An overview of polyallylamine applications in gene delivery.

A chief objective of gene transportation studies is to manipulate clinically accepted carriers that can be utilized to combat incurable diseases. Despite various strategies, efficiency and application of these vectors have been hindered, owing to different obstacles. Polyallylamine (PAA) is a synthetic water-soluble, weak base cationic polymer with different properties that could be administrated as an ideal candidate for biomedical applications such as gene delivery, drug delivery, or even tissue engineering. However, some intrinsic properties of this polymer limit its application. The two associated problems with the use of PAA in gene delivery are low transfection efficiency (because of low buffering capacity) and cytotoxic effects attributed to intense cationic character. Most of the strategies for structural modification of the PAA structure have focused on introducing hydrophobic groups to the polymeric backbone that target both cytotoxicity and transfection. In this perspective, we concentrate on PAA as a gene delivery vehicle and the existing approaches for modification of this cationic polymer to give insight to researchers for exploitation of PAA as an efficient carrier in biomedical applications.