Senior Scientist, LNP Formulations

Flagship Pioneering•Cambridge, MA

18h•Onsite

About The Position

Serif Biomedicines is seeking a highly motivated Senior Scientist II with deep expertise in lipid chemistry to advance the design of novel ionizable lipids and next-generation lipid nanoparticle (LNP) formulations for nucleic acid delivery. The position focuses on rational design and synthesis of ionizable lipids, optimization of LNP molar compositions, and preparation of formulations to screen and benchmark new lipids. It offers the opportunity to work across medicinal and organic chemistry, formulation science, and delivery biology, moving molecules from the bench into functional LNPs. The successful candidate will work independently, influence cross-functional program direction, and identify innovative approaches to advance platform capabilities. The role also involves mentoring junior scientists, contributing to scientific strategy and intellectual property, and engaging with the broader scientific community.

Requirements

PhD in Organic Chemistry, Medicinal Chemistry, Chemical Biology, Pharmaceutical Sciences, or a related field with at least 5 years of relevant industry experience; or an M.S. with at least 8 years of experience.
Strong background in multi-step organic synthesis, purification, and structural characterization, ideally involving lipids, amphiphiles, or other delivery materials.
Hands-on experience with LNP formulation, such as microfluidic mixing or nanoprecipitation, and understanding of how lipid structure and molar composition affect potency, stability, and tolerability.
Experience designing and conducting formulation screens, including characterization by DLS, encapsulation assays, and pKa determination.
Demonstrated ability to design experiments, analyze data, and solve complex technical problems.
Strong communication and collaboration skills, and experience mentoring junior scientists.

Nice To Haves

Experience with nucleic acid delivery, including mRNA, DNA, or siRNA.
Familiarity with lipid analytics such as NMR, LC-MS, and HPLC-CAD/ELSD.
Familiarity with computational or data-driven approaches to lipid design.
A record of innovation, such as publications or patents.

Responsibilities

Design and synthesize novel ionizable lipids, including head-group, linker, and tail variants, using structure-activity relationships and lipid-series pKa, biodegradability, and tolerability profiles to guide design.
Lead the design of LNP molar compositions, optimizing ratios of ionizable lipid, helper lipid, cholesterol, and PEG-lipid, while exploring alternative or novel excipients for potency, stability, and tolerability.
Prepare small-scale LNP formulations using microfluidic or other mixing methods to support medium- to high-throughput screening of lipids and compositions.
Plan and conduct formulation screening studies, define critical formulation parameters, and build structure-property relationships across lipid libraries.
Characterize lipids and LNPs using appropriate analytical methods, including NMR, LC-MS, HPLC with CAD/ELSD, DLS, encapsulation assays, and apparent pKa assays; ensure lipid identity and purity.
Collaborate with biology, analytical, process development, and external partners to evaluate lead formulations in vitro and in vivo and use results to guide subsequent design cycles.
Analyze and interpret experimental data, maintain detailed documentation, and communicate findings to internal stakeholders.
Mentor junior scientists and contribute to the scientific strategy and intellectual property position of the delivery platform.
Stay current with advancements in ionizable lipid chemistry, LNP technologies, and nucleic acid delivery.