Wighteone, a prenylated flavonoid from licorice, inhibits growth of SW480 colorectal cancer cells by allosteric inhibition of Akt

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice is a frequently used herbal medicine worldwide, and is used to treat cough, hepatitis, cancer and influenza in clinical practice of traditional Chinese medicine. Modern pharmacological studies indicate that prenylated flavonoids play an important role in the anti-tumor activity of licorice, especially the tumors in stomach, lung, colon and liver. Wighteone is one of the main prenylated flavonoids in licorice, and its possible effect and target against colorectal cancer have not been investigated.

AIM OF THE STUDY

This study aimed to investigate the anti-colorectal cancer effect and underlying mechanism of wighteone.

MATERIALS AND METHODS

SW480 human colorectal cancer cells were used to evaluate the in vitro anti-colorectal cancer activity and Akt regulation effect of wighteone by flow cytometry, phosphoproteomic and Western blot analysis. Surface plasmon resonance (SPR) assay, molecular docking and dynamics simulation, and kinase activity assay were used to investigate the direct interaction between wighteone and Akt. A nude mouse xenograft model with SW480 cells was used to verify the in vivo anti-colorectal cancer activity of wighteone.

RESULTS

Wighteone inhibited phosphorylation of Akt and its downstream kinases in SW480 cells, which led to a reduction in cell viability. Wighteone had direct interaction with both PH and kinase domains of Akt, which locked Akt in a "closed" conformation with allosteric inhibition, and Gln79, Tyr272, Arg273 and Lys297 played the most critical role due to their hydrogen bond and hydrophobic interactions with wighteone. Based on Akt overexpression or activation in SW480 cells, further mechanistic studies suggested that wighteone-induced Akt inhibition led to cycle arrest, apoptosis and autophagic death of SW480 cells. Moreover, wighteone exerted in vivo anti-colorectal cancer effect and Akt inhibition activity in the nude mouse xenograft model.

CONCLUSION

Wighteone could inhibit growth of SW480 cells through allosteric inhibition of Akt, which led to cell cycle arrest, apoptosis and autophagic death. The results contributed to understanding of the anti-tumor mechanism of licorice, and also provided a rationale to design novel Akt allosteric inhibitors for the treatment of colorectal cancer.

Mass-Spectrometry-Based Assay at Single-Base Resolution for Simultaneously Detecting m6A and m6Am in RNA

The methylation modifications of adenosine, especially N6-methyladenosine (m6A) and N6, 2'-odimethyladenosine (m6Am), play vital roles in various biological, physiological, and pathological processes. However, current methods for detecting these modifications at single-base resolution have limitations. Mass spectrometry (MS), a highly accurate and sensitive technique, can be utilized to differentiate between m6A and m6Am by analyzing the molecular weight differences in their fragments during tandem MS analysis. In this study, we present an MS-based method that allows for the simultaneous determination of m6A and m6Am sites in targeted RNA fragments at single-nucleotide resolution. The approach involves the utilization of tandem MS in conjunction with targeted RNA enrichment and enzymatic digestion, eliminating the need for PCR amplification. By employing this strategy, we can accurately identify m6A and m6Am sites in targeted RNA fragments with high confidence. To evaluate the effectiveness of our method, we applied it to detect m6A and m6Am sites in cell and tissue samples. Furthermore, we verified the accuracy of our approach by performing CRISPR/Cas9-mediated knockout of the corresponding methyltransferases. Overall, our MS-based method offers a reliable and precise means for the simultaneous detection of m6A and m6Am modifications in targeted RNA fragments, providing valuable insights into the functional characterization of these modifications in various biological contexts.

Diprenylated flavonoids from licorice induce death of SW480 colorectal cancer cells by promoting autophagy: Activities of lupalbigenin and 6,8-diprenylgenistein

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice is a well-known herbal medicine, and we previously found that several licorice prenylated flavonoids could cause death of SW480 colorectal cancer cells by promoting autophagy. Given many kinds of prenylated flavonoids in licorice, the activities of other compounds deserve further investigation. In addition, the contribution of isoprenyl groups on the autophagy promotion activities has not been clarified.

