Polyzwitterionic hydrogels as wound dressings with enzymatic debridement functionality for highly exuding wounds

Wound debridement is crucial for proper wound care as it promotes fast and efficient wound healing through removal of necrotic tissue. The latter not only impairs new healthy tissue formation but also increases the odour and the wound exudate, allowing bacteria and other harmful foreign invaders to spread and infect the wound. Hydrogel wound dressings are usually applied for promoting autolytic wound debridement but this is slow and not a very efficient process. On the other hand, enzymatic products for wound debridement are either ointments or gels and they are easily washed out when used for treating highly exuding wounds. This study is an attempt to combine enzymatic debridement functionality with the high swelling ability of polyzwitterionic networks and to produce an innovative dressing with debridement functionality for the healing of highly exuding wounds. For this purpose, two polyzwitterionic hydrogels were synthesized, poly(sulfobetaine methacrylate) and poly(carboxybetaine methacrylate) hydrogels, which were loaded with the protease subtilisin DY for imparting debridement functionality. The swelling ability and mechanical properties of zwitterionic polymer (ZP) hydrogels were shown to depend on their different propensities to physical network formation. Poly(carboxybetaine methacrylate) hydrogels demonstrated better capacity for wound exudate absorption as well as for exerting higher enzymatic debridement activity. Both ZP hydrogels were shown to be non-cytotoxic which confirms their appropriateness for direct contact with injured tissues. Thus, the newly developed ZP hydrogels demonstrate the potential to be used as new dressing materials with enzymatic debridement functionality for highly exuding wounds. (c) 2019 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.