Scientist I/II, tLNP Formulation and Delivery

Profluent; San Francisco (CA); On-site; USD 90,000 - 130,000; Full time

Job summary

Profluent is seeking a resourceful Scientist I or II to build a next-generation targeted lipid nanoparticle platform. You will own formulation, bioconjugation, and physicochemical characterization of tLNPs, establish in vitro assay pipelines, and serve as the go-to contact for in vivo studies.

You will design in vivo biodistribution and PK studies, analyze structure–activity relationships, and document findings for leadership.

Qualifications

• PhD required with 0–4 years of relevant experience depending on Scientist I or II.

Responsibilities

• Design and run tLNP formulation work varying lipid ratios and structures to target extrahepatic biodistribution.
• Attach targeting ligands to nanoparticles via bioconjugation chemistries.
• Characterize particles: size, PDI, zeta potential, encapsulation efficiency, and labeling degree.
• Develop and optimize in vitro assays and cell culture models to assess binding, uptake, and cargo delivery.
• Design in vivo biodistribution and PK studies, analyze data, and inform formulation cycles.
• Maintain thorough ELN documentation and contribute to patent disclosures.

Skills

Mammalian cell culture

Flow cytometry

In vitro assay development

Analytical thinking

Education

PhD in Biomedical Engineering / Chemical Engineering / Pharmaceutical Sciences

Tools

NanoAssemblr / microfluidics

T-junction lipidation

HPLC-SEC / UPLC-CAD

DLS / zeta potential

RiboGreen encapsulation assay

DoE JMP software

ELISA

Job description

We’re looking for a resourceful, self-driven Scientist I or II to help build out a next-generation targeted lipid nanoparticle platform from the ground up. This role sits at the center of our push toward extrahepatic tissue tropism for next-generation genetic medicines. The person in it will own the formulation, bioconjugation, and physicochemical characterization of new tLNPs end to end, stand up the in vitro assay pipeline used to validate targeting and uptake, and act as the go-to technical contact for in vivo studies. It’s a highly visible role suited to someone with a strong drug delivery background who’s comfortable operating in a fast-moving, entrepreneurial setting.

What you’ll do

• Design and run tLNP formulation work encapsulating nucleic acid payloads (mRNA, sgRNA, etc.), systematically varying lipid ratios, ionizable lipid structure, and helper lipids to steer particles toward extrahepatic targets.
• Get hands‑on with surface modification and bioconjugation chemistry — maleimide‑thiol, click chemistry, enzymatic tagging — to attach targeting ligands (antibodies, VHHs/nanobodies, peptides) to the particle surface.
• Run both routine and advanced LNP characterization: particle size and polydispersity (DLS), zeta potential, encapsulation efficiency (e.g., RiboGreen), and degree of labeling for conjugated ligands.
• Build and maintain mammalian cell culture models for platform screening, and develop/optimize in vitro assays (flow cytometry, plate readers, fluorescence/luminescence imaging) to assess target binding, receptor‑mediated uptake, endosomal escape, and functional cargo delivery.
• Design in vivo biodistribution, PK, and organ‑targeting studies, then analyze the resulting data to build out structure‑activity relationships that inform the next formulation design cycle.
• Keep thorough ELN documentation, write up technical reports, contribute data toward patent disclosures, and present findings to scientific leadership across functions.

What you’ll need

• Scientist I: PhD in Biomedical Engineering, Chemical Engineering, Pharmaceutical Sciences, or a related field, with 0‒2 years of relevant experience. Scientist II: same academic background with 2‒4 years of relevant experience.
• Hands‑on experience with LNP assembly platforms (microfluidics/NanoAssemblr, T-junction, ethanol injection) and surface bioconjugation methods for functionalizing nanoparticles with targeting ligands.
• A track record of shifting nanoparticle biodistribution or tropism through changes in lipid composition, molar ratios, or lipid structure.
• Comfort running mammalian cell culture and quantitative cell‑based assays — flow cytometry, reporter assays, ELISAs.
• Solid grounding in systemic nanoparticle distribution, protein corona effects, vascular barriers, and in vivo study design (no hands‑on dosing or ex vivo tissue processing required).
• An entrepreneurial streak and the organizational instincts to build assays, protocols, and workflows from scratch in an early‑stage R&D setting.

Nice to have

• Experience with automated or high‑throughput liquid handling for formulation screening.
• Working knowledge of DoE software (e.g., JMP) for systematic library screening.
• Familiarity with advanced characterization methods like HPLC-SEC or UPLC-CAD.