Fabrication Of Ozone Oil-loaded Antibacterial Emulsion Hydrogels And Their Application In Wound Dressings

Antibacterial hydrogels are widely used in biomedical fields as drug carriers,tissue scaffolds and wound dressings,and are the research hotspots of biomedical materials.Ozone exhibits broad-spectrum antimicrobial activity,anti-inflammatory properties,immunomodulating properties,anti-hypoxia properties,and residue-free properties.Biomedical usage of ozone has been introduced to relieve postoperative pain,control plaque and biofilm,accelerate wound healing,and functionalize implant surfaces.However,the direct application of ozone in antibacterial hydrogel was limited due to its short half-life,and difficulties in storage.Here,we used ozonated oil as stable ozone source to prepare ozone oil-loaded antibacterial emulsion hydrogels.The ozone-releasing,skin-adhesive,antibacterial,emulsion hydrogels have potential application as antibacterial wound-healing dressings.This thesis mainly includes the following three parts:1)Ozone oil-loaded emulsion hydrogels were prepared and the physical and mechanical properties were characterized.We first prepared ozone oil-water emulsion with twen 80 and montmorillonite（MMT）as emulsifier.The monomer 3-[N,N-dimethyl-[2-（2-methylpropane-2-enoyloxy）ethyl]ammonium]propane-1-sulfonic acid inner salt]（DMAPS）,the crosslinker N,N’-methylenebis-acrylamide（MBA）and the photo-initiator diphenyl（2,4,6-trimethylbenzoyl）-phosphine oxide（TPO）were dissolved in the emulsion.Ozonated oil-containing emulsion hydrogels were prepared by visible light-initiated polymerization.The structure and properties of ozone oil antibacterial emulsion hydrogel were characterized.The results showed that the hydrogel had uniform porous structure,adjustable mechanical properties,good self-healing ability and adhesive property.2)The antibacterial activity and wound healing ability of ozone oil emulsion hydrogels were systematically studied.The stable storage of ozone oil hydrogel and the sustainable release of ozone were verified by model release experiments.The antimicrobial activity of emulsion hydrogels was determined by agar diffusion plate method,using ozonized oil loading of 3,5,10 and 20%,respectively.Hydrogels with 10%ozone oil bacteriostasis rate to four kinds of bacteria were all over 90%.Wound-healing performance was tested using biological mice with full-thickness skin wounds on the back as a model.At day nine,ozone oil hydrogel-10%has a wound healing rate of up to 97%,which confirmed the ability of the hydrogel to rapidly heal the wound,it has potential application in medical wound dressing.3)Hydrogels with enhanced mechanical strength were prepared by strain-induced orientation.The Polyacrylic acid-Polyacrylamide hydrogels were prepared by photopolymerization,and the anisotropic structure was induced by stretching,then through coordination crosslinking between carboxyl group and Fe³⁺,high strength anisotropic hydrogels were successfully prepared.At 100%and 200%pre-stretching,the mechanical strength reached 5.9 MPa and 7.1MPa,which is 1.9 times and 2.3 times stronger than unstretched hydrogels.Stretch-enhanced hydrogels have rapid response to stimuli,which extends their applications in soft robots,biomedical devices and other fields.