Graphene Oxide-chitosan Based Hydrogel For Management Of Non-healing Infected Wound

Non-healing wounds draw increasing attention for its high mortality and detained healing.Abuse of antibiotics makes conventional antibiotic therapy less effective due to antibiotic-resistant bacterial strain.Traditional wound dressing materials show limited antibacterial and repair capacity in the face of severe surgical incision infection.Advanced materials have been developed for antibacterial applications with chemical or physical methods.Graphene-based materials(GM)stand out for its extraordinary electroconductibility,photosensitivity,thermal conductivity and biocompatibility.Graphene-based photothermal therapy show higher capacity for accelerating regeneration and inactivity of bacteria.Our previous study has developed a hydrogel for wound healing which is synthesized from carboxymethyl chitosan and aldol hyaluronic acid.In combination with graphene-based material and photothermal therapy,enhanced repair of surgical infections is obvious in this novel graphene-based hydrogel.Clinical bacterial infections pose huge threat on perioperative patients.Conventional antibiotic therapy become less effective due to emergence of antibiotic-resistant bacterial strain.Multiple resistant bacteria(MDR)and extensively drug resistant bacteria(XDR)are increasingly common in hospital and cause a higher mortality.Advanced materials with extraordinary physical or chemical properties are designed to combat bacteria.Graphene oxide,with superior electroconductibility,thermal conductivity and photosensitivity,suggest great prospect for antibacterial applications.Mechanisms have been explained how graphene material interact with bacterial components.The most widely accepted mechanism is GM-induced Oxidative stress.Other antibacterial mechanisms are also reported,such as nanoknives derived from sharp edge of graphene,wrapping or trapping Of bacterial membranes derived from the flexible thin-film structure of graphene.Photothermal therapy(PTT)has been applied for tumor treatment.It employs agent with strong light-absorbing property to absorb irradiation and release heat for selectively killing abnormal cells or tissues.Graphene with superior thermal conductivity,high biocompatibility is an expectative material for photothermal therapy.Wu reported a magnetic reduced graphene oxide material which can capture bacteria and inactive bacteria with near infrared(NIR)irradiation.In addition,evidences show that light irradiation have potential to improve wound healing,reduce pain and inflammation.It has also been proved that phototherapy can be applied in tissue repair and regeneration including cardiac tissue,skin,bone and muscleChitosan-based hydrogel has potential to accelerate wound repair and tissue regeneration.Mechanism has been explained that chitosan can enhance the functions of inflammatory cells and promote granulation and organization.Researches have also reported that chitosan-based hydrogel has superior capacity for antibacterial activity.Our previous study has reported a hydrogel which is synthesized by carboxymethyl chitosan(CCS)and aldol hyaluronic acid(AHA)with Michael addition.It is demonstrated that this kind of hydrogel can be applied in open abdomen repair.Proliferation of macrophage was also observed in the wounds.