Enhancing Stability in Biological Fluids: The Role of Ion-Induced Water Structuring in Artificial Tears.

Biological fluid stability plays an irreplaceable role in maintaining physiological functions, and compromised stability can lead to health issues. Even tear instability can lead to vision impairment or dry eye disease (DED). Artificial tears (ATs) are a popular treatment; however, the comprehensive molecular mechanism by which ATs stabilize tears remains obscure. This study explores the effects of water structure rearrangement by electrolyte ions on the ATs stability. Through in situ observation and analysis of evaporation thermodynamics and hydration states, it is demonstrated that anions induce an ordered and strong hydration arrangement that significantly contributes to ATs film stability. Additionally, magnesium induces water molecule rearrangements that influence evaporation characteristics and overall stability. Notably, in vivo experiments underscore the efficacy of strong hydration anion buffers in mitigating dryness and inflammation associated with tear film instability. These insights provide personalized formulations for DED and establish a foundation for exploring biological fluid stability across various applications.