Lysine-appended polydiacetylene scaffolds for human mesenchymal stem cells

We report on the self-assembly based fabrication of fibrous polymers for tissue engineering applications. Directed self-assembly followed by polymerization of lysineappended diacetylenes generated a variety of polymers (P1. P5) with distinct chemical properties. The self-assembly along with the conjugated double and triple bonds and rigid geometry of diacetylene backbone imposed a nanofibrous morphology on the resulting polymers. Chemical properties including wettability of the polymers were tuned by using lysine (Lys) with orthogonal protecting groups (Boc and Fmoc). These Lys-appended polydiacetylene scaffolds were compared in terms of their efficiency toward human mesenchymal stem cells adhesion and spreading. Interestingly, polymer P4 containing Lys N^α-NH₂and Lys N^ε-Boc with balanced wettability supported cell adhesion better than the more hydrophobic polymer P2 with N^ε-Boc and N^α-Fmoc or more hydrophilic polymer P5 containing free N^εand N^αamino groups. The molecular level control in the fabrication of nanofibrous polymers compared with other existing methods for the generation of fibrous polymers is the hallmark of this work.