The effects of a series of carbon dots on fibrillation and cytotoxicity of human islet amyloid polypeptide

Abstract

Carbon dots (CDs) have been widely used as the candidates of drug carriers and bio-imaging probes because of their high drug loading capacity and intrinsic fluorescence property, as well as good biocompatibility. In this study, the potential role of CDs in regulating the aggregation behavior of human islet amyloid polypeptide (hIAPP) was explored for the first time. Five kinds of CDs belonging to three categories, namely polymer dots (PDs-1 and PDs-2), carbon nanodots (CNDs and CQDs), and graphene quantum dots (GQDs), were prepared and characterized. The fibrillation behaviors of hIAPP in the presence of these CDs were monitored by the ThT assay and TEM/AFM imaging and the cytotoxicity of the systems was tested by the MTT and LDH release assays. Our results showed that the polymer dots and carbon nanodots inhibit hIAPP fibrillation, while the GQDs promoted the formation of hIAPP fibrils. The PDs and GQDs that were nontoxic in INS-1 cells exerted efficiencies in decreasing the cell death induced by hIAPP through different mechanisms. The inhibitory activity and mechanism of the CDs were closely associated with their structures and surface properties. Our results shed light on a new potential application of CDs in therapeutics. .

Effect of carbonization degree of carbon dots on cytotoxicity and photo-induced toxicity to cells

“…In MCF-12A cells, the largest LDH release at 2.0 mg/ml of 160-50, 180-40, 200-30, and 220-20 formations were 14.76% ± 0.20, 10.81% ± 0.28, 9.87% ± 0.11, 10.73% ± 0.23, respectively, compared to 1.05% ± 0.05 when the control formation was used (Figure 6d). Therefore, even at high concentrations, these CDs exhibited little toxicity toward cells compared to other reports [45, 46]. Greater toxicity of the 160-50 sample than the other three formations is most likely due to its significantly larger zeta potential [47, 48], indicating uptake of the 160-50 CDs by SKBR3 and MCF-12A cells than the other formations.…”

Inhibitory effect of hydrophobic fullerenes on the β-sheet-rich oligomers of a hydrophilic GNNQQNY peptide revealed by atomistic simulations

“…Among them, carbon nanoparticles (including fullerenes, carbon nanotubes, and graphene oxides) have attracted considerable attention, 39,44,45 due to their good biocompatibility, low cytotoxicity and high capacity to cross blood brain barriers. [46][47][48] Fullerene C 60 with its 0.7 nm wide cage, presents the suitable size and shape for the formation of stable complexes with proteins. 49 The presence of both ve and six-membered rings in C 60 (one C 60 molecule containing 12 pentagons and 20 hexagons) suggests strong fullereneprotein interaction through aromatic stackings.…”

Lysine‐Derived Carbon Dots for Chiral Inhibition of Prion Peptide Fibril Assembly

“…Moreover, their small dimensions enable efficient transport in body tissues and delivery to target destinations, potentially even across the blood–brain barrier. Unlike other therapeutic nanoparticle vehicles comprising inorganic constituents, C‐dots are produced from natural carbonaceous building blocks, making them intrinsically biocompatible and less toxic …”