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Comprehensive Summary: Supramolecular‐polymeric hybrid hydrogels combining advantages of the assembled supramolecular networks and polymeric networks have attracted considerable attention recently. However, they are rarely used as multi‐functional wound dressing materials. In this work, we report a supramolecular‐polymeric hybrid hydrogel consisting of a co‐assembled DBS‐COOH/Naproxen network (DBS/NAP) and a polymeric gelatin (G)/quaternary ammonium group (Q) and phenylboronic acid groups (PBA)‐grafted chitosan (QCS‐PBA) network (G/QCS) for accelerating skin wound healing. The polymeric networks could obviously enhance the mechanical properties of the drug‐derived supramolecular networks. Q groups endowed the hydrogel with enhanced antibacterial properties. Borate ester crosslinking between PBA groups and diol groups in DBS‐COOH could effectively scavenge reactive radicals. The hybrid hydrogel exhibited tunable mechanical and adhesive properties due to the temperature‐responsive gelatin networks. NAP could gradually release from hybrid hydrogel networks thus continuously relieving inflammation. Finally, the biocompatible, adhesive, antibacterial and antioxidant hybrid G/QCS‐DBS/NAP gel could promote the in vivo healing stages in a full‐thickness wounds with increased collagen deposition, upregulated CD31 expression and down‐regulated TNF‐α expression. Overall, this multi‐functional supramolecular‐polymeric hybrid hydrogel exhibited great potential for treating skin defects as promising wound dressing materials. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Supramolecular‐polymeric hybrid hydrogels combining advantages of the assembled supramolecular networks and polymeric networks have attracted considerable attention recently. However, they are rarely used as multi‐functional wound dressing materials. In this work, we report a supramolecular‐polymeric hybrid hydrogel consisting of a co‐assembled DBS‐COOH/Naproxen network (DBS/NAP) and a polymeric gelatin (G)/quaternary ammonium group (Q) and phenylboronic acid groups (PBA)‐grafted chitosan (QCS‐PBA) network (G/QCS) for accelerating skin wound healing. The polymeric networks could obviously enhance the mechanical properties of the drug‐derived supramolecular networks. Q groups endowed the hydrogel with enhanced antibacterial properties. Borate ester crosslinking between PBA groups and diol groups in DBS‐COOH could effectively scavenge reactive radicals. The hybrid hydrogel exhibited tunable mechanical and adhesive properties due to the temperature‐responsive gelatin networks. NAP could gradually release from hybrid hydrogel networks thus continuously relieving inflammation. Finally, the biocompatible, adhesive, antibacterial and antioxidant hybrid G/QCS‐DBS/NAP gel could promote the in vivo healing stages in a full‐thickness wounds with increased collagen deposition, upregulated CD31 expression and down‐regulated TNF‐α expression. Overall, this multi‐functional supramolecular‐polymeric hybrid hydrogel exhibited great potential for treating skin defects as promising wound dressing materials. [ABSTRACT FROM AUTHOR]

It is important to investigate the phase transition mechanism of stimuli-sensitive hydrogels due to its great guiding significance for the application of stimuli-sensitive hydrogels in biomedical applications. In this work, the novel thermo-sensitive poly(N-vinylcaprolactam-co-hydroxyethyl methacrylate) (PVCL-co-HEMA) hydrogel was successfully synthesized via free radical polymerization, and then temperature-dependent FTIR spectra combined with the newly developed scaling moving-window two-dimensional (scaling-MW2D) correlation spectroscopy and generalized two-dimensional correlation analysis were utilized to investigate its volume phase transition (VPT) mechanism upon heating. Conventional 1D FTIR spectra and Boltzmann fitting results revealed that the PVCL-co-HEMA hydrogel exhibited a distinct VPT behavior from the neat PVCL hydrogel due to the incorporation of PHEMA. The essential reason is that some water molecules were still confined in the PVCL-co-HEMA network after phase transition at high temperature, rather than continuously being expelled out of the gel with the increase of temperature. Scaling-MW2D spectra revealed that the phase transition of the PVCL-co-HEMA hydrogel could be divided into two steps (I and II), and further confirmed that the transition regions of these two steps were 25.0–32.3 °C and 32.3–46.8 °C, respectively. The transition regions of both these steps were obviously lower than those of the neat PVCL hydrogel. According to the generalized 2D correlation analysis of step I, we concluded that the dissociation of the hydrogen bonds between the incorporated PHEMA moieties and water molecules is the driving force for the local hydrophobic domain formation process (step I), and its occurrence at a lower temperature is the main reason for the decrease of the VPTT of the PVCL segments. Furthermore, we found that the dissociation of the hydrogen bonds between the C=OVCL groups and water molecules is the driving force for the chain collapse (step II), and the driving effect of the PVCL segments on PHEMA during the phase transition was confirmed. Combined with the obtained sequential order of steps I and II, an unusual two-step VPT mechanism for the PVCL-co-HEMA hydrogel upon heating was proposed. [ABSTRACT FROM AUTHOR]