New Amphiphilic Conjugates of Amino–Poly(ethylene glycols) With Lipoamino Acids as Surface Modifiers of Colloidal Drug Carriers

Abstract

AbstractPoly(ethylene glycol) (PEG2000) polymers containing one or two amine residues are linked to α‐lipoamino acids (LAA) to produce mono‐ and homo‐disubstituted PEG–LAA conjugates as new materials for the surface coating of colloidal drug carriers. Conjugates are characterized by FT‐IR, 1H‐NMR, and MALDI–TOF mass spectrometry. Differential scanning calorimetry studies are performed to assess the interaction of PEG2000–LAAs with a biomembrane model (dipalmitoylphosphatidylcholine multilamellar liposomes). Whereas the parent PEGs affect only the superficial structure of the bilayers, the amphiphilic PEG–LAA conjugates exert a modulated perturbing effect on the thermotropic profile of liposomes. A molar concentration between 5% and 10% is individuated as the more suitable to produce stable vesicles.