Search

Hollow silica spheres have been widely studied for drug delivery because of their excellent biosecurity and high porosity. However, difficulties with degradation in the tumor microenvironment (TME) and premature leaking during drug delivery limit their clinical applications. To alleviate these problems, herein, hollow organosilica spheres (HOS) were initially prepared using a "selective etching strategy" and loaded with a photothermal drug: new indocyanine green (IR820). Then, the Cu 2+ -tannic acid complex (Cu-TA) was deposited on the surface of the HOS, and a new nanoplatform named HOS@IR820@Cu-TA (HICT) was finally obtained. The deposition of Cu-TA can gate the pores of HOS completely to prevent the leakage of IR820 and significantly enhance the loading capacity of HOS. Once in the mildly acidic TME, the HOS and outer Cu-TA decompose quickly in response, resulting in the release of Cu 2+ and IR820. The released Cu 2+ can react with the endogenous glutathione (GSH) to consume it and produce Cu + , leading to the enhanced production of highly toxic ·OH through a Fenton-like reaction due to the overexpressed H 2 O 2 in the TME. Meanwhile, the ·OH generation was remarkably enhanced by the NIR light-responsive photothermal effect of IR820. These collective properties of HICT enable it to be a smart nanomedicine for dually enhanced chemodynamic therapy through GSH depletions and NIR light-triggered photothermal effects.

Negatively charged fluorescent carbon dots (CDs, E m =608 nm) were hydrothermally prepared from thiophene phenylpropionic acid polymers and then successfully loaded with the positively charged anticancer cargo coptisine, which suffers from poor bioavailability. The formed CD-coptisine complexes were thoroughly characterized by particle size, morphology, drug loading efficiency, drug release, cellular uptake and cellular toxicity in vitro and antitumor activities in vivo. In this nano-carrier system, red emissive CDs possess multiple advantages as follows: 1) high drug loading efficiency (>96 %); 2) sustained drug release; 3) enhanced drug efficacy towards cancer cells; 4) EPR effect; 5) drug release tracing with near-infrared imaging. These properties indicated that red emissive CDs prepared from polymers could be used as a novel drug delivery system with integrated therapeutic and imaging functions in cancer therapy, which are expected to have great potential in future clinical applications., (© 2020 Wiley-VCH GmbH.)

Natural products show high potential for clinical translation because of their specific biological activities and molecular structure diversities. Sonosensitizers that originate from natural products play a crucial role as anti-inflammatory and anticancer agents. Herein, hypocrellin-derivative nanoparticles (APHB NPs) were constructed for synchronous near-infrared fluorescence (NIR FL) imaging and sonodynamic therapy (SDT) for deep-seated tumors in vivo. The prepared APHB NPs exhibit excellent water solubility, FL in the NIR region, and effective reactive oxygen species generation under ultrasound stimulation. Furthermore, the APHB NPs show excellent biocompatibility, suitable biodegradation rate, and enhanced tumor accumulation. Therefore, the APHB NPs exhibit promising clinical potential as novel safe and precise NIR FL imaging and SDT agents for deep-seated tumor therapy.

As phototheranostic agents, carbon dots (CDs), have recently drawn considerable attention due to their excellent physicochemical properties. However, the complex synthetic route and high-cost of CDs greatly limit their practical application. To address this issue, given their nearly infinite supply from nature, Hypocrella bambusae is used as the precursor for the preparation of CDs in this study. The obtained Hypocrella bambusae CDs (HBCDs) possess good water solubility, broad absorption (350-800 nm), red-light emission (maximum peak at 610 nm), and low biotoxicity. Moreover, HBCDs can highly generate 1 O 2 (0.38) and heat (27.6%) under 635 nm laser irradiation. These excellent properties of HBCDs capacitate them to be utilized for bimodal fluorescence/photoacoustic imaging-guided synergistic photodynamic therapy (PDT)/photothermal therapy (PTT). This work provides a new candidate for tumor treatment with the combination of PDT and PTT, and explores a novel approach for the preparation of CD-based phototheranostic agents with natural biomass as raw carbon sources., (Copyright © 2018 Elsevier Inc. All rights reserved.)

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 O 2 quantum yield; (2) the strong two-photon-induced fluorescence and efficient 1 O 2 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., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Nanocarbons such as carbon nanotubes, graphene derivatives, and carbon nanohorns have illustrated their potential uses as cancer theranostics owing to their intrinsic fluorescence or NIR absorbance as well as superior cargo loading capacity. However, some problems still need to be addressed, such as the fates and long-term toxicology of different nanocarbons in vivo and the improvement of their performance in various biomedical imaging-guided cancer therapy systems. Herein, a versatile and clearable nanocarbon theranostic based on carbon dots (CDs) and gadolinium metallofullerene nanocrystals (GFNCs) is first developed, in which GFNCs enhance the tumor accumulation of CDs, and CDs enhance the relaxivity of GFNCs, leading to an efficient multimodal imaging-guided photodynamic therapy in vivo without obvious long-term toxicity. Furthermore, biochemical analysis reveals that the novel nanotheranostic can harmlessly eliminate from the body in a reasonable period of time after exerting diagnostic and therapeutic function., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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)., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Abstract: Conjugated polymer dots (Pdots, also named polymer nanoparticles, PNPs), which consist of π‐conjugated organic polymers, are novel organic nanomaterials with size in the range of 1–100 nm. Compared with traditional organic small molecules, semiconductor quantum dots and inorganic nanomaterials, the Pdots exhibit significant potential applications in biological imaging, sensing and detection, drug delivery and theranostics, due to their advantages of special optical properties, diverse structure, easy surface modification and good biocompatibility. In this short review, we present a brief summary of the current development in Pdots as phototheranostic agents, including fluorescence imaging, photoacoustic imaging, photodynamic therapy and photothermal therapy. Current challenges in Pdot research and future directions in the field are proposed. [ABSTRACT FROM AUTHOR]