Loading on nanocarriers, however, would be more effective in enhancing delivery to tumor targets. Making complex with polymers in polyplexes, such as polyethylene glycol-poly(Llysine) (PEG-PLL) as a hydrophilic-cationic copolymer not only can confer the negative charge problem of high payloads and prevent nuclease degradation by providing steric hindrance but also can help in various cell uptake and crossing some physiological barriers .