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Lipidomic Insight into Membrane Remodeling in Aging and Neurodegenerative Diseases
Published in Abhai Kumar, Debasis Bagchi, Antioxidants and Functional Foods for Neurodegenerative Disorders, 2021
In contrast, the neuronal membranes are composed of 50% PUFAs, whereas the myelin sheath constitutes as much as ~70% of PUFAs. Arachidonic acid (ARA C20:4) and docosahexaenoic acid (DHA C22:6) are essential acids in nerve cells. Indeed, DHA levels reach 15%–50% of total fatty acids in neurons. The diversity of the structural conformations of PUFAs modulates properties to the membrane milieu because a high unsaturation of these molecules guarantees the required membrane fluidity and plasticity [27]. Phospholipid bilayer fluidity affects the functions of membrane proteins, such as enzymes and transporters, and its changes may contribute to the alteration of protein functions and protein–protein interactions [28].
Finding a Target
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
There are different ways in which membrane proteins can be associated with the phospholipid bilayer. Transmembrane proteins extend through the lipid bilayer and, like the lipids, are amphipathic, consisting of hydrophobic regions which interact with the lipid tails within the membrane, and hydrophilic regions that protrude the membrane and are exposed to water. This morphology is determined by the position and nature of the amino acid side chains. The final tertiary or quaternary structure of the protein will place side chains with polar functional groups to the outside in the regions exposed to water, while greasy side chains that are hydrophobic interact with the lipid membrane.
Basic Microbiology
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Plasma membrane—A phospholipid bilayer which creates a semi-permeable barrier and delineates the boundaries of the cell. This is the location of many important membrane-associated proteins including receptors and enzymes as well as transport proteins designed to internalize desired extracellular components and to extrude cellular contents such as waste.
A transfersomes hydrogel patch for cutaneous delivery of propranolol hydrochloride: formulation, in vitro, ex vivo and in vivo studies
Published in Journal of Liposome Research, 2023
Changzhao Jiang, Rui Ma, Xiumei Jiang, Renhua Fang, Jincui Ye
The orthogonal test results are shown in Table 1. The ratio of drug to lipid results showed that, at specific concentration ranges, as the phospholipid amounts increased, drug encapsulation was enhanced while the levels of free drug decreased. At very high phospholipid concentrations, the increase in encapsulation efficiency was not significant which only increased the costs. Since cholesterol can regulate the fluidity of phospholipid bilayers, a specific amount of cholesterol can stabilise the transfersomes structure and prevent drug leakage (Teong et al.2017). A lower ratio of oil/water inhibits the formation of transfersomes in the vacuum evaporation stage and affects the particle size as well as encapsulation efficiency of transfersomes. As an edge activator, sodium cholate can enhance the deformability of transfersomes, however, large amounts of sodium cholate can destroy the structure of transfersomes and transform them into mixed micelles. The deformability of mixed micelles decreases, their cutaneous ability is weakened, and encapsulation efficiency for drugs is also decreased (Kalam et al.2020).
Recent advances in targeting malaria with nanotechnology-based drug carriers
Published in Pharmaceutical Development and Technology, 2021
Hamid Rashidzadeh, Seyed Jamal Tabatabaei Rezaei, Seyed Masih Adyani, Morteza Abazari, Samaneh Rahamooz Haghighi, Hossien Abdollahi, Ali Ramazani
To propose a simple definition, liposomes are small synthetic vesicles of spherical shape that can be considered as an artificial model of a cell membrane (Rideau et al. 2018; Aibani et al. 2020). Moreover, Liposomes are composed of one or more non-toxic phospholipid bilayers. The unique feature of liposomal drug vehicles is their ability to encapsulate both hydrophobic and hydrophilic drugs (Figure 15), protecting them from degradation, and liberating their payload into the specific site (Daraee et al. 2016; Lee and Thompson 2017). Furthermore, due to their biocompatibility, biodegradability, amphiphilic character, small size, and non-toxicity, liposomes are considered as potential candidates for the delivery of therapeutic agents (Mallick and Choi 2014; Alavi et al. 2017). Liposomes’ instability, drug leakage, and opsonization are still major problems needed to be addressed to achieve the ideal drug vehicle effectively with the aforementioned features. Fotoran et al. in their study prepared multilayer liposomes for the delivery of both hydrophilic and hydrophobic antimalarial drugs. In this regard, chloroquine and artemisinin were encapsulated with high drug loading contents within liposomes due to the formation of strong hydrogen interactions (Figure 16).
Surface-modified polymeric nanoparticles for drug delivery to cancer cells
Published in Expert Opinion on Drug Delivery, 2021
Arsalan Ahmed, Shumaila Sarwar, Yong Hu, Muhammad Usman Munir, Muhammad Farrukh Nisar, Fakhera Ikram, Anila Asif, Saeed Ur Rahman, Aqif Anwar Chaudhry, Ihtasham Ur Rehman
Cell membrane functions as the main barrier for inward and outward movement of bio-entities [33]. Similarly, drug-loaded polymeric nanoparticles are also needed to cross the cell membrane to exhibit their efficiency. The composition, morphology, and functions of cell membrane have attracted scientists to fabricate nanoparticles, whose surfaces mimic cell membrane (Figure 3a). The cell membrane is composed of a phospholipid bilayer with embedded proteins and carbohydrates. Phospholipids consist of hydrophobic phosphate group-containing head linked to the hydrophobic tail of fatty acids. These phospholipids self-assemble into bilayers with hydrophilic regions facing toward outside and inside of the cell, while hydrophobic tails of phospholipids face each other. The incorporation of cholesterol and proteins enhances the stability of the cell membrane. Membrane proteins are inserted throughout the cell membrane asymmetrically. They are arranged in a way that their exterior surfaces can act as receptors for signaling molecules, whereas interior sides change their conformation in response to the binding signal. In some cases, membrane carbohydrates, in the form of glycolipids, work as recognition sites for proteins [34]. Research on biologically inspired nanoparticles has revealed that surface modification of nanoparticles with lipid bilayer or protein/carbohydrate embedding enhances the efficacy of drug-loaded nanoparticles [35], for instance increase in circulation time, improved biocompatibility, low toxicity and immunogenicity [36] and enhanced stability [37].