Nanostructured carriers as innovative tools for cancer diagnosis and therapy

Abstract

Cancer accounts for millions of deaths every year and, due to the increase and aging of the world population, the number of new diagnosed cases is continuously rising. Although many progresses in early diagnosis and innovative therapeutic protocols have been already set in clinical practice, still a lot of critical aspects need to be addressed in order to efficiently treat cancer and to reduce several drawbacks caused by conventional therapies. Nanomedicine has emerged as a very promising approach to support both early diagnosis and effective therapy of tumors, and a plethora of different inorganic and organic multifunctional nanomaterials have been ad hoc designed to meet the constant demand for new solutions in cancer treatment. Given their unique features and extreme versatility, nanocarriers represent an innovative and easily adaptable tool both for imaging and targeted therapy purposes, in order to improve the specific delivery of drugs administered to cancer patients. The current review reports an in-depth analysis of the most recent research studies aiming at developing both inorganic and organic materials for nanomedical applications in cancer diagnosis and therapy. A detailed overview of different approaches currently undergoing clinical trials or already approved in clinical practice is provided.

FIG. 1.

Main types of inorganic and organic nanoparticles. Nanomedicine comprises many kinds of nanovectors that can be used individually or in tandem to give the best medical performance (i.e., theranostic).

FIG. 2.

Passive targeting, active targeting, and triggered release. (a) Passive targeting relies on extravasation of nanoparticles through leaky tumor vasculature; (b) active targeting exploits surface modified nanoparticles; and (c) triggered release is based on stimuli-responsive nanoparticles.

FIG. 3.

Combination of magnetic nanoparticles and fluorescent probes for targeted imaging of cancer cells and tissues. Reprinted with permission from Chinen et al. Chem. Rev. 115, 72 (2015). Copyright 2015 American Chemical Society.

FIG. 4.

Apoptotic effect of combined treatment with hyperthermia and temozolomide (TMZ) on U-87 MG glioblastoma cells. Flow cytometer analysis shows that solid lipid nanoparticles loaded with SPIONs and TMZ (LMNVs) induce apoptosis, inhibition of proliferation, and reduction of cell number after application of an external magnetic field [(a) and (b)]. Confocal images of p53 and Ki-67 expression confirm the results obtained by flow cytometry [(a) and (c)]. Reproduced with permission from Tapeinos et al., Nanoscale 11, 72 (2019). Copyright 2019 The Royal Society of Chemistry.