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Organic & Biomolecular Chemistry Jan 2020Phosphocholine is a small haptenic molecule that is both a precursor and degradation product of choline. Phosphocholine decorates a number of biologics such as lipids...
Phosphocholine is a small haptenic molecule that is both a precursor and degradation product of choline. Phosphocholine decorates a number of biologics such as lipids and oligosaccharides. In this study, an air and bench stable phosphocholine donor has been developed and evaluated with a number of alcohol acceptors. Using a one-pot, three-step sequence, (phosphitylation, oxidation, and phosphate deprotection) phosphocholine derivatives are synthesized in high yields. Of particular interest is the synthesis of miltefosine, the lone oral drug approved to treat leishmaniasis. Due to its prohibitive expense ($1500 per g), miltefosine is not accesable for the majority of the world's patients. Based on the described reaction sequence, this drug can be produced for $25 per g.
Topics: Alcohols; Antiprotozoal Agents; Indicators and Reagents; Models, Chemical; Oxidation-Reduction; Phosphorylcholine
PubMed: 31912847
DOI: 10.1039/c9ob02582k -
Biophysical Journal May 2019The dynamics of phosphocholine and maltoside micelles, detergents frequently used for membrane protein structure determination, were investigated using electron...
The dynamics of phosphocholine and maltoside micelles, detergents frequently used for membrane protein structure determination, were investigated using electron paramagnetic resonance of spin probes doped into the micelles. Specifically, phosphocholines are frequently used detergents in NMR studies, and maltosides are frequently used in x-ray crystallography structure determination. Beyond the structural and electrostatic differences, this study aimed to determine whether there are differences in the local chain dynamics (i.e., fluidity). The nitroxide probe rotational dynamics in longer chain detergents is more restricted than in shorter chain detergents, and maltoside micelles are more restricted than phosphocholine micelles. Furthermore, the micelle microviscosity can be modulated with mixtures, as demonstrated with mixtures of 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate with n-dodecylphosphocholine, n-tetradecylphosphocholine, n-decyl-β-D-maltoside, or n-dodecyl-β-D-maltoside. These results indicate that observed differences in membrane protein stability in these detergents could be due to fluidity in addition to the already determined structural differences.
Topics: Cholic Acids; Maltose; Membrane Fluidity; Micelles; Oxygen; Phosphorylcholine
PubMed: 31023535
DOI: 10.1016/j.bpj.2019.03.019 -
BioMed Research International 2020Initial bacterial adhesion to medical devices and subsequent biofilm formation are known as the leading causes of surgical site infection (SSI). Therefore, inhibition of...
Initial bacterial adhesion to medical devices and subsequent biofilm formation are known as the leading causes of surgical site infection (SSI). Therefore, inhibition of bacterial adhesion and biofilm formation on the surface of medical devices can reduce the risk of SSIs. In this study, a highly hydrophilic, antibiofouling surface was prepared by coating the bioabsorbable suture surface with poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate) (PMB). The PMB-coated and noncoated sutures exhibited similar mechanical strength and surface morphology. The effectiveness of the PMB coating on the suture to suppress adhesion and biofilm formation of methicillin-resistant and methicillin-susceptible was investigated both and . The bacterial adhesion test revealed that PMB coating significantly reduced the number of adherent bacteria, with no difference in the number of planktonic bacteria. Moreover, fluorescence microscopy and scanning electron microscopy observations of adherent bacteria on the suture surface after contact with bacterial suspension confirmed PMB coating-mediated inhibition of biofilm formation. Additionally, we found that the PMB-coated sutures exhibited significant antibiofouling effects . In conclusion, PMB-coated sutures demonstrated bacteriostatic effects associated with a highly hydrophilic, antibiofouling surface and inhibited bacterial adhesion and biofilm formation. Therefore, PMB-coated sutures could be a new alternative to reduce the risk of SSIs.
Topics: Animals; Anti-Bacterial Agents; Bacterial Adhesion; Biofilms; Coated Materials, Biocompatible; Male; Methacrylates; Methicillin-Resistant Staphylococcus aureus; Mice; Mice, Inbred C57BL; Phosphorylcholine; Staphylococcus aureus; Sutures
PubMed: 33062684
DOI: 10.1155/2020/5639651 -
Antimicrobial Agents and Chemotherapy Jan 2022Failure of treatment of cutaneous leishmaniasis with antimonial drugs and miltefosine is frequent. Use of oral combination therapy represents an attractive strategy to...
