Qingyan Jia

A graphene quantum dot photodynamic therapy agent with high singlet oxygen generation

Clinical applications of current photodynamic therapy (PDT) agents are often limited by their low singlet oxygen (1O2) quantum yields, as well as by photobleaching and poor biocompatibility. Here we present a new PDT agent based on graphene quantum dots (GQDs) that can produce 1O2 via a multistate sensitization process, resulting in a quantum yield of ~1.3, the highest reported for PDT agents. The GQDs also exhibit a broad absorption band spanning the UV region and the entire visible region and a strong deep-red emission. Through in vitro and in vivo studies, we demonstrate that GQDs can be used as PDT agents, simultaneously allowing imaging and providing a highly efficient cancer therapy. The present work may lead to a new generation of carbon-based nanomaterial PDT agents with overall performance superior to conventional agents in terms of 1O2 quantum yield, water dispersibility, photo- and pH-stability, and biocompatibility.

Red‐Emissive Carbon Dots for Fluorescent, Photoacoustic, and Thermal Theranostics in Living Mice

Dr. J. Ge, Q. Jia, Dr. W. Liu, L. Guo, Dr. M. Lan, Prof. H. Zhang, Prof. X. Meng, Prof. P. Wang Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 , P. R. China E-mail: wangpf@mail.ipc.ac.cn Q. Jia, Prof. Q. Liu College of Chemical and Environmental Engineering Shandong University of Science and Technology Qingdao 266510 , P. R. China E-mail: qyliu@sdust.edu.cn

Carbon Dots with Intrinsic Theranostic Properties for Bioimaging, Red‐Light‐Triggered Photodynamic/Photothermal Simultaneous Therapy In Vitro and In Vivo

Cancer nanotheranostics combining therapeutic and imaging functions within a single nanoplatform are extremely important for nanomedicine. In this study, carbon dots (C-dots) with intrinsic theranostic properties are prepared by using polythiophene benzoic acid as carbon source. The obtained C-dots absorb light in the range of 400-700 nm and emit bright fluorescence in the red region (peaking from 640 to 680 nm at different excitations). More importantly, the obtained C-dots exhibit dual photodynamic and photothermal effects under 635 nm laser irradiation with a singlet oxygen ((1)O2) generating efficiency of 27% and high photothermal conversion efficiency of 36.2%. These unique properties enable C-dots to act as a red-light-triggered theranostic agent for imaging-guided photodynamic-photothermal simultaneous therapy in vitro and in vivo within the therapeutic window (600-1000 nm).

A Magnetofluorescent Carbon Dot Assembly as an Acidic H2O2‐Driven Oxygenerator to Regulate Tumor Hypoxia for Simultaneous Bimodal Imaging and Enhanced Photodynamic Therapy

Recent studies indicate that carbon dots (CDs) can efficiently generate singlet oxygen (1 O2 ) for photodynamic therapy (PDT) of cancer. However, the hypoxic tumor microenvironment and rapid consumption of oxygen in the PDT process will severely limit therapeutic effects of CDs due to the oxygen-dependent PDT. Thus, it is becoming particularly important to develop a novel CD as an in situ tumor oxygenerator for overcoming hypoxia and substantially enhancing the PDT efficacy. Herein, for the first time, magnetofluorescent Mn-CDs are successfully prepared using manganese(II) phthalocyanine as a precursor. After cooperative self-assembly with DSPE-PEG, the obtained Mn-CD assembly can be applied as a smart contrast agent for both near-infrared fluorescence (FL) (maximum peak at 745 nm) and T1 -weighted magnetic resonance (MR) (relaxivity value of 6.97 mM-1 s-1 ) imaging. More interestingly, the Mn-CD assembly can not only effectively produce 1 O2 (quantum yield of 0.40) but also highly catalyze H2 O2 to generate oxygen. These collective properties of the Mn-CD assembly enable it to be utilized as an acidic H2 O2 -driven oxygenerator to increase the oxygen concentration in hypoxic solid tumors for simultaneous bimodal FL/MR imaging and enhanced PDT. This work explores a new biomedical use of CDs and provides a versatile carbon nanomaterial candidate for multifunctional nanotheranostic applications.

Single Near‐Infrared Emissive Polymer Nanoparticles as Versatile Phototheranostics

Abstract Attaining consistently high performance of diagnostic and therapeutic functions in one single nanoplatform is of great significance for nanomedicine. This study demonstrates the use of donor–acceptor (D–A) structured polymer (TBT) to develop a smart “all‐five‐in‐one” theranostic that conveniently integrates fluorescence/photoacoustic/thermal imaging and photodynamic/photothermal therapy into single nanoparticle. The prepared nanoparticles (TBTPNPs) exhibit near‐infrared emission, high water solubility, excellent light resistance, good pH stability, and negligible toxicity. Additionally, the TBTPNPs exhibit an excellent singlet oxygen (1O2) quantum yield (40%) and high photothermal conversion efficiency (37.1%) under single‐laser irradiation (635 nm). Apart from their two phototherapeutic modalities, fluorescence, photoacoustic signals, and thermal imaging in vivo can be simultaneously achieved because of their enhanced permeability and retention effects. This work demonstrates that the prepared TBTPNPs are “all‐five‐in‐one” phototheranostic agents that can exhibit properties to satisfy the “one‐fits‐all” requirement for future phototheranostic applications. Thus, the prepared TBTPNPs can provide fundamental insights into the development of PNP‐based nanoagents for cancer therapy.

