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1.
Nat Nanotechnol ; 2024 May 13.
Article in English | MEDLINE | ID: mdl-38740934

ABSTRACT

Nutrient avidity is one of the most distinctive features of tumours. However, nutrient deprivation has yielded limited clinical benefits. In Gaucher disease, an inherited metabolic disorder, cells produce cholesteryl-glucoside which accumulates in lysosomes and causes cell damage. Here we develop a nanoparticle (AbCholB) to emulate natural-lipoprotein-carried cholesterol and initiate Gaucher disease-like damage in cancer cells. AbCholB is composed of a phenylboronic-acid-modified cholesterol (CholB) and albumin. Cancer cells uptake the nanoparticles into lysosomes, where CholB reacts with glucose and generates a cholesteryl-glucoside-like structure that resists degradation and aggregates into microscale crystals, causing Gaucher disease-like damage in a glucose-dependent manner. In addition, the nutrient-sensing function of mTOR is suppressed. It is observed that normal cells escape severe damage due to their inferior ability to compete for nutrients compared with cancer cells. This work provides a bioinspired strategy to selectively impede the metabolic action of cancer cells by taking advantage of their nutrient avidity.

2.
Nat Commun ; 15(1): 3902, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38724527

ABSTRACT

Radiation-induced in situ tumor vaccination alone is very weak and insufficient to elicit robust antitumor immune responses. In this work, we address this issue by developing chiral vidarabine monophosphate-gadolinium nanowires (aAGd-NWs) through coordination-driven self-assembly. We elucidate the mechanism of aAGd-NW assembly and characterize their distinct features, which include a negative surface charge, ultrafine topography, and right-handed chirality. Additionally, aAGd-NWs not only enhance X-ray deposition but also inhibit DNA repair, thereby enhancing radiation-induced in situ vaccination. Consequently, the in situ vaccination induced by aAGd-NWs sensitizes radiation enhances CD8+ T-cell-dependent antitumor immunity and synergistically potentiates the efficacy immune checkpoint blockade therapies against both primary and metastatic tumors. The well-established aAGd-NWs exhibit exceptional therapeutic capacity and biocompatibility, offering a promising avenue for the development of radioimmunotherapy approaches.


Subject(s)
Nanowires , Polymers , Nanowires/chemistry , Animals , Mice , Polymers/chemistry , Cell Line, Tumor , Gadolinium/chemistry , Gadolinium/pharmacology , Mice, Inbred C57BL , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/drug effects , Cancer Vaccines/immunology , Female , Humans , Vaccination/methods , Neoplasms/immunology
3.
ACS Nano ; 18(5): 4360-4375, 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38277483

ABSTRACT

Targeting nutrient metabolism has been proposed as an effective therapeutic strategy to combat breast cancer because of its high nutrient requirements. However, metabolic plasticity enables breast cancer cells to survive under unfavorable starvation conditions. The key mammalian target regulators rapamycin (mTOR) and hypoxia-inducible-factor-1 (HIF-1) tightly link the dynamic metabolism of glutamine and glucose to maintain nutrient flux. Blocking nutrient flow also induces autophagy to recycle nutrients in the autophagosome, which exacerbates metastasis and tumor progression. Compared to other common cancers, breast cancer is even more dependent on mTOR and HIF-1 to orchestrate the metabolic network. Therefore, we develop a cascade-boosting integrated nanomedicine to reprogram complementary metabolism coupled with regulators in breast cancer. Glucose oxidase efficiently consumes glucose, while the delivery of rapamycin inside limits the metabolic flux of glutamine and uncouples the feedback regulation of mTOR and HIF-1. The hydroxyl radical generated in a cascade blocks the later phase of autophagy without nutrient recycling. This nanomedicine targeting orchestrated metabolism can disrupt the coordination of glucose, amino acids, nucleotides, lipids, and other metabolic pathways in breast cancer tissues, effectively improving the durable antitumor effect and prognosis of breast cancer. Overall, the cascade-boosting integrated system provides a viable strategy to address cellular plasticity and efficient enzyme delivery.


