Live MSCs CharacterizerDisplays Stemness and DifferentiationUsing Colorful LV-cp Biosensors

Mesenchymal stem cells (MSCs) have garnered significant attention in biomedical research due to their accessibility and remarkable differentiation potential. However, the lack of efficient and convenient living cell monitoring methods limits their widespread application in tissue engineering and stem cell therapy. Therefore, we present progress in the development of a novel series of fluorescent protein (FP) sensors based on turn-on fluorescent protein biosensors (Turn-on FPBs), termed the LV-cp biosensor system (novel live cell permuted fluorescent protein biosensors). Utilizing phage display technology to screen for affinity peptides specifically targeting MSCs and chondrocytes, the LV-cp were engineered by subcloning these peptides into permuted fluorescent proteins, thereby integrating the fluorescence activation mechanism with the affinity peptides and achieving highly accurate detection and identification of these two cell types using living cells as “fluorescence keys.” This system provides a simplified, nontoxic method to replace traditional antibody kits, and strong fluorescence signals can be obtained through various fluorescence detection devices. In addition, the LV-cp biosensors enabled dynamic observation of MSCs differentiation into chondrocytes through changes in the cell fluorescence colors.