CD44‐Binding Peptide‐Functionalized Antibiofouling Polymer Surface for High‐Performance Separation of Human Mesenchymal Stromal Cells

Cell transplantation therapy is a promising strategy for next-generation regenerative medicine. However, its clinical application is limited by the absence of safe and label-free methods for obtaining pure populations of functional cells. This study reports a peptide-functionalized zwitterionic polymer system designed for the selective and noninvasive isolation of human mesenchymal stem cells (hMSCs) from heterogeneous cell populations. The substrate was modified with poly(CMBMAm-co-PGMAn-co-MPTMS1) (PC_mP_nM₁), which was synthesized via free radical polymerization, and subsequently conjugated with a CD44-binding peptide (CD44BP). Among the compositions examined, the PC₇P₂M₁-CD44BP surface exhibited superior antifouling properties, effectively suppressing nonspecific protein adsorption and adhesion of nontarget cells while selectively capturing hMSCs. A column packed with PC₇P₂M₁-CD44BP-modified silica microparticles successfully isolated high-purity hMSCs from mixed cell suspensions within 35 min. Flow cytometry confirmed that the cells eluted later exhibited higher CD44 and CD105 expression, indicating separation based on antigen expression. The isolated hMSCs maintained proliferation and differentiation capacities equivalent to those of the preseparated cells, demonstrating that this device preserved cell functionality. This peptide-polymer hybrid column provides a simple and clinically adaptable platform for safe, label-free purification of hMSCs intended for cell transplantation therapy.