Effects of gallium and clove oil embedded in porous phosphate coacervate glass fibres on wound healing.

Abstract

This study investigates Ga-loaded porous phosphate glass fibres (PGFs) coated with clove oil (clv) (1.5 and 3 w/v%) as multifunctional materials capable of antioxidant, antibacterial, and wound-healing properties. PGFs were prepared via coacervation combined with supramolecular templating and electrospinning (ES). Porosity was induced via the removal of the surfactant cetyltrimethylammonium bromide (CTAB) used as a soft template. Scanning Electron Microscopy (SEM) revealed that the majority of porous PGFs have diameters ranging from ∼0.5 to 4 µm. PGFs around 1-4 µm have highly porous walls (pores ∼300 nm in diameter), whereas the smaller ones are hollow, with non-porous walls and perfectly round channels. Results have identified PGFs loaded with 1 mol% Ga₂O₃ and 3 w/v% clv as ideal compositions, exhibiting the strongest radical scavenging (up to ∼70% DPPH, ∼53% ABTS), the highest inhibition of hydroxyl radicals (OH˙) (∼34% reduction) and the highest phenolic content (∼18 mg GAE/g). Reactive oxygen species (ROS) assays demonstrated that PGFs' dissolution products show a protective effect under oxidative stress by significantly reducing intracellular ROS levels while maintaining high keratinocyte (HaCaT) viability over 72 h. Similarly, in fibroblast-like (MC3T3-L1-E1), the same PGFs' dissolution products enhanced H₂O₂ scavenging activity and improved cytocompatibility. Time-dependent MTS assays in HaCaTs demonstrated sustained cell viability over 72 h across two tested concentrations (5% and 10% v/v), with stable metabolic activity and no evidence of significant cytotoxicity. Antibacterial activity against Escherichia coli (E. coli) was confirmed by optical density (OD) measurements and colony-forming unit (CFU) analysis, which showed a significant reduction in viable bacteria for PGFs containing 1 mol% Ga₂O₃ coated with 3 w/v%. This antibacterial effect is hypothesised to result from the release of Ga ions, while clv contributes mainly to the antioxidant activity. In contrast, PGFs' dissolution products, regardless of Ga and clv loading, did not exhibit a measurable antibacterial effect against Staphylococcus aureus (S. aureus). In vitro wound healing scratch assays showed that dissolution products from Ga- and clv-containing PGFs enhance cell migration, accelerating wound closure in both keratinocytes and fibroblasts. This work demonstrates the successful synthesis of porous PGFs by combining soft templating with the coacervation method and the enhanced beneficial properties of PGFs coated with a natural antioxidant, proving their potential for advanced wound-healing applications. Further in vivo studies will be required to confirm the in vitro potential.