Identification and evaluation of antiviral activity of novel compounds targeting SARS-CoV-2 virus by enzymatic and antiviral assays, and computational analysis

The viral genome of the SARS-CoV-2 coronavirus, the aetiologic agent of COVID-19, encodes structural, non-structural, and accessory proteins. Most of these components undergo rapid genetic variations, though to a lesser extent the essential viral proteases. Consequently, the protease and/or deubiquitinase activities of the cysteine proteases Mpro and PLpro became attractive targets for the design of antiviral agents. Here, we develop and evaluate new bis(benzylidene)cyclohexanones (BBC) and identify potential antiviral compounds. Three compounds were found to be effective in reducing the SARS-CoV-2 load, with EC50 values in the low micromolar concentration range. However, these compounds also exhibited inhibitory activity IC50 against PLpro at approximately 10-fold higher micromolar concentrations. Although originally developed as PLpro inhibitors, the comparison between IC50 and EC50 of BBC indicates that the mechanism of their in vitro antiviral activity is probably not directly related to inhibition of viral cysteine proteases. In conclusion, our study has identified new potential noncytotoxic antiviral compounds suitable for in vivo testing and further improvement.

In Vitro and In Vivo Evaluation of the Effects of Drug 2c and Derivatives on Ovarian Cancer Cells

BACKGROUND

The identification of novel therapeutic strategies for ovarian cancer (OC), the most lethal gynecological neoplasm, is of utmost urgency. Here, we have tested the effectiveness of the compound 2c (4-hydroxy-2,6-bis(4-nitrobenzylidene)cyclohexanone 2). 2c interferes with the cysteine-dependent deubiquitinating enzyme (DUB) UCHL5, thus affecting the ubiquitin-proteasome-dependent degradation of proteins.

METHODS

2c phenotypic/molecular effects were studied in two OC 2D/3D culture models and in a mouse xenograft model. Furthermore, we propose an in silico model of 2c interaction with DUB-UCHL5. Finally, we have tested the effect of 2c conjugated to several linkers to generate 2c/derivatives usable for improved drug delivery.

RESULTS

2c effectively impairs the OC cell line and primary tumor cell viability in both 2D and 3D conditions. The effectiveness is confirmed in a xenograft mouse model of OC. We show that 2c impairs proteasome activity and triggers apoptosis, most likely by interacting with DUB-UCHL5. We also propose a mechanism for the interaction with DUB-UCHL5 via an in silico evaluation of the enzyme-inhibitor complex. 2c also reduces cell growth by down-regulating the level of the transcription factor E2F1. Eventually, 2c activity is often retained after the conjugation with linkers.

CONCLUSION

Our data strongly support the potential therapeutic value of 2c/derivatives in OC.

A universal UHPLC-CAD platform for the quantification of polysaccharide antigens

Several glycoconjugate-based vaccines against bacterial infections have been developed and licensed for human use. Polysaccharide (PS) analysis and characterization is therefore critical to profile the composition of polysaccharide-based vaccines. For PS content quantification, the majority of Ultra High Performance Liquid Chromatography (UHPLC) methods rely on the detection of selective monosaccharides constituting the PS repeating unit, therefore requiring chemical cleavage and tailored development: only a few methods directly quantify the intact PS. The introduction of charged aerosol detector (CAD) technology has improved the response of polysaccharide analytes, offering greater sensitivity than other detector sources (e.g., ELSD). Herein, we report the development of a universal UHPLC-CAD method (UniQS) for the quantification and quality evaluation of polysaccharide antigens (e.g., Streptococcus Pneumoniae, Neisseria meningitidis and Staphylococcus aureus). This work laid the foundation for a universal UHPLC-CAD format that could play an important role in future vaccine research and development helping to reduce time, efforts, and costs.

Designing New Hybrid Antibiotics: Proline-Rich Antimicrobial Peptides Conjugated to the Aminoglycoside Tobramycin

Resistance to aminoglycoside antibiotics is a serious problem, typically arising from inactivating enzymes, reduced uptake, or increased efflux in the important pathogens for which they are used as treatment. Conjugating aminoglycosides to proline-rich antimicrobial peptides (PrAMPs), which also target ribosomes and have a distinct bacterial uptake mechanism, might mutually benefit their individual activities. To this aim we have developed a strategy for noninvasively modifying tobramycin to link it to a Cys residue and through this covalently link it to a Cys-modified PrAMP by formation of a disulfide bond. Reduction of this bridge in the bacterial cytosol should release the individual antimicrobial moieties. We found that the conjugation of tobramycin to the well-characterized N-terminal PrAMP fragment Bac7(1-35) resulted in a potent antimicrobial capable of inactivating not only tobramycin-resistant bacterial strains but also those less susceptible to the PrAMP. To a certain extent, this activity also extends to the shorter and otherwise poorly active fragment Bac7(1-15). Although the mechanism that allows the conjugate to act when its individual components do not is as yet unclear, results are very promising and suggest this may be a way of resensitizing pathogens that have developed resistance to the antibiotic.

