone and joint cancers and 1,470 individuals would die from primary bone and joint cancers in 2008 in the United States (ACS 2008). Primary bone cancer is rare as usually bone cancer is a result of the spread of cancer from

Table 1 Summary of advantages and disadvantages of the use of nanoparticles for cancer treatment to be discussed

Type of nanoparticle Advantages

Disadvantages

References

Liposomes

Quantum dots

Nanoshells

Superparamagnetic nanoparticles

Polymeric nanoparticles

Biocompatible; biodegradable; nonimmunogenic; amphiphilic; size, charge, and surface properties of liposomes can be easily changed Fluorescently bright; large extinction coefficients; high quantum yields; absorption coefficients across a wide spectral range; highly resistant to photobleaching Fine-tunable optical response in a broad region of the spectrum from the near-UV to the midinfrared; can be designed to strongly absorb or strongly scatter light in the NIR region; gold shell is compatible and rigid Controllable nano size; magnetic properties; easy to be directed using an external magnetic field; have controllable, specific Curie temperatures that allow for self-regulated hyperthermia

Tailorability of polymer; biocompatibility; biodegradability; various nanoparticle synthesis methods; versatility of drug-loading techniques; controllable drug release characteristics

Poor control over leakage of drugs; low encapsulation efficacy; poor stability during storage; poor manufacturability at the industrial scale Composition includes heavy metals which are toxic

Little-known fate following introduction to human bodies

Hard to be directed to tumors which have a large distance to possible position of magnets; occlusion of blood vessels can occur in the target regions; possible toxic responses to human bodies

Some preparation methods use toxic organic solvents; poor drug encapsulation for certain hydrophilic drugs and the possibility of drug leakage

Torchilin (2005); Tiwari and Amiji (2006); Soppimath et al. (2001); Hans and Lowman (2002) Gao et al. (2004a); Dubertret et al. (2002); Ballou et al.

(2004); Reiss et al. (2002); Niemeyer (2001); Alivisatos (1996)

(2005); Oldenburg et al. (1999); Hirsch et al. (2003)

Mornet et al. (2004); Wang et al. (2001); Jordan et al. (1996); Wust et al. (2002); Falk and Issels (2001); Kapp et al. (2000); Cerner et al. (2000); Alexiou et al. (2000) Hans and Lowman (2002); Anderson and Shive (1997); Soppimath et al. (2001)

other organs (such as the lungs, breasts, and the prostate (Miller and Webster 2007)). Because many deaths are officially attributed to the original cancer source, the true numbers of bone cancer-related deaths have been underreported. A common technique to treat bone cancer is the surgical removal of the cancerous tissue followed by insertion of an orthopedic implant to restore patient function. However, it is not always possible to remove all cancerous cells and therefore the remaining tumor cells can redevelop cancer. In these cases, it would be beneficial to have implants specifically designed to prevent the reoccurrence of bone cancer and simultaneously promote healthy bone tissue growth. This same argument can be made for numerous tissues (such as the lung, breast, etc.). This can be achieved by imparting conventional implant materials (such as titanium, stainless steel, ultrahigh molecular weight polyethylene, etc.) with anticancer chemistry. To promote healthy bone tissue growth, nanofeature surfacing can be utilized as studies have shown that osteoblast (bone-forming cells) function (from adhesion to proliferation and deposition of calcium-containing minerals) is greater on nanostructured compared to current implant surfaces (which are micron-scale rough and nanoscale smooth) (Webster et al. 1999, 2000a,b, 2001; Webster and Ejiofor 2004; Perla and Webster 2005).

This chapter will first give a brief introduction to the development and characteristics of cancerous tumors and different targeting strategies, then discuss the emerging roles of nanoparticles (such as liposomes, quantum dots (QDs), nanoshells, super-paramagnetic nanoparticles (SPMNPs), and polymeric nanoparticles) in cancer sensing, imaging, and therapeutic purposes.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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