Nature's carriers: leveraging extracellular vesicles for targeted drug delivery.

With the rapid development of drug delivery systems, extracellular vesicles (EVs) have emerged as promising stars for improving targeting abilities and realizing effective delivery. Numerous studies have shown when compared to conventional strategies in targeted drug delivery (TDD), EVs-based strategies have several distinguished advantages besides targeting, such as participating in cell-to-cell communications and immune response, showing high biocompatibility and stability, penetrating through biological barriers, etc. In this review, we mainly focus on the mass production of EVs including the challenges and strategies for scaling up EVs production in a cost-effective and reproducible manner, the loading and active targeting methods, and examples of EVs as vehicles for TDD in consideration of potential safety and regulatory issues associated. We also conclude and discuss the rigor and reproducibility of EVs production, the current research status of the application of EVs-based strategies to targeted drug delivery, clinical conversion prospects, and existing chances and challenges.

Effects of a chitosan nanoparticles encapsulation on the properties of litchi polyphenols.

Litchi polyphenols have very specific biological activities. Nevertheless, the low and inconsistent oral bioavailability and instability hinder the further application of litchi polyphenols in food systems. This work prepared litchi polyphenols loaded chitosan nanoparticles (LP-CSNPs) by ionic gelation method to enhance the encapsulation on the properties of litchi polyphenols. The optimum conditions of formation via single factors and the Box-Behnken design were chitosan (CS) concentration 1.065 mg/mL, sodium tripolyphosphate (TPP) concentration 0.975 mg/mL, and the mass ratios of polyphenols and CS 1:1 with encapsulation efficiency (EE%) of 45.53%. LP-CSNPs presented the nanosized range of particle size (mean 170 nm), excellent polydispersity index (PDI) (0.156 ± 0.025), and zeta potential values (+ 35.44 ± 0.59). The in vitro release in simulated gastric fluid (pH 1.2) and intestinal fluid (pH 6.8) during 100 h was 58.34% and 81.68%, respectively. LP-CSNPs could effectively improve the storage stability and had great antibacterial activity compared with unencapsulated litchi polyphenols.

Synthesis, and biological evaluation of pyrazole matrine derivatives as an insecticide against Spodoptera frugiperda.

As one of the major threats to global food security, Spodoptera frugiperda (S. frugiperda) is highly gaining consideration due to its severe damage. Matrine is a widely and effectively used botanical insecticide in controlling S.frugiperda but lacks a rapidly available effect. To further improved the insecticidal activity of matrine based on combination principles, this work synthesized five new pyrazole matrine derivatives (PMDs) using Michael addition and investigated insecticidal activity against 2nd instar larvae of S. frugiperda(in vivo) and its isolated cell(in vitro). Our result demonstrated that PMDs show higher pesticidal activity than that matrine in both in vitro and in vivo assays. The most toxic derivatives in vitro and in vivo are PMD-3 and PMD-1, with IC50 of 2.49 mM and LC50 of 22.76 mg/L respectively. This research also investigates the anti-proliferation mechanism of PMDs based on isolated cells. PMDs decrease mitochondria membrane potential, arrested cell cycle at the G2/M phase, and upregulated Caspase 3, Caspase 9, and Apaf-1 to induce Caspase-dependent apoptosis. For Caspase-independent apoptosis, AIF and Endo G were found to be upregulated. Besides, pro-apoptotic factors like p53, IBM-1, and anti-apoptotic factors like IAP were upregulated. Moreover, we supposed that there was a linkage between lysosomes and PMD-induced apoptosis according to increased apoptosis rate, activated lysosomes, and upregulated Cathepsin B. This research provides new ideas for the synthesis of matrine derivatives and further demonstrated the anti-proliferation mechanism of PMDs.

Excitatory somatostatin interneurons in the dentate gyrus drive a widespread seizure network in cortical dysplasia.