Subject(s)
Breast Neoplasms , Humans , Female , Breast Neoplasms/pathology , Glutamine/metabolism , Biomimetics , Nanomedicine , TOR Serine-Threonine Kinases/metabolism , Sirolimus , Glucose/metabolism
4.
Biomaterials ; 301: 122291, 2023 10.
Article in English | MEDLINE | ID: mdl-37619263

ABSTRACT

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent hepatic disease characterized as lipid accumulation, yet without any approved drug. And development of therapeutic molecules is obstructed by low efficiency and organ toxicity. Herein, we develop a long-term, low-toxic and liver-selected nano candidate, nabCK, to alleviate NAFLD. NabCK is simply composed by natural compound ginsenoside compound K (CK) and albumin. As a major metabolite of ginseng, ginsenoside CK has excellently modulating functions for lipid metabolism, but accompanied by an extremely poor bioavailability <1%. Albumin is a key lipid carrier secreted and metabolized by livers. Thereby, it can improve solubility and liver-localization of CK. In adipocytes and hepatocytes, nabCK prevents lipid deposition and eliminates lipid droplets. Transcriptomic analysis reveals that nabCK rectifies various pathways that involved in steatosis development, including lipid absorption, lipid export, fatty acid biosynthesis, lipid storage and inflammation. All these pathways are modulated by mTOR, the pivotal feedback sensor that is hyperactive in NAFLD. NabCK suppresses mTOR activation to restores lipid homeostasis. In high-fat diet (HFD) induced NAFLD mice, nabCK retards development of steatosis and fibrosis, coupling a protective effect on cardiac tissues from lipotoxicity. Together, nabCK is a safe and potent candidate to offer benefits for NAFLD treatment.


Subject(s)
Ginsenosides , Non-alcoholic Fatty Liver Disease , Animals , Mice , Non-alcoholic Fatty Liver Disease/drug therapy , Ginsenosides/pharmacology , Ginsenosides/therapeutic use , Albumins , Homeostasis , Lipids
5.
ACS Nano ; 17(13): 12087-12100, 2023 07 11.
Article in English | MEDLINE | ID: mdl-37327456

ABSTRACT

Radiation therapy (RT) has the capacity to induce immunogenic death in tumor cells, thereby potentially inducing in situ vaccination (ISV) to prime systemic antitumor immune responses. However, RT alone is often faced with various limitations during ISV induction, such as insufficient X-ray deposition and an immunosuppressive microenvironment. To overcome these limitations, we constructed nanoscale coordination particles AmGd-NPs by self-assembling high-Z metal gadolinium (Gd) and small molecular CD73 inhibitor AmPCP. Then, AmGd-NPs could synergize with RT to enhance immunogenic cell death, improve phagocytosis, and promote antigen presentation. Additionally, AmGd-NPs could also gradually release AmPCP to inhibit CD73's enzymatic activity and prevent the conversion of extracellular ATP to adenosine (Ado), thereby driving a proinflammatory tumor microenvironment that promotes DC maturation. As a result, AmGd-NPs sensitized RT induced potent in situ vaccination and boosted CD8+ T cell-dependent antitumor immune responses against both primary and metastatic tumors, which could also be potentiated by immune checkpoint inhibitory therapy.


Subject(s)
Immunotherapy , Neoplasms , Humans , CD8-Positive T-Lymphocytes/pathology , Immunity , Phagocytosis , Tumor Microenvironment , Neoplasms/pathology , Cell Line, Tumor
6.
Adv Sci (Weinh) ; 10(20): e2300286, 2023 07.
Article in English | MEDLINE | ID: mdl-37127892

