writer：Yang Xi, Chen Qixian, Yang Jinjun, Wu Sudong, Liu Jun, Li Zhen, Liu Deqiang, Chen Xiyi, Qiu Yongming
keywords：polymeric micelle, PEGylation, cyclic RGD, tumor accumulation, drug delivery
source：期刊
specific source：ACS Applied Materials & Interfaces
Issue time：2017年

With respect to the intriguing biocompatibility and the

stealthy functions of poly(ethylene glycol) (PEG), PEGylated

nanoparticulates have been intensively engineered for utilities as

drug delivery vehicles. To advocate the targeted drug transportation,

targeting ligands were strategically installed onto the surface of

PEGylated nanoparticulates. The previous in vitro investigations

revealed that the ligand-specified cell endocytosis of nanoparticulates

was pronounced for the nanoparticulates with adequately high PEG

crowdedness. The present study aims to explore insight into the

impact of PEGylation degree on in vivo tumor-targeted accumulation

activities of cRGD-installed nanoparticulates. The subsequent

investigations verified the importance of the PEGylation crowdedness

in pursuit of prolonged retention in the blood circulation post

intravenous administration. Unprecedentedly, the PEGylation crowdedness

was also identified as a crucial important parameter to pursue the tumor-targeted accumulation. A plausible reason is the

elevated PEGylation crowdedness eliciting the restricted involvement in nonspecific protein adsorption of nanoparticulates in the

biological milieu and consequently pronouncing the ligand-receptor-mediated binding for the nanoparticulates. Noteworthy was

the distinctive performance of the class of the proposed systems once utilized for transportation of the mRNA payload to the

tumors. The protein expression in the targeted tumors appeared to follow a clear PEGylation crowdedness dependence manner,

where merely 2-fold PEGylation crowdedness led to remarkably 10-fold augmentation in protein expression in tumors. Hence,

the results provided important information and implications for design of active-targeting PEGylated nanomaterials to fulfill the

targeting strategies in systemic applications.