Silanized and Cu-doped bioactive glass as filler for biobased photocurable 3D printed scaffolds

This research explores and characterizes a photo-curable, biobased resin reinforced with bioactive glass (BGs) to produce scaffolds 3D-printed for tissue engineering applications. Through a sol-gel were synthesized two types of BGs, standard and copper-doped. The BGs were silanized to enhance resin compatibility. Transmission FTIR, photoDSC and photoreology fully characterized the UV-curing behaviour of the resin formulation. 3D-printed scaffolds' mechanical properties were evaluated through tensile tests and dynamic mechanical thermal analysis (DMTA). At the same time, morphology and dispersion of the BGs inside the polymer matrix were assessed utilizing Scanning Electron Microscopy (SEM). Bioactivity was evaluated by immersing the scaffolds in a simulated body fluid (SBF) to evaluate hydroxyapatite (HAp) formation. Antibacterial activity tests following the ISO 22196 protocol demonstrated 57 % fewer viable Staphylococcus aureus cells adhered to the surfaces of A7I3-sil and A7I3–Cu-sil compared to the control. SEM and 3D-reconstructed images showed reduced bacterial aggregations (from 13-14 % to 8–9%) and Z-maximum (from 4.5 μm to 2.5 μm). On the treated samples most bacterial cells appeared as single and sporadic cells, making them more easily removable with mild antibiotics. This work aims to enhance bone scaffold design that combines mechanical strength with bioactivity using sustainable and biobased materials. The findings provide a foundation for future developments in tissue engineering.