PRESENTED ON-DEMAND ONLY: Supramolecular Hybrid Hydrogels as Rapidly On-Demand Dissoluble, Self-Healing and Biocompatible Burn Dressings

Supramolecular hydrogels (SHs), a novel class of PCHs, are held together by non-covalent crosslinks such as host-guest chemistry, electrostatic interactions, and hydrogen bonding. These hydrogels can respond to environmental stimuli such as light, pH, and electric field. Unlike most synthetic hydrogels with permanent chemical crosslinks, SHs can undergo dissolution in response to various environmental stimuli and self-heal when damaged.<br/>Despite decades of efforts, state-of-the-art synthetic burn dressings to treat partial-thickness burns are still far from ideal. Current dressings adhere to the wound and necessitate debridement. This work describes the first “supramolecular hybrid hydrogel (SHH)” burn dressing that is biocompatible, self-healable, and stimuli-responsive (on-demand dissoluble) for easy and trauma-free removal, prepared by a simple, fast, and scalable method. These SHHs leverage the interactions of a custom-designed cationic copolymer via host-guest chemistry with cucurbit[7]uril and electrostatic interactions with clay nanosheets coated with an anionic polymer to achieve enhanced mechanical properties and fast, on-demand dissolution. The SHHs show high mechanical strength (&gt; 50 kPa), self-heal rapidly in ~1 min, and dissolve quickly (4-6 min) using amantadine hydrochloride (AH) solution that breaks the supramolecular interactions in the SHHs. Neither the SHHs nor the AH solution have any adverse effects on human dermal fibroblasts or epidermal keratinocytes <i>in vitro</i>. The SHHs also do not elicit any significant immune response <i>in vitro</i>. Furthermore, <i>in vivo</i> murine experiments show no immune or inflammatory cell infiltration in the subcutaneous tissue and no change in circulatory cytokines compared to sham controls. Thus, these SHHs present excellent burn dressing candidates to drastically decrease pain and time associated with dressing changes.<br/>Due to the ease of their fabrication, which only involves two steps of mixing, we expect these novel SHHs will enable large-scale yet low-cost fabrication, addressing a critical bottleneck for translation to clinical applications. Further, due to this ease and the speed (15 seconds) of SHH formation, we envision that the dressings could even be formed at the bedside and on-field synthesis of the patients with customizations as necessary. Such novel and on-demand dissoluble SHHs have great potential as second-degree burn dressings. They will i) provide easy burn care, ii) eliminate mechanical and surgical debridement, iii) promote wound healing and enhance the healing process to treat second-degree burns. To this end, we will follow up this study with investigations on the <i>in vivo</i> efficacy of SHHs in burn wound healing progress. We expect our invention to remove the challenges and shortcomings associated with current burn dressings and bear pain-free (or reduced pain), easy to apply, and removable burn dressings.