Abstract
In this work we have developed hierarchically porous phosphate-based glasses (PPGs), as novel materials capable of promoting wound closure and simultaneously deliver antibacterial effects at the interface glass-biological tissue. PPGs are characterised by extended porosity which enhances the release of therapeutic ions in a controlled way, whilst facilitating cell infiltration and growth of tissues. 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 significant statistical reduction of the bacterial strains Staphylococcus aureus and Escherichia coli was observed in both series of PPGs, particularly those containing copper.
All PPGs present good cytocompatibility on keratinocytes (HaCaTs) and analysis of dissolution products of PPGs over a 7-day period demonstrates 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 on keratinocytes and ex vivo wound healing properties at the interface biomaterial-human tissue.
Keywords: phosphate-based glasses, gallium, copper, tissue engineering, sol-gel, bioresorbable glasses, antibacterial, in vitro, ex vivo, hierarchically porous.