Exploiting nanotechnology to target cancer

Abstract

Nanotechnology is increasingly finding use in the management of cancer. Nanoscale devices have impacted cancer biology at three levels: early detection using, for example, nanocantilevers or nanoparticles; tumour imaging using radiocontrast nanoparticles or quantum dots; and drug delivery using nanovectors and hybrid nanoparticles. This review addresses some of the major milestones in the integration of nanotechnology and cancer biology, and the future of nanoscale approaches for cancer management.

Figure 1

(A) s.e.m. of a cantilever. Reused with permission from A Gupta, D Akin and R Bashir, J of Vaccum Science and Technology B, 22, 2785 (2004). Copyright 2004, AVS The Science and Technology Society. (B) Schematic showing the functionalisation of the cantilever such that it can bind to a cancer marker. The cantilever can be set to a defined frequency that changes following the binding of a marker. Reducing the cantilever to the nanoscale size can enable highly sensitive detection of cancer markers. Reused with permission from A Gupta, D Akin and R Bashir. Applied physics letters, 84, 1996 (2004), copyright 2004, American Institute of Physics.

Figure 2

Electron micrographs of different types of nanoparticles. (A) Fe nanoparticles coated with poly(N-vinyl-2-pyrrolidone), which stabilises the nanoparticles. (B) TEM image of Au nanoparticles, (∼6 nm), which are being harnessed for sensing protein markers. The aggregation of these nanoparticles is visualised from a change in absorbance; (C) TEM image for Fe₃O₄ nanoparticles (size ∼5 nm), which are being developed as radiocontrast agents. (D) TEM image for CdSe quantum dots (size ∼4 nm). The size-dependent optical tunability of quantum dots make them ideal candidates for imaging. Courtesy of Dr Zhi-Hui Ban, MIT. Inset shows electron micrographs of a nanocore and a nanocell. (a) Scanning electron micrograph of a nanocore synthesised from doxorubicin-conjugated PLGA polymer. (b) Transmission electron micrograph of a cross-section of a nanocell. The dark centre is the nanocore entrapped inside the lipid layer. The hybrid two-chambered nanoparticle displays a spatiotemporal release kinetics, rapidly releasing an antiangiogenesis agent from the outer layer follwed by a delayed release of a chemotherapeutic agent. The release of the antiangiogenesis agent causes a vascular collapse entrapping the chemotherapy-loaded nanocore within the tumour. As the tumour becomes hypoxic, the nanocore degrades, focally releasing the chemotherapy agent. (Sengupta et al, 2005).