V. Krishnadoss, T. Hannah, C. Miller, E. Ellis, A. Kapetanakis, A. Patel, I. Noshadi
Keywords: adhesive, biocompatible, hemostatic
Summary:Traumatic injury damages the soft tissues and skeletal muscle, leading to fatality from hemorrhagic loss of blood and infection which needs to be addressed by early onset trauma management. The coagulation process, divided into primary hemostasis and the coagulation cascade, ensures the prevention of excessive bleeding and converts the blood into stable and insoluble fibrin. In cases of severe trauma, the rate of hemostasis is not rapid enough to prevent excessive loss of blood. Traditionally, compression using gauze and suturing the wounded tissues have been employed to achieve rapid coagulation. These traditional methods are ineffective in controlling hemorrhage involved in surgical procedures. When conjugated and polymerized using visible light the biocompatible polymers Gelatin methacryloyl (GelMA) and Polyethylene glycol diacrylate (PEGDA) forms a sticky hydrogel. In this study, we synthesized hydrogel-based surgical adhesives for wound healing with properties including mechanical characteristics comparable to the native tissues, antimicrobial, high adhesion, biodegradability, high biocompatibility, and ease-of-use. Functionalization of the BIL strengthens the favorable properties. Lap shear test and other mechanical testing methods were used to measure the adhesion strength and mechanical properties of the patch. The strength increased from 5N to 50N with a compression modulus of 50-250KPa and elastic modulus of 200-450KPa when percentage composition is varied indicating that this material is tuneable. Also, rapid clot formation (1 minute) can be seen when citrated human blood is added to bioadhesive, compared to the unfunctionalized GelMA and control, which take up to 7 minutes to clot. This bioadhesive can be harnessed further to produce a biocompatible adhesive patch. GelMA hydrogels have been widely used for various biomedical applications due to their suitable biological properties and tunable physical characteristics. GelMA resembles properties of native extracellular matrix due to the presence of cell-attaching and matrix metalloproteinase responsive peptide motifs, which allow cells to proliferate and spread in scaffolds. Similarly, PEGDA has proven extremely versatile for tissue engineering applications. PEG is FDA approved for a variety of applications and exhibits high biocompatibility and little or no immunogenicity. In addition, PEG-based hydrogels display tunable mechanical properties in the range appropriate to soft tissue regeneration. Ionic liquids are organic salts with a low melting point and high water solubility. The primary requirements of a hemostatic adhesive material for in vivo application are the ability to rapidly clot blood, adhere to the tissues, prevent infection, as well as biocompatibility and biodegradability. These requirements are met by the adhesive in our research. In addition, the novel conjugation of BILs to the hydrogel structure to induce the required properties is done such a way that it is applicable to wide variety of biomaterials including natural or synthetic polymers which makes it appropriate for use as a surgical adhesive.