Laser-based ion doping is a suitable alternative to dope biologically active ions into colloidal bioglass nanoparticles

Bioactive glass nanoparticles (nBGs) have demonstrated promising properties for bone regeneration due to their bone-binding ability. Incorporating multiple ions into nBGs can improve their bioactivity and provide them with additional functionalities aiding bone repair. However, incorporating multiple ions into nBGs combining different functionalities is still challenging as the additional ions often interfere with the nanoparticle properties. To overcome these challenges, here we report the use of pulsed laser doping and co-doping techniques as an alternative method for ion incorporation into colloidal nBGs. We demonstrate the simultaneous laser-induced incorporation of iron (Fe), strontium (Sr), and/or copper (Cu) ions into nBGs from simple salt solutions without altering the particles' morphology. Furthermore, laser-doped nBGs were biocompatible and could significantly increase alkaline phosphatase (ALP) production in human mesenchymal stromal cells (hMSC). Moreover, laser-co-doped nBGs containing Fe and Sr ions significantly increased vessel formation by human umbilical vein endothelial cells (HUVEC). Therefore, pulsed laser doping in liquids was shown to be a versatile technique to incorporate multiple ions into nBGs and allow systematic studies on cooperative effects of dopants in active biomaterials.