Background/Objectives: Toothpaste ingredients such as strontium chloride (SrCl₂) and potassium carbonate (K₂CO₃) are recognized for their desensitizing and remineralizing effects but may be absorbed through the oral mucosa. Their potential cytotoxic and cardiotoxic properties, however, remain inadequately characterized. Here, we investigated the effects of SrCl₂ and K₂CO₃ on mouse-induced pluripotent stem cells (iPSCs) and iPSC-derived cardiomyocytes (iPSC-CMs). Methods: Cells were exposed to varying concentrations of each compound for up to 72 h. Real-time cell analysis (xCELLigence RTCA Cardio system) was used to assess proliferation, and flow cytometry was used to evaluate cell viability. Functional properties of iPSC-CMs were examined using multi-electrode array (MEA) recordings and xCELLigence-based impedance measurements. Cardiac marker expression was examined via immunofluorescence and quantitative RT-PCR. Results: Both SrCl₂ and K₂CO₃ affected iPSC proliferation and reduced viability in a dose- and time-dependent manner, accompanied by altered embryoid body (EB) morphology and increased cell death. In iPSC-CMs, both compounds downregulated key cardiac genes and disrupted spontaneous beating activity, with effects intensifying at higher concentrations. Conclusions: These results demonstrate that SrCl₂ and K₂CO₃ induced dose-dependent cytotoxic and arrhythmogenic effects on iPSCs and iPSC-CMs. At elevated concentrations, these compounds impair iPSC-CM function and may pose safety concerns upon chronic exposure. Further mechanistic and long-term in vivo studies are warranted to assess their potential cardiotoxic risk in consumer oral care products.

Background/Objectives: Toothpaste ingredients such as strontium chloride (SrCl₂) and potassium carbonate (K₂CO₃) are recognized for their desensitizing and remineralizing ef-fects but may be absorbed through the oral mucosa. Their potential cytotoxic and cardio-toxic properties, however, remain inadequately characterized. Here, we investigated the effects of SrCl₂ and K₂CO₃ on mouse-induced pluripotent stem cells (iPSCs) and iPSC-derived cardiomyocytes (iPSC-CMs). Methods: Cells were exposed to varying con-centrations of each compound for up to 72 h. Real-time cell analysis (xCELLigence RTCA Cardio system) was used to assess proliferation, and flow cytometry was used to evaluate cell viability. Functional properties of iPSC-CMs were examined using multi-electrode ar-ray (MEA) recordings and the xCELLigence based impedance measurements. Cardiac marker expression was examined via immunofluorescence and quantitative RT-PCR. Results: Both SrCl₂ and K₂CO₃ affected iPSCs proliferation and reduced viability in a dose- and time-dependent manner, accompanied by altered embryoid body (EB) morphology and increased cell death. In iPSC-CMs, both compounds downregulated keys cardiac genes and disrupted spontaneous beating activity, with effects intensifying at the higher concentrations. Conclusions: These results demonstrate that SrCl₂ and K₂CO₃ induced dose-dependent cytotoxic and arrhythmogenic effects on iPSCs and iPSC-CMs. At elevated concentrations, these compounds impair iPSC-CMs function and may pose safety con-cerns upon chronic exposure. Further mechanistic and long-term in vivo studies are war-ranted to assess their potential cardiotoxic risk in consumer oral care products.

Human induced pluripotent stem cells (hiPSCs) hold immense promise for regenerative medicine. However, a critical barrier to the clinical application of hiPSCs is the difficulty in promoting robust cell proliferation while preserving their pluripotent state. Efficient hiPSC expansion without loss of pluripotency is crucial for generating high quality cells or therapeutic applications, disease modeling, and drug discovery. In our study, we investigated the effects of QuinoMit Q10^® fluid (QMF-Se), a nanoformulated supplement containing Ubiquinol (the active form of Coenzyme Q10) and Selenium, on hiPSC growth and maintenance in vitro. Interesting, QMF-Se supplementation significantly enhances hiPSC proliferation compared to control cultures. This increase in cell number was accompanied by heightened mitochondrial activity, suggesting improved cellular energy metabolism. Importantly, the expression of core pluripotency markers OCT4, NANOG, and SOX2 remained unaltered, confirming that the stem cells retained their undifferentiated status. Moreover, we observed that QMF-Se treatment conferred protective effects during the freeze–thaw process, reducing cell death and supporting post-thaw recovery. These results indicate that QMF-Se may improve both cell culture efficiency and cryopreservation outcomes. Overall, our findings highlight the potential of QMF-Se as a valuable additive for hiPSC culture systems, contributing to more efficient and reliable expansion protocols in regenerative medicine research.