Programmed T cells infiltration into lung metastases with harnessing dendritic cells in cancer immunotherapies by catalytic antigen-capture sponges.

T lymphocytes served as immune surveillance to suppress metastases by physically interacting with cancer cells. Whereas tumor immune privilege and heterogeneity protect immune attack, it limits immune cell infiltration into tumors, especially in invasive metastatic clusters. Here, a catalytic antigen-capture sponge (CAS) containing the catechol-functionalized copper-based metal organic framework (MOF) and chloroquine (CQ) for programming T cells infiltration is reported. The intravenously injected CAS accumulates at the tumor via the folic acid-mediated target and margination effect. In metastases, Fenton-like reaction induced by copper ions of CAS disrupts the intracellular redox potential, i.e., chemodynamic therapy (CDT), thereby reducing glutathione (GSH) levels. Furthermore, CQ helps inhibit autophagy by inducing lysosomal deacidification during CDT. This process leads to the breakdown of self-defense mechanisms, which exacerbates cytotoxicity. The therapies promote the liberation of tumor-associated antigens, such as neoantigens and damage-associated molecular patterns (DAMPs). Subsequently, the catechol groups present on CAS perform as antigen reservoirs and transport the autologous tumor-associated antigens to dendritic cells, resulting in prolonged immune activation. The CAS, which is capable of forming in-situ, serves as an antigen reservoir in CDT-mediated lung metastasis and leads to the accumulation of immune cells in metastatic clusters, thus hindering metastatic tumors.

A self-assembled electrochemical immunosensor for ultra-sensitive detection of ochratoxin A in medicinal and edible malt.

Trace residue of mycotoxins in complex medicinal and edible food matrices has brought huge challenges for the development of ultrasensitive analytical methods. Here, a green electrochemical immunosensor for the ultrasensitive detection of ochratoxin A (OTA) was fabricated by self-assembling a compact 2-mercaptoacetic (TGA) monolayer on the surface of the working Au electrode to form the Au/TGA/bovine serum aibumin (BSA)-OTA/anti-OTA monoclonal antibody composite probes for selective and ultra-sensitive detection of OTA based on indirect competitive principle and differential pulse voltammetry analysis. The electrochemical impedance spectroscopy and cyclic voltammetry methods were introduced to characterize the assemble situation of the TGA-modified Au electrode and optimize some critical parameters for the green electrochemical immunoseonsor. Under the optimal conditions, the developed immunosensor exhibited much lower limit of detection (0.08 ng/mL) in the range of 0.1-1.0 ng/mL for OTA compared with other direct or disposable electrochemical immunosensors. Real application in the spiked malt samples verified high accuracy with no matrix interferences of the proposed immunoseonsor. This is a meaningful study on a self-assembled electrochemical immunoseonsor for ultra-sensitive and rapid detection of OTA in malt samples, which suggested a general simple-to-use sensing platform and prospect as an economical and green tool for ultra-sensitive detection of much more trace-level of toxic small molecules in other complex matrices to ensure their quality and safety.

Development of an economic ultrafast liquid chromatography with tandem mass spectrometry method for trace analysis of multiclass mycotoxins in Polygonum multiflorum.

Rapid, economic, and highly effective determination of multiple mycotoxins in complex matrices has given huge challenges for the analytical method. In this study, an economic analytical strategy based on sensitive and rapid ultrafast liquid chromatography coupled to hybrid triple quadrupole/linear ion trap mass spectrometry technique was developed for the determination of seven mycotoxins of different chemical classes (aflatoxin B1 , B2 , G1 , and G2 , ochratoxin A, T-2 toxin, and HT-2 toxin) in Polygonum multiflorum. Target mycotoxins were completely extracted using a modified quick, easy, cheap effective, rugged, and safe method without additional clean-up steps. The types of extraction solvents and adsorbents for the extraction procedure were optimized to achieve high recoveries and reduce coextractives in the final extracts. Due to significant matrix effects for all analytes (≤68.9% and ≥110.0%), matrix-matched calibration curves were introduced for reliable quantification, exploring excellent linearity for the seven mycotoxins with coefficients of determination >0.9992. The method allowed high sensitivity with limit of detection in the range of 0.031-2.5 µg/kg and limit of quantitation in the range of 0.078-6.25 µg/kg, as well as satisfactory precision with relative standard deviations lower than 8%. Recovery rates were between 74.3 and 119.8% with relative standard deviations below 7.43%. The proposed method was successfully applied for 24 batches of P. multiflorum samples, and six samples were found to be positive with aflatoxin B1 , B2 , G1 , or ochratoxin A. The method with significant advantages, including minimum analytical time, low time and solvent consumption, and high sensitivity, would be a preferred candidate for economic analysis of multiclass mycotoxins in complex matrices.

