Table 3.

Advantages and disadvantages of polymer-based nonviral vectors of gene delivery.

Polymer-Based Vector	Advantages	Disadvantages
Protein-based vectors	Highly biocompatible, biodegradable, and non-toxic	Have low mechanical strength and are vulnerable to rapid degradation by biological components
Polysaccharide-based vectors	Highly biocompatible, biodegradable, hydrophilic, nontoxic, and easily modifiable with ligands and functional groups	Lack cationic groups of their own and need to be modified to make them interact with genetic materials
Polyesters	Have a compatible and biologically recognizable backbone that is analogous to nucleic acids	Complex molecular structure that is difficult to study and modify
Polycarbonates	Nontoxic, highly biocompatible, and controllable mechanical properties	Need to be modified with ligands to avoid unwanted immune reactions
Polyurethanes	Highly elastic, flexible, and biocompatible	Need strict control of molecular weight to form complex with DNA