---
title: 'Senior Scientist, LNP Formulations at Serif Biomedicines, Inc.'
canonical: 'https://feeny.ai/job/senior-scientist-lnp-formulations-serif-biomedicines-inc-cambridge-e6as2tmxztgp'
type: 'job'
last_seen: '2026-11-04'
---

# Senior Scientist, LNP Formulations at Serif Biomedicines, Inc.

- **Company:** Serif Biomedicines, Inc.
- **Location:** Cambridge, MA
- **Posted:** 2026-11-03
- **Last confirmed live:** 2026-11-04
- **Apply:** https://job-boards.greenhouse.io/serif/jobs/8929293002

## Job description

Company description

Serif Biomedicines is a privately held, early-stage biotechnology company developing a novel approach to gene therapy that can address currently untreatable diseases. It was founded by Flagship Pioneering, an innovation enterprise that conceives, creates, resources, and grows first-in-category life sciences companies.

Flagship Pioneering has created over 100 groundbreaking companies over the past twenty years, all of which are pioneering novel and proprietary biological, industrial, and engineering approaches to solve major needs in human health and sustainability. These companies include Moderna (MRNA), Syros Pharmaceuticals (SYRS), Seres Therapeutics (NASDAQ:MCRB), Generate Biomedicines, Tessera Tx, Evelo Biosciences (EVLO), and Indigo Agriculture.

## The role

We are seeking a highly motivated Senior Scientist II with deep expertise in lipid chemistry to drive the design of novel ionizable lipids and the next generation of lipid nanoparticle (LNP) formulations for nucleic acid delivery. This role will focus on the rational design and synthesis of new ionizable lipids, the design of optimized LNP molar compositions, and the preparation of LNP formulations to screen and benchmark those new lipids.

This is an ideal opportunity for a chemist who wants to see their molecules move rapidly from the bench into functional LNPs, working at the interface of medicinal and organic chemistry, formulation science and delivery biology.

As a senior scientific contributor, this individual will be expected to operate with a high degree of independence, influence cross-functional program direction, and identify innovative solutions to advance platform capabilities. The role also includes mentoring junior scientists and contributing to the broader scientific strategy through internal leadership and external scientific engagement.

## Key responsibilities

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

Professional experience and qualifications

- PhD. in Organic Chemistry, Medicinal Chemistry, Chemical Biology, Pharmaceutical Sciences or a related field, with 5+ years of relevant industry experience; or M.S. with 8+ years of experience.
- Strong background in multi-step organic synthesis, purification and structural characterization, ideally of lipids, amphiphiles or other delivery materials.
- Hands-on experience with LNP formulation (e.g., microfluidic mixing, nanoprecipitation) and an understanding of how lipid structure and molar composition drive potency, stability and tolerability.
- Experience designing and running formulation screens, including characterization by DLS, encapsulation assays and pKa determination.
- Experience with nucleic acid delivery (mRNA, DNA, siRNA) is highly preferred.
- Familiarity with lipid analytics (NMR, LC-MS, HPLC-CAD/ELSD) and with computational or data-driven approaches to lipid design is a plus.
- Demonstrated ability to design experiments, analyze data, and solve complex technical problems, with a record of innovation such as publications or patents.
- Strong communication and collaboration skills, and experience mentoring junior scientists.

## What we offer

- Opportunity to work at the forefront of ionizable lipid and LNP innovation
- Collaborative, science-driven culture with high impact research
- Competitive compensation and benefits package

LOCATION: Cambridge, MA

## ABOUT FLAGSHIP PIONEERING

Flagship Pioneering invents and builds platform companies, each with the potential for multiple products that transform human health, sustainability and beyond. Since its launch in 2000, Flagship has originated more than 100 companies. Many of these companies have addressed humanity most urgent challenges: vaccinating billions of people against COVID-19, curing intractable diseases, improving human health, preempting illness, and feeding the world by improving the resiliency and sustainability of agriculture.

