Sustained release of brimonidine from conjunctival sac insert to reduce intraocular pressure for glaucoma treatment.

BACKGROUND: Glaucoma is one of the major irreversible blinding eye diseases in the world. Reducing intraocular pressure (IOP) is the primary treatment option, and taking eye drops daily is the common method. However, short drug duration and poor bioavailability of eye drops may lead to unsatisfied therapeutic effects and inadequate patient compliance. METHODS: A brimonidine-loaded silicone rubber insert (BRI@SR@PT) was prepared by loading brimonidine into a surface-modified silicone rubber ring, followed by polydopamine/thermoplastic polyurethane coatings. The physical properties, in vitro cytocompatibility and drug release of BRI@SR@PT were investigated. The BRI@SR@PT was administrated in the conjunctival sac of rabbit eyes and its in vivo drug release, IOP-lowering efficacy and biosafety were assessed. RESULTS: The BRI@SR@PT presented great thermal stability and excellent elasticity. The BRI@SR@PT was able to release BRI sustainably for 28 days with little toxicity in vitro. Compared to BRI eye drops, the BRI@SR@PT effectively lowered IOP for 21 days based on the sustained BRI release with great biosafety when administrated in conjunctival sac of rabbit eyes in a noninvasive fashion. CONCLUSIONS: The conjunctival sac insert (BRI@SR@PT), as a promising drug-delivery platform, may provide a sustained IOP-lowering treatment for patients with ocular hypertension or glaucoma, without need for invasive procedures.

Obacunone, a Promising Phytochemical Triterpenoid: Research Progress on Its Pharmacological Activity and Mechanism.

Obacunone, a natural triterpenoid, is an active component of the herbs Dictamnus dasycarpus Turcz. and Phellodendron amurense Rupr, and an indicator of the herbs' quality. Owing to its multiple health benefits, several studies have investigated the multi-targeting potential action mechanisms of obacunone. To summarize recent developments on the pharmacological actions of obacunone and focus on the underlying molecular mechanisms and signaling networks, we searched PubMed, Europe PMC, Wiley Online Library, Web of Science, Google Scholar, Wanfang Medical Network, and China National Knowledge Infrastructure for articles published prior to March 2024. Existing research indicates obacunone has great potential to become a promising therapeutic option against tumors, fibrotic diseases, bone and cholesterol metabolism diseases, and infections of pathogenic microorganisms, among others. The paper contributes to providing up-to-date references for further research and clinical applications of obacunone.

Combined Therapy of Experimental Autoimmune Uveitis by a Dual-Drug Nanocomposite Formulation with Berberine and Dexamethasone.

Purpose: Autoimmune uveitis is a kind of sight-threatening ocular and systemic disorders. Recent treatments on autoimmune uveitis still remain many limitations due to extreme complexity and undetermined pathogenesis. In this study, a novel dual-drug nanocomposite formulation is developed to treat experimental autoimmune uveitis by a combined and sustained therapy method. Methods: The dual-drug nanocomposite formulation is constructed by integrating berberine (BBR)-loaded mesoporous silica nanoparticles (MSNs) into dexamethasone (DEX)-loaded thermogel (BBR@MSN-DEX@Gel). The BBR@MSN-DEX@Gel is characterized by transmission electron microscopy, dynamic light scattering, Fourier transform infrared spectrometer and rheometer. The in vitro drug release profile, cytotoxicity and anti-inflammation effectiveness of BBR@MSN-DEX@Gel on lipopolysaccharide-stimulated human conjunctival epithelial cells are investigated. After the in vivo drug release profile and biosafety of the dual-drug nanocomposite formulation are confirmed, its treatment effectiveness is fully assessed based on the induced experimental autoimmune uveitis (EAU) Lewis rat's model. Results: The dual-drug nanocomposite formulation has good injectability and thermosensitivity, suitable for administration by an intravitreal injection. The BBR@MSN-DEX@Gel has been found to sustainably release both drugs for up to 4 weeks. The carrier materials have minimal in vitro cytotoxicity and high in vivo biosafety. BBR@MSN-DEX@Gel presents obviously anti-inflammatory effectiveness in vitro. After administration of BBR@MSN-DEX@Gel into Lewis rat's eye with EAU by an intravitreal injection, the nanocomposite formulation significantly suppresses inflammatory reaction of autoimmune uveitis via a dual-drug combined and sustained therapy method, compared with the equivalent dose of single-component formulations. Conclusion: BBR@MSN-DEX@Gel serves as a promising dual-drug nanocomposite formulation for future treatment of autoimmune uveitis.

