Driving forces in aqueous two-phase systems for vaccine development

在世界范围内，人们需要更便宜的疫苗。为了实现更好的疫苗覆盖率，疫苗生产过程需要低成本并允许连续操作，这在目前的疫苗生产技术下是不可能的。该项目的一个主要目标将是探索双水相系统(ATPS)，以满足对新的病毒颗粒纯化工艺的需求，这种工艺可以降低疫苗成本并作为连续操作运行。ATP还可以缩短新疫苗的开发时间，使大流行疫苗能够更快地进入市场。除了疫苗，对ATP的更好理解可能有助于未来先进细胞疗法的细胞分离。全球疫苗制造的显著增加创造了重新思考当前疫苗制造方法的机会。目前，由于疫苗过程开发团队在很短的开发时间内需要确定大量的变量，ATPS还没有在工业上使用。该项目的长期目标是确定ATP中分离病毒颗粒的主导力量，以帮助工业采用。初步工作表明，疏水性是聚乙二醇柠檬酸盐ATPS中病毒颗粒分离的主导力量。预期的结果是减少在开发病毒颗粒纯化过程中测试的变量，并提供实施ATPS分离的框架。亲和力ATP将被用来维持病毒进入富含聚乙二醇相的恒定驱动力。随着这一恒定驱动力的建立，聚乙二醇的相对分子质量将发生变化，并将病毒分离与恒定亲和驱动力进行比较。渗透剂将被添加到聚乙二醇柠檬酸盐ATP中，以增加疏水性，并将疏水性驱动力与限制病毒恢复的表面张力的增加分开。所有的工作将通过提供一个使用实验设计(DOE)方法的框架来集成，以分离病毒ATP的疏水效应。该项目的结果将提供对ATP中的驱动力的详细了解，从而使该方法更容易地用于病毒颗粒制造。通过这种方法，PI将系统地确定控制病毒颗粒分离的关键变量。一个重要的目标是确定疏水性对病毒分离的影响，并确定疏水性对ATPS分离的影响程度。就更广泛的影响而言，从这项工作中获得的基本知识可能会指导低成本分离和制造工艺的设计，这将增加全世界获得疫苗的机会。重要的是，实验设计框架可以应用于其他大的生物分子，如那些用于病毒基因治疗和细胞治疗的生物分子。将通过暑期青年计划(SYP)向高中生进行外展。SYP活动将探索ATP中金纳米颗粒的分离，并向学生传授生物处理、模型系统和ATPS中控制的必要性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Worldwide, there is a need for less expensive vaccines. To achieve better vaccine coverage, vaccine production processes need to be low-cost and allow for continuous operation, which is not possible with current vaccine production technology. A primary objective of this project will be to explore aqueous two-phase systems (ATPSs) to fulfill the need for new viral particle purification processes that could reduce the cost of vaccines and be run as a continuous operation. ATPS could also reduce the development time for a new vaccine, allowing for pandemic vaccines to come to market sooner. In addition to vaccines, a better understanding of ATPS could aid in future cell separations for advanced cell therapeutics.The significant increase in the manufacturing of vaccines worldwide has created an opportunity to re-think current vaccine manufacturing methods. Currently, ATPS is not used industrially due to the large number of variables that need to be determined during the short development timelines that are imposed on vaccine process development teams. The long-term goal of this project is to determine the dominant forces in ATPS for the separation of viral particles to aid industrial adoption. Preliminary work has indicated that hydrophobicity is the dominant force in viral particle separation in a polyethylene glycol (PEG)-citrate ATPS. The expected outcome is to reduce the variables tested in the development of viral particle purification processes and provide a framework to implement ATPS separations. Affinity ATPS will be used to maintain a constant driving force for the virus to partition to the PEG-rich phase. With this constant driving force established, the PEG molecular weight will be changed and the viral separation will be compared to the constant affinity driving force. Osmolytes will be added to the PEG-citrate ATPS to increase the hydrophobicity and to separate the hydrophobicity driving force from the increase in surface tension that restricts virus recovery. All of the work will be integrated by providing a framework using the Design of Experiments (DOE) approach to isolate the hydrophobic effect of viral ATPS. Results of the project will provide a detailed understanding of the driving forces in ATPS that will allow easier implementation of this method for viral particle manufacturing. Through this approach the PI will systematically determine the key variables that control viral particle separations. An important goal is to determine the effect of hydrophobicity on the separation of viruses and to determine the magnitude of the hydrophobic force on the ATPS separation. In terms of the broader impacts, the fundamental knowledge gained from this work may guide the design of low-cost separation and manufacturing processes that will increase access to vaccines worldwide. Importantly, the experimental design framework can be applied to other large biomolecules such as those employed in viral gene therapies and cell therapies. Outreach to high school students will be conducted through Summer Youth Programs (SYP). The SYP activity will explore the separation of gold nanoparticles in ATPS and teach students about bioprocessing, model systems, and the need for control in ATPS.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.