Functionalization and characterization of collagen sponges with TiO2 nanoparticles as potential use for the preservation of the alveolar ridge

Collagen sponges are widely used as hemostatic agents in oral surgery due to their biocompatibility and ability to promote clotting. However, their inherent mechanical fragility in wet environments limits their performance. This study proposes the functionalization of commercial collagen sponges with titanium dioxide nanoparticles (TiO₂-NPs) using polycaprolactone (PCL) as a dispersant vehicle, aiming to enhance mechanical integrity while maintaining biocompatibility and hemostatic function. Spongostan™ collagen sponges were functionalized with a PCL solution containing 0.03% TiO₂-NPs (< 25 nm). The resulting composite (Col-PCL-TiO₂) and control sponges (Col) were characterized using FTIR, XRD, and SEM. The mechanical strength was assessed using compression testing. Biocompatibility was evaluated using human fetal osteoblasts (hFOB) through WST-1 viability assays on days 3, 7, 10, and 14, and cell-material interactions were analyzed via SEM and fluorescence microscopy (DAPI/CellTracker). FTIR and XRD confirmed the successful incorporation of TiO₂-NPs and PCL without altering the chemical structure of collagen. SEM revealed a homogeneous coating that preserved the porous architecture. A tenfold increase in compressive strength was observed in the Col-PCL-TiO₂ group (434.69 ± 92.34 kPa) compared to control (41.11 ± 5.39 kPa). Cell viability remained high and comparable to that of the control at all time points, with no significant differences (p > 0.05). Fluorescence and SEM imaging revealed robust cell adhesion, proliferation, and extracellular matrix formation with both materials. These findings demonstrate that the functionalization of collagen sponges with TiO₂-NPs using PCL significantly enhances their mechanical strength while preserving their porous microstructure and excellent biocompatibility, making this composite a promising candidate for alveolar ridge preservation post-extraction.