Sulphur doped carbon dots enhance photodynamic therapy via PI3K/Akt signalling pathway

Abstract

Objectives: Photodynamic therapy (PDT) is a promising approach for cancer treatment, and the underlying signalling pathway changes has been carried out for studying the PDT mechanisms, but is majorly limited to organic photosensitizers (PSs). For the emerging nano-PSs typically possessing higher 1 O 2 quantum yield, few mechanistic studies were carried out, which limited their further applications in clinical therapeutics. PI3K/Akt signalling pathway, a most frequently activated signalling network in cancers, could promote cancer cell survival, but was seldom reported in previous PDT studies mediated by nano-PSs. Materials and Methods:Sulphur doped carbon dots (S-CDs) was prepared via a hydrothermal synthetic route and was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and so on. CCK-8 assay and Annexin V/PI staining were performed to demonstrate the death of cancer cells, Western blot, RT-PCR and immunofluorescence were employed to explore the underlying mechanism, and variation of PI3K/Akt and other signalling pathways was detected by Western blot.Results: S-CDs was successfully synthesized, and it was much more efficient compared with classic organic PSs. S-CDs could induce cancer cell death through mitochondria mediated cell apoptosis with the imbalance of Bcl-2 family proteins and caspase cascade via several signalling pathways. Low concentration of S-CDs could effectively inhibit PI3K/Akt pathway and promote p38/JNK pathway, on one way inhibiting cancer cell survival and on the other way promoting cell apoptosis. Conclusions:Herein, we found that S-CDs acted as an inhibitor of the PI3K/Akt pathway for efficient cancer cell killing, thus yielding in a higher PDT performance over the existing photosensitizers. S U PP O RTI N G I N FO R M ATI O NAdditional supporting information may be found online in the Supporting Information section.

Tetrahedral Framework Nucleic Acid-Based Delivery of Resveratrol Alleviates Insulin Resistance: From Innate to Adaptive Immunity

“…RNA extraction and cDNA acquisition and purification were performed as described in our previous studies [ 30 , 31 ]. RT-PCR was performed using SYBR® Green I PCR master mix in an ABI QuantStudio 6 Real-Time PCR System (Thermo Scientific, USA).…”

Decagram-Scale Synthesis of Multicolor Carbon Nanodots: Self-Tracking Nanoheaters with Inherent and Selective Anticancer Properties

“…19,20 Very recently, it has been proposed that heteroatom doping leads to the ability of CDs to cause oxidative stress by reactive oxygen species (ROS) production inside cells. 5,21,22 In particular, dose-and time-dependent compromised cell viability has been observed for both cancer (Hepa 1−6; A549) and healthy cell (EA.hy926) lines, inducing increasing intracellular levels of ROS and autophagy at high concentrations (i.e., >400 μg mL −1 ). 21,23 This suggests that the sulfurcontaining groups of CDs may stimulate ROS generation by interacting with the electron transport chain in the mitochondrial membrane thus provoking cell death.…”

Semiconductor quantum dots for photodynamic therapy: Recent advances

“…Selenium doped CDs were shown to selectively bind to RNA and damage the nuclear membrane by ROS generation ( Xu et al, 2020 ). There are ample reports in literature suggesting the doping of CD with heteroatoms or metals such as N, P ( Zhao et al, 2019 ), Cu ( Wang et al, 2019 ), S ( Li et al, 2020b ), F/N ( Wu et al, 2022 ), Hf ( Su et al, 2020b ), Sn ( Hu et al, 2021 ) with enhanced bioimaging and PDT applications.…”