Evaluation of a Photo‐Sterilizable Polyvinyl Chloride Embedded With Methylene Blue for the Inactivation of <scp> <i>Candida albicans</i> </scp> : A Study on Efficacy, Reusability, and Storage

ABSTRACT Medical device–associated candidiasis remains a persistent challenge, particularly on polyvinyl chloride (PVC) surfaces widely used in clinical settings. Here, we evaluate photo‐sterilizable PVC prepared by a simple swell–encapsulation–shrink (SES) method to embedded methylene blue (MB) and test its ability to inactivate Candida albicans under red light. The material was characterized by visible absorption spectroscopy, microscopy (optical/SEM), and contact angle measurements, and its performance was examined in two practical scenarios: weekly reuse and long‐term storage. Antifungal activity was quantified by CFU assays after standardized contamination and biofilm recovery. Under 630 nm irradiation (total fluence 240 J/cm 2 ), MB–PVC achieved an ~83% initial reduction in C. albicans viability and retained ~58% reduction after 24 weeks of dark storage. A parallel ambient‐light storage set was used to track MB photostability by absorbance at , revealing spectral signatures consistent with photobleaching/phototransformation. Per the stopping rule, once the MB‐specific aPDT effect disappeared, we ran one confirmation cycle. Photoactivity was already lost after a single autoclave cycle (15 psi, 30 min), and the third cycle again showed no aPDT, supporting a single‐use strategy for the current formulation. Collectively, these results provide direct antifungal evidence on MB‐only PVC, establish months‐long shelf‐readiness, and define practical reuse limits, advancing the translational prospects of photo‐sterilizable PVC for device‐associated.