Hierarchically porous copper and gallium loaded sol-gel phosphate glasses for enhancement of wound closure.

In this work, we have developed hierarchically porous phosphate-based glasses (PPGs) as novel materials capable of promoting wound closure and simultaneously delivering antibacterial effects at the glass-biological tissue interface. PPGs are characterised by extended porosity, which enhances the controlled release of therapeutic ions, whilst facilitating cell infiltration and tissue growth. Two series of PPGs in the systems P2O5-CaO-Na2O-CuO and P2O5-CaO-Na2O-Ga2O3 with (CuO and Ga2O3 0, 1, 5 and 10 mol%) were manufactured using a supramolecular sol-gel synthesis strategy. Significant wound healing promotion (up to 97%) was demonstrated using a human ex vivo wound model. A statistically significant reduction of the bacterial strains Staphylococcus aureus and Escherichia coli was observed in both series of PPGs, particularly those containing copper. All PPGs exhibited good cytocompatibility on keratinocytes (HaCaTs), and analysis of PPG dissolution products over a 7-day period demonstrated controlled release of phosphate anions and Ca, Na, Cu, and Ga cations. These findings indicate that Cu- and Ga-loaded PPGs are promising materials for applications in soft tissue regeneration given their antibacterial capabilities, in vitro biocompatibility with keratinocytes and ex vivo wound healing properties at the biomaterial-human tissue interface.