Novel synthesis of 1,2-diaza-1,3-dienes with potential biological activity from cinnamic acids and diazonium salts of anilines

Cinnamic acids are an important class of phenolic compounds, which have many beneficial effects on human health but are also interesting synthetic intermediates thanks to the presence of several reactive sites. While studying the reactivity of cinnamic acids with diazonium salts from aromatic amines, an unexpected reactivity has been discovered, leading to the formation of 1,2-diaza-1,3-dienes instead of traditional diazo-coupling products. The new compounds have been fully characterized by mono and bidimensional NMR spectroscopy and mass spectrometry. Preliminary studies on the biological activity of the compounds have been carried out testing both their antibacterial and antitumor activity, leading to promising results.

Fluorescent Imprinted Nanoparticles for Sensing of Chlorogenic Acid in Coffee Extracts

Green coffee beans are particularly rich in chlorogenic acids (CGAs), and their identification and quantification are usually performed by HPLC, coupled with mass spectrometry (LC-MS). Although there are a few examples of molecularly imprinted polymers (MIPs) for chlorogenic acid (5-CQA) recognition present in the literature, none of them are based on optical fluorescence, which is very interesting given its great sensitivity. In the present manuscript, fluorescent polymeric imprinted nanoparticles were synthetized following the non-covalent approach using hydrogenated 5-O-caffeoylquinic acid (H-5-CQA) as the template. The capability of the polymer to bind 5-CQA was evaluated by HPLC and fluorescence. A real sample of coffee extract was also analyzed to verify the selectivity of the polymer. Polymer fMIP01, containing 4-vinylpyridine and a naphtalimide derivative as monomers, showed a good response to the fluorescence quenching in the range 39 μM-80 mM. In the real sample, fMIP01 was able to selectively bind 5-CQA, while caffeine was not recognized. To demonstrate this, there is a promising system that can be exploited in the design of an optical sensor for 5-CQA detection. Polymer fMIP01 was immobilized by physical entrapment on a functionalized glass surface, showing a quenching of fluorescence with an increase of the CGA concentration between 156 μM and 40 mM.

AB1586-PARE MULTI-CENTER, RANDOMIZED, OPEN-LABEL, 2-ARM PARALLEL STUDY TO COMPARE THE PHARMACOKINETICS, SAFETY AND TOLERABILITY OF AVT02 ADMINISTERED SUBCUTANEOUSLY VIA PREFILLED SYRINGE OR AUTOINJECTOR IN HEALTHY ADULT VOLUNTEERS

Background

AVT02 is an investigational biosimilar to adalimumab. It is approved in Europe, Canada, and the UK. It is not approved by the US Food and Drug Administration (FDA).

Objectives

To evaluate the pharmacokinetic similarity of 100 mg/mL AVT02, an investigational biosimilar of adalimumab, when administered either via a pre-filled syringe, or with a newly developed autoinjector in healthy adult subjects.

Methods

This was a Phase 1, randomized, open-label, parallel-group study in which 207 healthy adult subjects were randomized in a 1:1 ratio to receive 100 mg/mL AVT02 either via a pre-filled syringe, or with an autoinjector, stratified by body weight. Subjects received a single subcutaneous 40 mg dose on Day 1. Pharmacokinetics, immunogenicity, local injection site reactions, and adverse events were assessed prior to, and up to 64 days after, study drug administration.

Results

The results observed supported the assessment of pharmacokinetic similarity of investigational AVT02 administered by pre-filled syringe or with an autoinjector. The 90% CIs for the ratios of geometric least square means for the primary pharmacokinetic parameters Cmax, AUC0-t, and AUC0-∞ were contained within prespecified margins 80% and 125%, based on an analysis of variance model with treatment as a fixed effect. The mean serum concentration-time profile of adalimumab by treatment group is shown in Figure 1.

Figure 1.

Mean Serum Concentration-Time Profile of Adalimumab by Treatment Group on Semilogarithmic Scale (Pharmacokinetic Population)

Binding anti-drug antibodies were detectable at the end of study visit on Day 64 in 100% and 97.0% of subjects in the pre-filled syringe administration and the autoinjector groups, respectively. Of those subjects positive for anti-drug antibodies, 85.7% and 86.5% further tested positive for neutralizing antibodies in the pre-filled syringe administration and autoinjector groups, respectively. The frequency of local administration site reactions was 11.8% overall and similar between treatment groups. The most frequently reported treatment-emergent adverse events in both treatment groups were under the SOC: Infections and infestations (56.0% in the AVT02-pre-filled syringe group and 45.2% in the AVT02-autoinjector group). The safety profiles were generally similar between treatment groups.

