Novel photocatalytic carbon dots: efficiently inhibiting amyloid aggregation and quickly disaggregating amyloid aggregates.

Amyloid aggregation is implicated in the pathogenesis of various neurodegenerative disorders, such as Alzheimer's disease (AD) and Parkinson's disease (PD). It is critical to develop high-performance drugs to combat amyloid-related diseases. Most identified nanomaterials exhibit limited biocompatibility and therapeutic efficacy. In this work, we used a solvent-free carbonization process to prepare new photo-responsive carbon nanodots (CNDs). The surface of the CNDs is densely packed with chemical groups. CNDs with large, conjugated domains can interact with proteins through π-π stacking and hydrophobic interactions. Furthermore, CNDs possess the ability to generate singlet oxygen species (1O2) and can be used to oxidize amyloid. The hydrophobic interaction and photo-oxidation can both influence amyloid aggregation and disaggregation. Thioflavin T (ThT) fluorescence analysis and circular dichroism (CD) spectroscopy indicate that CNDs can block the transition of amyloid from an α-helix structure to a ß-sheet structure. CNDs demonstrate efficacy in alleviating cytotoxicity induced by Aß42 and exhibit promising blood-brain barrier (BBB) permeability. CNDs have small size, low biotoxicity, good fluorescence and photocatalytic properties, and provide new ideas for the diagnosis and treatment of amyloid-related diseases.

Preparation of lysozyme-imprinted mesoporous Zr-based metal-organic frameworks with remarkable specific recognition.

The development of high-performance protein-imprinted materials remains challenging due to defects concerning high mass transfer resistance and non-specific binding, which are crucial for protein purification and enrichment. In this paper, lysozyme-imprinted mesoporous Zr-based MOF (mesoUiO-66-NH2@MIPs) with specific and selective recognition of lysozyme (Lyz) were prepared by surface imprinting technology. In particular, the excellent hydrophilicity mesoporous MOFs (mesoUiO-66-NH2) with a pore size of 10 nm was prepared as a carrier for Lyz immobilization by an auxiliary modulation strategy to regulate the microporous structure of UiO-66-NH2 with the propionic acid solution, enabling massive loading of the macromolecular protein Lyz. The mesoUiO-66-NH2@MIPs reached a maximum saturation adsorption of 206.54 mg g-1 on Lyz in 20 min at 25 °C with an imprinting factor of 2.57 and selection factors of 2.02, 2.34, and 2.45 for cytochrome c (Cyt c), bovine serum albumin (BSA) and bovine hemoglobin (BHb), respectively. More importantly, the mesoUiO-66-NH2@MIPs could specifically recognize Lyz from the mixed protein system. The adsorption capacity of Lyz could still reach 78.55% after 5 cycles with good cyclic regeneration performance. This provides a new research option for developing and applying novel porous MOF in biomolecule imprinting technology and the specific separation of biomolecules.

Photooxidative inhibition and decomposition of ß-amyloid in Alzheimer's by nano-assemblies of transferrin and indocyanine green.

Photoinduced modulation of Aß42 aggregation has emerged as a therapeutic option for treating Alzheimer's disease (AD) due to its high spatiotemporal controllability, noninvasive nature, and low systemic toxicity. However, existing photo-oxidants have the poor affinity for Aß42, low depolymerization efficiency, and difficulty in crossing the blood-brain barrier (BBB), hindering their application in the treatment of AD. Here, through hydrophobic interactions and hydrogen bonding, we integrated the near-infrared (NIR) photosensitizer indocyanine green with transferrin (denoted as TF-ICG), a protein with a high affinity for Aß42, and demonstrated its anti-amyloid activity in vitro. TF-ICG was shown to bind to Aß42 residues via hydrophobic interaction, impeding π-π stacking of Aß42 peptide monomers and disassembling mature Aß42 protofibrils in a concentration-dependent manner. More importantly, under NIR (808 nm, 0.6w/cm2) irradiation, TF-ICG completely inhibited the fibrillation process of Aß42 to generate amorphous aggregates, with an inhibition rate of 96 % at only 65 nM. Meanwhile, TF-ICG could photo-oxidize rigid Aß42 aggregates and break them down into small amorphous structures. Tyrosine fluorescence assay further demonstrated the intrinsic affinity and targeting of TF-ICG to Aß42 fibrils. In vitro studies validated the anti-amyloid activity of TF-ICG, which provided a theoretical basis for further in vivo application as a BBB-penetrating nanotherapeutic platform.

Curcumin-loaded protein imprinted mesoporous nanosphere for inhibiting amyloid aggregation.

