China
Africa
Explore chapters and articles related to this topic
Extracellular Vesicles (EVs)
Published in Peixuan Guo, Kirill A. Afonin, RNA Nanotechnology and Therapeutics, 2022
Alice Braga, Giulia Manferrari, Jayden A. Smith, Stefano Pluchino
Another approach that has been explored with regard to enhancing EV uptake relies on alteration of the tropism of the vesicles through pseudotyping, a method commonly used in virology. This technique, based on the packaging of the genetic component of a particular virus into the envelope proteins derived from different viruses, results in an increased infectivity of the resultant recombinant virus (Cronin, Zhang, and Reiser 2005). Adapting this approach, Meyer et al. demonstrated the possibility of augmenting exosome uptake in different cell types (Meyer et al. 2017). The authors expressed VSVG in HEK293 cells, based on the knowledge that VSVG is often used for viral pseudotyping due to its broad tropism and high efficacy in transduction. VSVG expression was then validated by fluorescent co-localization of red signal associated with VSVG and green with the vesicular tetraspanin CD63, revealing similar intracellular and temporal pattern and thus suggesting the incorporation of VSVG into exosomes through the endocytic pathway. Finally, after demonstrating the efficient release of VSVG exosomes from parental cells by using VSVG-luciferase fusion, increased uptake of VSVG-expressing exosomes was measured in various cell types (HEPG2, a human liver cancer cell line; U87, a human glioblastoma cell line; HEK293; and commercial human iPSCs).
Application of Bioresponsive Polymers in Gene Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Tamgue Serges William, Drashti Pathak, Deepa H. Patel
To achieve it, two major systems have been used for a while; viral and non-viral mediated systems. Viral mediated system is based on the uses of various viruses as carriers to insert genetic sequence into the host cell. The viruses have the ability to cross cell barriers and insert their genetic material inside the host cell. Some examples of viruses used include retroviral vectors as human immunodeficiency virus (HIV), adeno-associated virus (AAV), herpes simplex virus (HSV), Epstein Barr virus (EBV), adeno-viruses (AV), hepatitis B virus (HBV), Moloney murine leukemia virus (MoMLV). Creating a viral vector involves producing a recombinant virus lacking replication but maintaining its ability to infect cells [2]. These viral vectors are generally efficient tools of transfection but they possess some disadvantages like high production cost, difficulty in targeting to certain cells, size limitation of DNA constructs safety concerns, immunogenic reactions, toxic side effects, and possibility of triggering oncogenes, possibility to revert back or to retain an infectious form. The tentative to overcome such drawbacks has opened the gates to exploration of alternatives methods, which are non-viral mediated systems. In the recent past, non-viral mediated gene transfer has gained much more interest as potentially safe and effective methods to transfer genes in a wide range of genetic disease.
Applications in Nanomedicine and Drug Delivery Systems
Published in Yaser Dahman, Biomaterials Science and Technology, 2019
Viruses are considered one of the potential vehicles for drug and gene therapies due to their natural ability to infect specific cells and transport genomic material to the nucleus. Using a recombinant virus can improve transfection efficiency by enhancing drug delivery and avoiding degradation by lysosomes (Eliyahu, 2005). Various viruses have been tested, and the most commonly used are retroviruses, lentiviruses, and adenoviruses (Taratula, 2009). However, the use of viruses raises concerns related to their safety because of the risks of insertion mistakes, the activation of proto-oncogenes, viral replication, and strong immune responses (Blau, 1995). Moreover, retroviruses have size loading limitations as they can only infect dividing cells. Therefore, they are mostly used for ex-vivo delivery. Lentiviruses, on the other hand, can deliver a gene into non-dividing cells as well as adenoviruses (the virus remains extrachromosomal which reduces the chances of disrupting the cellular genome) (Blau, 1995). These systems are most likely to be applied in cytotoxic gene therapy (Thaci, 2011). In contrast to these, the nonviral vectors such as virosomes and nanoparticles have rapidly increased due to their weak immune response and ease of synthesis (Cusi, 2006).