Seizures due to cortical dysplasia are notorious for their poor prognosis even with medications and surgery, likely due to the widespread seizure network. Previous studies have primarily focused on the disruption of dysplastic lesions, rather than remote regions such as the hippocampus. Here, we first quantified the epileptogenicity of the hippocampus in patients with late-stage cortical dysplasia. We further investigated the cellular substrates leading to the epileptic hippocampus, using multiscale tools including calcium imaging, optogenetics, immunohistochemistry and electrophysiology. For the first time, we revealed the role of hippocampal somatostatin-positive interneurons in cortical dysplasia-related seizures. Somatostatin-positive were recruited during cortical dysplasia-related seizures. Interestingly, optogenetic studies suggested that somatostatin-positive interneurons paradoxically facilitated seizure generalization. By contrast, parvalbumin-positive interneurons retained an inhibitory role as in controls. Electrophysiological recordings and immunohistochemical studies revealed glutamate-mediated excitatory transmission from somatostatin-positive interneurons in the dentate gyrus. Taken together, our study reveals a novel role of excitatory somatostatin-positive neurons in the seizure network and brings new insights into the cellular basis of cortical dysplasia.

(+)-Borneol enantiomer ameliorates epileptic seizure via decreasing the excitability of glutamatergic transmission.

Epilepsy is one common brain disorder, which is not well controlled by current pharmacotherapy. In this study we characterized the therapeutic potential of borneol, a plant-derived bicyclic monoterpene compound, in the treatment of epilepsy and elucidated the underlying mechanisms. The anti-seizure potency and properties of borneol were assessed in both acute and chronic mouse epilepsy models. Administration of (+)-borneol (10, 30, 100 mg/kg, i.p.) dose-dependently attenuated acute epileptic seizure in maximal-electroshock seizure (MES) and pentylenetetrazol (PTZ)-induced seizure models without obvious side-effect on motor function. Meanwhile, (+)-borneol administration retarded kindling-induced epileptogenesis and relieved fully kindled seizures. Importantly, (+)-borneol administration also showed therapeutic potential in kainic acid-induced chronic spontaneous seizure model, which was considered as a drug-resistant model. We compared the anti-seizure efficacy of 3 borneol enantiomers in the acute seizure models, and found (+)-borneol being the most satisfying one with long-term anti-seizure effect. In electrophysiological study conducted in mouse brain slices containing the subiculum region, we revealed that borneol enantiomers displayed different anti-seizure mechanisms, (+)-borneol (10 µM) markedly suppressed the high frequency burst firing of subicular neurons and decreased glutamatergic synaptic transmission. In vivo calcium fiber photometry analysis further verified that administration of (+)-borneol (100 mg/kg) inhibited the enhanced glutamatergic synaptic transmission in epilepsy mice. We conclude that (+)-borneol displays broad-spectrum anti-seizure potential in different experimental models via decreasing the glutamatergic synaptic transmission without obvious side-effect, suggesting (+)-borneol as a promising anti-seizure compound for pharmacotherapy in epilepsy.

Synthesis of Halopyrazole Matrine Derivatives and Their Insecticidal and Fungicidal Activities.

Matrine is a traditional botanical pesticide with a broad-spectrum biological activity that is widely applied in agriculture. Halopyrazole groups are successfully introduced to the C13 of matrine to synthesize eight new derivatives with a yield of 78-87%. The insecticidal activity results show that the introduction of halopyrazole groups can significantly improve the insecticidal activity of matrine on Plutella xylostella, Mythimna separata and Spodoptera frugiperda with a corrected mortality rate of 100%, which is 25-65% higher than matrine. The fungicidal activity results indicate that derivatives have a high inhibitory effect on Ceratobasidium cornigerum, Cibberella sanbinetti, Gibberrlla zeae and Collectot tichum gloeosporioides. Thereinto, 4-Cl-Pyr-Mat has the best result, with an inhibition rate of 23-33% higher than that of matrine. Therefore, the introduction of halogenated pyrazole groups can improve the agricultural activity of matrine.

Reply to Schramm, L. Comment on "Li et al. BDP1 Variants I1264M and V1347M Significantly Associated with Clinical Outcomes of Pediatric Neuroblastoma Patients Imply a New Prognostic Biomarker: A 121-Patient Cancer Genome Study. Diagnostics 2021, 11, 2364".

We thank Professor Laura Schramm for her comment on the history and clarification of BDP1 nomenclature, her contribution to gene cloning [...].

