Preparation Of A Printable Hydrogel With Antibacterial And Drug Sustained-release Functions Based On Ergonomics

With the increasing attention of human beings to health issues,traditional wound dressings have been unable to meet the increasingly diverse clinical needs due to their lacking of outstanding micro-preparation and drug regulatory capacity.Thanks to the characteristics of precise computer control,three-dimensional(3D)printing technology has broad prospects for the development of customized ergonomic biomaterials in medicine.Therefore,the preparation of biocompatible printing materials with certain toughness is of great significance for the development of new medical sciences.In order to meet the requirements of 3D printing,the material needs to have shear thinning or thermoplastic ability to pass through the printer nozzle smoothly,and self-healable in a short time after printing to ensure the shape stability of the printed structure.However,most printing materials have unnecessary toxicity due to the introduction of initiators and cross-linking agents,which is not conducive to their application in the medical field;Moreover,ordinary printing materials are mostly single polymer with single function,which greatly limits their applications.In response to this problem,a printable dualnetwork hydrogel was designed for p H responsive drug delivery in this study.As a hydrophilic three-dimensional network and capable of simulating the microenvironment of extracellular matrix(ECM),hydrogel is considered as a promising candidate for printable dressing.The double network structure allows the hydrogel to have high mechanical properties and high elasticity,which can meet the needs of human movement as a wound dressing.It is thermodynamically stable and has the ability of rapid self-healing,that can avoid the secondary infection caused by external bacterial invasion.The specific research contents showing as follows:(1)Hydrogels with self-healing and shear thinning properties are experimentally designed so that they could be easily extruded through printing nozzles(shear-thinning),and the shape and mechanical properties could be quickly recovered after printing(selfhealing).Based on this mechanism,a printable dual network hydrogel(HFF / PAM DN)was prepared by combining physical crosslinking with chemical crosslinking.The structure and bonding mechanism of hydrogel were analyzed by spectrum characterization.And the further experiment results showed that the hydrogel has the ability of rapid self-healing,high elasticity and anti-fatigue,and can be used as a wound dressing to fit on the surface of human body in the state of motion.(2)Based on the above studies,the biocompatibility of HFF / PAM DN hydrogel was further verified.Acetylsalicylic acid(ASA)was used as a model drug to investigate the drug release behavior of hydrogels in vitro.The results illustrated that the hydrogels showed sustained drug release behavior with p H response.In the end,the release kinetics and mechanism were analyzed by fitting different mathematical models.(3)The volatile natural plant essential oil was formulated into oil-in-water microemulsions and encapsulated in HFF / PAM hydrogels.The prepared M-HFF / PAM microemulsion hydrogel showed sustained antibacterial activity and enhanced antibacterial ability compared to pure essential oils.