Pectin–Coated Polyethylenimine Polyplexes as Effective Gene Delivery Systems

Gene therapy is believed to be the therapy of the future because it aims to eradicate causes rather than symptoms of diseases. The generic aim of gene therapy is to deliver DNA inside cells in order to achieve a stable and regulated expression of transgenes in the target cells or tissues without side effects. Spontaneous entry of naked DNA inside cells is an inefficient process, consequently, a major hurdle to the therapeutic application of gene therapy is the lack of suitable vectors for the delivery of nucleic acids. The principal strategies for gene delivery involve viral-mediated and nonviral methods. Among non-viral vectors, polycationic polymer branched polyethylenimine (b-PEI) has proved to be an efficient gene delivery vector but features high cytotoxicity and instability in presence of serum proteins and extracellular matrix components, in particular polyanionic glycosaminoglycans, limiting in vivo application of this transfectant. To overcome these limitations we coated b-PEI polyplexes with pectin, an anionic polysaccharide, obtaining Pectin Coated Polyplexes (PCP) with reduced polyplex positive charge. The effect of pectin coating on b-PEI polyplex chemico-physical and biological properties was evaluated demonstrating that pectin coating is a suitable strategy to enhance polyplex stability.