Sequence-specific dynamic DNA bending explains mitochondrial TFAM's dual role in DNA packaging and transcription initiation.

Mitochondrial transcription factor A (TFAM) employs DNA bending to package mitochondrial DNA (mtDNA) into nucleoids and recruit mitochondrial RNA polymerase (POLRMT) at specific promoter sites, light strand promoter (LSP) and heavy strand promoter (HSP). Herein, we characterize the conformational dynamics of TFAM on promoter and non-promoter sequences using single-molecule fluorescence resonance energy transfer (smFRET) and single-molecule protein-induced fluorescence enhancement (smPIFE) methods. The DNA-TFAM complexes dynamically transition between partially and fully bent DNA conformational states. The bending/unbending transition rates and bending stability are DNA sequence-dependent-LSP forms the most stable fully bent complex and the non-specific sequence the least, which correlates with the lifetimes and affinities of TFAM with these DNA sequences. By quantifying the dynamic nature of the DNA-TFAM complexes, our study provides insights into how TFAM acts as a multifunctional protein through the DNA bending states to achieve sequence specificity and fidelity in mitochondrial transcription while performing mtDNA packaging.

The obligate intracellular bacterium Orientia tsutsugamushi differentiates into a developmentally distinct extracellular state.

Orientia tsutsugamushi (Ot) is an obligate intracellular bacterium in the family Rickettsiaceae that causes scrub typhus, a severe mite-borne human disease. Its mechanism of cell exit is unusual amongst Rickettsiaceae, as Ot buds off the surface of infected cells enveloped in plasma membrane. Here, we show that Ot bacteria that have budded out of host cells are in a distinct developmental stage compared with intracellular bacteria. We refer to these two stages as intracellular and extracellular bacteria (IB and EB, respectively). These two forms differ in physical properties: IB is both round and elongated, and EB is round. Additionally, IB has higher levels of peptidoglycan and is physically robust compared with EB. The two bacterial forms differentially express proteins involved in bacterial physiology and host-pathogen interactions, specifically those involved in bacterial dormancy and stress response, and outer membrane autotransporter proteins ScaA and ScaC. Whilst both populations are infectious, entry of IB Ot is sensitive to inhibitors of both clathrin-mediated endocytosis and macropinocytosis, whereas entry of EB Ot is only sensitive to a macropinocytosis inhibitor. Our identification and detailed characterization of two developmental forms of Ot significantly advances our understanding of the intracellular lifecycle of an important human pathogen.

Impact of FtsZ Inhibition on the Localization of the Penicillin Binding Proteins in Methicillin-Resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant pathogen of acute clinical importance. Combination treatment with an FtsZ inhibitor potentiates the activity of penicillin binding protein (PBP)-targeting ß-lactam antibiotics against MRSA. To explore the mechanism underlying this synergistic behavior, we examined the impact of treatment with the FtsZ inhibitor TXA707 on the spatial localization of the five PBP proteins expressed in MRSA. In the absence of drug treatment, PBP1, PBP2, PBP3, and PBP4 colocalize with FtsZ at the septum, contributing to new cell wall formation. In contrast, PBP2a localizes to distinct foci along the cell periphery. Upon treatment with TXA707, septum formation becomes disrupted, and FtsZ relocalizes away from midcell. PBP1 and PBP3 remain significantly colocalized with FtsZ, while PBP2, PBP4, and PBP2a localize away from FtsZ to specific sites along the periphery of the enlarged cells. We also examined the impact on PBP2a and PBP2 localization of treatment with ß-lactam antibiotic oxacillin alone and in synergistic combination with TXA707. Significantly, PBP2a localizes to the septum in approximately 15% of the oxacillin-treated cells, a behavior that likely contributes to the ß-lactam resistance of MRSA. Combination treatment with TXA707 causes both PBP2a and PBP2 to localize in malformed septum-like structures. Our collective results suggest that PBP2, PBP4, and PBP2a may function collaboratively in peripheral cell wall repair and maintenance in response to FtsZ inhibition by TXA707. Cotreatment with oxacillin appears to reduce the availability of PBP2a to assist in this repair, thereby rendering the MRSA cells more susceptible to the ß-lactam. IMPORTANCE MRSA is a multidrug-resistant bacterial pathogen of acute clinical importance, infecting many thousands of individuals globally each year. The essential cell division protein FtsZ has been identified as an appealing target for the development of new drugs to combat MRSA infections. Through synergistic actions, FtsZ-targeting agents can sensitize MRSA to antibiotics like the ß-lactams that would otherwise be ineffective. This study provides key insights into the mechanism underlying this synergistic behavior as well as MRSA resistance to ß-lactam drugs. The results of this work will help guide the identification and optimization of combination drug regimens that can effectively treat MRSA infections and reduce the potential for future resistance.

