Characterization of nucleic acid molecule/liposome complexes and rheological effects on pluronic/alginate matrices

The delivery of short nucleic acid molecules (NAM), complexed with liposomes, to diseased vessel walls is dramatically limited by blood wash. We thus started investigations to study the possibility of embedding NAM/liposome complexes into a novel polymeric blend focusing attention on their effects on the rheological properties of the selected polymeric blend. Two different liposomes, able to transduce NAM efficiently into vascular smooth muscle cells, were embedded into a thermosensitive alginate/pluronic polymeric blend. Liposome particles, with and without NAM, were characterized for their sizes, superficial charges, morphologies and initial delivery studies performed in vitro. Whereas both liposomes with and without NAM do not substantially affect the final polymeric blend properties, NAM presence differentially influences the structuring process. This behavior is attributed both to particle sizes and superficial charge, with this last parameter appearing more relevant. Moreover, the presence of the polymeric blend substantially retards the delivery of NAM/liposome to vascular smooth muscle cells. In conclusion, our results indicate that both types of liposome/NAM complexes are suitable for the development of a delivery system for NAM-liposome complexes to vessel walls.