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The Emerging Role of Exosome Nanoparticles in Regenerative Medicine
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Zahra Sadat Hashemi, Mahlegha Ghavami, Saeed Khalili, Seyed Morteza Naghib
Methods for accommodation of small molecules, protein, or nucleic acids into the exosomes are: (1) physical methods such as electroporation (in the range of 150–700 V), sonication, extrusion procedures, freeze–thaw cycles, incubation at RT (with or without the use of saponin permeabilisation), or other temperature. The small-sized molecules can cross the lipid bilayer of exosome by simple incubation. (2) Chemical methods such as transfection by Lipofectamine 2000. This method is frequently used for siRNA (small interference RNA) packaging into the exosomes. (3) Biological methods called transfection of exosome-producing cells. In this method, the parent cells are genetically modified to overexpress a certain gene. The overexpressed gene would ultimately be collected into the parent cell-derived exosomes. For example, various sources of Mesenchymal Stem Cells (MSCs) were transfected with miR-146b and the exosomes containing the miR-146a cargo were collected from culture media (Johnsen et al. 2014).
Genome Editing and Gene Therapies: Complex and Expensive Drugs
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2020
A special type of nanoscale drug delivery systems are liposomes, that have the ability to cross the blood–brain barrier and hence can deliver molecules including plasmids to the brain. Liposomes formed via free-energy-driven self-assembly of, e.g., fatty acids or diacylphospholipids are spherical vesicles with at least one lipid bilayer; their structural characteristics are polar head group and a hydrophobic hydrocarbon tails which may be connected via a backbone linker such as glycerol. (Multivalent) cationic liposomes with, e.g., quaternary ammonium residues in the head group can interact with negatively charged moieties as found, e.g., in DNA. Lipofectamine (a 1:1 (w/w) liposome formulation of the cationic lipid N-[1-(2,3-dioleyloxy)propyl]-n,n,n-trimethylammonium chloride (DOTMA), and dioleoyl phosphatidylethanolamine (DOPE) in water) is a commercially available transfection reagent sold by Invitrogen (Thermo Fisher Scientific corporation). PEGylated liposomes (lipoplexes) show several advantages such as increased transfection efficiencies and circulation times together with decreased immune responses (Balazs and Godbey, 2011). For examples of liposome-mediated gene delivery across the BBB see, e.g., Pardridge (2010), Xing et al. (2016), and Rodrigues et al. (2018).
Lipid Nanoparticle Induced Immunomodulatory Effects of siRNA
Published in Raj Bawa, János Szebeni, Thomas J. Webster, Gerald F. Audette, Immune Aspects of Biopharmaceuticals and Nanomedicines, 2019
Ranjita Shegokar, Prabhat Mishra
An efficient systemic delivery of the siRNA to tumor and ocular neovasculature tissue in a herpes simplex virus (HSV) eye infection model was achieved through a Arg-Gly-Asp (RGD)-motif peptide ligand-targeted nanoparticle [122]. In another study, siRNA oligos of cationic lipid or polymer carriers containing the 5′-UGUGU-3′ motif induced a Toll-like receptor-mediated interferon response after either i.v. or i.p. administration [29]. Systemic and targeted delivery systems for siRNA have been studied using a protamine-antibody fusion protein [123]. siRNAs specific for human immunodeficiency virus (HIV)-1 capsid protein gag were complexed to a fusion protein composed of cationic protamine and HIV-1 envelope antibody. Aptamers have been suggested as targeting moieties for delivery systems. Lipofectamine 2000 [124] or cardiolipin analogs [125] are widely used for in vitro for a delivery of plasmid DNA or siRNA.
Lipid-based nanocarrier mediated CRISPR/Cas9 delivery for cancer therapy
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Aisha Aziz, Urushi Rehman, Afsana Sheikh, Mohammed A. S. Abourehab, Prashant Kesharwani
Nanoparticles with no surface modifications are cleared by the reticuloendothelial system (RES) by rapid opsonisation. This can be resolved by functionalizing the surface with PEG which prevents absorption and clearance of the nanoparticles [61]. The carrier size, shape and choice of material strongly influence the cellular uptake of the nanoparticles, which is the ultimate goal. The vehicle’s condensation capacity as well as the release of the cargo at the desired site can be maximized by optimizing the lipid to nucleic acid ratio. Lipofectamine 2000 is widely used commercially available cationic transfection reagent, due to its excellent transfection efficacy and expression of proteins. It has been further optimized to work with range of cell lines of mammalian nature [62]. However, a positive correlation was observed between the toxicity of the commonly used transfection reagents and their transfection efficacy [63]. Lipids that are capable of ionization show the extra advantage of pH-dependent change allowing the encapsulation of genetic material in an acidic environment while becoming neutral at physiological ph [64]. Studies have revealed tumor cells to overexpress secreted protein acidic and rich in cysteine and albumin binding glycoprotein receptors [65]. If albumin is incorporated as a surface modification on a nanoparticle, it will facilitate the cellular uptake of the NP’s contents. These modifications can also be made using ligands such as iRGD also called internalizing RGD that are used for targeting cancer. However, the genome can be modified permanently only if NP enters the nucleus. This is made possible by incorporating ligands that target the nuclear membrane, cell-penetrating peptides, and nuclear localization sequences. Checking effective internalization is crucial and for this purpose bio reducible lipid NP’s have been designed and tested in human embryonic kidney cells where they have shown successful knockdown of GFP expression up to 90% [66]. Phospholipids have shown potential as a component of nanoparticle coatings that improve biocompatibility and stability in synthetic inorganic substance-based nanoparticles. These materials are both unstable in aqueous suspensions and cytotoxic [67].