Dataset Information

Tumor-specific activated photodynamic therapy with an oxidation-regulated strategy for enhancing anti-tumor efficacy.

ABSTRACT: Photodynamic therapy relies on photosensitizers to generate cytotoxic reactive oxygen species (ROS) resulting in the apoptois of tumor cells. However, there is an antioxidant system that impedes the elevation of oxidation levels in tumor cells. Thus, photodynamic therapy may exhibit insufficient curative effects due to ungenerous reactive oxygen species levels. Herein, we describe tumor-specific activated photodynamic therapy using an oxidation-regulating strategy. Methods: We first synthesised a reactive oxygen species-sensitive amphipathic prodrug of gambogic acid-grafted hyaluronic acid (HA-GA). The hydrophobic photosensitizer chlorin e6 (Ce6) was then loaded into HA-GA by hydrophobic interactions between GA and Ce6, forming amphipathic nanomicelles (HA-GA@Ce6). The ROS-responsive behavior, cytotoxicity, cell uptake, tumor cell killing, in vivo biodistribution and in vivo anti-tumor efficacy of HA-GA@Ce6 were investigated. The in vitro and in vivo experiments were performed on 4T1 murine breast cancer cells and 4T1 tumor model. Results: We validated that the micelles of HA-GA@Ce6 showed stronger cell uptake in 4T1 tumor cells and lower cytotoxicity in normal cells compared with free Ce6 and GA, which exhibited the benefits of nanomicelles on enhancing the tumor cell acumulation and reducing the side effects on normal cells synchronously. Additionally, the cytotoxic free radicals of photodynamic therapy were generated after irradiation and the high oxidation levels activated the ROS-sensitive GA prodrug efficiently, which killed the tumor cells and depleted intracellular glutathione (GSH), thereby impairing antioxidant levels and enhancing photodynamic therapy. Conclusion: With the successfully eradicated tumor growth in vivo. Our work represents a new photodynamic therapy concept, achieving superior anti-tumor efficacy by reducing intracellular antioxidant levels.

SUBMITTER: Liang H

PROVIDER: S-EPMC6217056 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Tumor-specific activated photodynamic therapy with an oxidation-regulated strategy for enhancing anti-tumor efficacy.

Liang Huan H Zhou Zhanwei Z Luo Renjie R Sang Mangmang M Liu Bowen B Sun Minjie M Qu Wei W Feng Feng F Liu Wenyuan W

Theranostics 20181005 18

Photodynamic therapy relies on photosensitizers to generate cytotoxic reactive oxygen species (ROS) resulting in the apoptois of tumor cells. However, there is an antioxidant system that impedes the elevation of oxidation levels in tumor cells. Thus, photodynamic therapy may exhibit insufficient curative effects due to ungenerous reactive oxygen species levels. Herein, we describe tumor-specific activated photodynamic therapy using an oxidation-regulating strategy. <b>Methods:</b> We first synth ...[more]

