Cross-linked poly(lactic acid)/dextran nanofibrous scaffolds with tunable hydrophilicity promoting differentiation of embryoid bodies

Poly(lactic acid) (PLA) and polysaccharide have been extensively studied for biomedical applications. However, the hydrophobicity of PLA makes it less desirable for cell adhesion, while dextran, a polysaccharide, is highly hydrophilic but its linear form is not very useful for tissue engineering because it readily dissolves in water. This study aimed to fabricate biodegradable cross-linked PLA-dextran nanofibrous scaffolds with tunable hydrophilicity and to test their effects on the attachment, differentiation and biological activities of mouse embryonic stem cells (ES cells). The cross-linked nanofibers of various compositions of PLA-g-dextran (10-88% dextran) were fabricated by grafting dextran onto PLA through maleic anhydride followed by co-axially reactive electrospinning with in situ photo-cross-linking of methacrylated dextran under UV irradiation. The results have shown that contact angles of electrospun PLA-g-dextran nanofibers decreased with increasing dextran content. The hydrophilic nanofibrous scaffolds containing 30% or 50% dextran can significantly enhance the attachment and differentiation of ES cells, which have demonstrated spontaneous contractions.