Versatile Polymer Nanoparticles as Two-Photon-Triggered Photosensitizers for Simultaneous Cellular, Deep-Tissue Imaging, and Photodynamic Therapy

Clinical applications of current photodynamic therapy (PDT) photosensitizers (PSs) are often limited by their absorption in the UV-vis range that possesses limited tissue penetration ability, leading to ineffective therapeutic response for deep-seated tumors. Alternatively, two-photon excited PS (TPE-PS) using NIR light triggered is one the most promising candidates for PDT improvement. Herein, multimodal polymer nanoparticles (PNPs) from polythiophene derivative as two-photon fluorescence imaging as well as two-photon-excited PDT agent are developed. The prepared PNPs exhibit excellent water dispersibility, high photostability and pH stability, strong fluorescence brightness, and low dark toxicity. More importantly, the PNPs also possess other outstanding features including: (1) the high 1 O2 quantum yield; (2) the strong two-photon-induced fluorescence and efficient 1 O2 generation; (3) the specific accumulation in lysosomes of HeLa cells; and (4) the imaging detection depth up to 2100 µm in the mock tissue under two-photon. The multifunctional PNPs are promising candidates as TPE-PDT agent for simultaneous cellular, deep-tissue imaging, and highly efficient in vivo PDT of cancer.

Graphene quantum dots as efficient, metal-free, visible -light-active photocatalysts

This paper reports on new applications of water- dispersible graphene quantum dots (GQDs) that we recently developed. The prepared GQDs not only show broad absorption in the visible spectrum from 400 to 700 nm, but can also serve as smart photosensitizers with high singlet oxygen (1O2) production under visible-light irradiation (≥420 nm). We showed that the prepared G QDs can potentially be used as a metal-free, visible-light-active, sensitized photocatalyst via e nergy transfer mechanism, in which the light energy was converted by GQDs to produce 1O2, which can kill nearby microorganisms and degrade organic dyes.摘要本文提供了石墨烯量子点的应用新领域. 在此前的研究中, 我们发现以聚噻吩衍生物(PT2);为前驱物制备的石墨烯量子点在太阳光的照 射下可高效产生单线态氧. 本文进一步研究发现, 此类石墨烯量子点在模拟太阳光的照射下(大于420 nm);可以快速多次降解水中有机污染物 和高效灭杀细菌, 表明石墨烯量子点在环境保护领域拥有巨大的应用潜力.

Polymer nanoparticles with high photothermal conversion efficiency as robust photoacoustic and thermal theranostics

Synthesis of photothermal agents with absorption in the near-infrared (NIR) region and featuring excellent photostability, high photothermal conversion efficiency, and good biocompatibility is necessary for the application of photothermal therapy (PTT). In this work, a low band gap thiophene-benzene-diketopyrrolopyrrole (TBD)-based polymer was synthesized and used to fabricate TBD polymer nanoparticles (TBDPNPs) through a one-step nanoprecipitation method. The obtained near-infrared-absorbing TBDPNPs presented good water dispersibility, high photothermal stability, and low toxicity. Significantly, the TBDPNPs exhibited an ultrahigh photothermal conversion efficiency of approximately 68.1% under 671 nm laser irradiation. In addition, photoacoustic (PA) imaging, with high spatial resolution and deep tissue penetration, showed that the TBDPNPs targeted tumor sites through the enhanced permeability and retention effect. Therefore, the robust TBDPNPs with a photothermal conversion efficiency of 68.1% can serve as an excellent therapeutic agent for PA-imaging-guided PTT.

Biocompatible Iron Phthalocyanine-Albumin Assemblies as Photoacoustic and Thermal Theranostics in Living Mice.

Exploring novel and versatile nanomaterials for the construction of personalized multifunctional phototheranostics with significant potentials in bioimaging-guided tumor phototherapies has attracted considerable attention. Herein, the phototheranostic agent human serum albumin-iron (II) phthalocyanine FePc nanoparticles (HSA-FePc NPs) were fabricated for photoacoustic (PA) imaging-guided photothermal therapy (PTT) of cancer in vivo. The prepared HSA-FePc NPs exhibited high stability, efficient NIR absorption, good capability and stability of photothermal behavior with a high photothermal conversion efficiency of ∼44.4%, high contrast and spatial resolution of PA imaging, efficient cancer therapy, and low long-term toxicity. This potent multifunctional phototheranostic is, therefore, very promising and favorable for effective, precise, and safe antitumor treatment in clinical application.

A facile high-speed vibration milling method to mass production of water-dispersible silicon quantum dots for long-term cell imaging

A high-speed vibration milling (HSVM) method was applied to synthesize water-dispersible silicon quantum dots (SiQDs). Highly reactive free radicals (HOOCCH2CH2˙) produced from an acyl peroxide under HSVM conditions reacted with hydrophobic Si chips to produce highly water-dispersible SiQDs, which were characterized in detail by spectroscopic and microscopic techniques. Further experiments showed that the SiQDs are photostable, biocompatible, and suitable for long-term fluorescent cellular imaging. Our results provide a new methodology for large-scale synthesis of water-dispersible SiQDs, which are promising for various optoelectronic and biological applications.