Tunable PEGylation platform for efficient siRNA delivery using mesoporous silica nanoparticles.

Source: PubMed, NCBI / U.S. National Library of Medicine

Poly(ethylene glycol) (PEG) coatings are widely used to improve nanoparticle stability and biocompatibility, yet conventional PEGylation methods rely on multi-step conjugation that limits reproducibility and restricts control over charge-shielding balance critical for siRNA delivery. Here, we present a composition-tunable PEGylation strategy based on poly(2-(dimethylamino)ethyl methacrylate-co-poly(ethylene glycol) methacrylate) (poly(DMAEMA-co-PEGMA), hereafter referred to as AP) copolymers for the efficient delivery of PD-L1 siRNA using mesoporous silica nanoparticles (MSNs). Copolymers with varying DMAEMA: PEGMA ratios (2:1, 1:1, 0.5:1) and PEG chain lengths (Mn 450 or 950 Da) were synthesized via one-step free-radical polymerization, enabling precise tuning of surface charge and steric stabilization. The optimized MSN/copolymer complexes exhibited enhanced siRNA loading, colloidal stability, and serum resistance while maintaining favorable cytocompatibility. Cellular studies demonstrated improved uptake and significant PD-L1 gene silencing. This work establishes a composition-tunable and scalable PEGylation platform that overcomes the limitations of conventional surface modification and provides a potential strategy for siRNA-based applications.