About Sail 

Sail Biomedicines is pioneering the integrative design and deployment of fully programmable medicines to transform patient care. Sail’s platform combines first-in-class programmable circular RNA technology (Endless RNA™ or eRNA), and an industry-leading platform of programmable nanoparticles, utilizing natural components, to unlock comprehensive programming of medicines for the first time. By leveraging cutting-edge eRNA and nanoparticle deployment technology, Sail is also making unparalleled use of AI techniques to identify and design fully programmable medicines that are potent, targeted, versatile, and tunable. Sail was founded by Flagship Pioneering. 

The Role

The Sr Director, Delivery will be responsible for advancing Sail’s targeted nanoparticle delivery platform, with a particular focus on lipid nanoparticle (LNP) technologies for cell-specific delivery of RNA therapeutics. This role will lead the strategy and execution of delivery innovation from early discovery through preclinical development, enabling robust, scalable, and translatable delivery solutions across Sail’s pipeline.

This individual will bring deep technical expertise in lipid nanoparticle design and formulation, as well as demonstrated experience in targeted delivery approaches, including ligand-mediated targeting, bioconjugation, and receptor-specific delivery strategies. They will play a central role in shaping Sail’s delivery capabilities, expanding tissue and cell-type reach, and unlocking new therapeutic applications.

The Sr Director will operate at the intersection of Platform, Programs and Technical Development, working cross-functionally to translate delivery innovations into high-impact programs. They will lead a team of scientists and serve as a key thought partner to senior leadership on delivery strategy, platform investments, portfolio prioritization, and technical risk.

This role is accountable for the foundational and Delivery capability at Sail, ensuring that targeted nanoparticle systems are not only innovative but also translatable and scalable, enabling continued pipeline progression to development candidates.

Responsibilities 

Delivery Leadership and Strategy

• Lead and grow Sail’s Delivery team, advancing lipid nanoparticle (LNP) and targeted delivery technologies.
• Drive innovation in targeted nanoparticles, including design, formulation, ligand selection and conjugation, receptor-mediated uptake, and cytosolic delivery.
• Define and execute delivery strategy across tissues and disease areas, guiding nanoparticle engineering for precise targeting and biodistribution.
• Develop and apply high-throughput screening approaches to evaluate delivery performance, including biodistribution, cellular uptake, and functional expression.
• Partner with Program teams to advance multiple development candidates, improving efficiency, specificity, and translatability.
• Partner with Technical Development to ensure scalable, robust processes supporting progression to clinic.

Cross-Functional & Operational Leadership

• Lead cross-functional delivery efforts to advance programs from concept through candidate nomination.
• Collaborate with ligand design and program teams to align delivery strategies with disease biology and therapeutic goals.
• Identify and mitigate key delivery risks to enable program success.
• Drive integrated planning across delivery activities, aligning timelines, milestones, and resources.
• Manage external collaborations, including CROs and technology partners.
• Advise senior leadership on delivery strategy, portfolio prioritization, and execution risks.

Qualifications

• PhD or MD in drug delivery, chemical engineering, materials science, pharmaceutical sciences, or a related discipline with 12+ years of relevant industry experience.
• Deep expertise in lipid nanoparticle (LNP) systems, including formulation development, lipid chemistry, and in vitro/in vivo evaluation of delivery performance.
• Demonstrated experience in targeted delivery approaches, including ligand conjugation, receptor-mediated targeting, and nanoparticle surface engineering.
• Strong understanding of nucleic acid delivery challenges, including biodistribution, cellular uptake, endosomal escape, and immunogenicity.
• Experience advancing delivery technologies toward IND-enabling studies or clinical translation, with an appreciation for scalability, manufacturability, and regulatory considerations.
• Proven track record of advancing delivery technologies from discovery through preclinical development.
• Experience building and leading multidisciplinary scientific teams in a fast-paced biotech environment.
• Ability to operate strategically while remaining deeply connected to scientific detail and execution.
• Strong cross-functional leadership skills, with experience working across chemistry, biology, process development, and translational teams.
• Excellent communication skills, with the ability to influence senior stakeholders and clearly articulate complex technical concepts.

Salary Range: $235,000 - $290,000 

Sail Biomedicines is an Equal Opportunity Employer. Sail does not discriminate based on race, religion, color, sex, gender identity, sexual orientation, age, national origin, veteran status, or any other status protected under federal, state, or local law. 