BDP1 Variants I1264M and V1347M Significantly Associated with Clinical Outcomes of Pediatric Neuroblastoma Patients Imply a New Prognostic Biomarker: A 121-Patient Cancer Genome Study.

BACKGROUND: Neuroblastoma (N.B.) is the most common tumor in children. The gene BDP1 (B Double Prime 1) plays a role in cancers but is less known in N.B. Thus, we conducted this study to investigate the value of BDP1 mutations in N.B. METHODS: A dataset of 121 NB patients from the Cancer Genome Atlas database was used to analyze BDP1 gene mutations by RNA sequencing. Kaplan-Meier estimates were performed for overall survival (O.S.) analysis on BDP1 variants, and Cox's proportional hazards regression model was used for multivariate analysis. RESULTS: In 121 NB patients, we identified two variants of BDP1 associated with N.B., located at chr5:71511131 and chr5:71510884. The prevalence of these BDP1 variants, I1264M and V1347M, was 52.9% (64/121) and 45.5% (55/121), respectively. O.S. analysis showed a significant difference between subgroups with or without BDP1 variants (p < 0.05). Multivariate analysis further revealed that BDP1ariants were independent prognostic variables in N.B. (p < 0.05). CONCLUSION: Our results suggest BDP1 variants are associated with significantly improved clinical outcomes in N.B., thus providing clinicians with a new tool.

[Study on inhibitory effect of Ag+-loaded TiO2 on the biofilm of Staphylococcus aureus].

OBJECTIVE: To observe the antibacterial effect of Ag+-loaded TiO2 (Ag-TiO2) and Ag-TiO2 coated endotracheal tube (ETT) on the bacterial biofilm (BF) of Staphylococcus aureus. METHODS: 2, 3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) colorimetric method was used to detect minimal inhibitory concertation (MIC) of Ag-TiO2 for inhibition of BF of Staphylococcus aureus. The Ag-TiO2 coated ETT were prepared, and divided into 11 mg/L, 8 mg/L, 5 mg/L, 2 mg/L and 0 mg/L ETT group, according to the concentration gradient, then impregnated in the liquid with Staphylococcus aureus at a concentration of 1.0×109 cfu/L. The influence of antibacterial coated ETT on the formation of Staphylococcus aureus BF was determined by detecting the colonies of bacteria and BF on the ETT. RESULTS: Ag-TiO2 had a significant inhibitory effect on Staphylococcus aureus BF in a concentration-dependent manner, and its MIC was 10 mg/L. Ag-TiO2 coated ETT has significant anti-Staphylococcus aureus BF effect, and the higher the concentration, the stronger the effect. The absorbance (A) values of Ag-TiO2 5 mg/L, 8 mg/L, 11 mg/L ETT groups were significantly lower than that in control group (0.176±0.004, 0.147±0.002, 0.094±0.002 vs. 0.267±0.045, all P < 0.05). The inhibitory rates of Ag-TiO2 2 mg/L, 5 mg/L, 8 mg/L ETT groups were increased gradually, and 11 mg/L Ag-TiO2 coated ETT group had the highest inhibitory rate for BF, the inhibitory rates were 6.4%, 34.1%, 44.9% and 64.8%, respectively. CONCLUSIONS: Both Ag-TiO2 and Ag-TiO2 coated ETT have significant inhibitory effects on Staphylococcus aureus BF.

Continued gefitinib retreatment beyond progression in patients with advanced non-small cell lung cancer harboring sensitive EGFR mutations.

PURPOSE: To evaluate the effectiveness and safety of gefitinib retreatment beyond disease progression in patients with advanced non-small cell lung cancer (NSCLC) with sensitive epidermal growth factor receptor (EGFR) mutations. METHODS: Data from patients with stage III/IV NSCLC were analyzed retrospectively. Patients with sensitive EGFR mutations received first-line treatment with gefitinib followed by retreatment with gefitinib after disease progression. Progression-free survival (PFS) after the first treatment (PFS-1) was defined as the time to progression or death using the Response Evaluation Criteria in Solid Tumors criteria (RECIST) v1.1 criteria. The second PFS (PFS-2) was defined as the interval between the first and second progressions, at the investigator's discretion. Toxicities were recorded in accordance with the National Cancer Institute (NCI)-Common Terminology Criteria (CTC) version 4.0. RESULTS: Sixteen patients aged 53 to 80 years (median 66 years) were included in the analysis. The median PFS-1 and PFS-2 were 10.0 months and 14.0 months, respectively. The median overall survival (OS) was 36.0 months. No toxicity of grade 3 or worse was observed. CONCLUSIONS: Our findings suggest that gefitinib retreatment beyond disease progression may be an effective and tolerable approach for NSCLC patients with sensitive EGFR mutations.

