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Nanomaterials for Theranostics: Recent Advances and Future Challenges *
Published in Valerio Voliani, Nanomaterials and Neoplasms, 2021
Eun-Kyung Lim, Taekhoon Kim, Soonmyung Paik, Seungjoo Haam, Yong-Min Huh, Kwangyeol Lee
Lipid-based nanocarriers are particularly useful because of their biocompatibility and excellent ability to contain both hydrophilic and hydrophobic drugs. Various carrier systems can be formulated using readily available, naturally occurring molecules [593]. In addition, widely available lipid membrane modification methods can be applied to achieve desired targeting ability and surface charge for effective drug delivery [378, 456, 481, 559–568]. While these obvious advantages are very attractive, practical application of lipid-based nanocarriers has limitations. For example, intravenously injected large lipid-based nanocarrier particles are rapidly cleared from the bloodstream by the RES [20, 372, 534, 579], which affects the drug efficacy significantly. Furthermore, the instability of the lipid-based carrier in the bloodstream might lead to premature drug release, i.e., before reaching the target, causing drug side effects; in addition, an undesired release of the drug results in reduced drug efficacy.
Drug Delivery
Published in David A. Walker, Giorgio Perilongo, Roger E. Taylor, Ian F. Pollack, Brain and Spinal Tumors of Childhood, 2020
Gudrun Fleischhack, Martin Garnett, Kévin Beccaria
Taking the circulatory system as a starting point, intravenous administration is quite common in cancer chemotherapy, and this is also the compartment where oral drug first reaches following absorption from the gut. Drugs are typically amphiphilic, which means that they have both hydrophilic and hydrophobic characteristics. This is an important property of drugs so that they are sufficiently soluble to reach their target sites in the aqueous cell milieu, but can partition across lipid membranes and diffuse to all sites. These drugs can therefore readily pass out of the capillaries of the blood stream into tissues and diffuse into cells. The rate of diffusion is related to concentration, so high concentrations of drug will diffuse more readily into tissues. However, at the same time that drug is diffusing into tissues, it is also being eliminated from the circulation in an exponential fashion by the kidney, giving a continually reducing concentration. There is, therefore, a limited time window in which drug can move out of the circulation and accumulate in tissues before another dose needs to be given. The rate at which drug passes from blood into the tissues will also depend on how well perfused the tissue is with blood. There is an additional problem with brain in that the blood–brain barrier (BBB) reduces entry of drugs into brain, in some cases very dramatically, to the extent that there is essentially no useful uptake of drug in the brain.
The Importance of Temperature Control When Investigating High Threshold Calcium Currents in Mammalian Neurones
Published in Avital Schurr, Benjamin M. Rigor, BRAIN SLICES in BASIC and CLINICAL RESEARCH, 2020
R. Hamish McAllister-Williams, John S. Kelly
Accelerated run-down at 30°C, coupled with the shift in voltage dependency probably accounts for the nonlinearity of the Arrhenius plot of the peak current amplitude between 25°C and 30°C (Figure 6). It is possible that some nonlinearity is due to a transition temperature occurring in these cells. This has previously been observed for calcium currents,3 though not by all workers,4,6, and occurred at 18 to 20°C. This is also the case for acetylcholine channel conductance,10 though it is a higher temperature than that seen for sodium currents (10°C11,67) and potassium currents (8°C12). All have been postulated to occur as a result of changes in the fluidity of the lipid membrane where the critical temperature for saturated fatty acid flexibility is 9 to 10°C.9 Therefore, a transition temperature for calcium current amplitude in DR neurones between 25°C and 30°C seems rather unlikely. In addition, Narahashi’s group observed a Q10 for peak current amplitude above 20°C in the same order, three, as observed here, while below this temperature the value was 15 to 17, far higher than anything observed in DR cells.