AIM OF THE STUDY

This study aimed to investigate whether lupalbigenin (LPB) and 6,8-diprenylgenistein (DPG), two licorice diprenylated flavonoids, could induce autophagic cell death of SW480 cells, and clarify the contribution of isoprenyl groups.

MATERIALS AND METHODS

Cytotoxic activities of LPB and DPG were tested by using an MTT method, and apoptosis induction effects were evaluated by PI-Annexin V staining-based flow cytometry and protein levels of caspase-3 and PARP-1. Autophagy promotion effects of LPB and DPG were assessed by protein levels of LC3, p62, Akt and mTOR as well as number of autophagosomes in cells, and autophagy inhibitor chloroquine (CQ) was involved to identify the role of autophagy on LPB or DPG-caused death of SW480 cells. In addition, two groups of structurally similar diprenylated, mono-prenylated and free flavonoids were obtained from licorice, which were used to investigate the contribution of isoprenyl groups on their autophagy promotion activities.

RESULTS

Both LPB and DPG significantly induced apoptosis of SW480 cells with strong cytotoxic activities, and meanwhile, they also promoted autophagy probably through the Akt/mTOR signaling pathway. Further studies indicated that LPB and DPG could induce autophagic cell death of SW480 cells. Moreover, isoprenyl groups contributed mainly to the cytotoxic and autophagy promotion activities of licorice prenylated flavonoids.

CONCLUSION

This study reported for the first time that licorice diprenylated flavonoids LPB and DPG induced death of SW480 cells by promoting autophagy, which was mainly attributed to the isoprenyl groups. The results provided theoretical basis for researches on anti-colorectal cancer drugs and their structural modification.

Prenylated phenolic compounds from licorice (Glycyrrhiza uralensis) and their anti-inflammatory activity against osteoarthritis

Osteoarthritis is a significant driver of disability in the elderly with increasing prevalence, and inflammation plays a vital role on its etiology. Licorice is commonly used as a traditional Chinese medicine or food additive, and its prenylated phenolic compounds were recently reported to be able to inhibit osteoarthritis with anti-inflammatory activity. In order to explore more anti-osteoarthritic prenylated phenolic compounds from licorice, we isolated ten compounds (1-10), with three new ones (1-3), from the ethyl acetate extract of Glycyrrhiza uralensis. Compound 2 (glycyuralin R) was a racemic 3-phenoxy-chromanone, and we achieved its chiral separation for the first time. Compounds 1, 2, 7 and 8 showed significant NO inhibitory ability in IL-1β-stimulated mouse primary chondrocytes, and we further confirmed the anti-inflammatory activity of 1 (glycyuralin Q) by evaluating its effect on osteoarthritis-related iNOS, COX-2, TNF-α, IL-6, MMP3, MMP13 and NF-κB based on various experimental methods. These results clarified the potential of several prenylated phenolic compounds, especially 1 in licorice, as the lead compounds for osteoarthritis.

Morus alba leaves ethanol extract protects pancreatic islet cells against dysfunction and death by inducing autophagy in type 2 diabetes

BACKGROUND

Protection of pancreatic islet cells against dysfunction or death by regulating autophagy is considered to be an effective method for treatment of type 2 diabetes mellitus (T2DM). Morus alba leaves (mulberry leaves), a popular herbal medicine, have been used for prevention of T2DM since ancient times.

PURPOSE

This study aimed to clarify whether Morus alba leaves ethanol extract (MLE) could protect islet cells in vivo and in vitro by regulating autophagy in T2DM, and explore the possible mechanism of action.

METHODS

The main chemical constituents in MLE were analyzed by HPLC. The T2DM rat model was induced via high-fat diet combined with peritoneal injection of low-dose streptozotocin, and MLE was administered by oral gavage. Fasting blood glucose (FBG) and plasma insulin were measured, and homeostatic model assessment of β cell function (HOMA-β) and insulin resistance (HOMA-IR) were determined. The histomorphology of pancreas islets was evaluated by haematoxylin and eosin staining. In palmitic acid (PA)-stressed INS-1 rat insulinoma cells, cell viability was assayed by an MTT method. Expression of the autophagy-related proteins LC3 I/II, p62, p-AMPK and p-mTOR in islet tissues and INS-1 cells was evaluated by western blotting or immunohistochemistry analysis.

