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Thomas SP, Spinelli MM, Rghei AD, Lopes JA, Zielinska N, McLeod BM, Pei Y, Zhang W, Thebaud B, Karimi K, Wootton SK. Analysis of the impact of pluronic acid on the thermal stability and infectivity of AAV6.2FF. BMC Biotechnol 2024; 24:22. [PMID: 38664752 PMCID: PMC11045451 DOI: 10.1186/s12896-024-00853-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/19/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND The advancement of AAV vectors into clinical testing has accelerated rapidly over the past two decades. While many of the AAV vectors being utilized in clinical trials are derived from natural serotypes, engineered serotypes are progressing toward clinical translation due to their enhanced tissue tropism and immune evasive properties. However, novel AAV vectors require formulation and stability testing to determine optimal storage conditions prior to their use in a clinical setting. RESULTS Here, we evaluated the thermal stability of AAV6.2FF, a rationally engineered capsid with strong tropism for lung and muscle, in two different buffer formulations; phosphate buffered saline (PBS), or PBS supplemented with 0.001% non-ionic surfactant Pluronic F68 (PF-68). Aliquots of AAV6.2FF vector encoding the firefly luciferase reporter gene (AAV6.2FF-ffLuc) were incubated at temperatures ranging from -20°C to 55°C for varying periods of time and the impact on infectivity and particle integrity evaluated. Additionally, the impact of several rounds of freeze-thaw treatments on the infectivity of AAV6.2FF was investigated. Vector infectivity was measured by quantifying firefly luciferase expression in HEK 293 cells and AAV particle integrity was measured by qPCR quantification of encapsidated viral DNA. CONCLUSIONS Our data demonstrate that formulating AAV6.2FF in PBS containing 0.001% PF-68 leads to increased stability and particle integrity at temperatures between -20℃ to 21℃ and protection against the destructive effects of freeze-thaw. Finally, AAV6.2FF-GFP formulated in PBS supplemented with 0.001% PF-68 displayed higher transduction efficiency in vivo in murine lung epithelial cells following intranasal administration than vector buffered in PBS alone further demonstrating the beneficial properties of PF-68.
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Affiliation(s)
- Sylvia P Thomas
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Marcus M Spinelli
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Amira D Rghei
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Jordyn A Lopes
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Nicole Zielinska
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Benjamin M McLeod
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Yanlong Pei
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Wei Zhang
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Bernard Thebaud
- The Ottawa Hospital Research Institute, Ottawa, ON, K1Y 4E9, Canada
| | - Khalil Karimi
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Sarah K Wootton
- Department of Pathobiology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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Isachenko V, Isachenko E, Mallmann P, Rahimi G. High cryo-resistance of SARS-CoV-2 virus: Increased risk of re-contamination at transplantation of cryopreserved ovarian tissue after COVID-19 pandemic. Cryobiology 2021; 103:1-6. [PMID: 34571024 DOI: 10.1016/j.cryobiol.2021.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 12/16/2022]
Abstract
Cryopreservation and re-transplantation of ovarian tissue after anticancer treatment is important medical technology. Today, during a pandemic, the risk of contamination of transplanted cells with SARS-CoV-2 virus is extremely high. Data about cryo-resistance (virulence and/or infectivity) of SARS-CoV-2 are limited. Analysis and systematization of literature data allow us to draw the following conclusions: 1) The cytoplasmic membrane of somatic cell, like envelope of corona viruses, consists of lipid bilayer and this membrane, like envelope of corona virus, contains membrane proteins. Thus, we can consider the cytoplasmic membrane of an ordinary somatic cell as a model of the envelope membrane of SARS-CoV-2. It is expected that the response of the virus to cryopreservation is similar to that of a somatic cell. SARS-CoV-2 is more poor-water and more protein-rich than somatic cell, and this virus is much more cryo-resistant. 2) The exposure of somatic cells at low positive temperatures increases a viability of these cells. The safety of the virus is also in direct proportion to the decrease in temperature: the positive effect of low temperatures on SARS-CoV-2 virus has been experimentally proven. 3) Resistance of SARS-CoV-2 to cryoprotectant-free cryopreservation is extremely high. The high viability rate of SARS-CoV-2 after freezing-drying confirms its high cryo-resistance. 4) The risk of SARS-CoV-2 infection after transplantation of cryopreserved ovarian tissues that have been contaminated with this virus, increases significantly. Our own experimental data on the increase in the viability of cancer cells after cryopreservation allow us to formulate a hypothesis about increasing of viability (virulence and/or infectivity) of SARS-CoV-2 virus after cryopreservation.
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