Nanoparticles for Cancer Treatment

Abstract

An overview is presented of an approach for treating cancer that uses nanoparticles to deliver heat to diseased areas after absorbing energy from a laser of the appropriate wavelength. The implications are discussed of the relationship of parameters necessary to raise the temperature to therapeutically beneficial levels. Tight focusing is required for a continuous-wave laser to sufficiently heat individual nanoparticles because of heat loss to the surrounding fluid during the period of exposure. The natural thermal confinement of pulse lasers minimizes this effect because of the finite thermal diffusion time, which restricts the absorbed energy to a region around the particle, that offers the potential for achieving high temperatures that can promote phase change on the surface of a nanoparticle or even melting of the particle. A discussion of a way to potentially measure temperature on the scale of an individual nanoparticle is included based on using a single-walled nanotube (SWNT) of carbon as a thermistor. The challenges of this undertaking are that SWNTs do not always follow Ohm's law, they may exhibit metallic or semiconductor behavior with an often unpredictable result in manufacturing, and no two SWNTs behave identically, which necessitates calibration for each SWNT. Some results are presented that show the electrical characteristics of SWNTs and their potential for exploitation in this application.

Anti-HER2 IgY antibody-functionalized single-walled carbon nanotubes for detection and selective destruction of breast cancer cells

“…The sharp local temperature increase may cause damage to subcellular structures such as cell membranes ultimately leading to cell death. The ability to directly measure temperature of an individual nanoparticle will help to validate the hypothesis, and such an endeavor is currently underway [48]. …”

Development of Iron-Containing Multiwalled Carbon Nanotubes for MR-Guided Laser-Induced Thermotherapy

“…They can be easily internalized by cells [2–4] and can therefore act as delivery vehicles for a variety of molecules relevant to therapy and diagnosis of disease [5]. Moreover, their unique combination of electrical, thermal and spectroscopic properties offers further opportunities for advances in the detection, monitoring and therapy of diseases, especially cancer [6–12]. …”

The Laser Technology: New Trends in Biology and Medicine

“…These can be an infrared pulsed laser or an UV or blue pulsed laser. This kind of experiment can be performed on any laser scanning microscope but several dedicated setups are available, such as iLas 2 from Roper Scientific [ Figure 4], a device that provides researchers with the ability to manage and modify the position and focalization of laser light in real time, or Micropoint from ANDOR.…”

“…The development of light-absorbing nanoparticles that are nontoxic to biological tissue has provided further potential for a more targeted delivery of heat with minimal damage to healthy tissue. At an appropriate wavelength, exposure of a nanoparticle to a laser can trigger a photothermal effect in the particle whereby electronic oscillations at the particle surface are converted to heat [2].…”