Synthesis, characterization of two matrine derivatives and their cytotoxic effect on Sf9 cell of Spodoptera frugiperda.

The invasion of Spodoptera frugiperda has imposed a serious impact on global food security. Matrine is a botanical pesticide with a broad spectrum of insecticidal activity which was recommended for controlling Spodoptera frugiperda. In order to discover effective insecticide for Spodoptera frugiperda, two matrine derivatives modified with carbon disulfide and nitrogen-containing groups were systhesized. And their inhibition activities on Sf9 cell were evaluated. The structural configuration of compounds were characterized by IR, HPLC, MS, NMR and XRD, with yields of 52% and 65%, respectively. The IC50 of the two newly synthesized compounds on Sf9 cell reduced to 0.648 mmol/L and 1.13 mmol/L, respectively, compared with that of matrine (5.330 mmol/L). In addition, microscopic observation of Sf9 cell treated with the compounds showed that the number of adherent cells decreased, the cells shrunk, vacuolated and apoptotic bodies appeared. The two newly synthesized compounds exhibited better inhibitory effect on Sf9 cell than that of the parent matrine, suggesting that the positive effect of the introduction of 1-pyrrolidinecarbodithioate and diethylcarbamodithioate groups to matrine. The morphological observation of Sf9 cell induced by derivatives indicated that apoptosis induction may be a mechanism that inhibits insect cell proliferation and exerts insecticidal effect.

Semi-synthesis and characterization of some new matrine derivatives as insecticidal agents.

BACKGROUND: Matrine is an important traditional plant-derived insecticide with broad-spectrum activity. However, due to its moderate activity, matrine is mainly applied in combination with other pesticides. In order to discover new potential natural-product-based crop protection agents, a series of matrine derivatives characterized by cyclohexylamine group were synthesized to screen their insecticidal activity against seven typically agricultural pests. RESULTS: The structural configurations of compounds were characterized by IR, 1 H NMR, 13 C NMR, MS and XRD, with the pure yields of 42%, 65% and 71%, respectively. Although all compounds showed poor insecticidal activity against five lepidoptera pests, the compounds 2 and 4 displayed remarkable insecticidal activities against Lipaphis erysimi and Mulberry Root-Knot Nematode with a concentration-dependent manner within 0.5~1.5 mg/ mL. Compared with matrine (60%), compounds 2 and 4 exhibited potent insecticidal activities against L. erysimi, with a corrected mortality of 83.3% and 89.7%, respectively. They also showed excellent control effects on Mulberry Root-Knot Nematode, with corrected mortality as high as 88% and 80%, respectively. CONCLUSION: All four synthesized matrine derivatives showed poor insecticidal activity against five lepidoptera pests, but the compounds 2 and 4 exhibited much stronger insecticidal activities against L. erysimi and Mulberry Root-Knot Nematode than matrine. Combined with the structural characteristics of compounds 1~4, we conclude that 4-methylcyclohexylamine, not the carbon disulfide group or cyclohexylamine group alone, mainly contributed to the improvement of insecticidal activities of matrine derivatives against these two agricultural pests. This work provides a direction and foundation for structural optimization of the matrine pesticides in the future. © 2020 Society of Chemical Industry.

Synthesis, characterization and in vitro biological evaluation of two matrine derivatives.