RESULTS

The four main chemical constituents in MLE were identified as chlorogenic acid, rutin, isoquercitrin and quercitrin. MLE ameliorated hyperglycemia, insulin resistance and dyslipidemia of T2DM rats with prominent therapeutic effect. Further study indicated that MLE observably improved islet function, alleviated islet injury of T2DM rats, and inhibited PA-induced INS-1 cell death. On the other hand, MLE significantly induced autophagy in islet cells both in vivo and in vitro, and autophagy inhibitors abolished its therapeutic effect on T2DM rats and protective effect on islet cells. Apart from this, MLE markedly activated the AMPK/mTOR pathway in INS-1 cells, and the AMPK inhibitor prevented the autophagy induction ability of MLE.

CONCLUSION

Together, MLE could protect islet cells against dysfunction and death by inducing AMPK/mTOR-mediated autophagy in T2DM, and these findings provide a new perspective for understanding the treatment mechanism of Morus alba leaves against T2DM.

Enrichment and Quantitative Determination of Free 3,5- Diiodothyronine, 3',5'-Diiodothyronine, and 3,5-Diiodothyronamine in Human Serum of Thyroid Cancer by Covalent Organic Hyper Cross-linked Poly-ionic Liquid

The incidence of thyroid cancer is increasing worldwide. So far, still no non-invasive clinical test biomarkers were developed for the diagnosis of thyroid cancer. The diiodothyronines (T2s) are precursors and metabolites of thyroid hormone (T4). Some reports predict that T2s may be associated with several thyroid diseases, especially the thyroid cancer. Detecting free T2s in human serum may help the diagnosis of thyroid cancer. However, few works have reported the detection of T2s due to their trace amounts. Here we developed a novel hyper organic cross-linked poly ionic liquid (PIL) material for the enrichment of three main compounds in T2s family, including 3,5- diiodothyronine (3,5-T2), 3',5'-diiodothyronine (3',5'-T2), and 3,5-diiodothyronamine (3,5-T2AM). This PIL material provided specific enrichment superiority for three T2s. After enrichment, the signal intensity of 3,5-T2, 3',5'-T2, and 3,5-T2AM increased 14, 132 and 1.6 folds, respectively, with LOQ of 76, 87, and 107 fM, respectively. Finally, we successfully applied PIL material coupled with HPLC-ESI-MS/MS in enrichment and quantitative determination of free 3,5-T2, 3',5'-T2, and 3,5-T2AM in human serum of 45 thyroid cancer patients and 15 healthy people. We also used free thyroid hormone (FT4) as the calibration reference to eliminate individual differences. We found that the levels of 3,5-T2 (P < 0.001), and 3',5'-T2 (P = 0.001) in patients with thyroid cancer were significantly higher than those in healthy people. Additionally, we further investigated the power of different T2 thyroid hormones divided FT4 to classify thyroid cancer patients and healthy people. And 3,5-T2/FT4 had the highest classification performance for discriminating thyroid cancer patients from healthy people at certain threshold, indicating that 3,5-T2/FT4 in human serum can act as potential biomarkers for "non-invasive" clinical diagnosis of thyroid cancer.

Metabolomics Based Comparison on the Biomarkers between Panax Notoginseng and its Counterfeit Gynura Segetum in Rats

Background:

Because of the similar appearance of Gynura segetum and panax notoginseng, the patients often mistakenly use Gynura segetum as Panax notoginseng, which causes serious liver damage. There is no comparative study on the metabolism of Gynura segetum and Panax notoginseng in the literature. This study was conducted to compare the difference between Panax notoginseng and its counterfeit Gynura segetum by using metabolomics method.

Methods:

In this paper, an ultra performance liquid chromatography coupled to quadrupole time-offlight mass spectrometric(UPLC-Q/TOF/MS) were used to detect the type of endogenous metabolites in urine and plasma of three groups (normal group, ethanol extract of panax notoginseng, decoction of Gynura segetum respectively, and different multivariate statistical analysis methods were established.

