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Recombinant vaccines: Gag-based VLPs
Published in Amine Kamen, Laura Cervera, Bioprocessing of Viral Vaccines, 2023
Laura Cervera, Irene González-Domínguez, Jesús Lavado-García, Francesc Gòdia
Depending on the complexity of the final structure, there are several production platforms available (Figure 10.1). The simpler VLP types could be produced in prokaryotes and assembled in cell-free environments [9,10]. The bacteria Escherichia coli or the yeast Pichia pastoris have been described as the most productive platforms with bulk concentrations up to 4.38 mg/mL [11] and 400 mg/mL [12], respectively, although post-translational modification (PTMs) may limit their application to the production of complex VLPs [3,7,13]. Transgenic plants such as potato or tobacco [3,7,14] and baculovirus-vector expression system (BEVS) with High Five or Sf9 insect cell lines are also used to produce VLPs. Despite their different PTM characteristics [14,15], several products have been licensed and numerous phase III clinical trials are ongoing with VLPs produced in these systems [5,10]. Finally, the mammalian CHO and HEK 293 cell lines, which present better glycosylation patterns, are preferred for the expression of highly complex VLP candidates.
Bioinspired Nano-Formulations
Published in Yasser Shahzad, Syed A.A. Rizvi, Abid Mehmood Yousaf, Talib Hussain, Drug Delivery Using Nanomaterials, 2022
Jahanzeb Mudassir, Muhammad Sohail Arshad
The therapeutic applications of virus-like particles (VLPs) are well-recognized. VLPs are envelope proteins that assemble to develop structures that mimic the native protein virus. Notably, these do not possess viral genome. The major applications of VLPs include gene delivery, packaging of anionic nucleic acids, and transduction. The examples of VLPs include brome mosaic virus (BMV)-like particles and cowpea chlorotic mottle virus (CCMV)-like particles (Lam and Steinmetz 2019). VLPs based on plant viruses have also been used for loading and delivery of anticancer drugs. More recently, VLPs have been engineered to obtain desired solubility, membrane stability, and cell internalization. It was also suggested that nanoscale structure of L particles can be modified for functional attributes, such as gene fusion, chemical conjugation, electroporation, as well as in terms of polymer and liposome fusion (Yamada et al. 2003).
Bioinspired Nanomaterials for Improving Sensing and Imaging Spectroscopy
Published in Kaushik Pal, Nanomaterials for Spectroscopic Applications, 2021
Janti Qar, Alaa A. A. Aljabali, Tasnim Al-Zanati, Mazhar S. Al Zoubi, Khalid M. Al-Batanyeh, Poonam Negi, Gaurav Gupta, Dinesh M. Pardhi, Kamal Dua, Murtaza M. Tambuwala
Virus-like particles (VLPs) are multi-protein complexes that emulate viral conformation and organization. VLPs consist of one or more structural units of viruses that are installed into a spherical or cylindrical structure. These can be designed to display highly ordered heterologous epitopes to maximize the antigenic complexity for vaccine development [8]. Similar to viruses, different epitopes are shown on VLPs can also be prepared, stored, and introduced to strong immune responses by antigen-presenting cells [6]. The created particles are self-assembled from at minimum one viral protein produced by a stable system of host expression, including mammalian cells, insect cells, yeasts, bacterium, and non-host systems [44].
Drying of Vaccines and Biomolecules
Published in Drying Technology, 2022
Bhaskar N. Thorat, Ayantika Sett, A. S. Mujumdar
Microwave vacuum drying, another subunit of MFD, is a speedy process to produce foods, plant and other biological materials. The stability of product obtained by this process is higher in comparison with air dried and freeze dried products.[80] The method comprises of following steps:An aqueous composition containing i) suitable buffer, ii) a virus that can be a live virus or inactivated virus or virus like particle or subunit, iii) for stabilization purpose lyoprotectants, mainly sugar solution of desired concentration.The next step is freezing of material in the form of pellets.Finally, the microwave radiations are applied to the frozen pellets under a pressure below atmospheric pressure, generally in the range of 20 to 500 mTorr to produce the final dried product.
A high resolution DMA covering the 1–67 nm size range
Published in Aerosol Science and Technology, 2020
Luis Javier Perez-Lorenzo, Vaibhav Khanna, Tarun Meena, Jerome J. Schmitt, Juan Fernandez de la Mora
The DMA was designed at Yale and was produced by the NanoEngineering Corporation, primarily for virus and virus-like particle diagnosis in the 20–70 nm size range. Three or four nylon laminarization screens [6] with open areas varying from 28% to 49% were glued under tension to three pairs of outer and inner supporting ring frames. The sheath gas flow was most of the time operated in recirculating mode, with a blower (with stabilized rotation speed) followed by an air-cooled heat exchanger. In these tests, the aerosol flow (q = 2–5 Lit/min) entering the DMA was controlled by a rotameter and was automatically matched to the exiting monodisperse particle flow. This gas was air from a laboratory compressor, dried by flowing through a silica gel bed and passed through a HEPA filter. The air flow went through a bipolar electrospray source previously described (Fernandez de la Mora and Barrios 2017), where positive and negative electrosprays of alcohol solutions of the same salt [A+B–] interact, producing dominantly singly charged clusters with the general composition [A+n± 1B–n]±1. Therefore, all mobility spectra shown in this study correspond to almost exclusively singly charged ions of either polarity. Two of the salts previously recommended to yield excellent mobility calibration standards were used here: 1-Methyl-3-pentylimidazolium-tris(pentafluoroethyl)PF3 (MPI-FAP, from Merk) and 1-Ethyl-3-methylimidazolium-tris(trifluoromethylsulphonyl) Methide (EMI-Methide, from Covalent).
Quantitative assessment of LPS-HBsAg interaction by introducing a novel application of immunoaffinity chromatography
Published in Preparative Biochemistry & Biotechnology, 2023
Alireza Kavianpour, Mohsen Ashjari, Seyed Nezamedin Hosseini, Maryam Khatami
The LPS level of r-HBsAg, as an active ingredient of the hepatitis B vaccine, should be checked and kept below the specified permissible limits like other biopharmaceuticals.[2] While the hepatitis B virus is a life-threatening liver infection that may lead to cirrhosis or liver cancer, routine vaccination is an efficient preventive measure against the infection.[9] In the late 20th century, the recombinant hepatitis B surface antigen vaccine superseded the plasma-derived Hepatitis B vaccine due to its considerable clinical, technical, and financial benefits.[9–11] The r-HBsAg production process has been studied in detail in order to improve different aspects of the process such as productivity, efficiency, and simplicity.[12–15] Recombinant HBsAg has been expressed in a variety of hosts, including mammalian cells, bacteria, and yeasts. Pichia pastoris (P. pastoris) has been identified as one of the most promising choices for large-scale r-HBsAg production because of its high potential for heterologous gene expression, low cost, protein-free growth media, and easy scaling up.[11,16–19] There are numerous studies in which the molecular structure of HBsAg has been investigated using DLS, TEM, and size exclusion high-performance liquid chromatography (SE-HPLC).[20–22] The structures of the HBsAg biomolecule were reported various forms: monomer, dimer, virus-like particle (VLP), and minor aggregated structures. Besides, it is outlined that VLP is the most dominant form, with a diameter of ∼22 nm.[23]