Failure of treatment of cutaneous leishmaniasis with antimonial drugs and miltefosine is frequent. Use of oral combination therapy represents an attractive strategy to increase efficacy of treatment and reduce the risk of drug resistance. We evaluated the potency of posaconazole, itraconazole, voriconazole, and fluconazole and the potential synergy of those demonstrating the highest potency, in combination with miltefosine (HePC), against infection with Leishmania (Viannia) panamensis. Synergistic activity was determined by isobolograms and calculation of the fractional inhibitory concentration index (FICI), based on parasite quantification using an model of human peripheral blood mononuclear cells (PBMCs) infected with a luciferase-transfected, antimony and miltefosine sensitive line of L. panamensis. The drug combination and concentrations that displayed synergy were then evaluated for antileishmanial effect in 10 clinical strains of L. panamensis by reverse transcription-quantitative (qRT-PCR) of 7SLRNA. High potency was substantiated for posaconazole and itraconazole against sensitive as well as HePC- and antimony-resistant lines of L. panamensis, whereas fluconazole and voriconazole displayed low potency. HePC combined with posaconazole (Poz) demonstrated evidence of synergy at free drug concentrations achieved in plasma during treatment (2 μM HePC plus 4 μM Poz). FICI, based on 70% and 90% reduction of infection, was 0.5 for the sensitive line. The combination of 2 μM HePC plus 4 μM Poz effected a significantly greater reduction of infection by clinical strains of L. panamensis than individual drugs. Orally administrable miltefosine/posaconazole combinations demonstrated synergistic antileishmanial capacity against L. panamensis, supporting their potential as a novel therapeutic strategy to improve efficacy and effectiveness of treatment.
Topics: Antiprotozoal Agents; Azoles; Humans; Leishmania guyanensis; Leukocytes, Mononuclear; Phosphorylcholine
PubMed: 34694879
DOI: 10.1128/AAC.01425-21 -
Tropical Medicine & International... Apr 2019Meglumine antimoniate (MA; Glucantime®), the 80-year-old first-line systemic treatment for all forms of American tegumentary leishmaniasis (ATL) caused by Leishmania... (Review)
Review
American tegumentary leishmaniasis in Brazil: a critical review of the current therapeutic approach with systemic meglumine antimoniate and short-term possibilities for an alternative treatment.
OBJECTIVES
Meglumine antimoniate (MA; Glucantime®), the 80-year-old first-line systemic treatment for all forms of American tegumentary leishmaniasis (ATL) caused by Leishmania (Viannia) braziliensis, Leishmania (Viannia) guyanensis and Leishmania (Leishmania) amazonensis, is highly toxic, presents adverse side-effects and may not attain clinical and parasitological cure. This critical review examines the necessity for intramuscular/intravenous administration of MA, the alternatives to this approach, and the possibilities of developing affordable, accessible and non-toxic drugs or new delivery methods.
METHOD
PubMed searches were performed using the terms 'cutaneous leishmaniasis' or 'American tegumentary leishmaniasis' in combination with 'meglumine antimoniate' or 'N-methyl glucamine' or 'drug repositioning' or 'nanotechnology'. Searches covered a period of 20 years of peer reviewed journals and technical bulletins. We explored the mode of action, pharmacokinetics, toxicity and efficacy of MA, evaluated the progress of ATL therapy in Brazil, and examined the potential of drug repositioning and nanotechnology in accelerating the introduction and/or optimisation of an alternative treatment.
RESULTS
The evidence suggests that ATL therapy will continue to rely on systemic MA in the foreseeable future even though an intralesional subcutaneous route has evolved over the last 10 years. The chances of developing a novel drug for ATL or a new mode of delivery of MA are low. While MA nanocarriers afford a promising approach, this technology is still in its infancy. A more immediate solution would be the production of a bioequivalent of miltefosine, an efficacious oral agent no longer protected by patent.
CONCLUSION
Development of a contemporary treatment requires governmental commitment in bringing together private and public sectors.
Topics: Antiprotozoal Agents; Brazil; Humans; Leishmania braziliensis; Leishmania guyanensis; Leishmaniasis, Cutaneous; Meglumine Antimoniate; Patents as Topic; Phosphorylcholine
PubMed: 30681239
DOI: 10.1111/tmi.13210 -
Clinical Microbiology and Infection :... Jun 2018To evaluate the evidence for use of different formulations of amphotericin B (AmB), minimum effective dose for each formulation and its comparative efficacy against... (Comparative Study)
Comparative Study Meta-Analysis Review
OBJECTIVES
To evaluate the evidence for use of different formulations of amphotericin B (AmB), minimum effective dose for each formulation and its comparative efficacy against other drugs in achieving definitive cure of visceral leishmaniasis.
