Successful gene therapy has been limited by safe and efficient delivery of nucleic acid to the target cells. Poly (d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) are able to deliver drugs and genes efficiently. This formulation has several advantages in comparison with other formulations including improvement in solubility, stability, controlling of degradation and release of the entrapped agents. For application of PLGA as a gene carrier, there exist many challenges. PLGA NPs could protect the encapsulated DNA from in vivo degradation but the DNA release is slow and the negative charge acts as a barrier to DNA incorporation and delivery. Also, during the preparation process, DNA could be exposed to high shear stress and organic solvents which could result in its inactivation. Moreover, PLGA NPs could be modified with different agents to reduce cytotoxicity, to enhance delivery efficiency and to target specific tissues/cells. This review summarizes different methods used for the preparation of PLGA NPs as gene carriers and recent strategies for the modification of PLGA particles applied in gene therapy.
Keywords: PLGA, gene delivery, encapsulation, modification, nanoparticles.