Part of the lacrimal functional unit, the cornea protects the ocular surface from numerous environmental aggressions and xenobiotics. Toxicological evaluation of compounds remains a challenge due to complex interactions between corneal nerve endings and epithelial cells. To this day, models do not integrate the physiological specificity of corneal nerve endings and are insufficient for the detection of low toxic effects essential to anticipate Toxicity-Induced Dry Eye (TIDE).

Using high-content imaging tool, we here characterize toxicity-induced cellular alterations using primary cultures of mouse trigeminal sensory neurons and corneal epithelial cells in a compartmentalized microfluidic chip.

We validate this model through the analysis of benzalkonium chloride (BAC) toxicity, a well-known preservative in eyedrops, after a single (6h) or repeated (twice a day for 15 min over 5 days) topical 5.10⁻⁴% BAC applications on the corneal epithelial cells and nerve terminals.

In combination with high-content image analysis, this advanced microfluidic protocol reveal specific and tiny changes in the epithelial cells and axonal network as well as in trigeminal cells, not directly exposed to BAC, with ATF3/6 stress markers and phospho-p44/42 cell activation marker. Altogether, this corneal neuroepithelial chip enables the evaluation of toxic effects of ocular xenobiotics, distinguishing the impact on corneal sensory innervation and epithelial cells. The combination of compartmentalized co-culture/high-content imaging/multiparameter analysis opens the way for the systematic analysis of toxicants but also neuroprotective compounds.

作为泪腺功能单位的一部分，角膜保护眼表面免受众多环境侵害和外源物质的影响。由于角膜神经末梢和上皮细胞之间复杂的相互作用，化合物的毒理学评估仍然是一个挑战。迄今为止，模型尚未整合角膜神经末梢的生理特异性，并且不足以检测预测毒性引起的干眼症 (TIDE) 所必需的低毒性效应。

使用高内涵成像工具，我们在区室微流控芯片中使用小鼠三叉神经感觉神经元和角膜上皮细胞的原代培养物来表征毒性诱导的细胞改变。

我们通过分析苯扎氯铵 (BAC) 的毒性来验证该模型，苯扎氯铵是一种众所周知的滴眼剂防腐剂，在单次（6 小时）或重复（每天两次，持续 15 分钟，持续 5 天）局部使用 5.10 ⁻⁴ % BAC 后角膜上皮细胞和神经末梢。

与高内涵图像分析相结合，这种先进的微流体协议揭示了上皮细胞和轴突网络以及三叉神经细胞中特定且微小的变化，未直接暴露于 BAC，具有 ATF3/6 应激标记和磷酸化 p44/42细胞活化标记。总而言之，这种角膜神经上皮芯片能够评估眼外异生物质的毒性作用，区分对角膜感觉神经支配和上皮细胞的影响。分区共培养/高内涵成像/多参数分析的结合为毒物和神经保护化合物的系统分析开辟了道路。