Thermosensitive in situ-forming dextran–pluronic hydrogels through Michael addition

A thiolated dextran (Dex-SH) with a degree of substitution of 10 was synthesized and used for in situ hydrogel formation via Michael-type addition using vinyl sulfone functionalized Pluronic 127 (PL-VS) or acrylated Pluronic 127 (PL-Ar). Dextran/Pluronic hydrogels were rapidly formed in situ under physiological conditions upon mixing the solutions of Dex-SH and PL-VS or PL-Ar at a PL concentration of 10 or 20 w/v%. Rheological studies showed that these hydrogels with a broad range of storage moduli of 0.3 to 80 kPa could be obtained by varying PL concentration from 5% to 20 w/v%. Moreover, the hydrogels at a PL concentration of 10% or 20 w/v% revealed thermosensitive property with a temperature increase from 10 to 37 °C. Dex-SH/PL-Ar hydrogels were degradable under physiological conditions and had lower cytotoxicity than Dex-SH/PL-VS hydrogels. These thermosensitive injectable hydrogels show promise for biomedical applications.