Silk fibroin (SF) and mucin are extensively recognized as promising biomaterials for wound dressings due to their outstanding biocompatibility, biodegradability, and ability to support cell growth and tissue regeneration. In this study, we developed a hybrid SF/mucin wound dressing (HYB) using tetrazine and norbornene click chemistry to enhance its structural and functional properties. The robust assembly resulted in a dual-phase material with a dense SF membrane and a porous mucin hydrogel (MH). Scanning electron microscopy confirmed the successful integration and tight adhesion between these polymers. The hybrid material exhibited a controlled release of bioactive agents, with epidermal growth factor (EGF) showing a sustained release of up to 48% over 48 h. The optimized 25 mg/mL mucin hydrogel showed efficient EGF release and performance comparable to higher concentrations. It was selected for papain loading to reduce material usage without compromising efficacy. HYB showed a higher papain release rate of 36% compared to the bare SF membrane. Additionally, the hybrid material exhibited enhanced mechanical strength, optimized water vapor permeability comparable to commercial wound dressings, and improved cell proliferation relative to its individual components. Cytotoxicity assays demonstrated that the papain-loaded hybrid material is a viable candidate for wound dressing applications. These results suggest that the click-chemistry-functionalized SF/mucin hybrid material holds significant potential as an advanced wound dressing, capable of promoting tissue regeneration while maintaining a moist environment conducive to healing.

Aim: Quorum sensing (QS) is a density-dependent chemical process of cell-to-cell communication in which certain signals are activated, leading to the coordination of pathogenic behaviors and the regulation of virulence in bacteria. Inhibition of QS can prevent biofilm formation and reduce virulence behaviors of bacteria. Herein, bovine serum albumin (BSA)-coated silver nanoparticles (NPs) (Ag-Ag2S@BSA NPs) were synthesized and studied as an anti-QS agent.

Materials & methods: Ag-Ag2S NPs prepared through a BSA-mediated biomineralization process under ambient aqueous conditions and their physicochemical properties were characterized. The anti-QS activity of the resulting BSA-coated NPs (Ag-Ag2S@BSA NPs) was investigated for the first time.

Results & conclusion: The result confirmed the potential of Ag-Ag2S@BSA NPs as novel and useful therapeutic tools for antibacterial purposes.

Pullulan (Pull) decorated with monodisperse Ag and Au nanoparticles (NPs) was synthesized by a simple and green method. Samples were characterized by FTIR, UV-vis, NMR, XRD, TGA, SEM, XPS, DLS, and TEM. SEM images showed highly oriented microforms reported for the first time for Pull, because of the supramolecular self-assembling behavior of Pull chains. Antimicrobial and quorum sensing (QS) inhibition activities were tested against six pathogen bacteria and reporter and biomonitor strain. Pull decorated with NPs, in particular, Ag-modified ones, outperformed pristine Pull. The cell proliferation was tested with an MTT assay. NPs-decorated Pull was studied for the first time as an inhibitory agent against bacterial signal molecules and found to be a good candidate. The promising performance of AgNPs@Pull compared to the commercial antibiotic gentamicin showed that it has great potential as a therapeutic approach to overcome the bacterial resistance that has developed against conventional antibiotics.

A series of new nonionic antimicrobial polymers with a biodegradable polyvinyl alcohol (PVA) backbone grafted with indole units and different hydrophobic alkyl or ether groups were synthesized by facile esterification. The chemical structures and thermal properties of the obtained polymers were characterized by GPC, NMR, FTIR, WAXD, TGA and DSC analyses. All these nonionic polymers showed a significant antibacterial effect similar to gentamicin against 9 food and human pathogenic bacteria according to the disk diffusion assay. The presence of alkyl or ether groups in most cases did not significantly affect the antibacterial effect compared to the polymer with unsubstituted indole units (with N–H moieties). The impacts of the OH conversion and molecular weight of the obtained polymers on their antimicrobial and anti-quorum sensing effects were also preliminarily investigated. Finally, the obtained indole-grafted PVAs were subjected to MTT assay using a mammalian cell line and hemolysis investigations, and the results showed excellent biocompatibility, particularly for those with ether substituents.

Most macromolecular antimicrobials are ionic and thus lack miscibility/compatibility with nonionic substrate materials. In this context, nonionic hyperbranched polyesters (HBPs) with indole or isatin functionality were rationally designed, synthesized, and characterized. Antimicrobial disk diffusion assay indicated that these HBPs showed significant antibacterial activity against 8 human pathogenic bacteria compared to small molecules with indole or isatin groups. According to DSC measurements, up to 20% indole-based HBP is miscible with biodegradable polyesters (polyhydroxybutyrate or polycaprolactone), which can be attributed to the favorable hydrogen bonding between the N-H moiety of indole and the C=O of polyesters. HBPs with isatin or methylindole were completely immiscible with the same matrices. None of the HBPs leaked out from plastic matrix after being immersed in water for 5 days. The incorporation of indole into HBPs as well as small molecules facilitated their enzymatic degradation with PETase from Ideonella sakaiensis, while isatin had a complex impact. Molecular docking simulations of monomeric molecules with PETase revealed different orientations of the molecules at the active site due to the presence of indole or isatin groups, which could be related to the observed different enzymatic degradation behavior. Finally, biocompatibility analysis with a mammalian cell line showed the negligible cytotoxic effect of the fabricated HBPs.