This study applied nanocellulose, a natural polymer, as an additive to compensate for the low wettability and mechanical strength of silicone hydrogel contact lenses and to impart additional functions such as ultraviolet blocking and antibacterial activity. For lens fabrication, nanocellulose was added at varying concentrations ranging from 0.03 wt% to 0.10 wt% to a silicone hydrogel formulation primarily composed of HEMA, NVP, DMA, and TRIS, and the optical properties, physical characteristics, and biological safety of the fabricated lenses were comprehensively evaluated. As a result, UV-B transmittance continuously decreased with increasing nanocellulose content from 76.22% in the control group to 36.21% at 0.10 wt%, confirming the expression of UV-blocking performance without an additional blocking agent. The water content increased from 42.2% in the control group to a maximum of 48.0%, while the refractive index remained within 1.4260–1.4265, indicating a trend of increased hydrophilicity without compromising optical transparency. Surface analysis of the fabricated lenses showed that the contact angle markedly decreased from 105° in the control group to 84°, and AFM and SEM analyses confirmed that a fine network structure formed by nanocellulose particles contributed to changes in surface roughness and improved hydrophilicity. In mechanical strength evaluation, tensile strength increased by more than approximately threefold, from 0.12 kgf/mm² to 0.38 kgf/mm², due to the physical crosslinking effect of the nanoparticles. In the safety evaluation, pH, potassium permanganate reduction, and UV absorbance all fell within the regulatory limits set by the Ministry of Food and Drug Safety, demonstrating chemical safety with respect to extractables. In addition, antibacterial tests showed that lenses containing nanocellulose exhibited excellent inhibitory effects against Escherichia coli and Staphylococcus aureus. In conclusion, nanocellulose is considered a multifunctional additive capable of simultaneously improving wettability, durability, and antibacterial performance without impairing the fundamental properties of silicone hydrogel lenses.

Keywords: Silicone hydrogel, Nanocellulose, Wettability, Mechanical strength, UV-protection