Nanotechnology-based detection and targeted therapy in cancer: nano-bio paradigms and applications

Abstract

The application of nanotechnology to biomedicine, particularly in cancer diagnosis and treatment, promises to have a profound impact on healthcare. The exploitation of the unique properties of nano-sized particles for cancer therapeutics is most popularly known as nanomedicine. The goals of this review are to discuss the current state of nanomedicine in the field of cancer detection and the subsequent application of nanotechnology to treatment. Current cancer detection methods rely on the patient contacting their provider when they feel ill, or relying on non-specific screening methods, which unfortunately often result in cancers being detected only after it is too late for effective treatment. Cancer treatment paradigms mainly rely on whole body treatment with chemotherapy agents, exposing the patient to medications that non-specifically kill rapidly dividing cells, leading to debilitating side effects. In addition, the use of toxic organic solvents/excipients can hamper the further effectiveness of the anticancer drug. Nanomedicine has the potential to increase the specificity of treatment of cancer cells while leaving healthy cells intact through the use of novel nanoparticles. This review discusses the use of nanoparticles such as quantum dots, nanoshells, nanocrystals, nanocells, and dendrimers for the detection and treatment of cancer. Future directions and perspectives of this cutting-edge technology are also discussed.

Figure 1.

Relative sizes of different matters. “Nano” is from the Greek word for “dwarf” and means 10⁻⁹ meters or 1 nanometer (nm). The National Nanotechnology Initiative (NNI) defines nanotechnology at dimensions of roughly 1 to 100 nm (shaded scale region). Adapted from the National Cancer Institute (http://nano.cancer.gov/learn/understanding).

Figure 2.

Nanoparticles as nano-carriers can increase solubility, stability, specificity, multimodality, and efficacy, while reducing toxic side effects and improving upon the non-specificity of conventionally delivered cancer treatments.

Figure 3.

Confocal microscopy images showing: (A) uptake of QDs conjugated to an anti-PSMA antibody by LNCaP cells (a PSMA-positive cell line); (B) uptake of void QDs (without PSMA conjugation) by LNCaP cells; (C) uptake of anti-PMSA-conjugated QDs in PC-3 cells (a PSMA-negative cell line). For each condition, QDs were incubated with cells for 4 hours [15].

Figure 4.

Confocal microscopy images showing uptake of Tetrac-PEG-QDs by Panc1 cells: (A) Cells were left untreated prior to incubation with QDs; (B) cells were pre-treated with T₄ (thyroxin, a thyroid hormone) for 2 hours prior to the addition of QDs [16].