Molecular origins of reduced activity and binding commitment of processive cellulases and associated carbohydrate-binding proteins to cellulose III.

Efficient enzymatic saccharification of cellulosic biomass into fermentable sugars can enable production of bioproducts like ethanol. Native crystalline cellulose, or cellulose I, is inefficiently processed via enzymatic hydrolysis but can be converted into the structurally distinct cellulose III allomorph that is processed via cellulase cocktails derived from Trichoderma reesei up to 20-fold faster. However, characterization of individual cellulases from T. reesei, like the processive exocellulase Cel7A, shows reduced binding and activity at low enzyme loadings toward cellulose III. To clarify this discrepancy, we monitored the single-molecule initial binding commitment and subsequent processive motility of Cel7A enzymes and associated carbohydrate-binding modules (CBMs) on cellulose using optical tweezers force spectroscopy. We confirmed a 48% lower initial binding commitment and 32% slower processive motility of Cel7A on cellulose III, which we hypothesized derives from reduced binding affinity of the Cel7A binding domain CBM1. Classical CBM-cellulose pull-down assays, depending on the adsorption model fitted, predicted between 1.2- and 7-fold reduction in CBM1 binding affinity for cellulose III. Force spectroscopy measurements of CBM1-cellulose interactions, along with molecular dynamics simulations, indicated that previous interpretations of classical binding assay results using multisite adsorption models may have complicated analysis, and instead suggest simpler single-site models should be used. These findings were corroborated by binding analysis of other type-A CBMs (CBM2a, CBM3a, CBM5, CBM10, and CBM64) on both cellulose allomorphs. Finally, we discuss how complementary analytical tools are critical to gain insight into the complex mechanisms of insoluble polysaccharides hydrolysis by cellulolytic enzymes and associated carbohydrate-binding proteins.

Novel self-floating tablet for enhanced oral bioavailability of metformin based on cellulose.

Metformin has several problems such as low bioavailability, short half-life, and narrow absorption window, sustained and site-specific drug delivery system is required. Floating drug delivery systems are very useful to achieve these purposes. However, conventional floating systems have several limitations; lag time, a high proportion of excipient in the tablet, using non-biocompatible excipient, and requirement of a complicated procedure. To overcome these obstacles, we developed a hollow-core floating tablet (HCFT). The HCFT immediately floated in pH 1.2, 4.0, 6.8 medium, and even distilled water. The floating duration time of HCFT was>24 h. From the in vitro release study, it was confirmed that HCFT showed the sustain release profile of metformin for 12 h. Water uptake and matrix erosion were evaluated for predicting the buoyancy and drug release kinetics of HCFT in the body. Factor analysis was applied to optimize the formulation. There were significant (p < 0.05) differences in metformin plasma concentration of 4 h and 6 h between two groups. Compared with Glucophage® XR, the relative bioavailability of metformin HCFT was 123.81 ± 3.52%. The X-ray imaging of optimized formulation revealed that HCFT was constantly floating in the stomach region of the rabbit, thereby indicating improved gastric retention for>6 h. Consequently, all the findings indicate that HCFT could be an effective gastric retention system and applied extensively to other drugs with narrow absorption windows.

Bioanalytical Method Development and Validation of Veratraldehyde and Its Metabolite Veratric Acid in Rat Plasma: An Application for a Pharmacokinetic Study.

