Polymers for virai gene delivery

Background: The development of viral vectors capable of providing efficient gene transfer in diseased tissues without causing any pathogenic effects is pivotal for overcoming the many challenges facing gene therapy. Objective: Immune responses against viral vectors, inadequate gene expression and inefficient targeting to specific cells in vivo are some of the major problems limiting the clinical utility of viral gene therapy. Methods: This review will focus on recent progress in strategic polymer-based modifications to improve the performance and biocompatibility of a variety of viral vectors. We will discuss the preclinical development of four approaches involving injectable polymers, polyelectrolytes, polymer microspheres and polymer-virus conjugates. Results/conclusion: Much progress has been made in creating 'hybrid' gene delivery vectors that combine the strengths of polymers and viruses. With further optimization, these hybrid vectors, which may be safer and more effective, are likely to succeed in clinical applications.