Aramid Fibers Modulated Polyethylene Separator as Efficient Polysulfide Barrier for High-Performance Lithium-Sulfur Batteries.

The separators with high absorbability of polysulfides are essential for improving the electrochemical performance of lithium-sulfur (Li-S) batteries. Herein, the aramid fibers coated polyethylene (AF-PE) films are designed by roller coating, the high polarity of AFs can strongly increase the binding force at AF/PE interfaces to guarantee the good stability of the hybrid film. As confirmed by the microscopic analysis, the AF-PE-6 film with the nanoporous structure exhibits the highest air permeability by the optimal coating content of AFs. The high absorbability of polysulfides for AF-PE-6 film can effectively hinder the migration of polysulfides and alleviate the shuttle effect of the Li-S battery. AF-PE-6 cell shows the specific capacity of 661 mAh g-1 at 0.1 C. After 200 charge/discharge cycles, the reversible specific capacity is 542 mAh g-1 with the capacitance retention of 82%, implying the excellent stability of AF-PE-6. The enhanced cell performance is attributed to the porous architecture of the aramid layer for trapping the dissolved sulfur-containing species and facilitating the charge transfer, as confirmed by SEM and EDS after 200 cycles. This work provides a facile way to construct the aramid fiber-coated separator for the inhibition of polysulfides in the Li-S battery.

UGT1A1 and UGT1A9 Are Responsible for Phase II Metabolism of Tectorigenin and Irigenin In Vitro.

Tectorigenin and irigenin are biologically active isoflavones of Belamcanda chinensis (L.) DC. Previous studies indicated that both compounds could be metabolized in vivo; however, the kinetic parameters of enzymes involved in the metabolization of tectorigenin and irigenin have not been identified. The aim of this study was to investigate UGTs involved in the glucuronidation of tectorigenin and irigenin and determine enzyme kinetic parameters using pooled human liver microsomes (HLMs) and recombinant UGTs. Glucuronides of tectorigenin and irigenin were identified using high-performance liquid chromatography (HPLC) coupled with mass spectrometry and quantified by HPLC using a response factor method. The results showed that tectorigenin and irigenin were modified by glucuronidation in HLMs. One metabolite of tectorigenin (M) and two metabolites of irigenin (M1 and M2) were detected. Chemical inhibition and recombinant enzyme experiments revealed that several enzymes could catalyze tectorigenin and irigenin glucuronidation. Among them, UGT1A1 and UGT1A9 were the primary enzymes for both tectorigenin and irigenin; however, the former mostly produced irigenin glucuronide M1, while the latter mostly produced irigenin glucuronide M2. These findings suggest that UGT1A1 and UGT1A9 were the primary isoforms metabolizing tectorigenin and irigenin in HLMs, which could be involved in drug-drug interactions and, therefore, should be monitored in clinical practice.

Simultaneous determination of eight constituents in rat plasma by HPLC-MS/MS and its application to a pharmacokinetic study after oral administration of Shejin-liyan Granule.

Shejin-liyan Granule (SJLY) is an effective traditional Chinese prescription medicine for the treatment of acute pharyngitis. In this study, a selective and convenient HPLC-MS/MS method was developed and validated for the simultaneous determination of the following eight constituents in the plasma: galuteolin, tectoridin, tectorigenin, iridin, irigenin, irisflorentin, arctiin and arctigenin. The plasma samples were prepared by a protein precipitation method using acetonitrile, and analysis was carried out on a C18 column using a gradient elution at a flow rate of 0.3 mL/min. The concentration of these analytes was quantified in the positive ion and multiple reaction monitoring modes. The method was validated for selectivity, linearity, accuracy, precision, recovery, matrix effect and sample stability. The obtained results were well within the acceptable limits. The established method was then successfully applied to study the pharmacokinetic profiles of the multiple constituents of Shejin-liyan Granule. According to the area under the curve and maximum concentration data, tectorigenin exhibited the highest exposure followed by arctigenin, irigenin, arctiin and irisflorentin. The concentrations of galuteolin, tectoridin and iridin were low, and a complete concentration-time curve could not be plotted. This research provides useful information for understanding the pharmacokinetics of Shejin-liyan Granule.

Application of High-Performance Liquid Chromatography Coupled with Linear Ion Trap Quadrupole Orbitrap Mass Spectrometry for Qualitative and Quantitative Assessment of Shejin-Liyan Granule Supplements.