Regeneration and Reuse of Immunoaffinity Column for Highly Efficient Clean-Up and Economic Detection of Ochratoxin A in Malt and Ginger.

Immunoaffinity columns (IACs) are most popularly used for mycotoxin clean-up in complex matrices prior to chromatographic analysis. But, their high cost has limited their wide application and the regeneration of IACs for multiple instances of reuse is important. This study aimed to investigate the feasibility of regeneration and reuse of IACs for purification of ochratoxin A (OTA) in spiked raw malt and dried ginger samples followed by high performance liquid chromatography-fluorescence detection. After each use, the IACs were filled with phosphate buffer saline (PBS) as the preservation solution and stored at 8 °C overnight for regeneration and reuse until the recovery rate was <70%. The results showed that matrix type, preparation procedure, and pH value of sample extraction exhibited major effects on the reuse of IACs for OTA clean-up. While, after modifying the sample preparation procedure using water as the diluent and the solution at a pH of 7 to 8, the IACs could be used eight and three times for the spiked raw malt and dried ginger samples with OTA after regeneration. Regarding the traditional procedure recommended in Chinese Pharmacopoeia (2015 edition), the IACs could be used for three and two times for the spiked raw malt and dried ginger samples with OTA, respectively. Therefore, the corresponding experimental cost could be reduced to one-eighth and one-third of the original cost. This is the first study on the regeneration and reuse of IACs for OTA clean-up in complex Chinese herbal medicines, providing a green and economical tool for a large number of samples analysis with low cost.

Multiclass mycotoxins in lotus seeds analysed by an isotope-labelled internal standard-based UPLC-MS/MS.

OBJECTIVES: This study aimed to explore the residue levels of multiclass mycotoxins in medicinal and edible lotus seeds. METHODS: A rapid and reliable isotope-labelled internal standard-based UPLC-MS/MS method was developed and validated for sensitive and accurate analysis of multiclass mycotoxins including aflatoxins (AFB1 , AFB2 , AFG1 and AFG2 ), ochratoxin A (OTA), zearalenone (ZEN), deoxynivalenol (DON), fumonisins (FB1 and FB2 ), T-2 and HT-2 toxins in lotus seeds. Some critical conditions such as extract solution with the addition of isotope-labelled internal standard, type of mobile phase and the elution condition were scientifically optimized. The 11 mycotoxins obtained satisfactory resolution and sensitive detection in multiple reactions monitoring scanning mode combined with the ion switching technology in positive and negative ion switching mode. KEY FINDINGS: The developed isotope-labelled internal standard-based UPLC-MS/MS method exhibited an approving linearity (r ≥ 0.9984), high sensitivity (limit of detection in the range of 0.015-30.05 µg/kg), acceptable precision (RSDs ≤6.3%) and good recovery (76.0-116.0%) for 11 analytes, respectively. Ten batches of real lotus seed samples were tested, and three batches out of which were contaminated with AFB1 , FB2 , T-2 and ZEN. AFB1 showed the highest occurrence rate (30%) with contents of 10.50 and 8.32 µg/kg in two samples over the official limit (5.0 µg/kg). CONCLUSIONS: The monitoring of multiclass mycotoxins in Chinese herbal medicines is in great urgency to ensure the security of consumers. The proposed method could be further utilized for simple, sensitive and rapid detection of more mycotoxins in other complex matrices to compensate for matrix effects.