Scientist, Delivery Sciences Lipid Chemistry

NewLimit; South San Francisco (CA); On-site; USD 130,000 - 171,000; Full time

Benefits offered by this job

Health, Dental, Vision insurance

401(k) plan with company match

Paid parental leave

20 days PTO + holidays

On-site meals

Job summary

NewLimit seeks a Lipid Chemist to design, synthesize, and characterize ionizable lipids and PEG-lipid conjugates for targeting LNPs, with emphasis on delivering nucleic acids beyond the liver. This hands-on bench role collaborates with Delivery Sciences and biology teams to build a robust ionizable lipid portfolio.

The ideal candidate will have a PhD (or MS with substantial lipid design experience) and a proven ability to execute synthetic routes, purification, and SAR-driven optimization across

Qualifications

• PhD in Chemistry, Pharmaceutical Chemistry, or a related discipline, plus 1–2 years of relevant work; or an MS with 5 years focused lipid design experience for liposomal or lipid nanoparticle applications.

Responsibilities

• Design new ionizable lipids and lipid conjugates for antibodies, peptides, and other targeting moieties across multiple structural families, pushing the platform beyond current-generation materials.
• Devise and execute practical synthetic routes to priority targets to support pipeline needs for targeting lipids.
• Plan synthesis and purification for these modalities with scale and final purity in mind from the outset, delivering against project timelines.
• Build ionizable and targeting lipids for the tLNP platform using an SAR-based approach to guide the next design cycle.
• Develop conjugation chemistry that links peptides, antibodies, nanobodies, and small‑molecule ligands to lipid anchors for cell‑ and tissue‑selective delivery.
• Turn in vitro and in vivo data from discovery teams into concrete structural hypotheses and revised molecules.
• Present synthetic strategy, experimental results, and SAR conclusions, authoring protocols and technical reports.

Skills

Lipid design

Lipid synthesis

Ionizable lipids

PEG-lipid conjugates

Conjugation chemistry

Analytical LC-MS/MS

NMR spectroscopy

HPLC purification

SAR-driven design

Education

PhD in Chemistry

Tools

ChemDraw

SciFinder

Reaxys

AI-based SAR tools

Job description

Company info

NewLimit is a biotechnology company working to radically extend human healthspan. We’re developing medicines to treat aging by reprogramming the epigenome, a new therapeutic mechanism to restore youthful function in aged cells. We’ve built the world’s leading experimental and artificial intelligence system to discover reprogramming medicines at massive scale. Our first products are focused on restoring youthful metabolic, endothelial, and immune function.

Description

NewLimit is seeking a Lipid Chemist to design, synthesize, and characterize ionizable lipids, PEG-lipid Conjugates, peptide and antibody conjugates to build our targeting LNP platform with a particular focus on getting nucleic acid payloads into target cells and tissues beyond the liver.

This is a hands-on bench role with real lipid design ownership. You will work closely with the Delivery Sciences and biology teams to design and build relevant Ionizable and targeting lipids portfolio for New Limit’s pipeline programs.

What you’ll do

• Design new ionizable lipids and lipid conjugates for antibodies, peptides, and other targeting moieties across multiple structural families, pushing the platform beyond current-generation materials.
• Devise and execute practical synthetic routes to priority targets to support NewLimit’s pipeline needs for targeting lipids.
• Plan synthesis and purification for these modalities with scale and final purity in mind from the outset, delivering against agreed project timelines.
• Build ionizable and targeting lipids for the tLNP platform using an SAR-based approach to guide the next design cycle rather than simply cataloging results.
• Develop conjugation chemistry that links peptides, antibodies, nanobodies, and small‑molecule ligands to lipid anchors, generating building blocks for cell‑ and tissue‑selective delivery to support tLNP research and pipeline targets.
• Turn in vitro and in vivo data from discovery teams into concrete structural hypotheses and revised molecules.
• Present synthetic strategy, experimental results, and SAR conclusions, authoring protocols and technical reports.

Requirements

• PhD in Chemistry, Pharmaceutical Chemistry, or a related discipline, plus 1–2 years of relevant work; or an MS with 5 years of focused lipid design experience for liposomal or lipid nanoparticle applications.
• Strong skill set in the design and synthesis of new lipids or other delivery chemistries, performed personally rather than with a supervisor directing each step.
• SAR-driven design, synthesis, purification, and characterization ofionizable lipids and PEG‑lipid conjugates, using tools such as ChemDraw, Sci‑Finder, Reaxsys, and AI‑based SAR prediction tools for tLNP applications.
• Working knowledge of conjugation chemistries for attaching targeting moieties such as peptides, antibodies, nanobodies, and small‑molecule ligands, including linker design and the selection of suitable biorthogonal or site‑specific handles.
• Practical purification skills spanning normal‑and reverse‑phase chromatography and preparative HPLC.
• Analytical characterization across LC‑CAD, LC‑UV, LC‑MS/MS, and NMR (¹H, ¹³C, and ³¹P as needed), with the ability to deconvolute the data to produce well‑characterized lipids.

Nice to have

• Familiarity with lipid degradation pathways and impurity work such as N‑oxides, hydrolysis products, and lipid–nucleic acid adducts, and how they affect potency and stability.
• Solid‑phase peptide synthesis, or antibody/nanobody modification experience.
• Exposure to scale‑up, CMC, or tech transfer to a CDMO.
• Experience with data visualization and statistical analysis (R, Python, JMP)

Benefits

NewLimit provides generous benefits so our team can remain focused on our mission:

• Comprehensive Health, Dental, and Vision insurance.
• 401(k) plan with company match.
• Paid parental leave.
• Industry‑leading PTO: 20 days per year plus holidays.
• On‑site meals and snacks.

Salary Range: $130,000 to $171,000. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. NewLimit offers a competitive benefits package, which includes a 401k, healthcare coverage, and 20 days of PTO. Learn more at: https://www.newlimit.com/careers *This compensation and benefits information is based on Company's good faith estimate as of the date of publication and may be modified in the future.