Fabrication and in vitro characterization of gadolinium-based nanoclusters for simultaneous drug delivery and radiation enhancement

Main Approaches to Enhance Radiosensitization in Cancer Cells by Nanoparticles: A Systematic Review

In recent years, high atomic number nanoparticles (NPs) have emerged as promising radio-enhancer agents for cancer radiation therapy due to their unique properties. Multi-disciplinary studies have demonstrated the potential of NPs-based radio-sensitizers to improve cancer therapy and tumor control at cellular and molecular levels. However, studies have shown that the dose enhancement effect of the NPs depends on the beam energy, NPs type, NPs size, NPs concentration, cell lines, and NPs delivery system. It has been believed that radiation dose enhancement of NPs is due to the three main mechanisms, but the results of some simulation studies failed to comply well with the experimental findings. Thus, this study aimed to quantitatively evaluate the physical, chemical, and biological factors of the NPs. An organized search of PubMed/Medline, Embase, ProQuest, Scopus, Cochrane and Google Scholar was performed. In total, 77 articles were thoroughly reviewed and analyzed. The studies investigated 44 different cell lines through 70 in-vitro and 4 in-vivo studies. A total of 32 different types of single or core-shell NPs in different sizes and concentrations have been used in the studies.

Gadolinium-based layered double hydroxide and graphene oxide nano-carriers for magnetic resonance imaging and drug delivery

Gadolinium (Gd)-based contrasts remain one of the most accepted contrast agents for magnetic resonance imaging, which is among the world most recognized noninvasive techniques employed in clinical diagnosis of patients. At ionic state, Gd is considered toxic but less toxic in chelate form. A variety of nano-carriers, including gadolinium oxide (Gd₂O₃) nanoparticles have been used by researchers to improve the T1 and T2 contrasts of MR images. Even more recently, a few researchers have tried to incorporate contrast agents simultaneously with therapeutic agents using single nano-carrier for theranostic applications. The benefit of this concept is to deliver the drugs, such as anticancer drugs and at the same time to observe what happens to the cancerous cells. The delivery of both agents occurs concurrently. In addition, the toxicity of the anticancer drugs as well as the contrast agents will be significantly reduced due to the presence of the nano-carriers. The use of graphene oxide (GO) and layered double hydroxides (LDH) as candidates for this purpose is the subject of current research, due to their low toxicity and biocompatibility, which have the capacity to be used in theranostic researches. We review here, some of the key features of LDH and GO for simultaneous drugs and diagnostic agents delivery systems for use in theranostics applications.

Advances in Molecular Imaging of Locally Delivered Targeted Therapeutics for Central Nervous System Tumors

Thanks to the recent advances in the development of chemotherapeutics, the morbidity and mortality of many cancers has decreased significantly. However, compared to oncology in general, the field of neuro-oncology has lagged behind. While new molecularly targeted chemotherapeutics have emerged, the impermeability of the blood–brain barrier (BBB) renders systemic delivery of these clinical agents suboptimal. To circumvent the BBB, novel routes of administration are being applied in the clinic, ranging from intra-arterial infusion and direct infusion into the target tissue (convection enhanced delivery (CED)) to the use of focused ultrasound to temporarily disrupt the BBB. However, the current system depends on a “wait-and-see” approach, whereby drug delivery is deemed successful only when a specific clinical outcome is observed. The shortcomings of this approach are evident, as a failed delivery that needs immediate refinement cannot be observed and corrected. In response to this problem, new theranostic agents, compounds with both imaging and therapeutic potential, are being developed, paving the way for improved and monitored delivery to central nervous system (CNS) malignancies. In this review, we focus on the advances and the challenges to improve early cancer detection, selection of targeted therapy, and evaluation of therapeutic efficacy, brought forth by the development of these new agents.