Described herein are compounds and compositions that are characterized by the Markush formulae (I), (II), (III), (IV), (V), and (VI) underneath, where at least one terminal amino group is further functionalized. Such compounds are obtained by reacting a terminal or internal amino group with epoxides, acrylates, or aldehydes bearing lipophilic groups. The resulting amino acid, peptide, polypeptide-lipids (named “APPLs” in the application) are deemed useful as drug delivery systems including nucleotide delivery to cells.