Scientist I/Scientist II, tLNP Formulation and Delivery

Profluent is the frontier AI lab for biology. Profluent builds powerful foundation models for all of life's molecules, unlocking solutions that transform medicine, agriculture, and beyond. Founded in 2022 and headquartered in Emeryville, CA, Profluent is backed by leading investors including Altimeter Capital, Bezos Expeditions, Spark Capital, Insight Partners, Air Street Capital, AIX Ventures, and Convergent Ventures and has raised over $150M to date.

We are seeking a talented, self-motivated, and highly resourceful Scientist I / Scientist II to serve as a foundational scientist in establishing our next-generation Targeted Lipid Nanoparticle (tLNP) platform. This role is central to our strategy of achieving extrahepatic tissue tropism for next-generation genetic medicines.

In this position, you will own the end-to-end design, formulation, bioconjugation, and physicochemical characterization of novel tLNPs. You will establish our internal in vitro cell culture and assay pipeline to validate targeting and cellular uptake, while serving as the primary technical interface for in vivo studies. This is a high-visibility, high-impact role ideal for an agile scientist with strong drug delivery foundations who thrives in an entrepreneurial environment.

Responsibilities

Design and execute tLNP formulations encapsulating nucleic acid payloads (e.g., mRNA, sgRNA), systematically altering lipid ratios, ionizable lipid structures, and helper components to drive extrahepatic tissue tropism.

Perform hands-on surface modifications and bioconjugation chemistries (e.g., maleimide-thiol, click chemistry, enzymatic tags) to attach targeting moieties (antibodies, VHHs/nanobodies, peptides) to LNP surfaces.

Perform routine and advanced LNP analytics, including particle size/polydispersity (e.g., dynamic light scattering), zeta potential and encapsulation efficiency (e.g., RiboGreen assays) and Degree of Labeling (DoL) for conjugated ligands.

Establish and maintain mammalian cell culture models to support platform screening needs. Develop, optimize, and execute robust in vitro assays (using Flow Cytometry/FACS, plate readers, and fluorescence/luminescence imaging) to evaluate target binding, receptor-mediated cellular uptake, endosomal escape, and functional cargo translation.

Design robust in vivo biodistribution, pharmacokinetic (PK), and organ-targeting studies to evaluate tLNP performance. Analyze, interpret datasets to establish clear structure-activity relationships (SAR) for the next round of formulation design.

Maintain detailed Electronic Lab Notebook (ELN) records, author technical reports, generate patent disclosure data, and present findings to cross-functional scientific leadership.

Qualifications

Scientist I: Ph.D. in Biomedical Engineering, Chemical Engineering, Pharmaceutical Sciences, or a related field with 0–2 years of relevant experience. Scientist II: Ph.D. in the same disciplines with 2–4 years of relevant experience.

Hands-on experience with LNP assembly platforms (microfluidic/NanoAssemblr, T-junction, or ethanol injection) and surface bioconjugation techniques to functionalize nanoparticles with targeting moieties.

Demonstrated understanding and experience in shifting nanoparticle biodistribution/tropism through lipid compositional tweaking, molar ratio modification, or structural lipid alteration.

Hands-on proficiency in mammalian cell culture and running quantitative cell-based assays (Flow Cytometry/FACS, reporter assays, ELISAs).

Understanding of systemic nanoparticle distribution, protein corona formation, vascular barriers, and in vivo study design principles. (Hands-on animal dosing or ex vivo tissue processing experience is not required).

Entrepreneurial drive and organizational skills suited for building assays, protocols, and workflows in an early-stage, growing R&D environment.

Preferences (Nice to Have)

Experience with automated or high-throughput liquid-handling platforms f …