PMID: 30429886

Similar Datasets

Project description:The delivery of therapeutics into tumors remains a challenge in nanoparticle-mediated drug delivery. However, effective therapies such as photothermal therapy (PTT) are limited by quick systemic clearance and non-specific biodistribution. Anti-tumor strategies tailored to accommodate both tumor accumulation/retention and cellular internalization under a single platform would be a promising strategy. This work demonstrates a hierarchical activating strategy that would exhibit enhanced circulation and rapid tumor-tropism as well as facilitate tumor penetration, followed by tumor-specific drug release to realize trackable photothermal/chemotherapy. Methods: We engineered a lithocholic acid-conjugated disulfide-linked polyethyleneimine micelle (LAPMi) loaded with paclitaxel (LAPMi-PTX, L), followed by the electrostatic adsorption of indocyanine green (ICG, I) on LAPMI-PTX and subsequently coated them with thermosensitive DPPC and DSPE-PEG-NH2 lipids (L), producing Lipid/ICG/LAPMi-PTX (LIL-PTX) nanoparticles (NPs). The characteristics of NPs, including physicochemical characterization, photothermal & pH responsiveness, cell uptake, tumor spheroid penetration, anti-tumor efficacy and hierarchical activation of LIL-PTX NPs were investigated in vitro and in vivo by using CT26 cell line. The anti-metastatic potential of LIL-PTX NPs were demonstrated using 4T1 orthotopic tumor model. Results: The NPs synthesized possessed charge switchability in the mildly acidic pH, and were laser- and pH-responsive. Dual stimuli-responsive nature of LIL-PTX NPs improved the disposition of therapeutics to the tumor, reflected by enhanced intracellular uptake, tumor spheroid penetration and in vitro cytotoxicity studies. LIL-PTX NPs readily switched its surface charge from neutral to positive upon reaching the tumor milieu, thus resulting in rapid tumor tropism and accumulation. Under near-infrared laser irradiation, the thermosensitive lipids on LIL-PTX NPs were deshielded, and the tumor-penetrating LAPMi-PTX was subsequently exposed to the tumor milieu, thus resulting in enhanced intracellular internalization. Next, LAPMi-PTX evaded the endo-lysosomes, thereby releasing the PTX through the degradation of LAPMi mediated by intracellular GSH in the tumor. LIL-PTX NPs significantly improved the therapy by eradicating primary tumors completely and suppressing their subsequent lung metastasis. Conclusion: The improved therapeutic index is due to enhanced passive targeting by rapid tumor-tropic accumulation and tumor penetration by laser-driven exposure of LAPMi, thereby improving the therapeutic delivery for image-guided photothermal/chemotherapy.

Project description:Pyroptosis, a unique lytic programmed cell death, inspired tempting implications as potent anti-tumor strategy in pertinent to its potentials in stimulating anti-tumor immunity for eradication of primary tumors and metastasis. Nonetheless, rare therapeutics have been reported to successfully stimulate pyroptosis. In view of the intimate participation of reactive oxygen species (ROS) in stimulating pyroptosis, we attempted to devise a spectrum of well-defined subcellular organelle (including mitochondria, lysosomes and endoplasmic reticulum)-targeting photosensitizers with the aim of precisely localizing ROS (produced from photosensitizers) at the subcellular compartments and explore their potentials in urging pyroptosis and immunogenic cell death (ICD). The subsequent investigations revealed varied degrees of pyroptosis upon photodynamic therapy (PDT) towards cancerous cells, as supported by not only observation of the distinctive morphological and mechanistic characteristics of pyroptosis, but for the first-time explicit validation from comprehensive RNA-Seq analysis. Furthermore, in vivo anti-tumor PDT could exert eradication of the primary tumors, more importantly suppressed the distant tumor and metastatic tumor growth through an abscopal effect, approving the acquirement of specific anti-tumor immunity as a consequence of pyroptosis. Hence, pyroptosis was concluded unprecedently by our proposed organelles-targeting PDT strategy and explicitly delineated with molecular insights into its occurrence and the consequent ICD. Graphical abstract Image 1 Highlights • Precise and specific organelle-targeting photosensitizers (mitochondria, lysosomes and endoplasmic reticulum) was synthesized.• The pyroptosis rates were much higher following mitochondria and endoplasmic reticulum-targeting photodynamics therapy in vitro.• Mitochondria and endoplasmic reticulum-targeting photodynamics therapy inhibited tumor progression by inducing pyroptosis in vivo.• Immune memory effect following specific organelle-targeting photodynamics therapy suppressed tumor metastasis in vivo.

Dataset Information

Tumor-specific activated photodynamic therapy with an oxidation-regulated strategy for enhancing anti-tumor efficacy.

Publications

Tumor-specific activated photodynamic therapy with an oxidation-regulated strategy for enhancing anti-tumor efficacy.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets