Using Electric Fields to Stick Hydrogels to Tissues—A Simple Way to Perform Suture-less Surgical Repairs

We demonstrate electroadhesion, i.e., adhesion induced by an electric field, between cationic hydrogels, animal and plant tissues [1]. When gel and tissue are placed under an electric field (DC, 10 V) for 20 – 60 s, the pair strongly adhere, and the adhesion persists indefinitely thereafter. Applying the DC field with reversed polarity reverses the adhesion. Electroadhesion works with tissues of many mammals (cow, pig, chicken, and mouse), and is especially strong in the case of the aorta, cornea, lung, and cartilage. Electroadhesion is also achieved with plant tissues such as with carrot, onion and strawberries. Only cationic gels can be electroadhered to tissues, which suggests that the tissues have anionic character. These findings show the potential for using electroadhesion in surgery while obviating the need for sutures or staples. Advantages include the ability to achieve adhesion on-command, and moreover the ability to reverse this adhesion in case of error.<br/><br/>We then explore variables that contribute towards adhesion in these diverse types of tissues. For instance, the higher the fraction of anionic polymers (proteins and/or polysaccharides) in the biological material, the higher the electroadhesive strength. Interestingly also, because tissues often have anisotropic structure, adhesion by electroadhesion can be strong in one tissue orientation, but weak or non-existent in the perpendicular orientation. Last, we see that electroadhesion occurs in both soft and hard animal and plant tissues.<br/><br/>[1] L. K. Borden, A. Gargava and S. R. Raghavan<br/>Reversible Electroadhesion of Hydrogels to Animal Tissues for Suture-less Repair of Cuts or Tears.<br/>Nature Communications, 12, 4419 (2021)