Silicone hydrogel contact lenses offer superior oxygen transport compared with conventional hydrogels, but they often suffer from insufficient surface wettability and limited multifunctionality. This study aimed to (i) establish an optically transpare...
Silicone hydrogel contact lenses offer superior oxygen transport compared with conventional hydrogels, but they often suffer from insufficient surface wettability and limited multifunctionality. This study aimed to (i) establish an optically transparent, TRIS-based silicone hydrogel baseline formulation and (ii) evaluate how low-dose inorganic and organic nanomaterials can impart ultraviolet (UV) shielding, mechanical reinforcement, improved surface wettability, acceptable polymerization stability (extractables), and antimicrobial activity.
A series of TRIS/DMA/NVP/HEMA silicone hydrogel lenses (S1–S4) were prepared to optimize composition. Formulations containing 40 wt% TRIS (S2, S4) produced transparent lenses (mean visible transmittance >90%), whereas 50 wt% TRIS (S1, S3) resulted in opaque lenses due to phase separation. The S4 formulation was selected as the reference because it combined stable water content (~41.7%) with the highest oxygen permeability (Dk = 26.73 × 10⁻¹¹ cm²/s·mL O₂/(mL·mmHg)).
Titanium dioxide (TiO₂) nanoparticles synthesized via hydrolysis–precipitation (H-TiO₂) and sol–gel (S-TiO₂) methods were incorporated into the S4 matrix at 0.03–0.10 wt%. Increasing TiO₂ loading reduced UV‑B transmittance from 76.3% (Ref) to 27.5% (H‑10) and 20.8% (S‑10) and increased tensile strength to 0.195 (H‑10) and 0.224 kgf/mm² (S‑10), with concurrent reductions in contact angle (to 84.2° and 77.8°, respectively). In addition, HEMA-based hydrogel lenses containing commercial CeO₂–ZrO₂ nanoparticles (0.015–0.300 wt%) exhibited pronounced improvements in mechanical and surface properties (maximum tensile strength 0.5937 kgf/mm²; contact angle reduced to 36.87°) while satisfying extractables criteria. Bio-derived nanochitosan (ionic gelation) and nanocellulose (enzymatic hydrolysis and freeze–thaw) also enhanced UV‑B blocking, tensile strength, and wettability nanocellulose notably increased water content up to 48.0% without meaningful refractive-index change. Antimicrobial assays against Staphylococcus aureus and Escherichia coli indicated overall inhibition trends for the nanocomposite lenses.
Overall, controlled incorporation of functional nanomaterials provides a practical route to next-generation hydrogel contact lenses with combined UV protection, enhanced durability, improved wettability, and antimicrobial potential.