Evaluation of Ethyl Cellulose-Ethanol Ablation in a Human-Sized 3D Construct of High-Grade Cervical Dysplasia.

Current preclinical models for cervical dysplasia rely on animal systems that poorly mimic human anatomy. To address this and align with emerging initiatives to reduce animal experimentation, we developed a human-sized, 3D in vitro model of high-grade cervical dysplasia. The construct integrates normal human fibroblasts, keratinocytes, and SiHa cancer cells within a gelatin methacrylate (GelMA) hydrogel, engineered with a cervical "os" and asymmetric lesion to replicate native human cervical architecture. We utilized this platform to evaluate the efficacy and safety of ethyl cellulose-ethanol (EC-ethanol), a novel ablation therapy designed to mitigate the off-target leakage associated with traditional ethanol injections. While control injections of pure ethanol resulted in widespread, non-specific necrosis (approximately 99% cell death), EC-ethanol successfully formed a localized gel depot. High-resolution mapping of the ablation zone demonstrated that EC-ethanol significantly concentrated cytotoxicity within the dysplastic lesion while preserving surrounding healthy tissue. Margin analysis revealed a sharp therapeutic gradient, with cell death normalizing to background levels within approximately 2 mm of the injection site. These findings validate the translational potential of EC-ethanol as a spatially precise intervention and demonstrate the utility of macro-scale 3D models as powerful, ethical alternatives to animal testing for optimizing local drug delivery.