Results:

In this experiment, main urine biomarkers were L-glutamate, L-methionine, cytidine, and Ltyrosine in the Panax notoginseng group, which are phytosphingosine, creatine and sphinganine in the Gynura segetum group. The plasma biomarkers identified in the Panax notoginseng group were arachidonic acid, L-tyrosine, linoleic acid, alpha-linolenoyl ethanolamide and lysoPC (15:0), and in the Gynura segetum group are L-arginine, L-valine, arachidonic acid and LysoPC(18:2(9Z,12Z)).

Conclusion:

There are significant difference between Panax notoginseng and Gynura segetum in biomarkers from the perspective of metabolomics in the body.

Glycogen Metabolism Impairment via Single Gene Mutation in the glgBXCAP Operon Alters the Survival Rate of Escherichia coli Under Various Environmental Stresses

Glycogen is a highly branched polysaccharide that is widely present in all life domains. It has been identified in many bacterial species and functions as an important energy storage compound. In addition, it plays important roles in bacterial transmission, pathogenicity, and environmental viability. There are five essential enzymes (coding genes) directly involved in bacterial glycogen metabolism, which forms a single operon glgBXCAP with a suboperonic promoter in glgC gene in Escherichia coli. Currently, there is no comparative study of how the disruptions of the five glycogen metabolism genes influence bacterial phenotypes, such as growth rate, biofilm formation, and environmental survival, etc. In this study, we systematically and comparatively studied five E. coli single-gene mutants (ΔglgC, ΔglgA, ΔglgB, ΔglgP, ΔglgX) in terms of glycogen metabolism and explored their phenotype changes with a focus on environmental stress endurance, such as nutrient deprivation, low temperature, desiccation, and oxidation, etc. Biofilm formation in wild-type and mutant strains was also compared. E. coli wild-type stores the highest glycogen content after around 20-h culture while disruption of degradation genes (glgP, glgX) leads to continuous accumulation of glycogen. However, glycogen primary structure was abnormally changed in ΔglgP and ΔglgX. Meanwhile, increased accumulation of glycogen facilitates the growth of E. coli mutants but reduces glucose consumption in liquid culture and vice versa. Glycogen metabolism disruption also significantly and consistently increases biofilm formation in all the mutants. As for environmental stress endurance, glycogen over-accumulating mutants have enhanced starvation viability and reduced desiccation viability while all mutants showed decreased survival rate at low temperature. No consistent results were found for oxidative stress resistance in terms of glycogen metabolism disruptions, though ΔglgA shows highest resistance toward oxidation with unknown mechanisms. In sum, single gene disruptions in glgBXCAP operon significantly influence bacterial growth and glucose consumption during culture. Accumulation and structure of intracellular glycogen were also significantly altered. In addition, we observed significant changes in E. coli environmental viabilities due to the deletions of certain genes in the operon. Further investigations shall be focused on the molecular mechanisms behind these phenotype changes.

Investigation into archaeal extremophilic lifestyles through comparative proteogenomic analysis

Archaea are a group of primary life forms on Earth and could thrive in many unique environments. Their successful colonization of extreme niches requires corresponding adaptations at proteogenomic level in order to maintain stable cellular structures and active physiological functions. Although some studies have already investigated the extremophilic lifestyles of archaeal species based on genomic features and protein structures, there is a lack of comparative proteogenomic analysis in a large scale. In this study, we explored 686 high-quality archaeal genomes (proteomes) sourced from the Pathosystems Resource Integration Center (PATRIC) database. General patterns of genomic features such as genome size, coding capacity (coding genes and non-coding regions), and G + C contents were re-confirmed. Protein domain distribution patterns were then identified across archaeal species. Domains with unknown functions (DUFs) and mini proteins were investigated in terms of their distributions due to their importance in archaeal physiological functions. In addition, physicochemical properties of protein sequences, such as stability, hydrophobicity, isoelectric point, aromaticity and amino acid compositions in corresponding archaeal groups were compared. Unique features associated with extremophilic lifestyles were observed, which suggested that evolutionary adaptations to different extreme environments had intrinsic impacts on archaeal protein features. Taken together, this systematic study facilitates a better understanding of the mechanisms behind the extremophilic lifestyles of archaeal species, which will further contribute to the evolutionary explorations of archaeal adaptations both experimentally and theoretically in the future studies.Communicated by Ramaswamy H. Sarma.

