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Vaccine Adjuvants in Immunotoxicology
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
A virosome is a vaccine adjuvant and carrier system for the subunit vaccines. They have a multifunctional activity thanks to their structure and composition (Moser, Amacker, and Zurbriggen 2011). Virosomes, which are “virus-like” phospholipid vesicles containing viral proteins (Cordeiro and Alonso 2016). Virosomes are non-proliferating viral glycoprotein-coated liposomes which can be used to deliver vaccine antigens directly into a host cell (Moser, Amacker, and Zurbriggen 2011). They accelerate the antigen uptake of the APCs (Glück, Burri, and Metcalfe 2005; Wilschut 2009). Despite increasing use of peptide vaccines, designation stage may cause declines in the immunogenic efficacy of the peptide vaccines. Virosomes are developed as the adjuvant or carrier systems to increase the immunogenic efficacy of the synthetic peptide vaccines. The synthetic peptides on the virosomes are safe and immunogenic for humans even at low doses (Moser, Amacker, and Zurbriggen 2011).
Liposome/Viral Hybrid Gene Delivery Systems
Published in Kenneth L. Brigham, Gene Therapy for Diseases of the Lung, 2020
For anionic liposomes to be useful as a gene delivery system to the lung, they should be formulated to target and enter lung cells, the majority of which are non-phagocytic. Viral proteins can be inserted on the outer surface of anionic liposomes to target specific lung cells and also to promote fusion of the lipid layer of the liposome with the cell membrane. Such viral/liposome hybrids are often termed virosomes.
Liposomes
Published in Danilo D. Lasic, LIPOSOMES in GENE DELIVERY, 2019
Typically, viruses are dissolved with detergent, normally C12E8 (dodecyl octaoxyethylene) and capsid material is removed by centrifugation. The system is reconstituted into vesicles by detergent removal by using detergent-adsorbing beads. In contrast to reconstituted virosomes, synthetic virosomes can be made from appropriate lipids and proteins (or their fragments) by using pure compounds and possible contamination with viral constituents is eliminated.
Comparison of Virosome vs. Liposome as drug delivery vehicle using HepG2 and CaCo2 cell lines
Published in Journal of Microencapsulation, 2021
Varun Kumar, Ramesh Kumar, V. K. Jain, Suman Nagpal
Virosome; is a membrane-based modern drug delivery carrier, containing viral glycoproteins without genetic material, these viral peplomers assist virosome in the recognition and attachment specifically to their target site. Virosome was first prepared from influenza viral spike proteins and used in the construction of lipid vesicle (Felnerova et al. 2004). The numeral property of virosomes makes them a promising candidate for drug and antigen delivery to the targeted cells. The virosome can withstand physicochemical and biological adverse reactions inside the body (Liu et al. 2015). Moreover, due to antigenic viral proteins on virosomes, these virosomes can serve as safe and effective vaccine and adjuvant models. These characteristics of virosomes can be employed for attaining clinical benefits.
Merits of the ‘good’ viruses: the potential of virus-based therapeutics
Published in Expert Opinion on Biological Therapy, 2021
Qianyu Zhang, Wen Wu, Jinqiang Zhang, Xuefeng Xia
Virus membranes were first solubilized by non-denaturing detergents such as octaethylene glycol mono-n-dodecyl ether, Triton X-100, and other nonionic detergents [91]. Lipids were collected after ultracentrifugation and self-assembled into virosomes after the addition of cholesterol and phospholipids. Both hydrophilic and hydrophobic small molecule drugs and macromolecules can be loaded during the preparation; therefore, virosomes can be used as either vaccines or drug delivery vehicles. Virosomes display viral envelop glycoproteins, which can be used as vaccine antigens as well as the receptor-binding or membrane-fusion component. For virosomes derived from influenza virus, hemagglutinin (HA) and neuraminidase (NA) from the virus can be incorporated into the lipid bilayer. HA is known to alter its structure under acidic pH to become fusion-competent, facilitating endosome escape after the virus is endocytosed [92]. On the other hand, NA removes the terminal sialic acid from cell surface sugar chains, promoting virus entry into cells [93]. Taken together, HA and NA-containing virosomes possess improved fusion activity compared with liposomes.
Research Progress in Bioinspired Drug Delivery Systems
Published in Expert Opinion on Drug Delivery, 2020
Qirong Tong, Na Qiu, Jianbo Ji, Lei Ye, Guangxi Zhai
Virosomes are virion-like phospholipid bilayer vesicles or rather membranous NPs devoid of the viral nucleocapsid and genetic material, containing incorporated glycoprotein [120,121]. In virosomes, the glycoprotein is responsible for carrying various cargos, promoting structural stability, and homogeneity. Like VNPs, virosomes can deliver genes and drugs and could be used as vaccines. They are relatively less toxic than VNPs, although they still carry the risk of inducing immunogenicity and this defect can be minimized through surface modification with targeting ligands. Rebecca et al. coupled virosomes to ovalbumin (OVA) and verified an enhanced OVA-specific CD4+ T cell proliferation after murine bone marrow-derived dendritic cells (BMDCs) were treated with OVA-coupled virosomes, suggesting that antigen-coupled virosomes induced dendritic cell-dependent adaptive immune responses [122]. Further, an in-depth comparison between virosomes and liposomes was undertaken, although both were taken up by BMDCs, antigen-coupled virosomes showed rapid uptake and the ability to induce a series of adaptive immune responses, indicating the advantage of virosomes in promoting efficacy through the immune system.