Composite microspheres of bioactive glass and hydrophilic biodegradable polymers to accelerate infected wound healing

Synthetic biodegradable microspheres hold great promise for complex wound repair. However, their clinical application is hindered by inflammatory responses triggered by acidic degradation byproducts. In this paper, we developed new composite microspheres as dressings to accelerate infected wound healing. Polyethylene glycol/poly(L-lactide)/poly(ε-caprolactone) multiblock copolymers were synthesized and engineered with Cu-doped bioactive glass to form composite microspheres. The Cu-doped bioactive glass not only improved the hydrophilicity of the composite microspheres but also neutralized the acidic degradation products of the copolymers. This helped preserve a physiologically neutral pH in wounds, thereby attenuating inflammatory stimulation and fostering a stabilized microenvironment supportive of efficient wound healing. Simultaneously, the Cu²⁺ ions within the bioactive glass network were released gradually over 24 h to maintain sustained antibacterial activity and promote wound regeneration. Animal experiments demonstrated that the composite microspheres significantly accelerated the healing of wounds infected with Staphylococcus aureus. These composite microspheres represent a feasible solution for infected wound healing.