Nanocarriers in gene therapy: a review.

With its rapid development in the past few decades, gene therapy has shown potential for use as a standard clinical intervention for the treatment of several conditions, including cancers, infectious diseases, cardiovascular disorders, inner ear disorders, dermatological, ophthalmologic, and neurological pathologies. Current gene therapy is not limited to the delivery of DNA only. Other therapeutic nucleic acid materials such as small interfering RNA, antisense oligonucleotides, or microRNA have also been included into the protocols of gene therapy. The correct choice of vector is a key factor in the success of gene therapy, where both viral and non-viral vectors are commonly used. Viral vectors are associated with some severe side effects (e.g., immunologenicity and carcinogenicity). They show poor target cell specificity, are unable to transfer large-sized genes, and are costly. Therefore, non-viral vectors, especially nanocarriers, have become a realistic alternative to viral vectors for achieving better efficacy in gene therapy. Different types of nanocarriers such as liposomes, metallic and polymeric nanoparticles, dendrimers, gelatins, and quantum dots/rods have been developed, and each shows distinct characteristics. Nevertheless, a variety of new challenges should be properly addressed for ensuring the success of nanocarriers in clinical applications. In this review article, we first discuss the advances and applications of nanocarriers in gene therapy, and then describe the drawbacks and existing challenges of the emerging gene delivery methods based on the use of nanomaterials.