Abstract: A lipid comprising a tri-chain cation having a cationic head group and three or more C7-24 hydrocarbyl groups for use in non-viral gene delivery systems, for example in the formation of lipopolyplex transfection vectors. Exceptionally good nucleic acid transfection is observed when nucleic acid and targeting peptides are formulated with the lipid of the invention (or lipid formulated with a co-lipid) into a LPD complex.

Abstract: A lipid comprising a tri-chain cation having a cationic head group and three or more C7-24 hydrocarbyl groups for use in non-viral gene delivery systems, for example in the formation of lipopolyplex transfection vectors. Exceptionally good nucleic acid transfection is observed when nucleic acid and targeting peptides are formulated with the lipid of the invention (or lipid formulated with a co-lipid) into a LPD complex.

Abstract: The invention provides a peptide derivative of formula A-B-C wherein A is a polycationic nucleic acid-binding component; B is a spacer element peptide that is susceptible to cleavage within a cell; and C is a cell surface receptor binding component. The invention also provides a lipid derivative of general formula (I): (PEG)q-Linker-Spacer-Cationic headgroup-carbon skeleton-(hydrophobic chain)o wherein: the Linker is a group susceptible to cleavage within a cell; the Spacer is a group linking the Linker to the Cationic headgroup; q denotes the number of PEG chains and q=1, 2 or 3; o denotes the number of hydrophobic chains and o=1, 2 or 3; the carbon skeleton is a group linking the hydrophobic chains to the cationic headgroup. The peptide and lipid derivatives find use in non-viral gene delivery systems.

Abstract: The invention provides a peptide derivative of formula A-B-C wherein A is a polycationic nucleic acid-binding component; B is a spacer element peptide that is susceptible to cleavage within a cell; and C is a cell surface receptor binding component. The invention also provides a lipid derivative of general formula (I): (PEG)q-Linker-Spacer-Cationic headgroup-carbon skeleton-(hydrophobic chain)o wherein: the Linker is a group susceptible to cleavage within a cell; the Spacer is a group linking the Linker to the Cationic headgroup; q denotes the number of PEG chains and q=1, 2 or 3; o denotes the number of hydrophobic chains and o=1, 2 or 3; the carbon skeleton is a group linking the hydrophobic chains to the cationic headgroup. The peptide and lipid derivatives find use in non-viral gene delivery systems.