Flagship has been recognized twice on FORTUNE Change the World list, an annual ranking of companies that have made a positive social and environmental impact through activities that are part of their core business strategies and has been twice named to Fast Company annual list of the World Most Innovative Companies. Learn more about Flagship https://url.us.m.mimecastprotect.com/s/xLXBCqxk3LTk9pwcZf3CEkjif?domain=flagshippioneering.com.

At Flagship, we accept impossible missions to enable bigger leaps. Our core values guide us through uncertainty and toward lasting impact.

We are an equal opportunity employer. All qualified applicants will be considered for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, protected veteran status, or any other characteristic protected by law.

Privacy Notice for Applicants: When you apply for a role at Flagship Pioneering or one of its portfolio companies, we collect and use personal information you provide (such as your name, contact details, work history, and application materials) to evaluate your application, communicate with you, and comply with legal obligations. Your application data is processed through Greenhouse, our applicant tracking system, and may also be reviewed using AI-assisted screening tools. We do not sell your personal information. California residents have rights under the CCPA/CPRA including to know, delete, and opt out of the sharing of their personal information. If you are located in the EU or UK, we process your data under GDPR and you have rights to access, rectify, and erase your data. To exercise your rights or for questions, contact privacy@flagshippioneering.com.

The salary range for this role is $126,000 - $181,500. Compensation for the role will depend on a number of factors, including a candidate’s qualifications, skills, competencies, and experience. Serif Biomedicines currently offers healthcare coverage, annual incentive program, retirement benefits and a broad range of other benefits. Compensation and benefits information is based on Serif Biomedicines's good faith estimate as of the date of publication and may be modified in the future. Privacy Notice for Applicants: When you apply for a role at Serif Biomedicines, Inc., a Flagship Pioneering portfolio company, we collect and use personal information you provide (such as your name, contact details, work history, and application materials) to evaluate your application, communicate with you, and comply with legal obligations. Your application data is processed through Greenhouse, our applicant tracking system, and may also be reviewed using AI-assisted screening tools. We do not sell your personal information. California residents have rights under the CCPA/CPRA including to know, delete, and opt out of the sharing of their personal information. If you are located in the EU or UK, we process your data under GDPR and you have rights to access, rectify, and erase your data. To exercise your rights or for questions, contact privacy@flagshippioneering.com.

## About Serif Biomedicines, Inc.

## Company Overview
- **One-liner**: Serif Biomedicines is pioneering Modified DNA as a new class of genetic medicine, using nucleic acid chemistry, synthetic biology, delivery science, and AI to create programmable, durable, and redosable DNA therapeutics.
- **Entity Type**: Private (Founded by Flagship Pioneering)
- **Headquarters**: Cambridge, MA, USA
- **Founded**: 2026 (public launch in April 2026)
- **Founders**: Originated at Flagship Pioneering; Founding team includes Jacob (Jake) Rubens, PhD (CEO), Matt Kennedy, PhD (CSO), and others.

## Core Business
- **Primary industry**: Biotechnology / Genetic Medicines
- **Target customers**: B2B (pharma/biotech partnerships) and B2G (therapeutic development for rare diseases and immune programming)
- **Mission**: To build a future where DNA becomes the source code for medicines that can be tailored across diseases and scaled for global impact.

## Products & Services
- **Modified DNA Platform**: A proprietary technology that chemically modifies DNA to minimize innate immunogenicity during delivery into cells. Once inside the nucleus, the Modified DNA reverts to unmodified DNA, enabling transcription into therapeutic RNA and proteins. This platform combines the best features of mRNA and gene therapy while mitigating their limitations (durability, redosability, cell-specific expression).
- **mRNA Co-factors**: Delivered alongside Modified DNA, these transiently express proteins that enhance nuclear entry and gene expression.
- **AI-Enabled Design-Build-Test-Learn Cycle**: Integrates AI to optimize DNA and mRNA co-factor sequences and lipid nanoparticle (LNP) formulations by learning from massive datasets.
- **Therapeutic Pipeline**: Initial drug discovery programs focused on rare diseases and immune programming.

