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Chemosensory Disorders and Nutrition
Published in Alan R. Hirsch, Nutrition and Sensation, 2023
Carl M. Wahlstrom, Alan R. Hirsch, Bradley W. Whitman
In an open label, followed by a double-blind trial of phosphatidylcholine at nine grams a day for three months, mixed results were seen (Hirsch and Dougherty 1992). A 40% improvement on the open-label study was followed by a negative result on the double-blind study. The double-blind study design is noteworthy due to the conclusions after two months. Experimental subjects on the active agent dropped out of the double-blind trial with phosphatidylcholine as a result of their severe dislike of the taste of the phosphatidylcholine. Since none of the patients voiced this complaint initially, it seems possible that their sense of smell, and therefore of flavor, improved during treatment, making them more aware of the taste of the active agent. None of the control subjects who dropped out mentioned the licorice taste as a reason (Hirsch, Dougherty, Aranda, Vanderbilt, and Weclaw 1996). Accordingly, in those with idiopathic hyposmia or anosmia, a three-month trial of phosphatidylcholine (Phoschol) at nine grams per day in three divided doses may be beneficial.
PET-CT
Published in Anju Sahdev, Sarah J. Vinnicombe, Husband & Reznek's Imaging in Oncology, 2020
Mario Jreige, Marie Nicod-Lalonde, John O Prior, Niklaus Schaefer
Phosphatidylcholine is an essential element of cell membrane phospholipids and choline is its precursor. Neoplastic tissue has elevated levels of phosphatidylcholine. Choline kinase, which catalyses the phosphorylation of choline, has elevated activity in neoplastic tissue. The classical indication for 18F or 11C-choline PET-CT is in suspected recurrence of prostate cancer with rising prostate-specific antigen (PSA) levels (116). However, a recent prospective study shows the superiority of 68Ga-PSMA PET-CT over choline PET-CT (117).
Features of Lipid Metabolism in Diabetes Mellitus and Ischemic Heart Disease
Published in E.I. Sokolov, Obesity and Diabetes Mellitus, 2020
Phosphatidylcholine (PC) and phosphatidylethanolamine (PEA) together with cholesterol are the main structural components of a cell membrane. We attach great significance to the ratio PEA/PC for appraising the structural and functional state inside a membrane.
A tale of nucleic acid–ionizable lipid nanoparticles: Design and manufacturing technology and advancement
Published in Expert Opinion on Drug Delivery, 2023
Phosphatidylcholine (PCs) is an essential natural component of biological membranes. The cylindrical geometry of PC facilitates the development of the bilayer phase [62]. Saturated 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) has a high melting temperature and is useful for the formation of more stable ionizable LNPs. Unsaturated ionizable lipids and saturated helper lipids create distinct membrane domains that stabilize and protect nucleic acid during endosomal escape [63]. The high temperature of the DSPC can maintain the structure of nucleic acid-ionizable LNPs during endosomal escape as well as colloidal storage. The addition of cholesterol stabilizes bilayers structure of DSPC helper lipids. For cellular stability and transfection activity of the ionizable LNPs, DSPC-based formulations are found to be better than DOPE-based formulations [64,65]. DSPC was utilized in the preparation of the Covid −19 vaccines, Comirnaty and Spikevax.
Bile acids as novel enhancers of CNS targeting antitumor drugs: a comprehensive review
Published in Pharmaceutical Development and Technology, 2021
Marija Gvoic, Sasa Vukmirovic, Hani Al-Salami, Armin Mooranian, Momir Mikov, Karmen Stankov
The conventional protocol for treating brain tumors includes surgical resection plus radiotherapy and chemotherapy (Laquintana et al. 2009). On the other hand, standard therapy for brain metastases is radiation therapy, although other therapies may be added, if the situation warrants (Bazan et al. 2019). Whether used to treat brain tumors or metastases, systemic therapy lacks effective results because of the BBB. Even if an antitumor drug was able to pass across the BBB, unfavorable events would follow. One drawback is that efflux drug pumps are expressed within the glioma cells. Additionally, adverse effects in the periphery could occur. Despite the significant efforts that have been made, the standard of care for brain tumor treatment remains the same. BAs appear to have some useful properties which certainly draw attention concerning antitumor drug delivery system design vis-a-vis interaction with TJs or cell membranes. They have been important excipients but not without negative aspects to be surmounted. Hydrophobic BAs have been cytotoxic, and DCA has been investigated as a tumor growth stimulator (Pavlović et al. 2018). Contrarily, hydrophilic BAs such as UDCA could oppose hydrophobic BAs, protecting cell integrity (van de Laarschot et al. 2016; Alvarez-Sola et al. 2018; de Haan et al. 2018; Han 2018; Hegyi et al. 2018; Wang et al. 2018; Mooranian et al. 2020). Phosphatidylcholine can protect gastrointestinal epithelial cells from a toxic effect of bile salts and reduce the toxicity of MM (Pavlović et al. 2018). Still, many more studies should be done to clarify the role of BAs as drug permeability enhancers.
Liposomes as vehicles for topical ophthalmic drug delivery and ocular surface protection
Published in Expert Opinion on Drug Delivery, 2021
José Javier López-Cano, Miriam Ana González-Cela-Casamayor, Vanessa Andrés-Guerrero, Rocío Herrero-Vanrell, Irene Teresa Molina-Martínez
Liposomes results of great interest in the treatment of DED. Soy phosphatidylcholine is widely used in the manufacture of liposomes. The main advantage of using phosphatidylcholine is that it is the main component present in the lipid layer of the tear film. In these liposomes, other lipophilic components such as vitamin A and vitamin E can also be added to the lipid bilayer preventing the oxidation of unsaturated lipids due to their antioxidants properties [15]. A liposomal spray formulation for the treatment of dry eye is currently marketed under the name of Tears Again®. This liposomal spray is made up of phospholipids (phosphatidylcholine) and vitamins A and E and is intended to be applied to the surface of the eyelid with the eye closed. A comparative study between Tears Again and a saline spray was reported. The controlled, double-blind, prospective and randomized study in design was carried out in 22 subjects with dry eye. The liposomal spray was applied once to the treated eye, while a saline spray was administered to the other eye (control). The results showed a significant increase in the thickness of the lipid layer (p < 0.005) at 30, 60 and 90 minutes after the application of the liposomal spray. Furthermore, there was an increase in tear film stability in the treated eyes (p < 0.001). Moreover, 70% patients reported greater comfort after 30 minutes of applying the liposomal spray [215].