Senior Scientist, LNP Platform & Process Development

About Tr1X Tr1X is a private, clinical-stage biotechnology company focused on developing a novel class of regulatory T cell-based products to cure autoimmune and inflammatory diseases. Founded by industry experts, including the scientists who discovered Type 1 regulatory T (Tr1) cells, the company is developing a pipeline of off-the-shelf allogeneic cell therapies for autoimmune diseases with high unmet medical need. Our TRX cells are designed to mimic the function of naturally occurring Tr1 cells, which work to restore immune tolerance, stopping severe autoimmune and inflammatory disease in its tracks. Tr1X is the first company ever to use an allogeneic engineered Tr1 cell therapy in clinical trials. Tr1X is headquartered in San Diego, CA. For more information, please visit www.tr1x.bio. Position Summary The Senior Scientist, LNP Platform & Process Development (Scientist) is an experienced hands-on, lab-based, individual contributor that leads the design, development, and optimization of lipid nanoparticle (LNP) formulation and process development efforts supporting the Tr1X in vivo CAR-Treg platform. This individual plays a central role in developing and advancing the targeted lipid nanoparticle (tLNP) delivery systems from early research optimization through scalable, IND-enabling development. This is a high-impact, foundational role within the company. The Scientist helps design and implement the LNP backbone of the platform and influence both short-term program execution and long-term manufacturability strategy. The Scientist brings deep hands-on expertise in LNP formulation and process development, strong analytical rigor, and the ability to thrive in a fast-paced startup environment. Key Responsibilities Contribute to the design, development, and optimization of LNP formulations for mRNA delivery, including targeted LNP systems incorporating conjugated or functionalized lipids. Evaluate lipid composition, formulation parameters, and mixing conditions to optimize particle size, polydispersity, encapsulation efficiency, stability, release characteristics, and biological performance. Develop scalable, GMP-compatible manufacturing processes to support program advancement. Apply Quality by Design (QbD) principles and Design of Experiment (DoE) studies to study design and execution. Lead the development and optimization of analytical characterization methods (both in-house and at the external CDMO), including but not limited to DLS, fluorescence-based assays such as Ribogreen, HPLC/UPLC methods (CAD, UV, IP-RP, SEC, IEX), LC-MS, and endotoxin testing. Interpret analytical and stability data to establish meaningful correlations between physicochemical properties and biological function. Collaborate closely with platform biology teams to support in vitro and in vivo studies, prepare development reports and technical documentation, and contribute to technology transfer activities with external CDMO partners. Spearhead IND-enabling documentation and contribute to defining the long-term strategy for scalable LNP platform development. Perform other responsibilities as required based on business needs. Required Qualifications & Experience Ph.D. in Chemical Engineering, Bioengineering, Pharmaceutical Sciences, Chemistry, or a related field with a minimum 4 years of relevant industry experience; or M.S. with 8+ years; or B.S. with 10+ years. Demonstrated in-depth expertise in LNP formulation and process development, including hands-on experience with microfluidic or scalable mixing technologies and downstream purification strategies such as TFF. Strong experience with analytical characterization of LNP systems and application of statistical design tools for process optimization. Highly organized, scientifically rigorous, and capable of independently driving projects while collaborating effectively in a multidisciplinary startup environment. Experience with mRNA therapeutics or nucleic acid delivery systems. Prior exposure to immunothe