Abstract: A biodegradable, positively-charged aminoalkyl polyester polymer for the delivery of bioactive agents, such as DNA, RNA, oligonucleotides, proteins, peptides, and drugs is disclosed. Biologically active moieties, such as drugs, ligands, and the like, can be coupled to the free amino groups of the polymer.

Abstract: Poly[&agr;-(4-aminobutyl)-L-glycolic acid] (PAGA) is disclosed as a biodegradable composition suitable for delivering a gene into a cell. Methods of making and using PAGA are also disclosed.

Abstract: A compound for targeted gene delivery is provided consisting of polyethylene glycol (PEG) grafted poly(L-lysine) (PLL) and a targeting moiety, wherein at least one free amino function of the PLL is substituted with the targeting moiety, and the grafted PLL contains at least 50% unsubstituted free amino function groups. TM is preferably lactose or galactose which are capable of specifically targeting a hepatoma cell or a liver cell. The new synthetic carriers with various substitution ratios of targeting moiety-PEG were characterized using NMR spectroscopy. The new polymeric gene carriers of this invention are capable of forming stable and soluble complexes with nucleic acids, which in turn are able to efficiently transform cells. PEG attached to the PLL gives better solubility properties to the gene/carrier complex and improved transfection efficiency without considerable cytotoxicity. Methods of preparing and using the targeting moiety-PEG-PLL as gene carriers to efficiently transfect cells are disclosed.