Thermo-sensitive keratin hydrogel against iron-induced brain injury after experimental intracerebral hemorrhage

In situ keratin hydrogel offer a promising strategy to relieve the brain injury after intracerebral hemorrhage (ICH) by delivering the iron chelator directly to the stroke site. However, the injectable property of traditional keratin hydrogel is unsatisfactory, which can't provide adaptable filling of lesion defects with irregular shapes. Herein, the thermo sensitive keratin-g-PNIPAM polymers with different graft ratios were synthesized, and deferoxamine mesylate (DFO) loaded thermo sensitive keratin hydrogels (TKGs) were prepared using the oxidative crosslinking method. The lower critical solution temperature of TKGs can be tailored from 28.5 to 31.8 °C by varying the graft ratios of keratin to NIPAM, and TKG can fill up the complex shapes of lesion cavities easily due to the characteristic of sol-gel transition. In addition, TKGs exhibit stronger adsorption and clearance capacities for the Fe²⁺ than keratin gel. Meanwhile, in situ injection of TKG with different DFO loadings (0.1, 1.0, and 10 mg/mL) into the hematoma region after ICH surgery showed a stronger effect on the reduction of ICH-induced iron deposits, brain non-heme iron content, brain edema and ROS level compared to the DFO treatment by intraperitoneal administration. Thus, the developed TKG can be potentially exploited for iron-induced brain injury after ICH.