To increase biocompatibility and get around the opsonins of nanocarriers, PEGylation have been an absolute boon in the nanomedicine eld (Verhoef and Anchordoquy 2013). PEGylation, however, may protect the targeting ligand and hinder the targeting of a particular cell, but un-PEGylated nanocarriers show fast clearance from the blood circulation. Because of this, there are less opportunities for targeted nanocarriers to engage with or be recognized by the appropriate recep­tor site, which will ultimately result in a less successful therapeutic outcome (Li and Huang 2010). Additionally, PEGylation causes nanocarriers to expand in size and molecular weight, which might change their biological capabilities. The charge, size, biocompatibility, contact with macrophages, and circulation duration of nano­carriers can all be affected by the molecular weight as well as density of PEG chains. When compared to PEG or targeting ligand conjugation alone, PEGylated targeted nanocarriers (PEG + targeting ligand) have demonstrated improved targeting out­comes at clinical level (van Vlerken etal. 2007). PEGylation is applicable to reduce the immunogenicity and prolong the circulation of various viral gene vectorssuch as adenovirus and associated virus (Wonganan and Croyle 2010)..