Conclusion

The results observed supported the assessment of pharmacokinetic similarity between the pre-filled syringe and autoinjector delivery systems after a single subcutaneous 40 mg dose. The autoinjector delivery system was generally well tolerated in healthy subjects, with a safety and immunogenicity profile similar to that observed with 100 mg/mL AVT02 administered using a pre-filled syringe.

ClinicalTrials.gov Identifier: NCT03983876

Disclosure of Interests

Christopher Wynne: None declared, Heimo Stroissnig Employee of: Alvotech, Roshan Dias Employee of: Alvotech, Joanna Sobierska Employee of: Alvotech, Eric Guenzi Employee of: Alvotech, Hendrik Otto Employee of: Alvotech, Abid Sattar Employee of: Alvotech, Halimu N. Haliduola Employee of: Alvotech, Elin Edwald Employee of: Alvotech, Fausto Berti Employee of: Alvotech

AB0350 ASSESSMENT OF REAL-LIFE PATIENT HANDLING EXPERIENCE OF AVT02 ADMINISTERED SUBCUTANEOUSLY VIA AUTOINJECTOR IN PATIENTS WITH MODERATE-TO-SEVERE ACTIVE RHEUMATOID ARTHRITIS: AN OPEN-LABEL, SINGLE-ARM CLINICAL TRIAL, THEN AN EXTENSION PHASE OF AVT02 ADMINISTERED WITH A PRE-FILLED SYRINGE (ALVOPAD-PEN)

Background

AVT02 is an investigational biosimilar to adalimumab. It is approved in Europe, Canada, and the UK. It is not approved by the US Food and Drug Administration (FDA).

Objectives

To assess the real-life patient handling of an autoinjector (AI) in adult patients with moderate-to-severe active rheumatoid arthritis (RA) who self-inject AVT02 subcutaneously (s.c.).

Methods

This open-label study enrolled 107 adalimumab-naïve subjects with moderate-to-severe active RA to self-inject AVT02 with the proposed AI 40 mg s.c. in Week 1, and every other week thereafter through Week 8. In an optional extension phase through Week 56, subjects were switched from AVT02 AI to pre-filled syringe and followed for safety and efficacy. The primary endpoint was the percentage of successful self-injections as reported by both the trial site and by subjects using standardized questionnaires at Week 8. Additional endpoints included ease of use and robustness of the AI at Week 8, and efficacy in RA, assessment of serum trough levels of AVT02, and detection of antidrug antibodies (ADA) throughout the study.

Results

The AI success rate was 100% as reported by both the trial site and by subjects. No handling events were noted through Week 8. Approximately 80% (78.1–84.9%) of subjects found the AI ‘very easy’ to use and, in general, less difficulty was reported as the study progressed. The first 110 AIs used were inspected for robustness and none showed any sign of damage or malfunction.

All subjects who completed Week 8 (n = 106) took part in and completed the optional extension phase through Week 56.

At Week 8, 49.1%, 5.7% and 0.9% subjects achieved ACR20, -50 and -70 responses, respectively. Improvement was also reported for the SDAI, DAS28 CRP and HAQ, with scores consistently decreasing through Week 8. In the extension phase, 70.8%, 47.2% and 13.2% subjects achieved ACR20, -50 and -70 responses at Week 56. Improvement was also reported for the SDAI, DAS28 CRP and HAQ, with scores consistently decreasing through Week 56.

From Baseline through Week 8 the mean serum concentrations of investigational AVT02 increased consistently at each visit, reaching a peak at Week 24. There was no significant difference in serum concentrations of AVT02 based on injection subsite (abdomen or thigh).

ADAs were detected in 65.1% of subjects through Week 8, reducing to 49.1% by Week 56. Of ADA-positive subjects, most were also positive for neutralizing antibodies through Week 8 (62.3%) increasing through Week 56 (90.4%). Subjects who were ADA-positive had lower serum concentrations of study drug compared with the overall population at Week 8 and Week 56 as expected.

There were no clinically relevant safety or tolerability issues. Overall, treatment-emergent adverse events reported in at least 5% of subjects at the PT level were anaemia and influenza (6 subjects [5.6%)] reported 6 events each), and no local ISRs were reported.

Conclusion

The fully successful self-injection with the AI in this study supported the use of the device while administering AVT02. Furthermore, subjects typically found the AI easy to use, with ease of use increasing as time progressed.

The ACR20, -50, and -70, SDAI, DAS28 CRP and HAQ results supported the use of AVT02 to treat adult patients with moderate-to-severe RA, with the treatment effect persisting beyond Week 8 and through Week 56.

