Assessing the Biocompatibility of Tannic Acid-Based Biomaterials: Addressing Challenges in Standard Cytotoxic Assays.

In this comprehensive study, we delve into the intricate binding properties of tannic acid (TA) and examine their dual role in the realm of biomaterial development. While TA's properties can enhance the functionality and performance of biomaterials, they also raise concerns regarding potential biases in in vitro biocompatibility assessments. We focus on the relevance and constraints of several widely employed cell viability assays, namely the DNA-based PicoGreen assay, the PrestoBlue assay, and the Live/Dead staining technique utilizing fluorescein diacetate (FDA) and propidium iodide (PI). We investigate how these assays perform when applied to TA-coated scaffolds and cell sheets. Through a detailed presentation of our experimental findings, we juxtapose them through a critical review of the existing literature, allowing us to identify and elucidate the limitations these assays face when assessing TA-based biomaterials. In doing so, we aim not only to enhance the understanding of these potential assay biases but also to provide actionable recommendations for accurately evaluating the biocompatibility of TA-modified substances. This dual approach, combining empirical research with literature analysis, offers vital insights for the research community, ensuring that the assessment of TA-coated biomaterials is scientifically sound and reproducible.