Green Metallic Nanoparticles for Cancer Therapy: Evaluation Models and Cancer Applications

Abstract

Metal-based nanoparticles are widely used to deliver bioactive molecules and drugs to improve cancer therapy. Several research works have highlighted the synthesis of gold and silver nanoparticles by green chemistry, using biological entities to minimize the use of solvents and control their physicochemical and biological properties. Recent advances in evaluating the anticancer effect of green biogenic Au and Ag nanoparticles are mainly focused on the use of conventional 2D cell culture and in vivo murine models that allow determination of the half-maximal inhibitory concentration, a critical parameter to move forward clinical trials. However, the interaction between nanoparticles and the tumor microenvironment is not yet fully understood. Therefore, it is necessary to develop more human-like evaluation models or to improve the existing ones for a better understanding of the molecular bases of cancer. This review provides recent advances in biosynthesized Au and Ag nanoparticles for seven of the most common and relevant cancers and their biological assessment. In addition, it provides a general idea of the in silico, in vitro, ex vivo, and in vivo models used for the anticancer evaluation of green biogenic metal-based nanoparticles.

Photothermal Therapy with HER2-Targeted Silver Nanoparticles Leading to Cancer Remission

“…However, these production methods are usually expensive, labor-intensive, and potentially hazardous to the environment and living organisms. Plant metabolites are especially promising for green synthesis: the low cost of growing plants, relatively short production times, and their safety and scalability make plants an attractive platform for the nanobiosynthesis [ 75 , 76 , 77 , 78 ].…”

Recent Developments in Metallic Nanomaterials for Cancer Therapy, Diagnosing and Imaging Applications

“…Metallic nanoconstructs can remodel the tumor microenvironment (TME) by turning unfavorable conditions into therapeutically accessible ones. For instance, external stimuli (e.g., light, heat, ultrasonic radiation, and magnetic fields) can enhance the targeting ability of metallic NPs towards altering the redox potential of biological systems and generating reactive oxygen species (ROS) that further sensitize target tissues [12]. Furthermore, certain metallic NPs can induce oxidative stress in cancer cells even in the absence of external stimulation [13,14]; internal conditions specific to tumor tissues, such as pH, redox potential, and hypoxia, represent additional viable stimuli for triggering metal-based NPs activity and drug release, enhancing therapeutic efficacy.…”

“…Furthermore, certain metallic NPs can induce oxidative stress in cancer cells even in the absence of external stimulation [13,14]; internal conditions specific to tumor tissues, such as pH, redox potential, and hypoxia, represent additional viable stimuli for triggering metal-based NPs activity and drug release, enhancing therapeutic efficacy. Furthermore, surface functionalization of metallic NPs with different organic molecules, macromolecules, or noble metal coatings is considered an excellent tool for stabilizing NPs and manipulating their properties towards responding to the above-mentioned stimuli (Figure 1) [12]. Examples of commonly used moieties for coating metal NPs to produce stimuli-sensitive nanosystems.…”

“…Examples of commonly used moieties for coating metal NPs to produce stimuli-sensitive nanosystems. Reproduced from [12].…”

Two Methods of AuNPs Synthesis Induce Differential Vascular Effects. The Role of the Endothelial Glycocalyx

“…AuNPs are widely used in biomedicine as antitumor drug delivery vehicle ( 5 – 7 ), theragnostic platforms ( 8 , 9 ), thermotherapy ( 10 , 11 ), gene therapy ( 12 , 13 ), and diagnostic ( 14 ).…”