A hydrogel adhesive fabricated from poly(ethylene glycol) diacrylate and poly(allylamine hydrochloride) with fast and spontaneous degradability and anti-bacterial property

Degradation adhesive is required in many applications such as skin grafting operation. In this study, a kind of hydrogel adhesive was prepared from poly(ethylene glycol) diacrylate (PEGDA) and poly(allylamine hydrochloride) (PAH) by aza-Michael addition between the amino groups of PAH and diacrylate groups of PEGDA. The PAH-PEGDA hydrogels could be fabricated at 37 degrees C when the pH value of PAH solution was above 6. Rheology tests showed that the gelation time was prolonged along with the decrease of pH value of PAH solution, which was over 1 h and 30 s at pH 6 and pH 8, respectively. The hydrogels could offer strong enough adhesion force between different types of substrates including hydrophilic matrix and pig skin. This kind of PAH-PEGDA hydrogel adhesives was spontaneously degraded in 2-3 days due to the large number of beta-amino ester structures which facilitate the degradation. No noticeable influence on pig skin was observed after the gauze was peeled off from the skin 1 day post adhesion. Moreover, the extracted solution of the hydrogel did not influence on the cell viability compared with the control. This kind of hydrogel adhesives has the potential for skin grafting operation.