Zwitterionic hydrogels, as highly hydrated and soft materials, have been considered as promising materials for wound dressing, due to their unique antifouling and mechanical properties. While the viscoelasticity and softness of zwitterionic hydrogels are hypothetically essential for creating adaptive cellular niches, the underlying mechanically regulated wound healing mechanism still remains elusive. To test this hypothesis, we fabricated zwitterionic poly(sulfobetaine methacrylate) (polySBMA) hydrogels with different elastic moduli prepared at different crosslinker contents, and then applied the hydrogels to full-thickness cutaneous wounds in mice. In vivo wound healing studies compared the mechanical cue-induced effects of soft and stiff polySBMA hydrogels on wound closure rates, granulation tissue formation and collagen deposition. Collective results showed that the softer and more viscoelastic hydrogels facilitated cell proliferation, granulation formation, collagen aggregation, and chondrogenic ECM deposition. Such high wound healing efficiency by the softer hydrogels is likely attributed to stress dissipation by expanding the cell proliferation, the up-regulation of blood vessel formation, and the enhanced polarization of M2/M1 macrophages, both of which would provide more oxygen and nutrients for cell proliferation and migration, leading to enhanced wound repair. This work not only reveals a mechanical property–wound healing relationship of zwitterionic polySBMA hydrogels, but also provides a promising candidate and strategy for the next-generation of wound dressings.
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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. © 2019 The Authors.
- NSF-PAR ID:
- 10460378
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Polymer International
- Volume:
- 68
- Issue:
- 9
- ISSN:
- 0959-8103
- Page Range / eLocation ID:
- p. 1626-1635
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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