Hydrogels have been the subject of significant research in the field of friction due to their exceptional lubricating properties. In this study, the G-quadruplex hydrogel with high selectivity for K⁺ ions was formed by introducing a mixture of G, 2-formylphenylboronic acid, and polyethylene glycol diamine into simulated artificial tears solution with high transparency, and an ultra-low coefficient of friction (COF) of about 0.004 was obtained based on the simulated ocular environment, thus achieving macroscopic superlubricity. In friction pairs simulating the ocular environment, to assess the frictional performance of the G-quadruplex hydrogel as both a lubricant and a friction pair based on the simulated ocular environment, we conducted experiments considering various factors such as concentration, sliding speed, and stress. Through these experiments, it was found that superlubricity was achieved when the G-quadruplex hydrogel was applied as lubricant or friction pair. This effect was attributed to the three-dimensional network structure and hydrophilicity of the hydrogel, which facilitated the formation of a highly bearing and flowing hydration layer, promoting macroscopic superlubricity. Compared to the G-quadruplex hydrogel with low concentration, the high concentration hydrogel (75 mM) exhibited increased mechanical strength and robustness in superlubricity. Combined with biocompatibility experiments, our synthesized G-quadruplex hydrogel has excellent biocompatibility and offers a novel approach to achieve superlubricity in ocular drug delivery.

由于其卓越的润滑性能，水凝胶一直是摩擦领域重要研究的主题。本研究通过将G、2-甲酰基苯基硼酸和聚乙二醇二胺的混合物引入具有高透明度和超低渗透系数的模拟人工泪液溶液中，形成了对K ⁺离子具有高选择性的G-四联体水凝胶。基于模拟眼部环境，获得了约0.004的摩擦力（COF），从而实现了宏观超润滑。在模拟眼部环境的摩擦副中，为了评估G-四联体水凝胶作为润滑剂和基于模拟眼部环境的摩擦副的摩擦性能，我们进行了考虑浓度、滑动速度和应力等各种因素的实验。通过这些实验，发现当G-四联体水凝胶用作润滑剂或摩擦副时，可以实现超润滑性。这种效应归因于水凝胶的三维网络结构和亲水性，有利于形成高承载和流动的水化层，促进宏观超润滑。与低浓度的G-四联体水凝胶相比，高浓度的水凝胶（75 mM）表现出更高的机械强度和超润滑性的鲁棒性。结合生物相容性实验，我们合成的G-四联体水凝胶具有优异的生物相容性，为实现眼部药物输送的超润滑性提供了一种新方法。