Matrine is a traditional Chinese medicine and botanical pesticide with broad biological activities, including pharmacological and agricultural activities. In present work, two matrine derivatives have been successfully synthesized via introducing indole and cyclohexylamino to 13 position of matrine, respectively, with sophocarpine as starting material, and structurally characterized via infrared spectroscopy(IR), MS, 1 H NMR, 13 C NMR and X-ray crystal diffraction. The results of the in vitro biological activity tests showed that these two matrine derivatives exhibited even better activities against human cancer cells Hela229 and insect cell line Sf9 from Spodoptera frugiperda (J. E. Smith) than that of parent matrine, suggesting that the heterocyclic or cyclic group can dramatically increase the biological activity of matrine. It is worth to mention that 13-indole-matrine could possibly inhibit the growth of insect cells or human cancer cells by inducing cell apoptosis. The results of the present study provide useful information for further structural modifications of these compounds and for exploring new, potent anti-cancer agents and environment friendly pesticides.

Bactericidal mechanisms and effector targets of TiO2 and Ag-TiO2 against Staphylococcus aureus.

PURPOSE: In our previous study, Ag+-loaded TiO2 and Ag+-loaded SiO2 coatings for tracheal intubation were prepared to prevent ventilator-associated pneumonia (VAP), but the antimicrobial targets and the underlying mechanisms of TiO2 and Ag-TiO2 (Ag+) are still unclear. We attempted to elucidate the antimicrobial activity and potential mechanisms against Staphylococcus aureus. METHODOLOGY: The study tested the TiO2 and Ag+ bacteriostatic activity against S. aureus strains by MIC assays and S. aureus growth curves, lesion in the membranes by surface hydrophobicity tests, conductivity tests and measurements of DNA and RNA contents in S. aureus cultures, and investigated the inhibition of soluble protein and nucleic acid synthesis by measurements of soluble protein content, fluorescent intensity and nucleic acid content of living S. aureus. RESULTS: The MIC values of TiO2 and Ag+ were 1.6 mg ml-1 and 5.781 µg ml-1. TiO2 and Ag+ could inhibit the growth of S. aureus. After treatment with TiO2 and Ag+, the surface hydrophobicity was significantly reduced, the conductivity of cultures increased, and DNA and RNA content in cultures showed no obvious changes. The expressions of soluble proteins and nucleic acid contents of living S. aureus were reduced after treatment with TiO2 and Ag+. CONCLUSION: TiO2 and Ag+ could cause slight lesion in the membrane to affect S. aureus membrane permeability, but not decomposition of membrane. Moreover, TiO2 and Ag+ could lead to reduced expression of soluble protein by inhibiting the synthesis of nucleic acids, thereby further inhibiting the growth of S. aureus.

Preparation of silicon-modified antimicrobial polyethylene endotracheal tubes.

Antimicrobial coating of polyethylene endotracheal tubes (PE ETTs) has proven to be an effective method to prevent endoluminal biofilm formation. A transparent silicon-modified antimicrobial PE ETT was obtained by coating PE with a SiO2 /γ-methacryloxypropyl trimethoxy silane (KH-570)/methyltriethoxysilane (MTES)/Ag-SiO2 solution prepared by chemically mixing Ag-SiO2 with SiO2 /KH-570/MTES in solution via a dip-coating method, with tetraethyl orthosilicate (TEOS) as the inorganic silicon source, followed by drying. All the films were characterized by various techniques, including the pencil hardness test, infrared spectroscopy, scanning electron microscopy, UV-vis analysis, and inductively coupled plasma mass spectrometry (ICP-MS). The results indicated that the TEOS/KH-570/MTES/Ag-SiO2 (15:6:1:0.6-1.0) films, which exhibited simple in-solution film formation on PE ETTs, had a homogeneous morphology, high transmittance above 87%, high hardness of 5H and strong adhesion to the tubes. The concentration of Ag+ ion dissolved out from the antibacterial coating is very low in ICP-MS results. The antibacterial test results show that the antibacterial coatings have excellent antibacterial property with antibacterial ratio up to 93.5% when Ag-SiO2 content is 2.6%. In pyrogen test and hemolytic test, the body temperature of rabbits rise 0.03°c for 3 h after inserting antibacterial PE ETT, and the hemolytic ratio is 0.7512%, which conform to the requirements of biomedical material. The results preliminarily proved that the antibacterial materials could be a good candidate of medical catheter material application or medical device surface coating materials. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 91-98, 2017.