ABSTRACT

In situ vaccination can elicit systemic antitumor immunity to potentiate immune checkpoint blockade (ICB) in poorly immunogenic tumors. Herein, an immunogenic cell death (ICD) inducer for in situ vaccination, which is based on a mitochondria-targeting modification of fenofibric acid (FFa), a lipid-lowering drug with potential inhibitory efficacy of respiratory complex I is developed. Mitochondria-targeting FFa (Mito-FFa) inhibits complex I efficiently and increases mitochondrial ROS (mtROS) generation, which further triggers endoplasmic reticulum (ER) stress with unprecedented calreticulin (CRT) exposure on tumor cellular membranes. Moreover, the generated mtROS also oxidizes mitochondrial DNA (mtDNA) and promotes it leakage into the cytoplasm for cGAS-STING-dependent type I interferon (IFN-I) secretion. The synchronous CRT exposure and IFN-I secretion successively improve the uptake of tumor antigens, maturation of dendritic cells (DCs) and cross-priming of CD8+ T cells. In a poorly immunogenic 4T1 tumor model, a single intratumoral (i.t.) Mito-FFa injection turns immune-cold tumors into hot ones and elicits systemic tumor-specific CD8+ T cells responses against primary and metastatic tumors. Furthermore, the synergistic effect with PD-L1 blockade and good bio-safety of i.t. Mito-FFa administration suggest the great translational potential of Mito-FFa in tumor immunotherapy.


Subject(s)
CD8-Positive T-Lymphocytes , Neoplasms , Humans , Dendritic Cells , Neoplasms/pathology , Immunotherapy , Mitochondria
7.
Biomater Sci ; 10(13): 3433-3440, 2022 Jun 28.
Article in English | MEDLINE | ID: mdl-35666242

ABSTRACT

Photocatalytic materials absorb photons ranging from the ultraviolet to near-infrared region to initiate photocatalytic reactions and have broad application prospects in various fields. However, high-energy ionizing radiations are rarely involved in photocatalytic research. In this study, we proposed a high-energy radiation-based photocatalysis method, namely "radiocatalysis", and prepared a TiO2-coated lanthanide pyrosilicate scintillator (LnPS@TiO2) as the radiocatalytic material. The lanthanide pyrosilicate post-radiation scintillators can efficiently convert radiation energy into ultraviolet energy, which can be resonantly transferred to TiO2 to selectively generate high-yield superoxide radicals (). Compared with traditional radiotherapy, this radiocatalytic process can significantly kill cancer cells while achieving long-term DNA damage by inhibiting the DNA self-repair process. Our research expands the energy response range of photocatalysis and is expected to extend radiocatalysis to the tumor treatment field.


Subject(s)
Lanthanoid Series Elements , Neoplasms , DNA , DNA Damage , Humans , Superoxides
8.
Adv Mater ; 34(13): e2109726, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35102614

ABSTRACT

In situ tumor vaccination is preliminarily pursued to strengthen antitumor immune response. Immunogenic tumor cell death spontaneously releases abundant antigens and adjuvants for activation of dendritic cells, providing a paragon opportunity for establishing efficient in situ vaccination. Herein, Phy@PLGdH nanosheets are constructed by integrating physcion (Phy, an inhibitor of the pentose phosphate pathway (PPP)) with layered gadolinium hydroxide (PLGdH) nanosheets to boost radiation-therapy (RT)-induced immunogenic cell death (ICD) for potent in situ tumor vaccination. It is first observed that sheet-like PLGdH can present superior X-ray deposition and tumor penetrability, exhibiting improved radiosensitization in vitro and in vivo. Moreover, the destruction of cellular nicotinamide adenine dinucleotide phosphate (NADPH) and nucleotide homeostasis by Phy-mediated PPP intervention can further amplify PLGdH-sensitized RT-mediated oxidative stress and DNA damage, which correspondingly results in effective ICD and enhance the immunogenicity of irradiated tumor cells. Consequently, Phy@PLGdH-sensitized RT successfully primes robust CD8+ -T-cell-dependent antitumor immunity to potentiate checkpoint blockade immunotherapies against primary and metastatic tumors.