A method for high-performance liquid chromatography coupled with linear ion trap quadrupole Orbitrap high-resolution mass spectrometry (HPLC-LTQ-Orbitrap MS) was developed and validated for the qualitative and quantitative assessment of Shejin-liyan Granule. According to the fragmentation mechanism and high-resolution MS data, 54 compounds, including fourteen isoflavones, eleven ligands, eight flavonoids, six physalins, six organic acids, four triterpenoid saponins, two xanthones, two alkaloids, and one licorice coumarin, were identified or tentatively characterized. In addition, ten of the representative compounds (matrine, galuteolin, tectoridin, iridin, arctiin, tectorigenin, glycyrrhizic acid, irigenin, arctigenin, and irisflorentin) were quantified using the validated HPLC-LTQ-Orbitrap MS method. The method validation showed a good linearity with coefficients of determination (r²) above 0.9914 for all analytes. The accuracy of the intra- and inter-day variation of the investigated compounds was 95.0-105.0%, and the precision values were less than 4.89%. The mean recoveries and reproducibilities of each analyte were 95.1-104.8%, with relative standard deviations below 4.91%. The method successfully quantified the ten compounds in Shejin-liyan Granule, and the results show that the method is accurate, sensitive, and reliable.

A core-shell structured polyacrylonitrile@poly(vinylidene fluoride-hexafluoro propylene) microfiber complex membrane as a separator by co-axial electrospinning.

A novel and facile core-shell structured polyacrylonitrile@poly (vinylidene fluoride-hexafluoro propylene) (PAN@PVDF-HFP) microfiber complex membrane was designed and fabricated via co-axial electrospinning, which was used as a separator in lithium-ion batteries. Poly(vinylidene fluoride-co-hexafluoro propene) (PVDF-HFP) and polyacrylonitrile (PAN) were used as the shell (outer) layer and core (inner), respectively. Structure, surface morphology, porosity, and thermal properties of the core-shell structured microfiber membranes were investigated. Compared with the traditional commercial porous polyethylene (PE) separator, the PAN@PVDF-HFP microfiber complex membranes exhibited higher porosity, superior thermal stability, better electrolyte wettability and higher ionic conductivity. As a consequence, batteries assembled with the PAN@PVDF-HFP microfiber complex membrane display better cycling stability and superior rate performance compared to those with the PE separator.

Mechanism analysis of colorectal cancer according to the microRNA expression profile.

The present study aimed to identify specific microRNAs (miRs) and their predicted target genes to clarify the molecular mechanisms of colorectal cancer (CRC). An miR expression profile (array ID, GSE39833), which consisted of 88 CRC samples with various tumor-necrosis-metastasis stages and 11 healthy controls, was downloaded from the Gene Expression Omnibus database. Subsequently, the differentially expressed miRs and their target genes were screened. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways of target genes were analyzed using the Database for Annotation Visualization and Integrated Discovery. A protein-protein interaction (PPI) network of the target genes was constructed using the Search Tool for the Retrieval of Interacting Genes database. The present study identified a total of 18 differentially expressed miRs (upregulated, 8; downregulated, 10) in the sera of the CRC patients compared with the healthy controls. Of these, 3 upregulated (let-7b, miR-1290 and miR-126) and 2 downregulated (miR-16 and miR-760) differentially expressed miRs and their target genes, including cyclin D1 (CCND1), v-myc avian myelocytomatosis viral oncogene homolog (MYC), phosphoinositide-3-kinase, regulatory subunit 2 (beta) (PIK3R2) and SMAD family member 3 (SMAD3), were significantly enriched in the CRC developmental pathway. All these target genes had higher node degrees in the PPI network. In conclusion, let-7b, miR-1290, miR-126, miR-16 and miR-760 and their target genes, CCND1, MYC, PIK3R2 and SMAD3, may be important in the molecular mechanisms for the progression of CRC.

A novel cyclic pentapeptide, H-10, inhibits B16 cancer cell growth and induces cell apoptosis.