A simple, sensitive, and rapid UHPLC-MS/MS method was developed for the simultaneous determination of veratraldehyde and its metabolite veratric acid in rat plasma. Cinnamaldehyde was used as an internal standard (IS) and the one-step protein precipitation method with 0.2% formic acid in acetonitrile (mobile phase B) was used for the sample extraction. Reversed C18 column (YMC-Triart C18 column, 50 mm × 2.0 mm, 1.9 µm) was used for chromatographic separation and was maintained at 30 °C. The total run time was 4.5 min and the electrospray ionization in positive mode was used with the transition m/z 167.07 → 139.00 for veratraldehyde, m/z 183.07 → 139.00 for veratric acid, and m/z 133.00 → 55.00 for IS. The developed method exhibited good linearity (r2 ≥ 0.9977), and the lower limits of quantification ranged from 3 to 10 ng/mL for the two analytes. Intra-day precision and accuracy parameters met the criteria (within ±15%) during the validation. The bioanalytical method was applied for the determination of veratraldehyde and veratric acid in rat plasma after oral and percutaneous administration of 300 and 600 mg/kg veratraldehyde. Using the analytical methods established in this study, we can confirm the absorption and metabolism of veratraldehyde in rats for various routes.

Characterization of Hepatitis B Surface Antigen Loaded Polylactic Acid-Based Microneedle and Its Dermal Safety Profile.

A surge of interest in microneedle (MN) vaccines as a novel vaccination system has emerged. Before the clinical application of MN vaccine, an assessment of potential biological risks to skin and quality control of MN must be performed. Therefore, the present study aims to evaluate the physicochemical properties of MN and to evaluate the histological changes and inflammatory cell infiltrations after the application of MN with hepatitis B surface antigen (HBsAg). During in vitro and in vivo release testing, HBsAg MN released over 70% of HBsAg at 30 min. During the pyrogen test of HBsAg MN in rabbit, no rabbit showed an individual rise in temperature of 0.5 °C or more. MN with HBsAg produced the moderate immunization in mice. MN application did not alter the thickness of dermal and epidermal layers in mice. In addition, the topical applications of MN and MN for hepatitis B vaccine did not acutely induce the inflammation, allergic reaction, dermal toxicity and skin irritation. Thus, the MN system for the delivery of HBsAg could be the promising technology in the hepatitis B vaccination.

Three-Dimensional Single-Molecule Localization Microscopy in Whole-Cell and Tissue Specimens.

Super-resolution microscopy techniques are versatile and powerful tools for visualizing organelle structures, interactions, and protein functions in biomedical research. However, whole-cell and tissue specimens challenge the achievable resolution and depth of nanoscopy methods. We focus on three-dimensional single-molecule localization microscopy and review some of the major roadblocks and developing solutions to resolving thick volumes of cells and tissues at the nanoscale in three dimensions. These challenges include background fluorescence, system- and sample-induced aberrations, and information carried by photons, as well as drift correction, volume reconstruction, and photobleaching mitigation. We also highlight examples of innovations that have demonstrated significant breakthroughs in addressing the abovementioned challenges together with their core concepts as well as their trade-offs.

Achyranthis radix Extract-Loaded Eye Drop Formulation Development and Novel Evaluation Method for Dry Eye Treatment.

Recently, Achyranthis radix extract has been studied as a therapeutic agent for dry eye disease that occurs from fine dust. The aim of this study was the development of Achyranthis radix extract-loaded eye drop formulations using lubricants, generally used for artificial tear eye drops. Ecdysterone was used as a marker compound for Achyranthis radix extract and 1% Achyranthis radix extract solution contained 14.37 ± 0.04 µg/mL of ecdysterone. Before formulation studies, a new method was performed to evaluate pigmentation, which might be caused by eye drops of herbal extract. A comparative study of the water retention ability of each formulation and ability to prevent the death of conjunctival epithelial cells in dry conditions was conducted. Moreover, treatment of Achyranthis radix extract (USL) eye drop formulation exhibited a significant inhibitory effect on inflammation in a concentration-dependent manner. The long-term and accelerated stability tests showed that lubricants could contribute to the stability of herbal extracts in solution. In conclusion, hyaluronic acid showed a good effect on the development of eye drop formulation using Achyranthis radix extracts for treating dry eye disease.

Extended Intake of Mulberry Leaf Extract Delayed Metformin Elimination via Inhibiting the Organic Cation Transporter 2.

