Exploring opportunities for biowaste valorization, herein,
humic
substances (HS) were combined with gelatin, a hydrophilic biocompatible
and bioavailable polymer, to obtain 3D hydrogels. Hybrid gels (Gel
HS) were prepared at different HS contents, exploiting physical or
chemical cross-linking, through 1-ethyl-(3-3-dimethylaminopropyl)carbodiimide
(EDC) chemistry, between HS and gelatin. Physicochemical features
were assessed through rheological measurements, X-ray diffraction,
attenuated total reflectance (ATR) spectroscopy, nuclear magnetic
resonance (NMR) spectroscopy, and scanning electron microscopy (SEM).
ATR and NMR spectroscopies suggested the formation of an amide bond
between HS and Gel via EDC chemistry. In addition, antioxidant and
antimicrobial features toward both Gram(−) and Gram(+) strains
were evaluated. HS confers great antioxidant and widespread antibiotic
performance to the whole gel. Furthermore, the chemical cross-linking
affects the viscoelastic behavior, crystalline structures, water uptake,
and functional performance and produces a marked improvement of biocide
action.