Sansalvamide A, a cyclic depsipeptide isolated from a marine fungus of the Fusarium genus, exhibits significant antitumor activity. In the present study, H-10 (molecular formula, C38H55N5O6; molecular weight, 677.8732), a novel sansalvamide A derivative, demonstrated an inhibitory effect on the proliferation of murine melanoma B16 cells. It was confirmed that H-10 induced the apoptosis of the B16 cells. The inhibitory rate of various concentrations of H-10 on the B16 cells was measured by sulforhodamine B colorimetric assay, and the results revealed that the inhibitory effect of H-10 on the B16 cells occurred in a concentration-dependent manner. In addition, a growth curve model of the B16 cells treated with 50 µM H-10 revealed that the effect of H-10 also occurred in a time-dependent manner. The apoptotic morphology of the B16 cells was observed using an optical microscope. Following the treatment of the cells with 50 µM H-10 for 24 h, the cell apoptosis rate was analyzed using flow cytometry. The expression levels of caspase-3, -8 and -9 were analyzed by western blot analysis, and the results indicated that H-10 may induce the apoptosis of B16 cells.

Development and validation of a sensitive LC-MS-MS assay for the quantification of betulonic acid in rat plasma.

A rapid, sensitive and reliable liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of betulonic acid in rat plasma. The plasma samples were prepared by protein precipitation. Chromatographic separation was achieved on an Agela MG-C18 analytical column (50 × 2.1 mm, 5 µm) using methanol-water-formic acid (80:20:0.1, v/v/v) as the mobile phase with a constant flow rate of 0.6 mL/min. Mass detection was conducted by electrospray ionization in positive ion multiple reaction monitoring mode. The calibration curves were linear over a concentration range of 3.00-3,000 ng/mL for the analyte. The intra-day and inter-day accuracy and precision were within the acceptable limits of ±15% at all concentrations. The method was successfully applied for the estimation of betulonic acid in rat plasma from a preclinical pharmacokinetics study.

LC-MS-MS determination and pharmacokinetic study of the novel anti-tumor candidate drug TEOA in rats.

2α, 3α, 24-Trihydroxyurs-12-en-28-oic acid (TEOA) is a prominent ursane-type triterpenoid isolated from the root of Actinidia deliciosa, which has numerous pharmacological activities. To date, there is no report on the pharmacokinetic characterization of TEOA in biological samples. A specific, sensitive and robust liquid chromatography-tandem mass spectrometry (LC-MS-MS) method is reported for the fast assay of TEOA in rat plasma. Plasma sample preparation was based on liquid-liquid extraction with ethyl acetate. The extracted samples were determined using LC-MS-MS coupled with an atmospheric-pressure chemical ionization source in multiple-reaction monitoring scan mode. Chromatographic separation was achieved on a C18 Capcell PAK UG120 column (100 × 4.6 mm, i.d., 5 µm) using an isocratic elution mode with a total running time of 2.8 min. The selected ion pairs m/z 471.3 → 203.1 for the analyte and m/z 309.2 → 163.1 for internal standard were monitored in positive ionization mode for MS-MS detection. This method has been fully validated and the results showed good linearity, precision, accuracy and recovery. A stability test was conducted under various sample preparation, analysis and storage conditions. The method was successfully applied for the pharmacokinetic study of TEOA in rat plasma after oral administration of 100 mg/kg TEOA.

Determination of oxaceprol in rat plasma by LC-MS/MS and its application in a pharmacokinetic study.

A sensitive method for the quantification of oxaceprol in rat plasma using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. Sample pretreatment involved a simple protein precipitation by the addition of 60 µL of acetonitrile-methanol (1:2, v/v) to 20 µL plasma sample volume. Separation was achieved on a Dikma ODS-C18 (5 µm, 150 mm × 4.6mm) reversed-phase column at 40 °C with acetonitrile/0.1% formic acid-4mM ammonium acetate in water (35:65,v/v) at a flow rate of 0.6mL/min. Detection was performed using an electrospray ionization (ESI) operating in negative ion multiple reaction monitoring (MRM) mode by monitoring the ion transitions from m/z 172 → 130 (oxaceprol) and m/z 153 → 109 (protocatechuic acid, internal standard). The calibration curve of oxaceprol in plasma showed good linearity over the concentration range of 1.25-800 ng/mL. The limit of detection and limit of quantification were 0.400 ng/mL and 1.25 ng/mL, respectively. Intra- and inter-day precisions in all samples were within 15%. There was no matrix effect. The validated method was successfully applied to a preclinical pharmacokinetic study of oxaceprol in rats. After oral administration of 20mg/kg oxaceprol to rats, the main pharmacokinetic parameters T(max), C(max), T(1/2), V(z/F) and AUC(0-t) were 1.4h, 1.2 µg/mL, 2.3h, 19.7 L/kg and 3.4 mg h/L, respectively.