IADR Abstract Archives
Electrospun membranes with osteogenic and antimicrobial properties for orthopaedic and dental surgery.
Objectives: Preventing deep bone infections and enhancing bone regeneration reduces the risk of post-surgical complications. To facilitate bone healing, surgeons currently employ nanoscale hydroxyapatite (nHA) pastes to stimulate bone regrowth, however this has no innate antimicrobial properties. Silver has long been used to successfully treat bacterial and fungal infections. We therefore investigated the substitution of silver into nHA, its incorporation into electrospun membranes, and the subsequent effects on bacterial and mammalian cells.
Methods: Silver substituted nHA was produced using a modified rapid mixing wet precipitation method at 2, 5, 10 mol % silver. The nHA was added to a PCL solution for electrospinning. Clinically relevant isolates of E. coli and S. aureus were collected and tested against the electrospun scaffolds. MSCs, collected from Wister Rat femurs, were used to study both toxicity and osteogenicity of the membranes using PrestoBlue®, ADH and ALP measurements.
Results: SEM, TEM and EDS identified silver nanoparticles within the HA and confirmed the presence of the HA within the fibres. Both diffusion and contact bacteria studies demonstrated reduced bacterial presence, with E. coli and S. aureus undetectable after 48 hours of contact exposure. Toxicity was observed in high silver content materials (10%) but was not observed at lower levels. An increase in MSC activity was observed over the culture period with the cells cultured on samples containing nHA producing increased alkaline phosphatase levels, a key marker for osteogenic differentiation.
Conclusions: Innovative silver nHA membranes significantly reduced E. coli and S. aureus bacterial populations while maintaining cytocompatibility with mammalian cells and enhancing the differentiation of MSCs into osteoblasts. Silver nHA containing membranes have the potential to act as an antimicrobial membrane while stimulating bone tissue regeneration.
We would like to acknowledge MeDe Innovation (EPSRC EP/K029592/1) for funding this research.
Methods: Silver substituted nHA was produced using a modified rapid mixing wet precipitation method at 2, 5, 10 mol % silver. The nHA was added to a PCL solution for electrospinning. Clinically relevant isolates of E. coli and S. aureus were collected and tested against the electrospun scaffolds. MSCs, collected from Wister Rat femurs, were used to study both toxicity and osteogenicity of the membranes using PrestoBlue®, ADH and ALP measurements.
Results: SEM, TEM and EDS identified silver nanoparticles within the HA and confirmed the presence of the HA within the fibres. Both diffusion and contact bacteria studies demonstrated reduced bacterial presence, with E. coli and S. aureus undetectable after 48 hours of contact exposure. Toxicity was observed in high silver content materials (10%) but was not observed at lower levels. An increase in MSC activity was observed over the culture period with the cells cultured on samples containing nHA producing increased alkaline phosphatase levels, a key marker for osteogenic differentiation.
Conclusions: Innovative silver nHA membranes significantly reduced E. coli and S. aureus bacterial populations while maintaining cytocompatibility with mammalian cells and enhancing the differentiation of MSCs into osteoblasts. Silver nHA containing membranes have the potential to act as an antimicrobial membrane while stimulating bone tissue regeneration.
We would like to acknowledge MeDe Innovation (EPSRC EP/K029592/1) for funding this research.