Application of Nanoparticles in Cancer Treatment: A Concise Review

Abstract

Timely diagnosis and appropriate antitumoral treatments remain of utmost importance, since cancer remains a leading cause of death worldwide. Within this context, nanotechnology offers specific benefits in terms of cancer therapy by reducing its adverse effects and guiding drugs to selectively target cancer cells. In this comprehensive review, we have summarized the most relevant novel outcomes in the range of 2010-2023, covering the design and application of nanosystems for cancer therapy. We have established the general requirements for nanoparticles to be used in drug delivery and strategies for their uptake in tumor microenvironment and vasculature, including the reticuloendothelial system uptake and surface functionalization with protein corona. After a brief review of the classes of nanovectors, we have covered different classes of nanoparticles used in cancer therapies. First, the advances in the encapsulation of drugs (such as paclitaxel and fisetin) into nanoliposomes and nanoemulsions are described, as well as their relevance in current clinical trials. Then, polymeric nanoparticles are presented, namely the ones comprising poly lactic-co-glycolic acid, polyethylene glycol (and PEG dilemma) and dendrimers. The relevance of quantum dots in bioimaging is also covered, namely the systems with zinc sulfide and indium phosphide. Afterwards, we have reviewed gold nanoparticles (spheres and anisotropic) and their application in plasmon-induced photothermal therapy. The clinical relevance of iron oxide nanoparticles, such as magnetite and maghemite, has been analyzed in different fields, namely for magnetic resonance imaging, immunotherapy, hyperthermia, and drug delivery. Lastly, we have covered the recent advances in the systems using carbon nanomaterials, namely graphene oxide, carbon nanotubes, fullerenes, and carbon dots. Finally, we have compared the strategies of passive and active targeting of nanoparticles and their relevance in cancer theranostics. This review aims to be a (nano)mark on the ongoing journey towards realizing the remarkable potential of different nanoparticles in the realm of cancer therapeutics.

Keywords: cancer treatments; drug delivery; nanomedicine; nanoparticles; nanotechnology; passive and active targeting; tumor environment.

Figure 1

Correlation between the number of publications and year of publication of the research covered in this review.

Figure 2

Map of the keywords found in the literature sources used in this review.

Figure 3

Schematic differences between healthy and tumor vasculature. Adapted from [39], with permission from Springer Nature, 2018.

Figure 4

Physicochemical properties of nanoparticles, their various interactions inside the body, and their behavior inside the cell. Adapted from [45], with permission from Elsevier, 2014.

Figure 5

Different strategies for tumor uptake of nanoparticles. Adapted from [40], with permission from MDPI, 2019.

Figure 6

Formation of protein corona layers: hard corona and soft corona.

Figure 7

Schematic representation of three generations of nanovectors (a) first generation, (b) second generation, and (c) third generation. Adapted from [10], with permission from Elsevier, 2022.

Figure 8

Liposomal drug delivery system. Adapted from [10], with permission from Elsevier, 2022.

Figure 9

TEM images of Au nanospheres (A) and Au nanostars (B), both obtained by colloid synthesis. Courtesy of Dr. Sara Fateixa (U. Aveiro).

Figure 10

Examples of applications of iron oxide nanoparticles in cancer therapies.

Figure 11

Examples of carbon nanomaterials. The structure and crystal lattice of graphene are shown.

Figure 12

Types of targeting for nanoparticle delivery to tumor tissue. (A). Passive targeting relies on the leaky vasculature that is exhibited by tumors, allowing nanoparticles to travel through the fenestrations and reach tumors. (B). Active targeting can be used when nanoparticles have ligands on their surface that can recognize and bind receptors that are overexpressed on tumor cells. (C). Triggered release allows nanoparticles to congregate if exposed to an external stimulus such as a magnetic field or light. Adapted from [52], with permission from Springer Nature, 2017.