Evaluation of the interaction and drug release from alpha,beta-polyaspartamide derivatives to a biomembrane model.

This article reports on a comparative study on the ability of various polymers, containing hydrophilic and/or hydrophobic groups, to interact with a biomembrane model using the differential scanning calorimetry (DSC) technique. Multilamellar vesicles of mixed dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidic acid (DMPA) were chosen as a model of cell membranes. The investigated samples were a water soluble polymer, the alpha,beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) and its derivatives partially functionalized with polyethylene glycol (PEG2000) to obtain PHEA-PEG2000, with hexadecylamine (C16) to obtain PHEA-C16, and with both compounds to obtain PHEA-PEG2000-C16. These polymers are potential candidates to prepare drug delivery systems. In particular, some samples give rise to polymeric micelles able to entrap hydrophobic drugs in an aqueous medium. The migration of drug molecules from these micelles to DMPC/DMPA vesicles also has been evaluated by DSC analysis, by using ketoprofen as a model drug.