Layer-by-layer coated chitosan-CRISPR/Cas9 mTOR nanoparticles: A novel approach to inhibit lens epithelial cell proliferation and migration for preventing posterior capsule opacification.

Posterior capsular opacification (PCO) is the most common complication following cataract surgery and a significant cause of vision impairment. PCO arises from the proliferation, migration, and epithelial-mesenchymal transition (EMT) of residual lens epithelial cells (LECs), driven by an activated mTOR signalling pathway. Previous research has demonstrated that inhibiting mTOR activity effectively reduces LEC proliferation and EMT in rabbit models. However, achieving sustained mTOR inhibition remains a challenge. In this study, we encapsulated the CRISPR/Cas9 system targeting mTOR into chitosan nanoparticles (Chi-gRNA) with an average size of 135 nm. These nanoparticles exhibited resistance to DNase I digestion. To prolong release duration, we incorporated these Chi-gRNA nanoparticles onto the surface of intraocular lenses (IOLs) via layer-by-layer (LbL) assembly. The LbL coatings consisted of alternating layers of positively charged polyethyleneimine (PEI) and negatively charged heparin, interspersed with Chi-gRNA nanoparticles over five consecutive cycles. Spectral analysis confirmed the successful integration and coating of nanoparticles, with characteristic peaks validating the electrostatic assembly of the layers. In vitro assays demonstrated that Chi-gRNA-coated IOLs significantly inhibited the proliferation, migration, and adhesion of human lens epithelial cells (hLECs). These findings highlight the potential of LbL-coated IOLs to deliver CRISPR/Cas9 system-targeting mTOR nanoparticles as a novel and effective strategy to prevent PCO in patients undergoing cataract surgery. This approach offers a promising avenue for the long-term management of this prevalent postoperative complication.