Characterization of glycogen molecular structure in the worm Caenorhabditis elegans

Glycogen, a glucose homopolymer with many glucose chains, is the primary blood-sugar reservoir in many organisms. It comprises β particles (∼20 nm) which can bind together to form large α particles with a rosette morphology. When dimethyl sulfoxide (DMSO) is added to glycogen from diabetic livers, α particles break apart to β particles ('fragility'), possibly due to H-bond disruption; this is not seen in healthy livers. Glycogen α and β particles, and α-particle fragility, are observed in mammals and bacteria, and are examined here in the worm Caenorhabditis elegans, with glycogen from two C. elegans strains, cultured in normal and high-glucose conditions. There were mainly β particles, with some large α particles. Most particles were fragile in DMSO. Growing in a high-glucose medium results in more long chains and more fragility, consistent with previous observations in diabetic animal models. Why high glucose levels facilitate fragility is worthy of further investigation.

Effects of fasting on liver glycogen structure in rats with type 2 diabetes

Liver glycogen, a highly branched glucose polymer, is important for blood sugar homeostasis. It comprises α particles which are made of linked β particles; the molecular structure changes diurnally. In diabetic liver, the α particles are fragile, easily breaking apart into β particles in chaotropic agents such as dimethyl sulfoxide. We here use size-exclusion chromatography to study how fasting changes liver-glycogen structure in vivo for mice in which type-2 diabetes had previously been induced. Diabetic glycogen degraded enzymatically more quickly in the fasted animals than did glycogen without fasting, with fewer α particles, which however were still fragile. The glycogen had fewer long chains and more shorter chains after fasting. This study gives an overview of the in vivo dynamic changes in α-particles under starvation conditions in both normal and diabetic livers.

Ultra-Early Diagnosis of Acute Myocardial Infarction in Rats Using Ultrasound Imaging of Hollow Double-Layer Silica Nanospheres

Timely diagnosis of acute myocardial infarction (AMI) strongly impacts the survival rate of patients. The authors report the development of a two-shell hollow silica contrast agent useful for ultrasound (US) imaging, which is able to provide ultra-early diagnosis of AMI. To target the characterization of fast blood flow and high blood pressure in the heart, two shells of hollow silica are adopted with opposite polarities, which assemble based on amino and perfluorodecyl silanes. The external amino silane facilitates the attachment of disease-targeted groups, while the internal perfluorodecyl silane provides great US imaging contrast. The material also possesses superior water dispersity, controllable morphology, low toxicity, and biodegradability both in vitro and in vivo, thus promoting its applications in the ultra-early diagnosis of AMI in rats, and is particularly useful for delineation of myocardial necrosis sites.

Recent progress in the structure of glycogen serving as a durable energy reserve in bacteria

Glycogen is conventionally considered as a transient energy reserve that can be rapidly synthesized for glucose accumulation and mobilized for ATP production. However, this conception is not completely applicable to prokaryotes due to glycogen structural heterogeneity. A number of studies noticed that glycogen with small average chain length g_c in bacteria has the potential to degrade slowly, which might prolong bacterial environment survival. This phenomenon was previously examined and later formulated as the durable energy storage mechanism hypothesis. Although recent research has been warming to the hypothesis, experimental validation is still missing at current stage. In this review, we summarized recent progress of the hypothesis, provided a supporting mathematical model, and explored the technical pitfalls that shall be avoided in glycogen study.

