Researchers from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences have developed an antioxidative bioactive glass reinforced injectable hydrogel possessing dual capacities of angiogenesis and reactive oxygen species (ROS) scavenging for the treatment of diabetic wounds. The study was published in Chemical Engineering Journal. 

"The hyperglycemic environment of diabetic wounds would lead to the excessive production of ROS, thus resulting in the oxidative stress damage of biomacromolecules and cells and hindrance of wound healing," said Prof. ZHAO Xiaoli, one of the corresponding authors of this study. "The treatment of diabetic wounds has been one of the challenges." 

In this study, nano-scaled cerium doped bioactive glass (CeBG) was synthesized by a sol–gel method. After loading quaternized chitosan (QCS) and CeBG nanoparticles into the thermo-sensitive methyl cellulose (MC) hydrogel, M/Q/CeBG hydrogel was prepared.  

The hydrogel achieved a sol–gel transition temperature close to body temperature due to the salting-out effect of MC, which is beneficial to injection and filling irregular wound shape.  

The hydrogel has good antioxidative ability due to the loaded CeBG, which can effectively scavenge ROS and active nitrogen (RNS), and protect the cells from oxidative stress damage. Meanwhile, the released bioactive ions including Si²⁺ and Ca²⁺ during the degradation of CeBG promoted the proliferation of dermal fibroblasts and tube formation of vascular endothelial cells. In addition, the QCS component conferred antibacterial ability on the hydrogel against E. coli and S. aureus, presenting the killing ratios of 99.11 % and 98.45 %, respectively. 

In vivo experiment in diabetic mouse model showed that the hydrogel effectively promoted wound healing by reducing inflammation, decreasing ROS level and improving angiogenesis. Further investigation of biological mechanism exhibited that the hydrogel was able to regulate NF-κb pathway through eliminating excessive ROS, resulting in the reduction of oxidative stress damage and apoptosis of cells. 

The study provided a promising strategy for the clinical treatment of diabetic wounds as well as the therapy of oxidative stress related diseases.