The safety and immunogenicity profiles were as expected for adalimumab.

ClinicalTrials.gov Identifier: NCT04224194

Disclosure of Interests

Nemanja Damjanov: None declared, Heimo Stroissnig Employee of: Alvotech, Matjaz Steiger Employee of: Alvotech, Joanna Sobierska Employee of: Alvotech, Eric Guenzi Employee of: Alvotech, Hendrik Otto Employee of: Alvotech, Abid Sattar Employee of: Alvotech, Halimu N. Haliduola Employee of: Alvotech, Elin Edwald Employee of: Alvotech, Fausto Berti Employee of: Alvotech

Chitosan-Based Biocompatible Copolymers for Thermoresponsive Drug Delivery Systems: On the Development of a Standardization System

Chitosan is a natural polysaccharide that is considered to be biocompatible, biodegradable and non-toxic. The polymer has been used in drug delivery applications for its positive charge, which allows for adhesion with and recognition of biological tissues via non-covalent interactions. In recent times, chitosan has been used for the preparation of graft copolymers with thermoresponsive polymers such as poly-N-vinylcaprolactam (PNVCL) and poly-N-isopropylamide (PNIPAM), allowing the combination of the biodegradability of the natural polymer with the ability to respond to changes in temperature. Due to the growing interest in the utilization of thermoresponsive polymers in the biological context, it is necessary to increase the knowledge of the key principles of thermoresponsivity in order to obtain comparable results between different studies or applications. In the present review, we provide an overview of the basic principles of thermoresponsivity, as well as a description of the main polysaccharides and thermoresponsive materials, with a special focus on chitosan and poly-N-Vinyl caprolactam (PNVCL) and their biomedical applications.

The Pseudo-Symmetric N-benzyl Hydroxyethylamine Core in a New Series of Heteroarylcarboxyamide HIV-1 Pr Inhibitors: Synthesis, Molecular Modeling and Biological Evaluation

Here, we report the synthesis, enzyme inhibition and structure–activity relationship studies of a new potent class of HIV-1 protease inhibitors, which contain a pseudo-symmetric hydroxyethylamine core and heteroarylcarboxyamide moieties. The simple synthetic pathway furnished nine compounds in a few steps with high yields. The compounds were designed taking into account our previous results on other series of inhibitors with different substituents at P’ and P’’ and different ways of linking them to the inhibitor core. Potent inhibitory activity was obtained with nanomolar IC₅₀ values measured with a standard fluorimetric test in 100 mM MES buffer, pH 5.5, containing 400 mM NaCl, 1 mM EDTA, 1 mM DTT and 1 mg/ml BSA. Compounds 9a–c, containing the indole ring in P1, exhibited an HIV-1 protease inhibitory activity more powerful than darunavir in the same assay. To obtain molecular insight into the binding properties of these compounds, docking analysis was performed, and their binding properties were also compared.

Thermoresponsive Chitosan-Grafted-Poly(N-vinylcaprolactam) Microgels via Ionotropic Gelation for Oncological Applications

Microgels can be considered soft, porous and deformable particles with an internal gel structure swollen by a solvent and an average size between 100 and 1000 nm. Due to their biocompatibility, colloidal stability, their unique dynamicity and the permeability of their architecture, they are emerging as important candidates for drug delivery systems, sensing and biocatalysis. In clinical applications, the research on responsive microgels is aimed at the development of "smart" delivery systems that undergo a critical change in conformation and size in reaction to a change in environmental conditions (temperature, magnetic fields, pH, concentration gradient). Recent achievements in biodegradable polymer fabrication have resulted in new appealing strategies, including the combination of synthetic and natural-origin polymers with inorganic nanoparticles, as well as the possibility of controlling drug release remotely. In this review, we provide a literature review on the use of dual and multi-responsive chitosan-grafted-poly-(N-vinylcaprolactam) (CP) microgels in drug delivery and oncological applications.

Characterization of Thermoresponsive Poly-N-Vinylcaprolactam Polymers for Biological Applications

Poly-N-Vinylcaprolactam (PNVCL) is a thermoresponsive polymer that exhibits lower critical solution temperature (LCST) between 25 and 50 °C. Due to its alleged biocompatibility, this polymer is becoming popular for biomedical and environmental applications. PNVCL with carboxyl terminations has been widely used for the preparation of thermoresponsive copolymers, micro- and nanogels for drug delivery and oncological therapies. However, the fabrication of such specific targeting devices needs standardized and reproducible preparation methods. This requires a deep understanding of how the miscibility behavior of the polymer is affected by its structural properties and the solution environment. In this work, PNVCL-COOH polymers were prepared via free radical polymerization (FRP) in order to exhibit LCST between 33 and 42 °C. The structural properties were investigated with NMR, FT-IR and conductimetric titration and the LCST was calculated via UV-VIS and DLS. The LCST is influenced by the molecular mass, as shown by both DLS and viscosimetric values. Finally, the behavior of the polymer was described as function of its concentration and in presence of different biologically relevant environments, such as aqueous buffers, NaCl solutions and human plasma.

