Polythiophene-Based Carbon Dots for Imaging-Guided Photodynamic Therapy

Abstract

Imaging-guided photodynamic therapy (PDT) represents an advantage in cancer therapy because of its optically controlled selectivity, negligible side effects, and ability to monitor the therapeutic effect in situ in real time. However, the photosensitizers currently in use have poor water solubility and an inability to target tumors, whereas semiconductor quantum dots and metal-based complexes that have excellent water dispersity have the disadvantage of exerting a potential toxicity because of the heavy metals. Therefore, this work describes the preparation of the red fluorescent N,S-doped carbon dots (N,S-CDs) from a polythiophene derivate that generate singlet oxygen ( 1 O 2 ) with a quantum yield of ∼8% under light irradiation. Moreover, these CDs possess the ability to penetrate tumor cells and mainly accumulate into the lysosome and mitochondria, as well as excellent biocompatibility, chemostability, and a large Stokes shift (215 nm). Hence, the N,S-CDs may be used as a potential effective photosensitizer for imaging-guided PDT.

Synthesis of Carbon Dots with Hemostatic Effects Using Traditional Chinese Medicine as a Biomass Carbon Source

“…The appearance of carbon dots has provided new possibilities and methods for the detections and treatments of various diseases, such as antibacterial, 4−6 anticancer, 7,8 chemotherapy, 9,10 photothermal therapy, 11,12 and photodynamic therapy. 13 For thousands of years, Chinese people have been using various medicinal materials to make charcoal medicine for hemostasis, which has been recorded as being used for traumacaused bleedings and diseases of people and animals in ancient Chinese medical books. The earliest record was in the ancient medical book Prescriptions for Fifty-Two Diseases in the third century B.C., and so far, there have been many charcoal medicines for hemostasis recorded in the Chinese Pharmacopoeia.…”

“…The appearance of carbon dots has provided new possibilities and methods for the detections and treatments of various diseases, such as antibacterial, − anticancer, , chemotherapy, , photothermal therapy, , and photodynamic therapy …”

Carbonized Polymer Dots with Aggregation-Induced Effect for Type I Photodynamic Therapy

“…As shown in Figure a, the fluorescence intensity at 532 nm of YCPDs with DCFH-DA increased significantly when irradiated with a white light LED lamp (2.5 mW/cm 2 ), while YCPDs + light (Figure S5a), YCPDs + DCFH-DA (Figure S5b), and DCFH-DA + light (Figure S5c) did not have an obvious characteristic signal generation, indicating that YCPDs have a strong ability to generate ROS under white light irradiation (Figure b). To elucidate the type of ROS, 9,10-anthracenediyl-bis (methylene) dimalonic acid (ABDA) was used to detect 1 O 2 ; , as shown in Figure c, the absorption of ABDA has little change for YCPDs, while the absorbance of rose bengal (RB) is significantly reduced (Figure S7), thus indicating that no 1 O 2 is produced in YCPDs + DCFH-DA + light. Finally, electron spin resonance (EPR) spectroscopy was used to determine the ROS species.…”

Regulating photochemical properties of carbon dots for theranostic applications

“…Carbon dots (CDs), such as graphene quantum dots (GQDs), carbon quantum dots (CQDs), carbon nanodots (CNDs), and carbonized polymer dots (CPDs) (Ding et al, 2020; Jia et al, 2020), are a new type of carbon‐based nanomaterials, have attracted extensive attention owing to their advantages such as small size distribution, easy preparation and surface modification, good biocompatibility, and water solubility (Ge et al, 2016; Liu et al, 2018; Phuong et al, 2020; Wang, Yu, et al, 2022; Zheng et al, 2014). Moreover, the tunable photochemical properties of CDs enabling them great advantages in fluorescence sensing (Liang et al, 2021; Pang et al, 2020; Shen, Lou, et al, 2020; Sun et al, 2019; Yi et al, 2021) and phototherapy (Chen et al, 2021; Elsherbiny et al, 2022; Ge et al, 2015; Kim et al, 2021; Nasrin et al, 2020; Zhao, Yan, et al, 2021; Zhao, Yang, et al, 2021). The photochemical properties of CDs include absorption, fluorescence, phosphorescence, reactive oxygen species (ROS) generation efficiency, and photothermal conversion efficiency (PEC).…”