Three‐Dimensionally Printed <scp>HEMA</scp> – <scp>TRIS</scp> Hydrogel Contact Lenses With Optimized Optical, Mechanical, and Antibacterial Performance

ABSTRACT This study integrates digital light processing (DLP)‐based additive manufacturing with systematic modulation of trimethylsilyl silane (TRIS) content to elucidate the combined effects of formulation and processing on the performance of 2‐hydroxyethyl methacrylate (HEMA)‐based hydrogel contact lenses. HEMA hydrogels containing 0–20 wt% TRIS were fabricated via DLP 3D printing and evaluated in terms of physical, optical, thermal, mechanical, and biological properties. Equilibrium water content ranged from 22% to 36%, reaching full swelling within 24 h, while static water contact angles varied between 43° and 63°. All samples exhibited excellent optical transparency (95.8%–98.5%) in the visible range, with effective UV blocking below 240 nm. Differential scanning calorimetry showed that the glass transition temperature increased from 14°C (HT0) to 47°C at 10 wt% TRIS, followed by a slight decrease at higher TRIS contents. Dry‐state tensile strength decreased with increasing TRIS, whereas hydrated samples exhibited reduced strength but enhanced elongation. Cytocompatibility tests using ARPE‐19 cells confirmed high viability (≥ 96%) for all formulations. Protein adsorption remained low, and bacterial adhesion was significantly reduced, particularly against Escherichia coli and Staphylococcus aureus , with maximum reductions observed at 5–10 wt% TRIS. Overall, formulations containing 5–10 wt% TRIS provided an optimal balance of hydration, transparency, thermal stability, mechanical compliance, and antimicrobial performance, highlighting their potential for biocompatible contact lens applications.