Oleocanthal Quantification Using 1H NMR Spectroscopy and Polyphenols HPLC Analysis of Olive Oil from the Bianchera/Belica Cultivar

The cultivar Bianchera is an autochthonous variety from the eastern part of northern Italy, but it is also cultivated in the Slovenian and Croatian peninsula of Istria where it is named Belica (Slovenia) and Bjelica (Croatia). The properties of oleocanthal, a natural anti-inflammatory ibuprofen-like compound found in commercial monocultivar extra virgin olive oils, were determined by means of both quantitative ¹H NMR (qNMR) and HPLC analyses, where qNMR was identified as a rapid and reliable method for determining the oleocanthal content. The total phenolic content (TPC) was determined by means of the Folin-Ciocalteau method and the major phenols present in the olive oils were also quantified by means of HPLC analyses. All these analyses confirmed that the cultivar Bianchera was very rich in polyphenols and satisfied the health claim provided by the EU Commission Regulation on the polyphenols content of olive oils and their beneficial effects on human health.

Simultaneous Quantification of Antioxidants Paraxanthine and Caffeine in Human Saliva by Electrochemical Sensing for CYP1A2 Phenotyping

The enzyme CYP1A2 is responsible for the metabolism of numerous antioxidants in the body, including caffeine, which is transformed into paraxanthine, its main primary metabolite. Both molecules are known for their antioxidant and pro-oxidant characteristics, and the paraxanthine-to-caffeine molar ratio is a widely accepted metric for CYP1A2 phenotyping, to optimize dose–response effects in individual patients. We developed a simple, cheap and fast electrochemical based method for the simultaneous quantification of paraxanthine and caffeine in human saliva, by differential pulse voltammetry, using an anodically pretreated glassy carbon electrode. Cyclic voltammetry experiments revealed for the first time that the oxidation of paraxanthine is diffusion controlled with an irreversible peak at ca. +1.24 V (vs. Ag/AgCl) in a 0.1 M H₂SO₄ solution, and that the mechanism occurs via the transfer of two electrons and two protons. The simultaneous quantification of paraxanthine and caffeine was demonstrated in 0.1 M H₂SO₄ and spiked human saliva samples. In the latter case, limits of detection of 2.89 μM for paraxanthine and 5.80 μM for caffeine were obtained, respectively. The sensor is reliable, providing a relative standard deviation within 7% (n = 6). Potential applicability of the sensing platform was demonstrated by running a small scale trial on five healthy volunteers, with simultaneous quantification by differential pulse voltammetry (DPV) of paraxanthine and caffeine in saliva samples collected at 1, 3 and 6 h postdose administration. The results were validated by ultra-high pressure liquid chromatography and shown to have a high correlation factor (r = 0.994).

One Pot Synthesis of Micromolar BACE-1 Inhibitors Based on the Dihydropyrimidinone Scaffold and Their Thia and Imino Analogues

A library of dihydropyrimidinones was synthesized via a “one-pot” three component Biginelli reaction using different aldehydes in combination with β-dicarbonyl compounds and urea. Selected 2-thiooxo and 2-imino analogs were also obtained with the Biginelli reaction from thiourea and guanidine hydrochloride, respectively. The products were screened in vitro for their β-secretase inhibitory activity. The majority of the compounds resulted to be active, with IC₅₀ in the range 100 nM–50 μM.

Fluorescent Imprinted Nanoparticles for the Effective Monitoring of Irinotecan in Human Plasma

Fluorescent, imprinted nanosized polymers for the detection of irinotecan have been synthesised using a napthalimide polymerisable derivative (2-allyl-6-[2-(aminoethyl)-amino] napthalimide) as functional monomer. The imprinted polymers contain ethylene glycol dimethacrylate (EGDMA) as a cross-linker and were prepared by high dilution radical polymerisation in dimethylsulphoxide (DMSO). The material was able to rebind irinotecan up to 18 nmol/mg with good specificity. Fluorescence emission at 525 nm (excitation at 448 nm) was quenched by increasing concentrations of irinotecan via a static mechanism and also in analytically useful environments as mixtures of human plasma and organic solvents. This allowed the direct detection of irinotecan (in the 10 nM-30 µM range) in human plasma treated with acetonitrile; the limit of detection (LOD) was 9.4 nM, with within-run variability of 10% and day-to-day variability of 13%.