Preparation of targeted theranostic red blood cell membranes-based nanobubbles for treatment of colon adenocarcinoma
Published in Expert Opinion on Drug Delivery, 2023
Tahoora Ghasemzadeh, Maliheh Hasannia, Khalil Abnous, Seyed Mohammad Taghdisi, Sirous Nekooei, Negar Nekooei, Mohammad Ramezani, Mona Alibolandi
Developments in nanothechnology led to the fabrication of various types of carriers for drug delivery comprising liposomes, solid lipid nanoparticles, polymer-based nanoparticles, hybrid nanoparticles, cell-based nanoparticles, and so on [10]. Among different types of nanocarriers, liposome is one of the effective nanocarriers in drug delivery due to its advantages including great loading capacity and excellent biocompatibility as evident from their approval for clinical applications [11]. In fact, chemical composition and lipid membrane of liposomes are extremely similar to the biological membranes, making them appropriate for studying the biological function of cells. However, it is hard to mimic the cell membrane using liposomes due to its simple structure compared with the living cell membrane. According to recent research, cell-based drug carriers have been widely applied in drug delivery due to their superior advantages including great half-life, modified pharmacokinetics, desirable biocompatibility, selectivity toward the target site, and reduced undesirable effects. Membranes of hepatocytes, platelets, fibroblasts, leukocytes, erythrocytes, stem cells, and cancer cells have been used for the preparation of therapeutic vehicles [12], among which carriers based on the blood cell membrane exhibited great advantages with extensive applications. In this regard, nanovesicles based on RBCs have been widely applied in different field of drug delivery including photodynamic therapy, photothermal therapy, chemotherapy, theranostic, and nanovaccine [13].
Campylobacter jejuni permeabilizes the host cell membrane by short chain lysophosphatidylethanolamines
Published in Gut Microbes, 2022
Xuefeng Cao, Chris H.A. van de Lest, Liane Z.X. Huang, Jos P.M. van Putten, Marc M.S.M. Wösten
What is causing lysoPE-induced cell damage? It has been shown that the incorporation of even a small amount (1 mol.%) of fatty acids or lysolipids in lipid membranes creates instabilities in the lipid bilayer.31 One theory for LPL-induced cell damage is that LPLs, such as lysoPC, can evoke an oxidant stress-dependent transient membrane permeabilization in cells.32 Our results support this hypothesis as two antioxidants, vitamin E and DPPD, protect the cells from the LPLs damage. Both inhibitors reduced the lysoPE 14:0 induced cytotoxicity and also inhibited the intracellular membrane staining (Figure 4d). The mechanism of toxicity of lysoPE 14:0 may thus resemble the effect of as lysoPC leading to a stress-dependent transient membrane permeabilization.32
The role of artificial cells in the fight against COVID-19: deliver vaccine, hemoperfusion removes toxic cytokines, nanobiotherapeutics lower free radicals and pCO2 and replenish blood supply
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2022
Artificial cells are attempts to mimic some of the properties of biological cells for use in medicine. This author prepared the first artificial cells by enclosing the content of red blood cells inside ultrathin polymer membranes of cellular dimensions (Figure 1) [3,4]. He then extended this research by going outside the box with variations in contents, membrane composition, and configurations (Figure 1). Contents of artificial cells include haemoglobin, enzymes, cells, vaccines, compartments, cytosol, organelles, magnetics, adsorbent, insulin and later, stem cells, gene, DNA, mRNA, silver, gold, miroorganisms, biotechnological products and others (Figure 1). Membrane composition include polymeric membrane, lipid membrane, biodegradable membrane, crosslinked protein membrane, conjugation, lipid-polymeric membrane, PEGalated membrane and others (Figure 1). It has since been developed around the world into many configurations and dimensions under different names for different specific applications (Figure 1) [2,5–19]. One can now taylor-made Artificial Cells to suit specific applications. It has now evolved into many different areas including blood substitutes, hemoperfusion, nanomedicine, nanobiotherapeutics, drug delivery, regenerative medicine, cell/stem cell encapsulation, nanoparticles, liposomes, bioencapsulation, and other areas. Artificial cell is now a very large area and reviews on artificial cells are available elsewhere [2,5,7]. Figure 1 is a summary of the area.