Subject(s)
Neoplasms , Pentose Phosphate Pathway , Cell Line, Tumor , Humans , Immunogenic Cell Death , Immunotherapy/methods , Neoplasms/metabolism , Neoplasms/therapy , Vaccination
9.
Nat Biomed Eng ; 6(1): 44-53, 2022 01.
Article in English | MEDLINE | ID: mdl-35058589

ABSTRACT

Because the tumour microenvironment is typically immunosuppressive, the release of tumour antigens mediated by radiotherapy or chemotherapy does not sufficiently activate immune responses. Here we show that, following radiotherapy, the intratumoural injection of a genetically attenuated strain of Salmonella coated with antigen-adsorbing cationic polymer nanoparticles caused the accumulation of tumour antigens at the tumour's periphery. This enhanced the crosstalk between the antigens and dendritic cells, and resulted in large increases in activated ovalbumin-specific dendritic cells in vitro and in systemic antitumour effects, and extended survival in multiple tumour models in mice, including a model of metastasis and recurrence. The antitumour effects were abrogated by the antibody-mediated depletion of CD8+ T cells, indicating that systemic tumour regression was caused by adaptive immune responses. Leveraging flagellate bacteria to transport tumour antigens to the periphery of tumours to potentiate the activation of dendritic cells may open up new strategies for in situ cancer vaccination.


Subject(s)
CD8-Positive T-Lymphocytes , Neoplasms , Animals , Antigens, Neoplasm , Bacteria , Lymphocyte Activation , Mice , Tumor Microenvironment
10.
ACS Nano ; 15(5): 8450-8465, 2021 05 25.
Article in English | MEDLINE | ID: mdl-33938751

ABSTRACT

Radiation therapy can potentially elicit a systemic immune response and cause the regression of nonirradiated tumors, and the checkpoint blockade immunotherapies have been introduced to improve their clinical response rate. However, the therapeutic benefits of radioimmunotherapy are still far from satisfactory. Herein, the self-assembled "carrier-free" coordination polymer nanorods are constructed based on gadolinium and zoledronic acid, which can deposit X-ray for improved reactive oxygen species production to induce potent immunogenic cell death (ICD), simultaneously deplete tumor-associated macrophages with regulatory cytokines inhibition, respectively. With the potent ICD induction and reprogrammed immunosuppressive microenvironment, this synergetic strategy can promote antigen presentation, immune priming and T-cell infiltration, and potentiate checkpoint blockade immunotherapies against primary, distant, and metastatic tumors.


Subject(s)
Immunogenic Cell Death , Nanotubes , Gadolinium/therapeutic use , Immunotherapy , Polymers , Radioimmunotherapy , Tumor Microenvironment , Zoledronic Acid/therapeutic use
11.
Small ; 17(18): e2007734, 2021 05.
Article in English | MEDLINE | ID: mdl-33738929

ABSTRACT

The production of oxygen by photosynthetic microorganisms (PSMs) has recently attracted interest concerning the in vivo treatment of multiple diseases for their photosynthetic oxygen production in vivo, since PSMs have good biological safety. Here, the first evidence that PSMs can be used as a photothermal source to perform biophotothermal therapy (bio-PTT) is provided. In vitro and in vivo experiments proved that PSMs can generate heat for the direct elimination of tumors and release a series of pathogen-associated molecular patterns and adjuvants for immune stimulation under light irradiation. Bio-PTT enabled a local tumor inhibition rate exceeding 90% and an abscopal tumor inhibition rate exceeding 75%. This strategy also produced a stronger antitumor immune memory effect to prevent tumor recurrence. The bio-PTT strategy provides a novel direction for photothermal therapy as it simultaneously produces local and abscopal antitumor effects.


