Erika Bowen

-Lab Maintenance and Organization: Ensure the lab is clean, organized, and well-stocked with necessary supplies and equipment.
-Inventory Management: Track and order laboratory supplies, chemicals, and equipment, ensuring adequate stock levels for ongoing experiments.
-Safety Compliance: Enforce safety protocols and compliance with institutional and regulatory standards, including chemical storage, waste disposal, and biosafety measures.
-Equipment Maintenance: Oversee the regular maintenance, calibration, and repair of laboratory instruments and equipment.
Training and Supervision: Train new students, researchers, and staff on lab procedures, equipment use, and safety protocols.
-Data and Record Keeping: Maintain accurate records of lab experiments, equipment usage, safety inspections, and chemical inventories.
-Protocol Development: Assist in developing and updating experimental protocols, standard operating procedures (SOPs), and safety guidelines.

I provide support to professors in Mass Transport and Rate Phenomena as well as Engineering Physiology. I assist with tasks such as grading assignments, proof reading quizzes, tutoring students, facilitating class in their absence, and helping manage the overall learning environment.

I am currently leading a project that focuses on optimizing a bioreactor for growing mesenchymal stem cells (MSCs) to be preconditioned to more efficiently differentiate into bone tissue. My project is affiliated with the Cell Manufacturing and Technologies (CMaT) organization: a sub-unit of the National Science Foundation (NSF). My lab is located in Riverbend South Research lab (Dr. Cheryl Gomillion's Lab)

This was an oral presentation at the Biomedical Engineering Society (BMES) 2024 conference. My REU student, Ava Porter, present alongside me with a poster fully supported by the Gomillion Lab. Introduction: Mesenchymal stem cells (MSCs) have exhibited promise for treating various diseases and injuries, including those related to bone. However, due to the low frequencies of MSCs in a donor’s body, consistently and cost-effectively producing the large quantities of these cells required for large-scale applications remains a challenge. Bioreactors offer a potential solution by providing controlled environments for cell expansion and conditioning of cells for subsequent osteogenic differentiation but, there are limitations with fully incorporating physiologically-relevant conditions found during the normal formation, development, and homeostasis of bone tissue. These mechanical cues, in the form of stress and strain, have specific optimal ranges that must be achieved for both two-dimensional (2D) and three-dimensional (3D) culture systems. The bioreactor developed in our lab (Figure 1A) can be used for either monolayer or microcarrier culturing via removable inserts that fit within a cylindrical vessel. It has a multi-channel inlet of media at the top of the vessel and an outlet exiting from the bottom that both connect to a controllable pump to produce varying fluid flows creating a range of possible dynamic conditions. This project focuses on optimizing this modulatory perfusion bioreactor by identifying the appropriate dynamic conditions for osteogenic cell priming and exploring MSC proliferation and osteogenic differentiation potential compared to traditional 2D and 3D cultivation methods. Materials and Methods: ANSYS, a computational fluid dynamics modeling software, was used to understand fluid flow conditions within the bioreactor system and identify optimal culture parameters pertaining to fluid flow for culture in 2D. Subsequently, given the success of 2D optimization, culture conditions will then be translated to 3D. The bulk fluid of the system was modeled with the inlet placed at varying distances from the monolayer insert, and fluid flow also varied to map the possibilities of dynamic conditions. Within this model, a stress analysis was performed on a cross-section of the vessel (Figure 1B) where cells adhere and grow to determine what fluid flow and inlet height produces a uniform stress profile. The resulting stresses were compared to ranges reported in literature as optimal for osteogenic conditioning. From this cross-section, estimations indicating stresses that are too high or too low can be obtained to elicit a design or protocol change pertaining to, but not limited to a fluid flow adjustment, inlet height change, or complete inlet redesign. Culture parameters gleaned from the ANSYS model were implemented and experimentally assessed within the bioreactor, using measures of cell number and viability as indicators of redesign success. Assays were performed on inserts with adhered cells harvested from the bioreactor after a culture period (Figure 1C) and include a cell count and Live/Dead assay. Iterations of modeling and experimental confirmation (compared to static culture controls) have been essential for identifying alterations needed for the bioreactor culture protocol and informing changes needed for optimizing bioreactor components. Results, Conclusions, and Discussions: Fluid flow rates within this bioreactor producing a 0.1-1Pa stress profile on the cells have been identified as appropriate conditioning levels yielding viable MSCs in monolayer. Evaluation of an original 12-channel inlet (Figure 1B) at its original height of 10mm from the culture insert surface with an original flow rate of 75 mL/min produced a stress profile exceeding 1Pa, falling short of our target of 0.1Pa. In addition, cavitation was observed causing inhomogeneous flow and cell death resulted. An updated inlet featuring 18 smaller channels was prototyped based on modeling results, which suggested that this design would produce the targeted stress range, as well as decrease cavitation (Figure 1E) present with the original design creating a more uniform stress profile for a more homogenous cell product. Modeling results indicate that this updated inlet (Figure 1D) is to be used 1mm away from the monolayer insert and at a suggested flow rate of 32 mL/min. Protocol updates were also made to determine optimal plasma treatment conditions for the monolayer insert to support increased initial cell attachment resembling standard tissue culture plastic, and thus, improving survivability and proliferation of cells cultured in the bioreactor vessel for these proof-of-concept experiments. Ultimately, this work aims to produce a bioreactor vessel capable of supporting increased MSC proliferation and osteogenic differentiation by optimizing stress conditions and nutrient supply with options to culture in 2D or 3D under dynamic conditions. Following initial proof-of-concept testing in 2D, this systematic process of computational modeling followed by experimental implementation will be executed for the microcarrier insert configuration, leading to an optimized vessel for both 2D and 3D culture. Future evaluation will focus on assessing the the osteogenic potential of cells conditioned within the bioreactor. Additional components such as novel microcarriers, sensors, etc. can be implemented in the future. Thus, successful completion will yield a scalable perfusion bioreactor for large-scale MSC production benefiting future clinical studies and therapeutic applications. Acknowledgements (Optional): This material is based upon work supported by the National Science Foundation under Grant No. EEC-1648035 for NSF Engineering Research Center for Cell Manufacturing Technologies (CMaT).

