Parylene C‐ Coated Natural Rubber Latex Sheet With Reduced Protein Leaching and Improved Biocompatibility

Type I and type IV allergies are a major drawback of surface‐contacting natural rubber‐based medical devices, which can be significantly reduced by providing a non‐leaching coating over the natural rubber latex‐based products. In this study, Parylene C was coated over natural rubber latex sheets to prevent/minimize the leaching of proteins and residual chemicals from latex sheets. Parylene C provides excellent barrier qualities, a chemically resistant coating with intrinsic biocompatibility and biostability. The chemical vapor deposition method was adopted for coating, and the coating effect was analyzed by varying the coating thickness (0.5, 1 and 2 μm). The leaching of proteins and additives from uncoated and coated latex sheets was compared under three pH levels. The protein estimation study reveals a significant leaching from the uncoated sheet at pH 9, whereas coating with 1 and 2 μm shows a notable decrease, highlighting the protective role of Parylene C. The cytocompatibility study using mouse fibroblast L929 cells further confirms the barrier property of Parylene C, with cytotoxic morphology for the uncoated sheet and spindle‐like morphology for the 1 and 2 μm coated sheets. As a novel approach, this research can be extended to biomedical surface coating devices made from natural rubber latex.