Biosensors and Sensing Systems for Rapid Analysis of Phenolic Compounds from Plants: A Comprehensive Review

Phenolic compounds are secondary metabolites frequently found in plants that exhibit many different effects on human health. Because of the relevant bioactivity, their identification and quantification in agro-food matrices as well as in biological samples are a fundamental issue in the field of quality control of food and food supplements, and clinical analysis. In this review, a critical selection of sensors and biosensors for rapid and selective detection of phenolic compounds is discussed. Sensors based on electrochemistry, photoelectrochemistry, fluorescence, and colorimetry are discussed including devices with or without specific recognition elements, such as biomolecules, enzymes and molecularly imprinted materials. Systems that have been tested on real matrices are prevalently considered but also techniques that show potential development in the field.

Signal-On Fluorescent Imprinted Nanoparticles for Sensing of Phenols in Aqueous Olive Leaves Extracts

The activation of signals in fluorescent nanosensors upon interaction with their targets is highly desirable. To this aim, several molecularly imprinted nanogels have been synthetized for the recognition of tyrosol, hydroxytyrosol and oleuropein in aqueous extracts using the non-covalent approach. Two of them contain fluorescein derivatives as co-monomers, and their fluorescence emission is switched on upon binding of the target phenols. The selection of functional monomers was previously done by analyzing the interactions by nuclear magnetic resonance (NMR) in deuterated dimethylsulfoxide (DMSO-d6) of the monomers with tyrosol and hydroxytyrosol. Polymers were synthetized under high dilution conditions to obtain micro- and nano-particles, as verified by transmission electron microscopy (TEM). 1,4-Divinylbenzene (DVB) was used in the fluorescent polymers in order to enhance the interactions with the aromatic ring of the templates tyrosol and hydroxytyrosol by π-π stacking. The results were fully satisfactory as to rebinding: DVB-crosslinked molecularly imprinted polymers (MIPs) gave over 50 nmol/mg rebinding. The sensitivity of the fluorescent MIPs was excellent, with LODs in the pM range. The sensing polymers were tested on real olive leaves extracts, with very good performance and negligible matrix effects.

The Use of Prophylactic Somatostatin Therapy Following Pancreaticoduodenectomy: A Meta-analysis of Randomised Controlled Trials

BACKGROUND

Prophylactic administration of somatostatin analogues (SA) to reduce the incidence of post-operative pancreatic fistula (POPF) remains contentious. This meta-analysis evaluated its impact on outcomes following pancreaticoduodenectomy (PD).

METHODS

The EMBASE, MEDLINE and Cochrane databases were searched for randomised controlled trials (RCTs) investigating prophylactic SA following PD. Comparative effects were summarised as odds ratio and weighted mean difference based on an intention to treat. Quantitative pooling of the effect sizes was derived using the random-effects model.

MAIN RESULTS

Twelve RCTs were included involving 1615 patients [SA-treated group (n = 820) and control group (n = 795)]. The SA used included somatostatin-14, pasireotide, vapreotide and octreotide. Pooling of the data showed no significant benefit of its use for the primary outcome measure of all grades of POPF, odds ratio (OR) 0.73 [95% confidence interval (CI), 0.51-1.05, p = 0.09] and clinically relevant POPF, OR 0.48 [95% CI, 0.22-1.06, p = 0.07]. There were no benefits in the secondary outcome measures of delayed gastric emptying, OR 0.98 [95% CI, 0.57-1.69, p = 0.94]; infected abdominal collections, OR 0.80 [95% CI, 0.44-1.43, p = 0.80]; reoperation rates, OR 1.24 [95% CI, 0.73-2.13, p = 0.42]; duration of hospital stay, - 0.23 [95% CI - .59 to 1.13, p = 0.74]; and mortality, 1.78 [95% CI, 0.94-3.39, p = 0.08].

CONCLUSION

SA did not improve the post-operative outcomes following PD, including reducing the incidence of POPF. The routine administration of SA cannot be recommended following PD.

Prediction of self-assembly of adenosine analogues in solution: a computational approach validated by isothermal titration calorimetry

The recent discovery of the role of adenosine-analogues as neuroprotectants and cognitive enhancers has sparked interest in these molecules as new therapeutic drugs. Understanding the behavior of these molecules in solution and predicting their ability to self-assemble will accelerate new discoveries. We propose a computational approach based on density functional theory, a polarizable continuum solvation description of the aqueous environment, and an efficient search procedure to probe the potential energy surface, to determine the structure and thermodynamic stability of molecular clusters of adenosine analogues in solution, using caffeine as a model. The method was validated as a tool for the prediction of the impact of small structural variations on self-assembly using paraxanthine. The computational results were supported by isothermal titration calorimetry experiments. The thermodynamic parameters enabled the quantification of the actual percentage of dimer present in solution as a function of concentration. The data suggest that both caffeine and paraxanthine are present at concentrations comparable to the ones found in biological samples.