Subject(s)
Hyperthermia, Induced , Neoplasms , Cell Line, Tumor , Humans , Immunity , Immunotherapy , Neoplasms/therapy , Phototherapy
12.
Small ; 17(8): e2006231, 2021 02.
Article in English | MEDLINE | ID: mdl-33522120

ABSTRACT

Insufficient T-cell infiltration seriously hinders the efficacy of tumor immunotherapy. Induction of immunogenic cell death (ICD) is a potentially feasible approach to increase T-cell infiltration. Since ionizing radiation can only induce low-level ICD, this study constructs Cu-based nanoscale coordination polymers (Cu-NCPs) with mixed-valence (Cu+ /Cu2+ ), which can simultaneously and independently induce the generation of Cu+ -triggered hydroxyl radicals and Cu2+ -triggered GSH elimination, to synergize with radiation therapy for potent ICD induction. Markedly, this synergetic therapy remarkably enhances dendritic cell maturation and promotes antitumor CD8+ T-cell infiltration, thereby potentiating the development of checkpoint blockade immunotherapies against primary and metastatic tumors.


Subject(s)
Immunogenic Cell Death , Neoplasms , Cell Line, Tumor , Copper , Humans , Immunotherapy , Polymers , Radioimmunotherapy , T-Lymphocytes
13.
Nat Commun ; 12(1): 145, 2021 01 08.
Article in English | MEDLINE | ID: mdl-33420008

ABSTRACT

Radiation therapy can potentially induce immunogenic cell death, thereby priming anti-tumor adaptive immune responses. However, radiation-induced systemic immune responses are very rare and insufficient to meet clinical needs. Here, we demonstrate a synergetic strategy for boosting radiation-induced immunogenic cell death by constructing gadolinium-hemin based nanoscale coordination polymers to simultaneously perform X-ray deposition and glutathione depletion. Subsequently, immunogenic cell death is induced by sensitized radiation to potentiate checkpoint blockade immunotherapies against primary and metastatic tumors. In conclusion, nanoscale coordination polymers-sensitized radiation therapy exhibits biocompatibility and therapeutic efficacy in preclinical cancer models, and has the potential for further application in cancer radio-immunotherapy.


Subject(s)
Coordination Complexes/administration & dosage , Immunogenic Cell Death/drug effects , Nanoparticles/administration & dosage , Neoplasms/radiotherapy , Radioimmunotherapy/methods , Animals , Cell Line, Tumor/transplantation , Combined Modality Therapy/methods , Coordination Complexes/chemistry , Disease Models, Animal , Female , Gadolinium/administration & dosage , Gadolinium/chemistry , Hemin/administration & dosage , Hemin/chemistry , Humans , Immunogenic Cell Death/radiation effects , Mice , Nanoparticles/chemistry , Neoplasms/immunology , Neoplasms/pathology , Oxidative Stress/drug effects , Oxidative Stress/immunology , Oxidative Stress/radiation effects , Polymers/chemistry
14.
Biomaterials ; 269: 120621, 2021 02.
Article in English | MEDLINE | ID: mdl-33383301

ABSTRACT

Hypoxia exists in most malignant tumors and often contributes to therapy resistance, especially for aerobic treatments such as photodynamic therapy (PDT) and radiotherapy. Here, we developed a novel light-controlled sustainable PDT in which light was used to help photosynthetic microorganisms (Chlorella) produce oxygen, and perfluorocarbon was used to enrich oxygen around the photosensitizer for sustained oxygen supply. After light stops, Chlorella further acts as an adjuvant to promote dendritic cell (DC) activation, promoting the antitumor immune response. We showed that sustainable PDT could continuously provide oxygen for photosensitizers and avoid PDT-induced local hypoxia. More importantly, sustainable PDT also promoted the activation of DCs and amplified the antitumor immune effects. Therefore, this novel strategy provides an effective but simple method for improving PDT in both tumor hypoxia and normoxia, and enhancing the antitumor immunity may be a new anti-resistance strategy for treating patients with advanced-stage cancer.