## Market Standing
- **Valuation/Market Cap**: Not disclosed (private, Flagship Pioneering portfolio company)
- **Key Metric**: Total Funding — Not publicly disclosed (launched with Flagship Pioneering backing; no specific funding round announced)
- **Notable Investors/Partners**: Flagship Pioneering (originator and primary backer); Board includes Noubar Afeyan (Flagship CEO), John Maraganore (founding CEO of Alnylam), Andrew Allen (CEO of Tessera Therapeutics), and others.
- **Growth Signals**: Public launch in April 2026 with significant press coverage; presenting data at ASGCT 2026; actively hiring across multiple R&D functions (Protein Engineering, LNP Process & Development, Immunology, Bioanalytics, Molecular Biology).

## Competitive Advantages
- **Novel Platform Technology**: Serif is the first company to establish Modified DNA as a therapeutic modality, creating a new category of genetic medicine that combines the durability of gene therapy with the redosability and programmability of mRNA.
- **Flagship Pioneering Backing**: Originated and funded by Flagship, a top-tier biotech venture creation firm with a track record of building category-defining companies (Moderna, Tessera, etc.).
- **Integrated Capability Stack**: Combines nucleic acid chemistry, synthetic biology, delivery science (LNPs), and AI/ML for optimization — a full-stack approach to genetic medicine.
- **Strong IP & Scientific Team**: Leadership includes veterans from Flagship, Alnylam, and Tessera, with deep expertise in nucleic acid discovery, development, and delivery.

## Strategic Focus
- **Initial Therapeutic Areas**: Rare diseases and immune programming, where Modified DNA’s durability, redosability, and cell-specific expression offer clear advantages.
- **Platform Expansion**: Building scalable manufacturing processes and AI-driven design cycles to enable broad therapeutic application across diseases.
- **Talent Acquisition**: Actively hiring across R&D functions to build out the platform and pipeline.

## Why Work Here
- **Pioneering Science**: Opportunity to work on a first-in-class technology that could redefine genetic medicine — comparable to the early days of mRNA therapeutics.
- **Flagship Ecosystem**: Access to the resources, network, and expertise of Flagship Pioneering, one of the most successful biotech incubators.
- **Culture**: Described as a team of scientists, engineers, and company builders united by a mission to create a new foundational biotechnology. Emphasis on collaboration and innovation.
- **Location**: Cambridge, MA — a global hub for biotech and life sciences.
- **Growth Stage**: Early-stage (just launched in April 2026), offering significant impact and career growth potential for early hires.
- **Work Policy**: Not explicitly stated, but typical for early-stage biotech in Cambridge — likely on-site or hybrid.

## Sources
1. [serifbiomedicines.com](https://serifbiomedicines.com)
2. [serifbiomedicines.com/team](https://serifbiomedicines.com/team)
3. [serifbiomedicines.com/science](https://serifbiomedicines.com/science)
4. [flagshippioneering.com](https://www.flagshippioneering.com/companies/serif-biomedicines)
5. [job-boards.greenhouse.io/serif](https://job-boards.greenhouse.io/serif/jobs/8511741002)

## Other roles at Serif Biomedicines, Inc.

- [Scientist, In Vivo Pharmacology](https://feeny.ai/job/scientist-in-vivo-pharmacology-serif-biomedicines-inc-cambridge-ss8e62xdrcqp) — Cambridge, MA
- [Associate Scientist, Bioanalytical Assays](https://feeny.ai/job/associate-scientist-bioanalytical-assays-serif-biomedicines-inc-cambridge-7e493d7k67nb) — Cambridge, MA
- [Senior Scientist, Analytical Development and Quality Control](https://feeny.ai/job/senior-scientist-analytical-development-and-quality-control-serif-biomedicines-1ewhtadm3tmg) — Cambridge, MA
- [Laboratory Operations Associate](https://feeny.ai/job/laboratory-operations-associate-serif-biomedicines-inc-cambridge-stbt1pbzxjn6) — Cambridge, MA