METHODS
This systematic review and meta-analysis included following data sources: PubMed, Embase, Scopus, Web of Science and CINAHL. Controlled prospective clinical trials (randomized or nonrandomized, including dose-ranging studies) conducted between 1996 and 2017 with at least one treatment group receiving AmB were included (published data only). The primary outcome was definitive cure at 6 months. Adverse events and mortality were assessed as secondary outcomes. The PROSPERO registration number for this review is CRD42017067488.
RESULTS
Thirty-one studies (26 from India) that enrolled 6903 patients into 84 study groups met the selection criteria. In India, liposomal AmB was not inferior to AmB deoxycholate (relative risk 1.00, 95% confidence interval (CI) 0.96-1.03, two randomized controlled trials (RCTs), 514 participants, high-quality evidence), and a single dose of the earlier formulation as low as 3.75 mg/kg achieved a cure rate of over 89% (95% CI 70.6-97.2). AmB deoxycholate was as effective as miltefosine (relative risk 0.99, 95% CI 0.95-1.03, two trials, 523 participants, high-quality evidence) and may be better than paromomycin (relative risk 1.04, 95% CI 1.02-1.07, one trial, 667 participants, low-quality evidence) in achieving definitive cure.
CONCLUSIONS
AmB is an efficacious drug in the Indian subcontinent. Further evidence is needed from prospective clinical trials in other endemic geographical regions.
Topics: Amphotericin B; Antiprotozoal Agents; Clinical Trials as Topic; Deoxycholic Acid; Drug Combinations; Drug Compounding; Evidence-Based Medicine; Female; Humans; Leishmaniasis, Visceral; Male; Paromomycin; Phosphorylcholine; Survival Analysis; Treatment Outcome
PubMed: 29138100
DOI: 10.1016/j.cmi.2017.11.008 -
Scientific Reports Aug 2016Cellular informational and metabolic processes are propagated with specific membrane fusions governed by soluble N-ethylmaleimide sensitive factor attachment protein...
Cellular informational and metabolic processes are propagated with specific membrane fusions governed by soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNARE). SNARE protein Ykt6 is highly expressed in brain neurons and plays a critical role in the membrane-trafficking process. Studies suggested that Ykt6 undergoes a conformational change at the interface between its longin domain and the SNARE core. In this work, we study the conformational state distributions and dynamics of rat Ykt6 by means of single-molecule Förster Resonance Energy Transfer (smFRET) and Fluorescence Cross-Correlation Spectroscopy (FCCS). We observed that intramolecular conformational dynamics between longin domain and SNARE core occurred at the timescale ~200 μs. Furthermore, this dynamics can be regulated and even eliminated by the presence of lipid dodecylphoshpocholine (DPC). Our molecular dynamic (MD) simulations have shown that, the SNARE core exhibits a flexible structure while the longin domain retains relatively stable in apo state. Combining single molecule experiments and theoretical MD simulations, we are the first to provide a quantitative dynamics of Ykt6 and explain the functional conformational change from a qualitative point of view.
Topics: Animals; Apoproteins; Binding Sites; Cloning, Molecular; Crystallography, X-Ray; Escherichia coli; Fluorescence Resonance Energy Transfer; Gene Expression; Kinetics; Membrane Fusion; Molecular Dynamics Simulation; Phosphorylcholine; Protein Binding; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Protein Interaction Domains and Motifs; R-SNARE Proteins; Rats; Recombinant Proteins; Single Molecule Imaging; Thermodynamics
PubMed: 27493064
DOI: 10.1038/srep30282 -
The Journal of Investigative Dermatology Feb 1996Spingosylphosphorylcholine (lysosphingomyelin or SPC) is an effective and broad spectrum cell growth promoting agent and a candidate for evaluation on wound healing. The...
Spingosylphosphorylcholine (lysosphingomyelin or SPC) is an effective and broad spectrum cell growth promoting agent and a candidate for evaluation on wound healing. The effect of SPC on full-thickness excision and incision wounds in genetically healing-impaired diabetic (db/db) mice was evaluated by measurement of wound area, skin strength, and tissue histology. The effect on cell proliferation was measured in vivo by incorporation of bromo-deoxyuridine and in vitro by [3H] thymidine incorporation. SPC increased the rate of wound closure, with a statistically significant improvement in measured wound areas (p < 0.02, compared with vehicle controls). The optimum concentration was 2-3 microM. SPC, alone and in combination with insulin, stimulated DNA synthesis in cells known to participate in wound healing, including microvascular endothelial cells. In vivo, SPC stimulated proliferation of keratinocytes, fibroblasts, endothelial cells, and cells around sebaceous glands and hair follicles at day 2-4 postwound, resulting in a complete re- epithelialization and profound granulation tissue formation in excisional and incisional wound sites of db.db and db/+ mice. Quantitative assessment of wound tissue section morphology indicated that SPC induced up to a 3-fold increase in the numbers of mitotic cells, resulted in smaller cross-sectional scar area, and led to more normalized tissue in the wound sites. SPC had no deleterious effect on wound skin strength. In conclusion, the acceleration of dermal wound healing animal models suggests that SPC could be an interesting candidate for clinical application.