Some natural variants of human lysozyme are associated with systemic non-neurological amyloidosis that leads to amyloid protein fibril deposition in different tissues. Inhibition of amyloid fibrillation by nanomaterials is considered to be an effective approach to treating amyloidosis. Here, we prepared a targeted, highly loaded curcumin lysozyme-imprinted nanosphere (CUR-MIMS) that could effectively inhibit the aggregation of lysozyme with lysozyme adsorption capacity of 193.57 mg g-1 and the imprinting factor (IF) of 3.72. CUR-MIMS could bind to lysozyme through hydrophobic interactions and effectively reduce the hydrophobicity of the total solvent-exposed surface in lysozyme fibrillation, thus reducing the self-assembly process triggered by hydrophobic interactions. Thioflavin T (ThT) analysis demonstrated that CUR-MIMS inhibited the aggregation of amyloid fibrils in a dose-dependent manner (inhibition efficiency of 56.07 %). Circular dichroism (CD) spectrum further illustrated that CUR-MIMS could significantly inhibit the transition of lysozyme from α-helix structure to ß-sheet. More importantly, biological experiments proved the good biocompatibility of CUR-MIMS, which indicated the potential of our system as a future therapeutic platform for amyloidosis.

Performance of different methods for detecting T790M mutation in the plasma of patients with advanced NSCLC after developing resistance to first-generation EGFR-TKIs in a real-world clinical setting.

Several approaches to the detection of T790M mutations in patient plasma or tissue samples have been implemented to date. The present study was designed to assess the ability of different technologies to detect the T790M mutation in plasma samples and to evaluate the relative rates of re-biopsy and subsequent patient management in a clinical setting. Data from patients with advanced NSCLC who visited the Department of Respiratory Medicine of the First Hospital Affiliated to Wenzhou Medical University between December 2014 and July 2018 were retrospectively collected. Following re-biopsy, these patients were evaluated for the presence of the T790M mutation via next-generation sequencing (NGS), amplification refractory mutation system or Roche Cobas z480 (Cobas) analyses of tissue samples. T790M mutation status in tumor tissue samples was calculated as a standard reference used to establish the sensitivity, specificity and concordance of three circulating tumor DNA detection approaches, including NGS, droplet digital PCR (ddPCR) and super amplification refractory mutation system (SuperARMS). Subsequent patient management was also recorded. In total, 287 patients with advanced non-small cell lung cancer were evaluated, of whom 55.4% (159/287) underwent tissue re-biopsy, 76.7% (122/159) underwent sequencing analysis of plasma and/or tissue samples, and 59.0% (72/122) were found to harbor the T790M mutation. The rates of plasma sample T790M detection via NGS, ddPCR and SuperARMS were 60.0, 59.3 and 60.0%, respectively. Only 32 patients with T790M mutations (44.4%, 32/72) were treated with third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), while 19 continued treatment with first-generation TKIs, 13 underwent chemotherapy, 1 switched to treatment with anlotinib, 4 succumbed to pericardial or brain metastases, and 3 were lost to follow-up. Additionally, 2 patients exhibited histological transformation from adenocarcinoma to small cell lung cancer, while 17/97 patients who were evaluated for brain metastases during treatment exhibited intracranial progression. Of these, 8 patients had been treated with osimertinib. In this study of a real-world clinical setting, fewer patients than expected underwent re-biopsy and gene sequencing. Of the tools available for the analysis of plasma samples, NGS exhibited the highest sensitivity and concordance with the results of tissue-based T790M detection strategies. It was additionally found that only a subset of patients harboring the T790M mutation were ultimately treated using third-generation EGFR-TKIs.

Clinical evaluation of a laboratory-developed test using clone E1L3N for the detection of PD-L1 expression status in non-small cell lung cancer.

BACKGROUND: Programmed death ligand 1 (PD-L1) has been used as a diagnostic marker to identify patients that will benefit from immune checkpoint inhibitors in non-small cell lung cancer (NSCLC). Immunohistochemistry with E1L3N clone is one of the most widely used and inexpensive laboratory-developed tests for PD-L1, but still need to be compared and validated with standard methods for clinical application. METHODS: We investigated the performance of E1L3N clone for PD-L1 testing in 299 tumor tissues of NSCLC patients and its comparability with FDA-approved 22C3 clone. RESULTS: The results show that the negative coincidence rate, weak positive coincidence rate, and positive coincidence rate were 97.4%, 92.2%, and 97.6% using the E1L3N assay relative to the 22C3 assay, respectively. An overall agreement of 96.3% was achieved between these two assays. We also found that the overall concordances were 97.8% and 93.9% for PD-L1 detection in large and small specimens, respectively, and no significant difference was obtained between these two assays (p = 0.076). In addition, the expression of PD-L1 was not detected in tumor tissues of benign lung disease using both the E1L3N and 22C3 assays. CONCLUSION: E1L3N can be used as a reliable alternative antibody clone to evaluate PD-L1 expression status for NSCLC patients.

