Synthesis of poly(propylene fumarate)-polyurethane urea composite with kartogenin-modified chitosan for cartilage tissue engineering

In this research, we explored the development of a cross-linked polymer composite, poly(propylene fumarate)-polyurethane urea (PPFUU), designed to foster the differentiation of human adipose-derived mesenchymal stem cells (hADMSCs) into chondrocytes. PPFUU was synthesized using PPF-diol, 1,6-diisocyanatohexane, and putrescin, which served as the soft section, hard section, and chain extender, respectively. To optimize its characteristics, PPFUU was integrated with a chitosan-kartogenin conjugate (CS-KGN) at varying weight fractions. The blend underwent chemical crosslinking via free radical polymerization, with benzoyl peroxide as the initiator and N-vinyl pyrrolidinone as the crosslinking agent. The resulting composites were rigorously analyzed for different properties, including thermal behavior, hydrophilicity, compressive strength, biocompatibility, and more. Significantly, the introduction of CS enhanced glycosaminoglycan formation. Furthermore, hADMSCs, when cultured in chondrogenic media on the CS-KGN-integrated PPFUU composite, exhibited upregulated SOX9 and aggrecan expression. Based on these in vitro results, the CS-KGN-conjugated PPFUU composite presents a promising avenue for cartilage tissue regeneration.