Molecular Structure of Glycogen in Escherichia coli

Glycogen, a randomly branched glucose polymer, provides energy storage in organisms. It forms small β particles which in animals bind to form composite α particles, which give better glucose release. Simulations imply β particle size is controlled only by activities and sizes of glycogen biosynthetic enzymes and sizes of polymer chains. Thus, storing more glucose requires forming more β particles, which are expected to sometimes form α particles. No α particles have been reported in bacteria, but the extraction techniques might have caused degradation. Using milder glycogen extraction techniques on Escherichia coli, transmission electron microscopy and size-exclusion chromatography showed α particles, consistent with this hypothesis for α-particle formation. Molecular density and size distributions show similarities with animal glycogen, despite very different metabolic processes. These general polymer constraints are such that any organism which needs to store and then release glucose will have similar α and β particle structures: a type of convergent evolution.

Multifunctional Fe3O4@Polydopamine@DNA-Fueled Molecular Machine for Magnetically Targeted Intracellular Zn2+ Imaging and Fluorescence/MRI Guided Photodynamic-Photothermal Therapy

For the precise treatment of tumors, it is necessary to develop a theranostic nanoplatform that has both diagnostic and therapeutic functions. In this article, we designed a new theranostic probe for fluorescence imaging of Zn²⁺ and fluorescence/MRI guided magnetically targeted photodynamic-photothermal therapy. The fluorescence imaging of Zn²⁺ was based on an endogenous ATP-driven DNA nanomachine that could perform repetitive stand displacement reaction. It modifies all units on a single PDA/Fe₃O₄ nanoparticle containing a hairpin-locked initiated strand activated by a target molecule in cells, a two-stranded fuel DNA triggered by ATP, and a two-stranded DNA track responding to an initiated strand and fuel DNA. After entering the cell, the intracellular target Zn²⁺ initiates the nanomachine via an autocatalytic cleavage reaction, and the machine programmatically and gradually runs on the assembled DNA track via fuel DNA driving and the intramolecular toehold-mediated stand displacement reaction. The Fe₃O₄ core first exhibits magnetic targeting, increasing the ability of nanoparticles to enter tumor cells at the tumor site. The Fe₃O₄ could also be employed as a powerful magnetic resonance imaging (MRI) contrast agent and guided therapy. Using 808 nm laser and 635 nm laser irradiation together at the tumor site, the PDA nanoshell produced an excellent photothermal effect and the TMPyP4 molecules entering the cell generated reactive oxygen species, followed by cell damage. A series of reliable experiments suggested that the Fe₃O₄@PDA@DNA nanoprobe showed superior fluorescence specificity, MRI, a remarkable photothermal/photodynamic therapy effect, and favorable biocompatibility. This theranostic nanoplatform offered a split-new insight into tumor fluorescence and MRI diagnosis as well as effective tumor therapy.

Assessment of quinazolinone derivatives as novel non-nucleoside hepatitis B virus inhibitors

Hepatitis B virus (HBV) infection is a worldwide public health issue. Search for novel non-nucleoside anti-HBV agents is of great importance. In the present study, a series of quinazolinones derivatives (4a-t and 5a-f) were synthesized and evaluated as novel anti-HBV agents. Among them, compounds 5e and 5f could significantly inhibit HBV DNA replication with IC₅₀ values of 1.54 μM and 0.71 μM, respectively. Interestingly, the selective index values of 5f was higher than that of lead compound K284-1405, suggesting 5f possessed relatively safety profile than K284-1405. Notably, 5e and 5f exhibited remarkably anti-HBV activities against lamivudine and entecavir resistant HBV strain with IC₅₀ values of 1.90 and 0.84 μM, confirming their effectiveness against resistant HBV strain. In addition, molecular docking studies indicated that compounds 5e and 5f could well fit into the dimer-dimer interface of HBV core protein dominated by hydrophobic interactions. Notably, their binding modes were different from the lead compound K284-1405, which may be attributed to the additional substituent groups in the quinazolinone scaffold. Taken together, 5e and 5f possessed novel chemical structure and potent anti-HBV activity against both drug sensitive and resistant HBV strains, thus warranting further research as potential non-nucleoside anti-HBV candidates.

