Doxorubicin-encapsulated thermosensitive liposomes modified with poly(N-isopropylacrylamide-co-acrylamide): Drug release behavior and stability in the presence of serum

In the field of the temperature sensitive drug delivery systems, we studied on the surface modification of liposomes, by using poly(N-isopropylacrylamide-co-acrylamide) (PNIPAM-AAM) and polyethyleneglycol (PEG) to increase the release of doxorubicin (DOX) from liposomes and prolong the stability of liposomes in the presence of serum. The release of DOX from the PNIPAM-AAM/PEG modified liposomes is enhanced around the transition temperature of the polymer. In addition, the stability of the PNIPAM-AAM/PEG modified liposomes in serum shows a high level comparing with polymer unmodified liposomes. These results suggest that the modification on the surface of liposomes, with both PNIPAM-AAM and PEG enhances the drug release from liposomes and reduces the protein adsorption in serum. (c) 2005 Elsevier B.V. All rights reserved.