About Sail:

Sail Biomedicines is pioneering the integrative design and deployment of fully programmable medicines to transform patient care. Sail’s platform combines first-in-class programmable circular RNA technology (Endless RNA™ or eRNA), and an industry-leading platform of programmable nanoparticles, utilizing natural components, to unlock comprehensive programming of medicines for the first time. By leveraging cutting-edge eRNA and nanoparticle deployment technology, Sail is also making unparalleled use of AI techniques to identify and design fully programmable medicines that are potent, targeted, versatile, and tunable. Sail was founded by Flagship Pioneering.

The Role:

Sail Biomedicines is seeking a motivated Senior Research Associate / Scientist I to join our Vaccines, Immunoassay & Pharmacology team. This role will develop, optimize, and execute bioassays to characterize biological activity, mechanism, and immune responses for candidates enabled by Sail’s eRNA™ delivery platform, supporting in vivo PK/PD, toxicology, and translational decision-making.

This is a lab-based, onsite role with substantial hands-on experimental work, collaborative problem-solving, and close partnership with cross-functional teams. The ideal candidate brings strong experience in mammalian cell culture, flow cytometry, serology/immunoassays (e.g., ELISA/MSD), qPCR, and excellent scientific documentation. You will generate high-quality data, troubleshoot assays, and contribute to advancing Sail’s platform and pipeline.

Responsibilities:

Bioassay Development & Execution

• Develop, optimize, and execute cell-based and immunoassay workflows to support PK/PD, tox, and pharmacology readouts (e.g., potency/functional assays, biomarker assays, serology).
• Design and build multiparameter flow cytometry panels (marker selection, titrations, controls, compensation, gating strategy) for in vivo study sample analysis.
• Develop and run serology assays (e.g., binding antibody, neutralization/surrogate neutralization where applicable, cytokine/chemokine readouts) using ELISA, MSD, or related platforms.
• Qualify/validate assays as appropriate: establish accuracy/precision, sensitivity, range, robustness, and implement cross-study controls and reference standards.
• Own assay readiness: generate SOPs, templates, and training materials; ensure reproducibility and knowledge transfer.

Sample Operations & Study Support

• Coordinate sample receipt, accessioning, and tracking from internal studies and CRO-supported work; maintain chain-of-custody, storage conditions, and inventory.
• Perform sample processing (e.g., PBMC isolation, plasma/serum handling), ensuring consistency and biosafety compliance.

Data, Documentation & Collaboration

• Analyze, interpret, and summarize data; maintain rigorous records in ELN and associated databases.
• Present findings internally (lab meetings, project teams) with clear conclusions, limitations, and next steps.
• Partner with Biology, Analytics, and Computational/AI teams to define assay requirements, experimental design, and data structure/metadata.
• Contribute to reports, tech memos, and experiments that support IP and regulatory-facing documentation where relevant.
• Manage multiple concurrent experiments while maintaining high standards for lab safety, quality, and timelines.

Required Qualifications:

• B.S. or M.S. in Immunology, Bioengineering, Biochemistry, Molecular Biology, Chemistry, or related field.
• 2–4+ years relevant laboratory experience (industry preferred).
• Hands-on experience with flow cytometry and mammalian cell culture; experience with one or more of: PBMC isolation, primary cell handling, qPCR, ELISA/MSD, or related immunoassays.
• Working knowledge of assay development principles (controls, standard curves, variability, qualification/validation concepts).
• Strong experimental design and troubleshooting skills; able to optimize protocols and document changes clearly.
• Excellent organization and time management; able to prioritize and execute in a fast-paced environment.
• Strong written/verbal communication, including presenting data and writing concise summaries.
• Self-directed, collaborative, detail-oriented; demonstrates scientific curiosity and integrity.

Preferred Qualifications:

• Experience working with non-human primate (NHP) samples and associated biosafety practices.
• Basic working knowledge of biostatistics (e.g., variability, curve fitting, outlier handling, assay acceptance criteria).
• Experience with FlowJo, GraphPad Prism, and Microsoft Office (Excel/PowerPoint); familiarity with ELN best practices.
• Experience in a matrixed project environment supporting multiple programs.

Salary Range: $80,000 - $115,000

Sail Biomedicines is an Equal Opportunity Employer. Sail does not discriminate based on race, religion, color, sex, gender identity, sexual orientation, age, national origin, veteran status, or any other status protected under federal, state, or local law.