Biological Responses of Onion-Shaped Carbon Nanoparticles

Abstract

Nanodiamonds are emerging as new nanoscale materials because of their chemical stability, excellent crystallinity, and unique optical properties. In this study, the structure of nanodiamonds was engineered to produce carbon nano-onion particles (CNOs) with multiple layers. Following a series of physicochemical characterizations of the CNOs, various evaluations for biological responses were conducted for potential biotechnological applications of the CNOs. The possibility of biological applications was first confirmed by assessment of toxicity to animal cells, evaluation of hemolysis reactions, and evaluation of reactive oxygen species. In addition, human immune cells were evaluated for any possible induction of an immune response by CNOs. Finally, the toxicity of CNOs to Escherichia coli present in the human colon was evaluated. CNOs have the chemical and physical properties to be a unique variety of carbon nanomaterials, and their toxicity to animal and human cells is sufficiently low that their biotechnological applications in the future are expected.

CARBON-BASED nanomaterials and SKIN: An overview

“…In a subsequent study, Jang and coworkers evaluated CNOs cytotoxicity toward human dermal fibroblasts (HDF), showing no cytotoxicity or increased secretion of cytokines (IL-2 and TNF-α) and only low ROS production. Since ROS are believed to be the major cause of carbon nanomaterials toxicity, these data suggest a good biocompatibility of CNOs with fibroblasts [96].…”

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

“…[419] CNOs were also shown to induce negligible systemic toxicity against 4T1 breast cancer cell lines and minimal hemolytic activity against blood cells, even at the maximum concentrations of 100 μg mL −1 (Figure 21a-f). [93] A study conducted by Jang et al [420] demonstrated the outstanding biocompatibility and non-toxicity of CNOs towards human cells at concentrations below 500 ng mL −1 . Amora et al [418] elucidated the possible biological impacts of benzoic-acid-functionalized CNOs on zebrafish development.…”

“…[ 93 ] A study conducted by Jang et al. [ 420 ] demonstrated the outstanding biocompatibility and non‐toxicity of CNOs towards human cells at concentrations below 500 ng mL −1 . Amora et al.…”

Biocompatibility of nanomaterials and their immunological properties

“…A recent study discussed functional immune response in workers from 12 different U.S. facilities exhibiting generally low levels of exposure to CNTs or nanofibers [19]. However, recent studies with macrophages and fibroblasts exposed to graphene and carbon-based nano-onions, respectively, showed very low ROS generation and cytotoxicity [89,90]. These observations prompted investigators to suggest that cytotoxicity results may be influenced by additional contaminating factors, such as bacterial endotoxin, introduced during manufacturing [89].…”

“…For example, Abraxane®, an FDA-approved NP formed by albumin with conjugated paclitaxel, dissolves into soluble complexes after intravenous injection [27]. The particles can then accumulate in tumors due to the EPR effect and can be transported across endothelial by binding to membrane protein gp60 [90]. Albumin serves as a delivery vehicle and allows Abraxane® to achieve a high response rate for treating breast and pancreatic cancer.…”