Table 1.

Summary of the immunoreaction of main polycations.

Immunoreaction of the Main Polycations
Polycation	Immunogenicity and inflammatory reaction
PLL	L conformation: none or low immunostimulation and even immunosuppression; D conformation: strong immunostimulation; (conformation-dependent, IgG, IgM own spatial specificity to D conformation)
PEI	None or low immunogenicity
PAMAM	Low Mw: none or low immunogenicity; High Mw: strong complement activator; (Mw-dependent)
Chitosan	Both immunostimulation and immunosuppression; Activation of macrophages to resist bacteria, virus, and tumor; Inducing type Th1 and lowering type Th2 immunoreaction
Gelatin	Low immunogenicity;Phagocytosed by macrophages; Resulting in immune response of T cells

PLL, polylysine; PAMAM, polyamidoamine dendrimers; PEI, polyethyleneimine; Mw, molecular weight.