Poly(ethylene glycol)-block-poly(amino acid) (PEG-b-poly)

Poly(ethylene glycol)-block-poly(amino acid) (PEG-b-poly) carriers are amphiphilic block copolymers widely utilized in the formulation of polymeric micelles for drug delivery (Kataoka et al., 2001). These structures consist of a hydrophilic PEG segment and a hydrophobic or functionalized poly(amino acid) segment, such as poly(aspartic acid) or poly(glutamic acid), which self-assemble into nanoscopic core-shell architectures in aqueous solutions (Yokoyama et al., 1990). The hydrophobic core encapsulates poorly water-soluble drugs, protecting them from degradation and increasing their systemic solubility, while the PEG corona provides a steric barrier that minimizes opsonization and clearance by the mononuclear phagocyte system (Matsumura et al., 2004). This stealth effect leads to prolonged blood circulation and enhanced accumulation in tumor tissues through the enhanced permeability and retention (EPR) effect (Maeda et al., 2000). Clinically, these carriers have been employed to deliver various chemotherapeutic agents, including paclitaxel (NK105) and cisplatin (NC-6004), aiming to improve therapeutic indices and reduce off-target toxicities (Hamaguchi et al., 2005). The versatility of the poly(amino acid) block allows for the attachment of various ligands for active targeting or the incorporation of stimuli-responsive elements for controlled release (Nishiyama et al., 2006). However, repeated administration can trigger the production of anti-PEG antibodies, leading to the accelerated blood clearance (ABC) phenomenon and potential hypersensitivity reactions (Ishida et al., 2006).

Other names

PEG-b-PAAPEG-block-poly(amino acid)Polymeric micelle carrierPEG-poly(amino acid) block copolymerPEGylated block copolymer

Encapsulation of therapeutic agents within self-assembled polymeric micelles to improve solubility, prolong circulation time, and facilitate targeted delivery via the enhanced permeability and retention (EPR) effect.