Drying of Vaccines and Biomolecules
Published in Drying Technology, 2022
Bhaskar N. Thorat, Ayantika Sett, A. S. Mujumdar
The primary requirement for a vaccine is the antibody generation to avert disease caused by intracellular as well as extracellular microorganism. This specific property identified by such antibodies are generally limited to very less number of surface attachments present on the surface of microorganism and these surface paraphernalia could be protein molecules or carbohydrate moieties. The first step of synthesis of subunit vaccine of viral as well as bacterial subgroup is identification and isolation of those components including polysaccharides, carbohydrate/conjugate preparations, and toxoids. A subunit vaccine is commonly a surface protein which is used to activate an immune response. It is derived from a pathogen and stimulate the immunity (acquired) against that pathogen. An interesting option is to isolate the specific protein from a virus and making dosages out of it. In another method, an antigen’s gene from the targeted virus or bacterium is put into another virus. An example of this is hepatitis B vaccine. A recombinant virus from an attenuated bacterium can serve as the important component of recombinant vaccine. The antigen obtained in this fashion is expected to be patient compliant. The vaccines for both Ebola and HIV viruses can be manufactured following the above technique. There are several polysaccharide vaccines which falls under the same category, where, the signature polysaccharides are linked to the capsular vaccine. Influenza surface antigens such as neuraminidase and hemagglutinin are responsible for making of viral vaccines.
Demonstrated SARS-CoV-2 Surface Disinfection Using Ozone
Published in Ozone: Science & Engineering, 2021
Savannah J. Volkoff, Trevor J. Carlson, Kelsey Leik, Jacques J. Smith, Duane Graves, Philip Dennis, Taylor Aris, Doug Cuthbertson, Andrew Holmes, Kirk Craig, Bruce Marvin, Eric Nesbit
An additional round of sampling was performed in a shop laboratory environment using paper discs prepared in duplicate dosed with 4,500 copies of AccuPlex™ Recombinant Virus (Seracare Life Science Inc., Milford, MA, USA). The Sanozone™ O3 generator produced average concentrations of 4.5 and 9 ppmv O3 for an exposure period of 90 minutes. A hold time of 60 minutes was applied before personnel reentered the exposure chamber and transferred the discs to 1 mL of TRIzol™ LS reagent to extract and preserve RNA (Invitrogen, Carlsbad, CA, USA). Samples were stored at 4 °C until further processing.
Nanomaterials against pathogenic viruses: greener and sustainable approaches
Published in Inorganic and Nano-Metal Chemistry, 2020
Ghazaleh Jamalipour Soufi, Siavash Iravani
Mesoporous silica NPs functionalized with three district organic chemical groups in one-pot synthesis were applied to control viral transduction.[44] Because of the hydrophobicity and hydrophilicity properties of their surfaces, the mesoporous silica NPs may provide better interactions with a precise virus envelope with similar surface characteristics. At low concentrations, these NPs demonstrated no toxicity to the mammalian cells evaluated, and were capable of reducing transduction of a recombinant virus harboring vesicular stomatitis virus G glycoprotein envelope. This envelope is mainly employed in basic investigation in comparison with another recombinant lentivirus that harbors a HIV-gp120 envelope. The mesoporous silica particles interactions with precise virus envelope are the basis of the antiviral activity of these materials, as stronger virus-mesoporous silica bonds disturb the attachment of cell receptors to the virus envelope, and the viral transduction ability is abridged.[44] Interestingly, the nanoformulation consisted of mesoporous silica nanospheres functionalized with amine groups (NH2) and loaded with shikimic acid or quercetin prodrug was introduced; these nanoformulations exhibited antiviral and anti-inflammatory effects, and caused the inhibition of virus titers and plaque formation.[45] Remarkably, the NPs and prodrugs alone are less efficient as antiviral formulations than the drug-loaded mesospheres, and the effect depended on the concentration of NPs in the nanoformulation. The main mechanism of antiviral effect of the nanoformulations against H5N1 was through direct interaction between the virus and NPs, which inactivated the virus at early stages.[45] Importantly, in order to reduce the cytotoxic effects of nevirapine (a medication used to treat and prevent HIV/AIDS) and to enhance its anti-HIV efficacy, mesoporous silica NPs mediated delivery was introduced.[46] The in vitro evaluation of the anti-HIV1 potential of nevirapine and nevirapine-mesoporous silica NPs in HIV1 infected TZM-bl cells and peripheral blood mononuclear cells exhibited improved efficacy of this drug upon loading within these mesoporous NPs with remarkable acceleration in therapeutic index. It was revealed that entrapment of nevirapine within mesoporous silica NPs caused an improved efficacy with reduced cytotoxic effect resulting in the enhanced therapeutic index (Figure 3).[46]