Subject(s)
Chlorella , Photochemotherapy , Cell Line, Tumor , Humans , Hypoxia/drug therapy , Oxygen , Photosensitizing Agents/therapeutic use , Tumor Hypoxia
15.
Theranostics ; 10(17): 7683-7696, 2020.
Article in English | MEDLINE | ID: mdl-32685013

ABSTRACT

Tumor hypoxia, acidosis, and excessive reactive oxygen species (ROS) were the main characteristics of the bladder tumor microenvironment (TME), and abnormal TME led to autophagy activation, which facilitated cancer cell proliferation. The therapeutic efficacy of autophagy inhibitors might also be impeded by abnormal TME. To address these issues, we proposed a new strategy that utilized manganese dioxide (MnO2) nanoparticles to optimize the abnormal TME and revitalize autophagy inhibitors, and both oxygenation and autophagy inhibition may sensitize the tumor cells to radiation therapy. Methods: By taking advantage of the strong affinity between negatively charged MnO2 and positively charged chloroquine (CQ), the nanoparticles were fabricated by integrating MnO2 and CQ in human serum albumin (HSA)-based nanoplatform (HSA-MnO2-CQ NPs). Results: HSA-MnO2-CQ NPs NPs efficiently generated O2 and increased pH in vitro after reaction with H+/H2O2 and then released the encapsulated CQ in a H+/H2O2 concentration-dependent manner. The NPs restored the autophagy-inhibiting activity of chloroquine in acidic conditions by increasing its intracellular uptake, and markedly blocked hypoxia-induced autophagic flux. In vivo studies showed the NPs improved pharmacokinetic behavior of chloroquine and effectively accumulated in tumor tissues. The NPs exhibited significantly decreased tumor hypoxia areas and increased tumor pH, and had remarkable autophagy inhibition efficacy on bladder tumors. Finally, a significant anti-tumor effect achieved by the enhanced autophagy inhibition and radiation sensitization. Conclusions: HSA-MnO2-CQ NPs synergistically regulated the abnormal TME and inhibited autophagic flux, and effectively sensitized radiation therapy to treat bladder cancers.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Chemoradiotherapy/methods , Drug Carriers/chemistry , Radiation-Sensitizing Agents/administration & dosage , Urinary Bladder Neoplasms/therapy , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Autophagy/drug effects , Autophagy/radiation effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/radiation effects , Cell Survival/drug effects , Cell Survival/radiation effects , Chloroquine/administration & dosage , Chloroquine/pharmacokinetics , Drug Synergism , Humans , Hydrogen-Ion Concentration/drug effects , Male , Manganese Compounds/administration & dosage , Manganese Compounds/pharmacokinetics , Mice , Nanoparticles/chemistry , Oxides/administration & dosage , Oxides/pharmacokinetics , Radiation Tolerance/drug effects , Radiation-Sensitizing Agents/pharmacokinetics , Reactive Oxygen Species/metabolism , Serum Albumin, Human/chemistry , Tumor Hypoxia/drug effects , Tumor Hypoxia/radiation effects , Tumor Microenvironment/drug effects , Tumor Microenvironment/radiation effects , Urinary Bladder/pathology , Urinary Bladder Neoplasms/pathology , Xenograft Model Antitumor Assays
16.
Biomater Sci ; 8(17): 4739-4749, 2020 Sep 07.
Article in English | MEDLINE | ID: mdl-32706009

ABSTRACT

Radiotherapy (RT) is one of the most extensive and effective approaches available for clinical tumor treatment. However, tumor microenvironments including hypoxia and histone deacetylase (HDAC) overexpression could induce radiation resistance, leading to tumor recurrence. Herein, nanoparticles (CAT-SAHA@PLGA) encapsulating catalase and HDAC inhibitor SAHA exhibited protected catalytic activity of catalase and prolonged the pharmacokinetic exposure of the HDAC inhibitor. Overall, the established CAT-SAHA@PLGA nanoparticles could overcome radiation resistance by synergistically increasing tumor oxygenation and inhibiting HDAC activity.


