Neutral Block Copolymer Assisted Gene Delivery using Hydrodynamic Limb Vein Injection.

Three different amphiphilic block copolymer families are synthesized to investigate new opportunities to enhance gene delivery via Hydrodynamic Limb Vein (HLV) injections. First a polyoxazoline-based family containing mostly one poly(2-methyl-2-oxazoline) (PMeOx) block and a second block POx with an ethyl (EtOx), isopropyl (iPrOx) or phenyl substituent (PhOx) is synthesized. Then an ABC poly(2-ethyl-2-oxazoline)-b-poly(2-n-propyl-2-oxazoline)-b-poly(2-methyl-2-oxazoline) triblock copolymer is synthesized, with a thermosensitive middle block. Finally, polyglycidol-b-polybutylenoxide-b-polyglycidol copolymers with various molar masses and amphiphilic balance are produced. The simple architecture of neutral amphiphilic triblock copolymer is not sufficient to obtain enhanced in vivo gene transfection. Double or triple amphiphilic neutral block copolymers are improving the in vivo transfection performances through HLV administration as far as a block having an lower critical solution temperature is incorporated in the vector. The molar mass of the copolymer does not seem to affect the vector performances in a significant manner.