Diabetes mellitus (DM) has become a major health problem in most countries of the world. DM causes many complications, including hyperglycemia, diabetic ketoacidosis, and death. In Asia, mulberry has been used widely in the treatment of DM. Combination of drugs with herbal medicine may reduce the unwanted side effects caused by drugs. In this study, the influence of extended mulberry leaves extract (MLE) intake on metformin (Met) was evaluated in terms of pharmacokinetics and pharmacodynamics in DM-induced rats. Three week-treatment of MLE alone produced the anti-hyperglycemic effect (around 24%) if compared to the control. Interestingly, Met administration after MLE treatment for 3 weeks enhanced about 49% of the anti-hyperglycemic effect of Met. In addition, the extended intake of MLE potentiated the anti-hyperglycemic effect of Met on various concentrations. This potentiated anti-hyperglycemic effect of Met appears to be due to the pharmacokinetic change of Met. In this study, 3 week-treatment of MLE reduced the elimination of Met in DM-induced rats. In addition, MLE reduced the human organic cation transporter 2 (hOCT2) activity in a concentration-dependent manner. Thus, these findings suggest that MLE lowered the elimination of Met via inhibiting the hOCT2.

Development and evaluation of a film-forming system hybridized with econazole-loaded nanostructured lipid carriers for enhanced antifungal activity against dermatophytes.

Treatment of skin infection by dermatophytes is still limited, and the application of conventional topical formulations (ointments, creams, etc.) cause patient discomfort due to repeated administration and low efficacy. This study describes the film-forming system (FFS) hybridized with econazole (ECO)-loaded nanostructured lipid carriers (NLC) for enhanced antifungal activity against dermatophytes. We assumed that the application of NLC could effectively increase the skin permeability of ECO, thereby suppressing the growth of dermatophytes in stratum corneum as well as in epidermis. Meanwhile, ECO-NLC hybrid FFS (ECO-NLC@FFS) could increase the adhesion of ECO-NLC to the skin and prolong the antifungal activity of ECO. First, we optimized ECO-NLC, which shows nanosized particle (199 nm), high encapsulation efficiency (92.5%), and biocompatibility. ECO-NLC@FFS formed a transparent, homogeneous, and hard-to-remove film after topical application. In vitro skin permeation and deposition studies demonstrated that ECO-NLC@FFS showed 1.5-fold higher skin permeation and 3-fold higher ECO deposition in the epidermis layer than a commercial product, which resulted from the nanosized particle and its occlusion effect. And, ex vivo and in vivo antifungal activity studies confirmed that ECO-NLC@FFS improved the skin adhesion of ECO-NLC, thereby allowing ECO to be continuously exposed to the infection sited and reducing the number of applications with a single dose. These results showed that this hybrid system could be a potential for effectively improving the efficacy of antifungal agents and the patient compliance in the treatment of dermatophytes. STATEMENT OF SIGNIFICANCE: Treatment of skin infection by dermatophytes is difficult due to the inconvenience and low efficacy of conventional topical formulations. Here, we demonstrated the potential of a film-forming system (FFS) hybridized with nanostructured lipid carriers (NLC). First, we confirmed that the enhanced skin permeability of drug was improved by NLC. In addition, the hybridization of NLC with FFS improved the skin adhesion of NLC, allowing the drug to exhibit a sustained release profile and prolong antifungal activity. Given the maximized antifungal activity, this hybrid system can be used as a potential pharmaceutical technique to improve patient convenience and achieve complete treatment of skin infection.

Statistical approach for solidifying ticagrelor loaded self-microemulsifying drug delivery system with enhanced dissolution and oral bioavailability.

The aim of this study was to solidify a ticagrelor loaded self-microemulsifying drug delivery system (TCG-SM) with enhanced dissolution and bioavailability of ticagrelor (TCG) for developing TCG-SM granules and tablets. TCG was dissolved in the self-microemulsifying drug delivery system (SMEDDS) and TCG-SM was solidified by adsorption to the optimized adsorbent through statistical design. In order to select an appropriate adsorbent, the physical properties (bulk density, tapped density, angle of repose, and liquid adsorption capacity) of silica-based adsorbents (Neusilin US2, Florite R, Aerosil 200, and Florite PS-10) and non silica-based adsorbents (Avicel PH102, Pharmatose 100M, Pearlitol 200, LH-11, and Emcompress) were investigated. Neusilin US2 and Florite R were selected as suitable adsorbents and their mixing ratios were optimized using statistical experimental design. The predicted values of physical properties by statistical design showed the error percentage of <10% compared to actual values. As a result of the statistical approach, TCG-SM (490 mg) was successfully solidified with Nesulin US2 (167.8 mg) and Florite R (82.2 mg), which showed good powder properties and improved dissolution of TCG. The solidified TCG-SM (Sol-TCG-SM), disintegrant (croscarmellose sodium), diluent (microcrystalline cellulose), binder (polyvinylpyrrolidone), and lubricant (magnesium stearate) were mixed to prepare granules. And, the granules with total weight of 900 mg were tableted using 16 mm oval-shape punch. The prepared Sol-TCG-SM tablet showed good tablet properties and maintained self-microemulsifying ability, such as microemulsion formation and enhanced dissolution of TCG. In vivo pharmacokinetic study, the relative bioavailability of Sol-TCG-SM exhibited 108.1% and 632.7% compared to TCG-SM and raw TCG powder, respectively. In conclusion, we successfully solidified SMEDDS with improved oral bioavailability of insoluble drugs such as TCG through a statistical design. This suggests a new approach that can be utilized in the production of solidified SMEDDS.