Emodin prevents intima thickness via Wnt4/Dvl-1/ß-catenin signaling pathway mediated by miR-126 in balloon-injured carotid artery rats.

Neointimal proliferation after vascular injury is a key mechanism of restenosis, a major cause of percutaneous transluminal angioplasty failure and artery bypass occlusion. Emodin, an anthraquinone with multiple physiological activities, has been reported to inhibit proliferation of vascular smooth muscle cells (VSMCs) that might cause intimal arterial thickening. Thus, in this study, we established a rat model of balloon-injured carotid artery and investigated the therapeutic effect of emodin and its underlying mechanism. Intimal thickness was analyzed by hematoxylin and eosin staining. Expression of Wnt4, dvl-1, ß-catenin and collagen was determined by immunohistochemistry and/or western blotting. The proliferation of VSMC was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and electron microscopy. MicroRNA levels were quantified by real-time quantitative PCR. Emodin relieved injury-induced artery intimal thickness. Results of western blots and immunohistochemistry showed that emodin suppressed expression of signaling molecules Wnt4/Dvl-1/ß-catenin as well as collagen protein in the injured artery. In addition, emodin enhanced expression of an artery injury-related microRNA, miR-126. In vitro, MTT assay showed that emodin suppressed angiotensin II (AngII)-induced proliferation of VSMCs. Emodin reversed AngII-induced activation of Wnt4/Dvl-1/ß-catenin signaling by increasing expression of miR-126 that was strongly supported by transfection of mimic or inhibitor for miR-126. Emodin prevents intimal thickening via Wnt4/Dvl-1/ß-catenin signaling pathway mediated by miR-126 in balloon-injured carotid artery of rats.

[Study on antibacterial property of silver loaded titanium dioxide antibacterial coated endotracheal intubation tube].

OBJECTIVE: To study the antibacterial property of silver loaded titanium dioxide (TiO2) antibacterial coated endotracheal intubation tube, and to determine the minimum effective antibacterial concentration. METHODS: Intubation tubes coated with different concentrations of antibacterial agents were prepared with sol gel method. Polyethylene endotracheal intubation tubes were used as substrate, and silver loaded TiO2 was used as the antibacterial agent. According to the different antibacterial concentrations of the antibacterial agent, the tubes were divided into nine groups: 10.0% group, 5.0% group, 2.0% group, 1.5% group, 1.0% group, 0.8% group, 0.6% group, 0.2% group, and control group. They were respectively immersed in three standard bacteria suspensions with 1.0×10(5) cfu/mL: Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Together with standard bacteria liquid group, there were 10 experimental groups. They were kept overnight for 24 hours. 10 µL of respective culture medium was smeared on blood agar culture medium. After being cultured overnight in 35 centigrade, the number of bacteria colonies was respectively counted. RESULTS: In 1.0×10(5) cfu/mL of three standard bacteria liquids with antibacterial agent concentration ≥1.0%, three bacterial colonies had un-obviously growth rate. Almost the same strong antibacterial effects to achieve sterilizing rates of more than 98% was shown in each group of the antibacterial coating endotracheal intubation tubes (all P>0.05). As the antibacterial agent concentration decreased, three bacterial colonies were increasing gradually. Intermediate antibacterial effects were shown in tubes of 0.8% group, with significant statistic difference as compared with 1.0% and 0.6% groups [Pseudomonas aeruginosa: 7.300 (4.050, 8.350) vs. 0.200 (0.050, 1.200), 9.700(9.000, 10.000); Staphylococcus aureus: 4.100 (3.300, 4.650) vs. 0.000 (0.000, 0.150), 5.800 (5.350, 7.650); Escherichia coli: 1.400 (0.750, 3.750) vs. 0.050 (0.025, 0.050), 9.500 (8.500, 9.800), all P<0.01]. CONCLUSIONS: Silver loaded TiO2 antibacterial coated endotracheal intubation tube had definite antibacterial properties, which were related to the antibacterial concentration. Strong antibacterial effects were shown when antibacterial concentration was above 1.0%, with bacteria almost completely killed in the immersing liquid.