Distribution of p-coumaroylquinic acids in commercial Coffea spp. of different geographical origin and in other wild coffee species

Quantitative analyses of mono-p-coumaroylquinic acids (pCoQAs) and total chlorogenic acids (CGAs) in green coffee commercial lots of C. arabica, C. canephora and C. liberica from different geographical origins and eight wild Coffea species were carried out. Among the commercial lots, pCoQAs average content of C. arabica (0.67 mg/g) is higher than that of C. canephora (0.40 mg/g) being C. liberica intermediate (0.58 mg/g). As far as the analyzed wild Coffea species is concerned, C. pseudozanguebariae is characterized by the lower pCoQAs content (0.12 mg/g) whereas C. sessiliflora is by far the richest source of pCoQAs (2.18 mg/g). Effect of the roasting process on the mono-p-coumaroylquinic acids profile was evaluated for the economically exploited species C. arabica and C. canephora. For the first time distribution of mono-p-coumaroylquinic acid isomers in wild coffee species by fast and accurate UHPLC-DAD analyses using authentic standards previously synthetized, is reported.

Aqueous extracts of walnut (Juglans regia L.) leaves: quantitative analyses of hydroxycinnamic and chlorogenic acids

Identification of both hydroxycinnamic and chlorogenic acids present in aqueous extracts of walnut leaves (Juglans regia L.) were carried out by using, for the first time, standard compounds not commercially available for qualitative identification. In particular, in addition to caffeic, ferulic, p-coumaric and sinapic acids, cis and trans mono-caffeoylquinic, dicaffeoylquinic, mono-feruloylquinic and cis and trans mono-p-coumaroylquinic acid isomers were detected and quantified by Ultra High Pressure Liquid Chromatography and the seasonal variations of these secondary metabolites were investigated.

Efficient Biginelli Synthesis of 2-Aminodihydropyrimidines under Microwave Irradiation

A practical and general method for the Biginelli cyclocondensation of guanidine with aldehydes and β-dicarbonyl compounds is described and illustrated with the synthesis of a set of 26 functionalized 2-amino-3,4-dihydropyrimidines. The simple protocol involves the ­microwave-mediated reaction of a twofold excess of guanidine hydrochloride with the required reaction partners in an alcohol at 120 °C. Yields are generally good, with short reaction times and a simple workup. The scope is considerably wider than that of similar reactions ­carried out under conventional heating.

Chlorogenic Compounds from Coffee Beans Exert Activity against Respiratory Viruses

Chlorogenic acids are secondary metabolites in diverse plants. Some chlorogenic acids extracted from traditional medicinal plants are known for their healing properties, e.g., against viral infections. Also, green coffee beans are a rich source of chlorogenic acids, with 5-O-caffeoylquinic acid being the most abundant chlorogenic acid in coffee. We previously reported the synthesis of the regioisomers of lactones, bearing different substituents on the quinidic core. Here, 3,4-O-dicaffeoyl-1,5-γ-quinide and three dimethoxycinnamoyl-γ-quinides were investigated for in vitro antiviral activities against a panel of 14 human viruses. Whereas the dimethoxycinnamoyl-γ-quinides did not show any antiviral potency in cytopathogenic effect reduction assays, 3,4-O-dicaffeoyl-1,5-γ-quinide exerted mild antiviral activity against herpes simplex viruses, adenovirus, and influenza virus. Interestingly, when the compounds were evaluated against respiratory syncytial virus, a potent antiviral effect of 3,4-O-dicaffeoyl-1,5-γ-quinide was observed against both subtypes of respiratory syncytial virus, with EC₅₀ values in the submicromolar range. Time-of-addition experiments revealed that this compound acts on an intracellular post-entry replication step. Our data show that 3,4-O-dicaffeoyl-1,5-γ-quinide is a relevant candidate for lead optimization and further mechanistic studies, and warrants clinical development as a potential anti-respiratory syncytial virus drug.

