DSPE-Polysarcosine40 (DSPE-pSar40)

Key Properties

• A well-defined amphiphilic lipid–polypeptoid conjugate composed of a hydrophobic DSPE anchor and a hydrophilic linear polysarcosine chain with 40 sarcosine (N-methylglycine) repeating units.
• Provides stronger hydrophilic shielding and better stealth performance than shorter-chain analogs such as DSPE-pSar10.
• Near‑neutral, non‑fouling, and minimally immunogenic; effectively reduces protein adsorption and cellular nonspecific binding.
• Biocompatible, biodegradable, and non-toxic, serving as a high-performance alternative to PEGylated lipids.
• Forms stable monolayers and inserts efficiently into lipid bilayers of liposomes and lipid nanoparticles (LNPs).
• Soluble in chloroform, methanol, and DMSO; dispersible in aqueous buffers.
• Appears as a white to off-white solid or waxy powder.
• Storage: −20 °C, desiccated, protected from light and oxidation.

Applications

• Used as a long‑chain stealth lipid in LNP and liposome formulations for mRNA, DNA, siRNA, and protein delivery.
• Improves colloidal stability and prolongs systemic circulation lifetime of nanocarriers.
• Mitigates accelerated blood clearance (ABC) and immune responses commonly associated with PEG lipids.
• Enables surface modification of exosomes, micelles, and biomimetic membranes.
• Applied in vaccine delivery systems, targeted drug carriers, and imaging probes.
• Ideal for long-circulating nanomedicines requiring sustained blood exposure and low immunogenicity.