N-Tetradecyl-pSar25 is a poly(sarcosine) (pSar) derivative composed of a tetradecyl hydrophobic head group covalently linked to a polymeric tail containing 25 repeating poly(sarcosine) units. Sarcosine, the amino acid derivative forming the backbone of this compound, is being developed as a potential substitute for polyethylene glycol (PEG) in in vivo applications due to its advantageous characteristics, which include enhanced biodegradability and substantially reduced antigenicity. N-Tetradecyl-pSar25 is particularly relevant in the formulation and development of lipid nanoparticles, where its structural design contributes to improved delivery and biocompatibility profiles.