Functionalized Nanomaterials as Tailored Theranostic Agents in Brain Imaging

Abstract

Functionalized nanomaterials of various categories are essential for developing cancer nano-theranostics for brain diseases; however, some limitations exist in their effectiveness and clinical translation, such as toxicity, limited tumor penetration, and inability to cross blood–brain and blood-tumor barriers. Metal nanomaterials with functional fluorescent tags possess unique properties in improving their functional properties, including surface plasmon resonance (SPR), superparamagnetism, and photo/bioluminescence, which facilitates imaging applications in addition to their deliveries. Moreover, these multifunctional nanomaterials could be synthesized through various chemical modifications on their physical surfaces via attaching targeting peptides, fluorophores, and quantum dots (QD), which could improve the application of these nanomaterials by facilitating theranostic modalities. In addition to their inherent CT (Computed Tomography), MRI (Magnetic Resonance Imaging), PAI (Photo-acoustic imaging), and X-ray contrast imaging, various multifunctional nanoparticles with imaging probes serve as brain-targeted imaging candidates in several imaging modalities. The primary criteria of these functional nanomaterials for translational application to the brain must be zero toxicity. Moreover, the beneficial aspects of nano-theranostics of nanoparticles are their multifunctional systems proportioned towards personalized disease management via comprising diagnostic and therapeutic abilities in a single biodegradable nanomaterial. This review highlights the emerging aspects of engineered nanomaterials to reach and deliver therapeutics to the brain and how to improve this by adopting the imaging modalities for theranostic applications.

Stimuli-responsive ferroptosis for cancer therapy

“…The tumor microenvironment is slightly acidic (around pH 5.5) compared to the surrounding tissues (pH 7.4) due to the abnormally high metabolic activity of cancer cells. 61,62 Even though the pH difference is rather small, various types of functional groups and nanomaterials 63 that respond to the difference in such subtle pH differences have been used as nanocarriers. Hence, their physiochemical characteristics are highly sensitive to even a slight fluctuation in pH, leading to significant changes in their characteristics, such as size, shape, and surface charge.…”

Red emissive carbon dots: a promising next-generation material with intracellular applicability

“…chemotherapy, immunotherapy, radiotherapy, and PT) as image-guided therapy. 56,[100][101][102][103] RCDs are extensively engaged in theranostics owing to their unique non-invasiveness, non-destruction, improved tissue penetration depth and real-time tracking.…”

Multifunctional Magnetic Nanoparticles for Dynamic Imaging and Therapy

“…MRI utilizing the radiofrequency (RF) magnetic field plays an important role in the current medical scenario by enabling precise visualization of biological activity, diagnosis of disease, and prognosis of the treatment for cure. [171,172] MRI is one of the most popular technologies specialized for the evaluation of soft tissues with imaging conditions [173] that does not require ionizing radiation or radioisotopes, which can be harmful to the body. [174] MRI works with the RF magnetic field that polarizes hydrogen nuclei of water in the body and detects the relaxation of protons stabilized in the magnetic field.…”