Spontaneous symmetry breaking on ordered, racemic monolayers of achiral theophylline: formation of unichiral stripes on Au(111)

We report the observation of spontaneous chiral symmetry breaking within ordered, racemic monolayers of theophylline, manifesting itself as extended, nanoscale unichiral stripes at the interface between molecular domains. Theophylline is a xanthine derivative playing an important role in several biochemical processes. Molecular chirality is induced by adsorption on the Au(111) surface, resulting in extended domains with two different racemic, ordered structures, coexisting with a disordered phase. By combining low-temperature scanning tunneling microscopy (LT-STM) and ab initio density functional theory calculations, we first provide a detailed picture of the interactions within the ordered assemblies, and we uncover the origin of the distinct contrast features in STM images. Secondly, experiments reveal the existence of nanoscale stripes of unichiral molecules separating racemic domains of one of the two ordered phases, giving rise to a local enantiomeric imbalance. Systematic theoretical investigation of their structure and chiral composition confirm their unichirality, with the specific handedness related to the registry between the two ordered domains facing the stripes. These findings can open the way to new insights into the elusive mechanisms leading to local chiral imbalances in racemic systems, possibly at the origin of biomolecular homochirality, as well as suggest novel approaches for stereoselective heterogeneous catalysis.

Preclinical studies on new proteins as carrier for glycoconjugate vaccines

Glycoconjugate vaccines are made of carbohydrate antigens covalently bound to a carrier protein to enhance their immunogenicity. Among the different carrier proteins tested in preclinical and clinical studies, five have been used so far for licensed vaccines: Diphtheria and Tetanus toxoids, the non-toxic mutant of diphtheria toxin CRM197, the outer membrane protein complex of Neisseria meningitidis serogroup B and the Protein D derived from non-typeable Haemophilus influenzae. Availability of novel carriers might help to overcome immune interference in multi-valent vaccines containing several polysaccharide-conjugate antigens, and also to develop vaccines which target both protein as well saccharide epitopes of the same pathogen. Accordingly we have conducted a study to identify new potential carrier proteins. Twenty-eight proteins, derived from different bacteria, were conjugated to the model polysaccharide Laminarin and tested in mice for their ability in inducing antibodies against the carbohydrate antigen and eight of them were subsequently tested as carrier for serogroup meningococcal C oligosaccharides. Four out of these eight were able to elicit in mice satisfactory anti meningococcal serogroup C titers. Based on immunological evaluation, the Streptococcus pneumoniae protein spr96/2021 was successfully evaluated as carrier for serogroups A, C, W, Y and X meningococcal capsular saccharides.

Designing High-Affinity Peptides for Organic Molecules by Explicit Solvent Molecular Dynamics

Short peptides offer a cheap alternative to antibodies for developing sensing units in devices for concentration measurement. We here describe a computational procedure that allows designing peptides capable of binding with high affinity a target organic molecule in aqueous or nonstandard solvent environments. The algorithm is based on a stochastic search in the space of the possible sequences of the peptide, and exploits finite temperature molecular dynamics simulations in explicit solvent to check if a proposed mutation improves the binding affinity or not. The procedure automatically produces peptides which form thermally stable complexes with the target. The estimated binding free energy reaches the 13 kcal/mol for Irinotecan anticancer drug, the target considered in this work. These peptides are by construction solvent specific; namely, they recognize the target only in the solvent in which they have been designed. This feature of the algorithm calls for applications in devices in which the peptide-based sensor is required to work in denaturants or under extreme conditions of pressure and temperature.

Carrier priming with CRM 197 or diphtheria toxoid has a different impact on the immunogenicity of the respective glycoconjugates: biophysical and immunochemical interpretation

Glycoconjugate vaccines play an enormous role in preventing infectious diseases. The main carrier proteins used in commercial conjugate vaccines are the non-toxic mutant of diphtheria toxin (CRM197), diphtheria toxoid (DT) and tetanus toxoid (TT). Modern childhood routine vaccination schedules include the administration of several vaccines simultaneously or in close sequence, increasing the concern that the repeated exposure to conjugates based on these carrier proteins might interfere with the anti-polysaccharide response. Extending previous observations we show here that priming mice with CRM197 or DT does not suppress the response to the carbohydrate moiety of CRM197 meningococcal serogroup A (MenA) conjugates, while priming with DT can suppress the response to DT-MenA conjugates. To explain these findings we made use of biophysical and immunochemical techniques applied mainly to MenA conjugates. Differential scanning calorimetry and circular dichroism data revealed that the CRM197 structure was altered by the chemical conjugation, while DT and the formaldehyde-treated form of CRM197 were less impacted, depending on the degree of glycosylation. Investigating the binding and avidity properties of IgGs induced in mice by non-conjugated carriers, we found that CRM197 induced low levels of anti-carrier antibodies, with decreased avidity for its MenA conjugates and poor binding to DT and respective MenA conjugates. In contrast, DT induced high antibody titers able to bind with comparable avidity both the protein and its conjugates but showing very low avidity for CRM197 and related conjugates. The low intrinsic immunogenicity of CRM197 as compared to DT, the structural modifications induced by glycoconjugation and detoxification processes, resulting in conformational changes in CRM197 and DT epitopes with consequent alteration of the antibody recognition and avidity, might explain the different behavior of CRM197 and DT in a carrier priming context.