Lasting Tracking and Rapid Discrimination of Live Gram-Positive Bacteria by Peptidoglycan-Targeting Carbon Quantum Dots.

Selective discrimination and lasting tracking of live bacteria are primary steps for microbiology research and treatment of bacterial infection. However, conventional detection methods, such as the gold standard of Gram staining, are being challenged under actual test conditions. Herein, we provided a novel method, namely, three excitation peaks and single-color emission carbon quantum dots (T-SCQDs) for the rapid (5 min) peptidoglycan-targeting discrimination of Gram-positive bacteria and lasting tracking (24 h) through one-step staining. Bacterial viability testing indicates that T-SCQDs can achieve nondestructive identification of Gram-positive bacteria within 50-500 µg mL-1. Interestingly, the fluorescence imaging system suggests that T-SCQDs can also selectively distinguish the type of colonies based on fluorescence intensity. Furthermore, T-SCQDs were successfully used to visually distinguish Gram-positive bacteria from the microbial environment of A549 cells by confocal fluorescence microscopy. These properties endow T-SCQDs with excellent functions for the diagnosis of infection and other biological applications.

Drug-based magnetic imprinted nanoparticles: Enhanced lysozyme amyloid fibrils cleansing and anti-amyloid fibrils toxicity.

Lysozyme amyloid fibrils, the misfolding structures generated from natural state of lysozyme, are found to be related with non-neuropathic systemic amyloidosis. Therefore, inhibiting the formation of amyloid and disaggregating amyloid fibers are both effective strategies. Herein, we present a combination of Epigallocatechin-3-gallate (EGCG), imprinting technology and magnetic nanoparticles to obtain a kind of promising nanomaterials (MINs@EGCG) for amyloid inhibition, drug carrier and facile separation triple functions. We declared the efficacy of MINs@EGCG from two perspectives. For inhibition, Circular dichroism (CD) spectrum illustrated that the miss transition from α-helix structure to ß-sheet could be blocked by MINs@EGCG, and the inhibition efficiency was higher than 80%. These results were further verified by Thioflavin T (ThT) analysis. For disaggregation and cleansing, the helical and highly periodic structure of amyloid fibrils could be converted into their counterparts by MINs@EGCG. Furthermore, with the aid of external magnetic field, the cleansing efficiency of counterparts-MINs@EGCG complex was up to 80%. Most importantly, bio-related experiments showed superior biocompatibility and anti-amyloid fibrils toxicity of MINs@EGCG, indicating the great potential of our system to work as an effective amyloidosis therapy platform.

Autophagy regulates the therapeutic potential of adipose-derived stem cells in LPS-induced pulmonary microvascular barrier damage.

Adipose-derived stem cells (ADSCs) have been shown to be beneficial in some pulmonary diseases, and the paracrine effect is the major mechanism underlying ADSC-based therapy. Autophagy plays a crucial role in maintaining stem cell homeostasis and survival. However, the role of autophagy in mediating ADSC paracrine effects has not been thoroughly elucidated. We examined whether ADSCs participate in lipopolysaccharide (LPS)-induced pulmonary microvascular endothelial cell (PMVEC) barrier damage in a paracrine manner and illuminated the role of autophagy in regulating ADSC paracrine effects. PMVECs and ADSCs with or without autophagy inhibition were cocultured without intercellular contact, and the microvascular barrier function was assessed after LPS treatment. ADSC paracrine function was evaluated by detecting essential growth factors for endothelial cells. For in vivo experiments, ADSCs with or without autophagy inhibition were transplanted into LPS-induced lung-injury mice, and lung injury was assessed. ADSCs significantly alleviated LPS-induced microvascular barrier injury. In addition, ADSC paracrine levels of VEGF, FGF, and EGF were induced by LPS treatment, especially in the coculture condition. Inhibiting autophagy weakened the paracrine function and the protective effects of ADSCs on microvascular barrier injury. Moreover, ADSC transplantation alleviated LPS-induced lung injury, and inhibiting autophagy markedly weakened the therapeutic effect of ADSCs on lung injury. Together, these findings show that ADSC paracrine effects play a vital protective role in LPS-induced pulmonary microvascular barrier injury. Autophagy is a positive mediating factor in the paracrine process. These results are helpful for illuminating the role and mechanism of ADSC paracrine effects and developing effective therapies in acute lung injury.