DNA-Templated Silver Nanocluster/Porphyrin/MnO2 Platform for Label-Free Intracellular Zn2+ Imaging and Fluorescence-/Magnetic Resonance Imaging-Guided Photodynamic Therapy

Developing a theranostic platform that integrates diagnosis and treatment in one single nanostructure is necessary for efficient tumor treatment. Here, we presented a novel theranostic nanoprobe for nonlabeled fluorescence imaging of Zn²⁺ and 635 nm red light-triggered photodynamic therapy (PDT) by a multifunctional DNA-templated silver nanocluster/porphyrin/MnO₂ nanoplatform. MnO₂ nanosheets adsorbed hairpin DNA-silver nanoclusters (AgNCs) and porphyrin (P) by facile physisorption, which accelerate the transfection of nanoprobes and P into tumor cells. After entering the cells, the biodegradation of MnO₂ nanosheets by glutathione and acidic hydrogen peroxide released AgNCs for label-free Zn²⁺ fluorescence imaging by the hairpin DNA-fueled dynamic self-assembly of three-way DNA junction architectures, and the released Mn²⁺ could act as an effective magnetic resonance imaging (MRI) contrast agent. In addition, MnO₂ was decomposed in the acidic H₂O₂-ample environment and produced O₂ to overbear hypoxia-related PDT resistance, highly efficient PDT was obtained by excess singlet oxygen (¹O₂) release of P-AgNCs-MnO₂ nanoprobes under light irradiation compared with free P. In vitro and in vivo studies confirmed that P-AgNCs-MnO₂ exhibited high fluorescence specificity, excellent PDT effect, and good biocompatibility and could be used as a contrast agent for MRI. This theranostic platform provided a new avenue for the fluorescence and MRI diagnosis of tumors and efficient tumor treatment.

Microporous polymer based on the new compound "bi-(4-vinyl phenylquinoline) amide" for enrichment and quantitative determination of lamotrigine in rat and human serum

Lamotrigine is one of the most widely used antiepileptic drugs in the treatment of epilepsy. This kind of drug needs to be used in the long term and should be quantitatively detected in the blood of patients to avoid drug toxicity caused by individual differences and environmental and pathological changes in the process of taking. The detection of antiepileptic drugs in human blood is challenging because of their low contents and the interference of complex matrices. Thus, the sample enrichment method has been commonly used to improve the sensitivity of detection. In this work, we have synthesized a new "bi-(4-vinyl phenylquinoline) amide" compound and used it as the monomer to produce the hyper-cross-linked microporous polymer for the enrichment of lamotrigine. This material has a high adsorption capacity, specificity, and linearity, which can improve the detection sensitivity of lamotrigine by high-performance liquid chromatography (HPLC). The mechanism of this phenomenon has also been investigated. Finally, we have developed the microporous polymer enrichment coupled with HPLC method for the quantitative determination of lamotrigine in rat and human serum samples. This method has excellent precision, accuracy, and recovery, meeting the test of biological sample. The low limit of quantitation was 0.625 μg/mL. Graphical abstract.

Simultaneous Monitoring of Amyloid-β (Aβ) Oligomers and Fibrils for Effectively Evaluating the Dynamic Process of Aβ Aggregation

Herein, we provide a proof of concept for a novel strategy that targets the assessment of the aggregation of amyloid-β (Aβ) by simultaneously determining its oligomers (Aβo) and fibrils (Aβf) in one analytical system. By fabricating and combining two immunosensors for Aβo and Aβf, respectively, we constructed a two-channel electrochemical system. The ratio of Aβf to Aβo was calculated and taken as a possible criterion for evaluating the extent of aggregation. Thereby, the presence of and transformation between oligomers and fibrils were accurately probed by incubating the Aβ monomer for different times and then calculating the ratios of Aβf to Aβo. The applicability of this method was further validated by tracking the dynamic progress of Aβ aggregation in the cerebrospinal fluid and tissues of Alzheimer's disease (AD) rats, which revealed that the ratio of Aβf to Aβo in rat brain gradually increased with the progression of AD, which was indicative of the severity of peptide aggregation during this process. Overall, this study represents the first example of a quantitative strategy for precisely evaluating the aggregation process that is related to pathological events in AD brain.