Subject(s)
Chromatin Assembly and Disassembly , Hydroxamic Acids , Cell Line, Tumor , Humans , Hypoxia , Vorinostat
17.
Chem Commun (Camb) ; 56(56): 7753-7756, 2020 Jul 14.
Article in English | MEDLINE | ID: mdl-32613216

ABSTRACT

We utilized albumin as a reducing agent to establish novel copper-based and pH-sensitive nanocarrier CuNPs with abundant Cu+, which can encapsulate histone deacetylase (HDAC) inhibitor vorinostat to form uniform and stable nanomedicine V-CuNPs for synergistic chromatin remodelling and chemodynamic therapy.


Subject(s)
Copper/chemistry , Hydrogen-Ion Concentration , Metal Nanoparticles/chemistry , Molecular Targeted Therapy/methods , Vorinostat/pharmacology , Animals , Cell Line, Tumor , Coordination Complexes/chemistry , Histone Deacetylase Inhibitors/chemistry , Histone Deacetylase Inhibitors/pharmacokinetics , Histone Deacetylase Inhibitors/pharmacology , Humans , Mice , Vorinostat/chemistry , Vorinostat/pharmacokinetics
18.
Theranostics ; 10(7): 2943, 2020.
Article in English | MEDLINE | ID: mdl-32194846

ABSTRACT

[This corrects the article DOI: 10.7150/thno.27598.].

19.
Nanoscale ; 12(13): 7376-7382, 2020 Apr 03.
Article in English | MEDLINE | ID: mdl-32207476

ABSTRACT

Photooxidation provides a promising strategy for photocatalysis, photodynamic therapy, and environmental protection. Unfortunately, most organic photosensitizers possess weak hydrophilicity and a π-π conjugated structure, leading to singlet oxygen self-quenching, poor loadability and therefore unsatisfactory photooxidation efficiency. Thus, dispersion of these photosensitizers within a two-dimensional porous covalent organic framework has become a feasible strategy to hinder their self-aggregation and augment their loading capacity. Here, we report a phthalocyanine-based photosensitizer loaded on covalent organic framework nanosheets. This nano-photosensitizer exhibits highly dispersed organic fluorescent phthalocyanines and a high loading capacity. The fabricated nanosheets restrict self-aggregation of photosensitizer molecules and enhance the photooxidation activity, which may offer a new paradigm for photooxidation and its multiple applications.

20.
J Pharm Biomed Anal ; 180: 113072, 2020 Feb 20.
Article in English | MEDLINE | ID: mdl-31891873

ABSTRACT

(S)-oxiracetam is undergoing clinical trials as an active ingredient in the racemic oxiracetam. Here, we report a specific analytical method for analyzing (S)-oxiracetam and four related impurities in the bulk drug of (S)-oxiracetam by using high-performance liquid chromatography (HPLC) system. The chromatographic system included a Capcell pak NH2 analytical column, a mobile phase containing acetonitrile-water (95:5, v/v; pH adjusted to 2.0 with trifluoroacetic acid) at a flow rate of 1.0 mL/min, column temperature at 35 ℃ and the UV detection wavelength is set at 210 nm. This analytical method has shown effective and specific analysis for (S)-oxiracetam and four related substances. Moreover, the molecular weight and chemical structure preliminarily speculated of related substances were characterized by mass spectrometry. The methodology was verified by HPLC and results collected of the method validation included the system suitability, specificity sensitivity, linearity and accuracy, good linear correlation coefficient R2 was more than 0.9991. The analytical method developed and verified in the study, as far as we know, is the most exhaustive HPLC determination report which could be applied for the quality control and stability monitor purposes of the bulk drug of (S)-oxiracetam in the routine pharmaceutical analysis.


Subject(s)
Chromatography, High Pressure Liquid/methods , Drug Contamination , Mass Spectrometry/methods , Pyrrolidines/analysis , Pyrrolidines/standards , Molecular Structure , Molecular Weight , Reference Standards , Reproducibility of Results , Sensitivity and Specificity , Stereoisomerism
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