Topics: Animals; Cell Division; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Phosphorylcholine; Sphingosine; Time Factors; Wound Healing; Wounds and Injuries
PubMed: 8601721
DOI: 10.1111/1523-1747.ep12340570 -
PloS One 2022In the field of cell and tissue engineering, there is an increasing demand for techniques to spatially control the adhesion of cells to substrates of desired sizes and...
In the field of cell and tissue engineering, there is an increasing demand for techniques to spatially control the adhesion of cells to substrates of desired sizes and shapes. Here, we describe two novel methods for fabricating a substrate for adhesion of cells to a defined area. In the first method, the surface of the coverslip or plastic dish was coated with Lipidure, a non-adhesive coating material, and air plasma was applied through a mask with holes, to confer adhesiveness to the surface. In the second method, after the surface of the coverslip was coated with gold by sputtering and then with Lipidure; the Lipidure coat was locally removed using a novel scanning laser ablation method. These methods efficiently confined cells within the adhesive area and enabled us to follow individual cells for a longer duration, compared to the currently available commercial substrates. By following single cells within the confined area, we were able to observe several new aspects of cell behavior in terms of cell division, cell-cell collisions, and cell collision with the boundary between adhesive and non-adhesive areas.
Topics: Adhesiveness; Adhesives; Cell Adhesion; Cell Engineering; Dictyostelium; Lipids; Methacrylates; Phosphorylcholine; Plastics; Surface Properties; Tissue Engineering
PubMed: 35030217
DOI: 10.1371/journal.pone.0262632 -
PLoS Neglected Tropical Diseases Mar 2021There is a continued need to develop effective and safe treatments for visceral leishmaniasis (VL). Preclinical studies on pharmacokinetics and pharmacodynamics of...
BACKGROUND
There is a continued need to develop effective and safe treatments for visceral leishmaniasis (VL). Preclinical studies on pharmacokinetics and pharmacodynamics of anti-infective agents, such as anti-bacterials and anti-fungals, have provided valuable information in the development and dosing of these agents. The aim of this study was to characterise the pharmacokinetic and pharmacodynamic properties of the anti-leishmanial drugs AmBisome and miltefosine in a preclinical disease model of VL.
METHODOLOGY / PRINCIPAL FINDINGS
BALB/c mice were infected with L. donovani (MHOM/ET/67/HU3) amastigotes. Groups of mice were treated with miltefosine (orally, multi-dose regimen) or AmBisome (intravenously, single dose regimen) or left untreated as control groups. At set time points groups of mice were killed and plasma, livers and spleens harvested. For pharmacodynamics the hepatic parasite burden was determined microscopically from tissue impression smears. For pharmacokinetics drug concentrations were measured in plasma and whole tissue homogenates by LC-MS. Unbound drug concentrations were determined by rapid equilibrium dialysis. Doses exerting maximum anti-leishmanial effects were 40 mg/kg for AmBisome and 150 mg/kg (cumulatively) for miltefosine. AmBisome displayed a wider therapeutic range than miltefosine. Dose fractionation at a total dose of 2.5 mg/kg pointed towards concentration-dependent anti-leishmanial activity of AmBisome, favouring the administration of large doses infrequently. Protein binding was >99% for miltefosine and amphotericin B in plasma and tissue homogenates.
CONCLUSION / SIGNIFICANCE
Using a PK/PD approach we propose optimal dosing strategies for AmBisome. Additionally, we describe pharmacokinetic and pharmacodynamic properties of miltefosine and compare our findings in a preclinical disease model to available knowledge from studies in humans. This approach also presents a strategy for improved use of animal models in the drug development process for VL.
Topics: Amphotericin B; Animals; Antiprotozoal Agents; Drug Therapy, Combination; Homeodomain Proteins; Humans; Leishmaniasis, Visceral; Liver; Male; Mice; Mice, Inbred BALB C; Mice, Knockout; Parasite Load; Phosphorylcholine; Protein Binding
PubMed: 33651812
DOI: 10.1371/journal.pntd.0009013