Effect of Ticagrelor, a Cytochrome P450 3A4 Inhibitor, on the Pharmacokinetics of Tadalafil in Rats.

Tadalafil is a cytochrome P450 (CYP) 3A4 substrate. Because there are few data on drug-drug interactions, it is advisable to take sufficient consideration when co-administering tadalafil with CYP3A4 inducers or inhibitors. This study was conducted to assess the effect of ticagrelor, a CYP3A4 inhibitor, on the pharmacokinetic properties of tadalafil after oral administration to rats. A total of 20 Sprague-Dawley male rats were randomly divided into the non-pretreated group and ticagrelor-pretreated group, and tadalafil was orally administered to each group after pretreatment with or without ticagrelor. Blood samples were collected at predetermined time points after oral administration of tadalafil. As a result, systemic exposure of tadalafil in the ticagrelor-pretreated group was significantly increased compared to the non-pretreated group (1.61-fold), and the clearance of tadalafil in the ticagrelor-pretreated group was significantly reduced than the non-pretreated group (37%). The prediction of the drug profile through the one-compartment model could explain the differences of pharmacokinetic properties of tadalafil in the non-pretreated and ticagrelor-pretreated groups. This study suggests that ticagrelor reduces a CYP3A-mediated tadalafil metabolism and that tadalafil and a combination regimen with tadalafil and ticagrelor requires dose control and specific pharmacotherapy.

The Delivery Strategy of Paclitaxel Nanostructured Lipid Carrier Coated with Platelet Membrane.

Strategies for the development of anticancer drug delivery systems have undergone a dramatic transformation in the last few decades. Lipid-based drug delivery systems, such as a nanostructured lipid carrier (NLC), are one of the systems emerging to improve the outcomes of tumor treatments. However, NLC can act as an intruder and cause an immune response. To overcome this limitation, biomimicry technology was introduced to decorate the surface of the nanoparticles with various cell membrane proteins. Here, we designed paclitaxel (PT)-loaded nanostructured lipid carrier (PT-NLC) with platelet (PLT) membrane protein because PLT is involved with angiogenesis and interaction of circulating tumor cells. After PLT was isolated from blood using the gravity-gradient method and it was used for coating PT-NLC. Spherical PT-NLC and platelet membrane coated PT-NLC (P-PT-NLC) were successfully fabricated with high encapsulation efficiency (EE) (99.98%) and small particle size (less than 200 nm). The successful coating of PT-NLC with a PLT membrane was confirmed by the identification of CD41 based on transmission electron microscopy (TEM), western blot assay and enzyme-linked immunosorbent assay (ELISA) data. Moreover, the stronger affinity of P-PT-NLC than that of PT-NLC toward tumor cells was observed. In vitro cell study, the PLT coated nanoparticles successfully displayed the anti-tumor effect to SK-OV-3 cells. In summary, the biomimicry carrier system P-PT-NLC has an affinity and targeting ability for tumor cells.

How Does a Plasmon-Induced Hot Charge Carrier Break a C-C Bond?

Hot-electron chemistry at gold nanoparticle (AuNP) surfaces has received much attention recently because its understanding provides a basis for plasmonic photocatalysis and photovoltaics. Nonradiative decay of excited surface plasmons produces energetic hot charge carriers that transfer to adsorbate molecules and induce chemical reactions. Such plasmon-driven reactions, however, have been limited to a few systems, notably the dimerization of 4-aminobenzenethiol to 4,4'-dimercaptoazobenzene. In this work, we explore a new class of plasmon-driven reactions associated with a unimolecular bond cleavage process. We unveil the mechanism of the decarboxylation reaction of 4-mercaptobenzoic acid and extend the mechanism to account for the ß-cleavage reaction of 4-mercaptobenzyl alcohol. Combining the construction of well-controlled nanogap systems and sensitive Raman spectroscopy with methodical changes of experimental conditions (laser wavelengths, interface materials, pH, ambient gases, etc.), we track the hot charge carriers from the formation to the transfer to reactants, which provides insights into how plasmon excitation eventually leads to the C-C bond cleavage of the molecules in the nanogap.

