Ligand targeting and peptide functionalized polymers as non-viral carriers for gene therapy
Polymeric gene carriers have been developed to deliver therapeutic genes for treating various genetic diseases. They may diminish the problems related with the viral vectors in terms of safety, immunogenicity and mutagenesis. But ineffective endosomal release, cytoplasmic transport and nuclear entry are the main limiting issues in the practice of polymeric carriers. Different strategies have been proposed to functionalize gene carriers for individually overcoming these barriers. For this aim, various polymeric carriers have been developed and further modified with certain ligands and peptides to gain properties like good cargo DNA protection, excellent colloidal stability, high cellular uptake efficiency, efficient endo/lysosome escape, effective import into the nucleus and specific to target cells. These multifunctional polymeric carriers are beneficial for efficient gene delivery. In this review, we provide a comprehensive summary of the interaction between gene and polymeric carriers, mechanism and challenges of gene carriers. We also highlight and discuss recent developments and advancements in the synthesis of ligands targeting and peptides functionalized gene carriers.