Zn-based Metal-Organic Frameworks (MOFs) Incorporated into Collagen-Polysaccharide-based Composite Hydrogels for Their Use in Wound Healing

Based on the physicochemical properties of metal-organic frameworks (MOFs), and the need of having an anti-inflammatory and antibacterial effect at the same time in a material for wound healing applications, a multicomponent polymer system was synthesized. Zn-based MOFs having different amino acids acting as ligands (L-tryptophan (Trp), L-phenylalanine (Phe), and L-histidine (His)) in their coordination sphere were successfully prepared and validated by FTIR and XRD. Each MOF was incorporated into a semi-interpenetrated polymeric network (semi-IPN) based on collagen (C)-guar gum (GG)-polyurethane (PU), given composite hydrogels as end products. The physicochemical properties of these novel composite hydrogels, their in vitro biocompatibility, and their use as cell carriers were studied. The maximum swelling capacity was shown by CGG-Zn(Trp) while the crosslinking index was higher for CGG-Zn(Phe) and CGG-Zn(His), indicating that the chemical structure of the amino acid of the Zn-based MOF tailors these physicochemical properties. All composite hydrogels were resistant to a hydrolysis degradation process (at pH=5 and 7.4) being not entirely degraded after 14 days and having residual masses above 57%. The incorporation of Zn-based MOFs increased the biocompatibility in terms of metabolic activity and proliferation of porcine fibroblast in contact with the composite hydrogels. The low release capacity of fibroblast encapsulated inside hydrogels evaluated for 10 days indicated the non-efficient capacity of these matrixes as cell carriers, regardless of the structure of the Zn-based MOF. The strong adhesion of porcine fibroblast to the composite hydrogels is related to improving metabolic activity allowing its proliferation, making these multicomponent polymeric systems useful as efficient materials in biomedical applications such as wound dressing and tissue engineering.