Systemic Design and Evaluation of Ticagrelor-Loaded Nanostructured Lipid Carriers for Enhancing Bioavailability and Antiplatelet Activity.

Ticagrelor (TGL), a P2Y12 receptor antagonist, is classified as biopharmaceutics classification system (BCS) class IV drug due to its poor solubility and permeability, resulting in low oral bioavailability. Nanostructured lipid carriers (NLC) are an efficient delivery system for the improvement of bioavailability of BCS class IV drugs. Hence, we prepared TGL-loaded NLC (TGL-NLC) to enhance the oral bioavailability and antiplatelet activity of TGL with a systemic design approach. The optimized TGL-NLC with Box-Behnken design showed a small particle size of 87.6 nm and high encapsulation efficiency of 92.1%. Scanning electron microscope (SEM), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) were performed to investigate the characteristics of TGL-NLC. Furthermore, TGL-NLC exhibited biocompatible cytotoxicity against Caco-2 cells. Cellular uptake of TGL-NLC was 1.56-fold higher than that of raw TGL on Caco-2 cells. In pharmacokinetic study, the oral bioavailability of TGL-NLC was 254.99% higher than that of raw TGL. In addition, pharmacodynamic study demonstrated that the antiplatelet activity of TGL-NLC was superior to that of raw TGL, based on enhanced bioavailability of TGL-NLC. These results suggest that TGL-NLC can be applied for efficient oral absorption and antiplatelet activity of TGL.

Strategic approach to developing a self-microemulsifying drug delivery system to enhance antiplatelet activity and bioavailability of ticagrelor.

BACKGROUND: Ticagrelor (TCG) is used to inhibit platelet aggregation in patients with acute coronary syndrome, but its poor solubility and low bioavailability limit its in vivo efficacy. The purpose of this study was to manufacture an optimized TCG-loaded self-microemulsifying drug delivery system (SMEDDS) to enhance the oral bioavailability and antiplatelet activity of TCG. MATERIALS AND METHODS: Solubility and emulsification tests were conducted to determine the most suitable oils, surfactants, and cosurfactants. Scheffé's mixture design was applied to optimize the percentage of each component applied in the SMEDDS formulation to achieve optimal physical characteristics, ie, high solubility of TCG in SMEDDS, small droplet size, low precipitation, and high transmittance. RESULTS: The optimized TCG-loaded SMEDDS (TCG-SM) formulation composed of 10.0% Capmul MCM (oil), 53.8% Cremophor EL (surfactant), and 36.2% Transcutol P (cosurfactant) significantly improving the dissolution of TCG in various media compared with TCG in Brilinta® (commercial product). TCG-SM exhibited higher cellular uptake and permeability in Caco-2 cells than raw TCG suspension. In pharmacokinetic studies in rats, TCG-SM exhibited higher oral bioavailability with 5.7 and 6.4 times higher area under the concentration-time curve and maximum plasma concentration, respectively, than a raw TCG suspension. Antiplatelet activity studies exhibited that the TCG-SM formulation showed significantly improved inhibition of platelet aggregation compared with raw TCG at the same dose of TCG. And, a 10 mg/kg dose of raw TCG suspension and a 5 mg/kg dose of TCG-SM had a similar area under the inhibitory curve (907.0%±408.8% and 907.8%±200.5%⋅hours, respectively) for antiplatelet activity. CONCLUSION: These results suggest that the developed TCG-SM could be successfully used as an efficient method to achieve the enhanced antiplatelet activity and bioavailability of TCG.

A novel composition of ticagrelor by solid dispersion technique for increasing solubility and intestinal permeability.