Mesenchymal stem cells (MSCs) have displayed promise for treating various diseases and injuries, including those related to bone. However, producing the large quantities of MSCs consistently and cost-effectively needed for large scale applications remains a challenge. Bioreactors offer a solution by providing controlled environments for cell growth and conditioning for inevitable osteogenic differentiation. This project focuses on optimizing a modulatory perfusion bioreactor to explore MSC proliferation and osteogenic differentiation potential compared to traditional cultivation methods. This novel bioreactor allows for testing different environments by culturing cells in monolayer or on microcarriers and features a unique multi-channel showerhead-like inlet to enhance media perfusion and flow dynamics. Computational fluid dynamics (CFD) modeling has been utilized to understand fluid flow conditions within the system and identification of optimal culture parameters. This has been joined with cell culture viability assessments and material analysis of the culturing platforms to guide bioreactor protocol alteration and redesign for updated bioreactor components, which will be tested against controls using the same cell line, microcarriers, media, etc. The project ultimately aims to produce a vessel capable of increasing MSC proliferation and osteogenic differentiation by optimizing stress conditions and nutrient supply. This work also provides a platform for implementing novel microcarriers, sensors, etc. Thus, successful completion will yield a scalable perfusion bioreactor for large-scale MSC production benefiting clinical studies and therapeutic applications in the future. This poster was presented at the Regenerative Bioscience Center (RBC) and Animal Dairy Science (ADS) Symposium 2024 and the Regenerative Engineering & Medicine Conference 2024 (2nd place)

This was a collaboration with Oglethorpe University undergraduate and NanoBio REU Mentee Lindsay Lerma, UGA Ph. D. student Joshua Bledsoe, UGA postdoctoral researcher Jessica Bramhall, and UGA faculty Cheryl Gomillion and Jason Locklin. Presented at the CMaT REU Symposium, my part of the collab was assessing what affect these scaffolds produced by the Locklin lab has on supporting stem cell proliferation and osteogenic differentiation for therapeutic applications in bone tissue regeneration. So, I seeded MSCs, differentiated them, and assessed viability and calcium deposition onto the scaffolding.