Enhancing Near-Infrared Photothermal Efficiency of Biocompatible Flame-Synthesized Carbon Nano-Onions with Metal Dopants and Silica Coating

Abstract

As an alternative to eliminating cancer cells with minimal impacts on the nearby tissues, biocompatible nanoparticles based on silica-coated carbon nano-onions, with outstanding photothermal efficiency, are presented. Metal-doped carbon nano-onion@SiO2 materials are produced using flame synthesis. Metal complexes are injected in the flame to tune the carbon organization levels, which results in materials with excellent photostability and total photothermal conversion efficiency, regarding the incident light input, as higher as 48% for 785 nm laser. It was found that the metal dopant, even at a very low content, plays an interesting role in photothermal efficiency. We tested the effect of thin silica layers on the carbon nanosphere, first as a way to improve biocompatibility and provide a more reactive surface toward the modifications process to add vectorizing agents. Despite the primary goal of the silica shell, a notable increase in photothermal efficiency was observed. In vivo studies of the biological response to the materials as probed by the zebrafish model found that the as-prepared carbon nanospheres and the SiO2-coated particles are highly biocompatible. The SiO2-coated samples were found to be more suitable for photothermal application, due to the higher colloidal stability and higher photothermal efficiency.

Fluorescent Nanocarbons: From Synthesis and Structure to Cancer Imaging and Therapy

“…Introducing nonmetal and metal dopants, even at deficient levels, into the structure of CNOs could significantly improve their photothermal efficiency. [384] Heteroatom doping into CNOs could effectively reduce the charge-transfer resistance, thus increasing the number of capacitive sites. Mahapatra et al [381] introduced a pyrolysis technique to obtain hydrophilic sulfur-doped CNOs.…”

Nanocomposite Hydrogels as Functional Extracellular Matrices

“…GNPs are the most widely used optical absorbers converting near-infrared (NIR) light into heat via localized surface plasmon generation and are often chosen over other metallic nanostructures (Ag, Pt), carbon particles, and other potential mediators [154][155][156][157][158][159][160] because of their biocompatibility and tunable plasmon absorption bands. For details regarding other photothermal nanoparticles that have recently been developed for biomedical applications, readers are invited to consult recent reviews specialized in the topic [161].…”

Dynamic tracking of onion-like carbon nanoparticles in cancer cells using limited-angle holographic tomography with self-supervised learning

“…With its precision and non-invasive characteristics, PTT has attracted substantial scholarly attention [ 4 ]. Onion-like carbon (OLC) nanoparticles, being carbon-based materials with high biocompatibility, have drawn considerable interest in PTT due to their low toxicity, high cellular uptake rate, and remarkable photothermal conversion efficiency [ 5 , 6 ]. The real-time monitoring of the dynamic three-dimensional distribution of OLC inside cancer cells is essential for comprehending the interaction between OLC and cells and for the development of accurate photothermal conversion models.…”