The aim of this study is to improve the bioavailability of ticagrelor, BCS class 4 drug, using solid dispersion technique, and to evaluate the potential of ticagrelor loaded-solid dispersion, as a new formulation. The solid dispersion formulation was prepared via solvent evaporation method using ethanol. TPGS and Neusilin® US2 selected via screening studies were used for preparing formulation. The results of scanning electron microscopy, differential scanning calorimetry and powder X-ray diffraction showed that the crystallinity of the ticagrelor was completely transformed to an amorphous form and maintained in the solid dispersion formulation. The released amount of the optimized solid dispersion significantly increased by 2.2- and 34-fold in comparison with physical mixture (Ticagrelor:TPGS:Neusilin® US2 = 1:2:2, w/w/w) and commercial product (Brilinta®) in distilled water at 90 min, respectively. The absorptive permeability was improved (1.4-fold) and the efflux ratio was decreased (0.45-fold) by formulation containing TPGS acting as a P-gp inhibitor compared to pure drug. The solid dispersion formulation improved the peak plasma concentration (Cmax) and relative bioavailability compared to that of pure drug as 238.09 ±â€¯25.96% and 219.78 ±â€¯36.33%, respectively, after oral administration in rats. Thus, we successfully prepared the solid dispersion formulation for enhancing oral bioavailability of ticagrelor, and then this formulation would be recommended as a practical oral pharmaceutical product.

Reducing Agent-Assisted Excessive Galvanic Replacement Mediated Seed-Mediated Synthesis of Porous Gold Nanoplates and Highly Efficient Gene-Thermo Cancer Therapy.

Porous Au nanoplates (pAuNPs) were manufactured by a reducing agent-assisted galvanic replacement reaction on Ag nanoplates using a seed-mediated synthetic approach. Two core additives, poly(vinylpyrrolidone) and l-ascorbic acid, prevented fragmentation and proceeded secondary growth. By controlling the concentration of the additives and the amount of replacing ion AuCl4-, various nanostructures including nanoplates with holes, nanoframes, porous nanoplates, and bumpy nanoparticles with unity and homogeneity were synthesized. The present synthetic method is advantageous, because it can be used to manufacture pAuNPs with ease, robustness, and convenience. The prepared pAuNPs exhibited a highly efficient photothermal conversion effect and cargo loading capacity on exposed surfaces by Au-thiol linkage. By using dual cargo mixed loading of the hepatitis C virus (HCV) targeting gene drug DNAzyme and cell-penetrating peptide TAT onto the surface of the pAuNPs and photothermal conversion-mediated hyperthermic treatment, successful gene-thermo therapy against HCV genomic human hepatocarcinoma cells were demonstrated.

Label-free quantitative secretome analysis of Xanthomonas oryzae pv. oryzae highlights the involvement of a novel cysteine protease in its pathogenicity.

Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the most devastating diseases resulting in a huge loss of the total rice productivity. The initial interaction between rice and Xoo takes place in the host apoplast and is mediated primarily by secretion of various proteins from both partners. Yet, such secretory proteins remain to be largely identified and characterized. This study employed a label-free quantitative proteomics approach and identified 404 and 323 Xoo-secreted proteins from in vitro suspension-cultured cells and in planta systems, respectively. Gene Ontology analysis showed their involvement primarily in catalytic, transporter, and ATPase activities. Of a particular interest was a Xoo cysteine protease (XoCP), which showed dramatic increase in its protein abundance in planta upon Xoo interaction with a susceptible rice cultivar. Knock-out mutants of XoCP showed reduced pathogenicity on rice, highlighting its potential involvement in Xoo virulence. Besides, a parallel analysis of in planta rice-secreted proteins resulted in identification of 186 secretory proteins mainly associated with the catalytic, antioxidant, and electron carrier activities. Identified secretory proteins were exploited to shed light on their possible role in the rice-Xoo interaction, and that further deepen our understanding of such interaction. BIOLOGICAL SIGNIFICANCE: Xanthomonas oryzae pv. oryzae (Xoo), causative agent of bacterial blight disease, results in a huge loss of the total rice productivity. Using a label-free quantitative proteomics approach, we identified 727 Xoo- and 186 rice-secreted proteins. Functional annotation showed Xoo secreted proteins were mainly associated with the catalytic, transporter, and ATPase activities while the rice secreted proteins were mainly associated with the catalytic, antioxidant, and electron carrier activities. A novel Xoo cysteine protease (XoCP) was identified, showing dramatic increase in its protein abundance in planta upon Xoo interaction with a susceptible rice cultivar. Knock-out mutants of XoCP showed reduced pathogenicity on rice, highlighting its potential involvement in Xoo virulence.