Biocompatible and antibacterial soy protein isolate/quaternized chitosan composite sponges for acute upper gastrointestinal hemostasis

Innovative biomedical applications have high requirements for biomedical materials.Herein,a series of biocompatible,antibacterial and hemostatic sponges were successfully fabricated for the treatment of acute upper gastrointestinal bleeding(AUGB).Quaternized chitosan(QC)and soy protein isolate(SPI)were chemically cross-linked to obtain porous SPI/QC sponges(named SQS-n,with n¼30,40,50 or 60 corresponding to the weight percentage of the QC content).The chemical composition,physical properties and biological activity of SQS-n were investigated.SQS-n could support the adhesion and proliferation of L929 cells while triggering no obvious blood toxicity.Meanwhile,SQS-n exhibited good broad-spectrum antibacterial activity against both grampositive bacteria(Staphylococcus aureus)and gram-negative bacteria(Escherichia coli).The in vivo hemostatic effect of SQS-n was evaluated using three different bleeding models.The results revealed that SQS-50 performed best in reducing blood loss and hemostatic time.The overall hemostatic effect of SQS-50 was comparable to that of a commercial gelatin sponge.The enhanced antibacterial and hemostatic activities of SQS-n were mainly attributed to the QC component.In conclusion,this work developed a QC-functionalized hemostatic sponge that is highly desirable for innovative biomedical applications,such as AUGB.