Synthesis,Characterization And Application Of MoS₂-ACF For Wound Healing

Wound healing is a vital physiological process to maintain skin integrity after trauma.Its process is usually characterized as four distinct but overlapped programmed phases:hemostasis,inflammation,proliferation,and remodeling.For a wound to heal successfully,these four phases must occur in an appropriate sequence and time frame.Among the whole wound healing process,the transition from the inflammatory phase to the proliferative phase is the critical step.Macrophages play multiple roles in the inflammatory phase to the proliferative phase transition.In the early wound,macrophages assume M1‘classically activated’phenotype through releasing cytokines,that promote the inflammatory response by recruiting and activating additional leukocytes to prevent pathogenic bacterial infection.Macrophages are also responsible for inducing and scavenging apoptotic cells（including neutrophils）,thus paving the way for a phenotypic transition from M1 phenotype to an‘alternatively activated’M2 phenotype that stimulates keratinocytes,fibroblasts,angiogenesis,secretion of anti-inflammatory mediators and growth factors to promote tissue ingrowth and proliferation.In this way,the transition from the inflammatory phase to the proliferative phase could be orchestrated by the immune macrophage phenotype and functions.Phenotypic transformation of macrophages is a dynamic and reversible process,which can be driven by the factor in the extracellular environmental stimuli.Herein,taking advantage of electron transfer being enhanced by coupling molybdenum disulfide（MoS₂）with highly conductive activated carbon fiber（ACF）network,MoS₂-ACF heterojunction structure was constructed as macrophage M1-M2phenotype switcher（MAPS）for regulating inflammation-proliferation transition to accelerate the wound healing.MoS₂has the advantages of high biocompatibility,good photothermal properties and stable chemical properties.It has great application potential in the fields of antibacterial therapy,drug loading and electrochemical catalysis.After coupled with ACF,its photothermal conversion ability and antioxidant enzyme activity were significantly improved,which could play an obvious role in wound treatment.In the early stage of wound repair,MAPS-mediated photothermal effect with 808 nm laser irradiation could promote macrophages reprogramming to M1 phenotype,which can expedite inflammation.The released pro-inflammatory cytokine TNF-αwould combine with photo-induced hyperthermia to kill bacteria.Later during the healing process,MAPS could induce macrophages switch towards M2 phenotype by its inherent（Reactive Oxygen Species,ROS）scavenging ability to resolve inflammation,and meanwhile the expressed anti-inflammatory cytokine IL-10 would promote cell proliferation.Therefore,this facile MoS₂-ACF heterojunction structure provides a new strategy to modulate inflammation-proliferation transition by rebalance the immuno-environmental equilibrium of macrophage M1/M2 phenotype.