PLGA/TiO₂ nanocomposite scaffolds for biomedical applications: fabrication, photocatalytic, and antibacterial...

Porous 3D scaffolds synthesized using biocompatible and biodegradable materials could provide suitable microenvironment and mechanical support for optimal cell growth and function. The effect of the scaffold porosity on the mechanical properties, as well as the TiO₂ nanoparticles addition on the bioactivity, antimicrobial, photocatalytic, and cytotoxicity properties of scaffolds were investigated. In the present study, porous scaffolds consisting poly (lactide-co-glycolide) (PLGA) containing TiO₂ nanoparticles were fabricated via air-liquid foaming technique, which is a novel method and has more advantages due to not using additives for nucleation compared to former ways. Adjustment of the foaming process parameters was demonstrated to allow for textural control of the resulting scaffolds and their pore size tuning in the range of 200-600 μm. Mechanical properties of the scaffolds, in particular, their compressive strength, revealed an inverse relationship with the pore size, and varied in the range of 0.97-0.75 MPa. The scaffold with the pore size 270 μm, compressive strength 0.97 MPa, and porosity level 90%, was chosen as the optimum case for the bone tissue engineering (BTE) application. Furthermore, 99% antibacterial effect of the PLGA/10 wt.% TiO₂ nanocomposite scaffolds against the strain was achieved using Escherichia coli. Besides, no negative effect of the new method was observed on the bioactivity behavior and apatite forming ability of scaffolds in the simulated body fluid (SBF). This nanocomposite also displayed a good cytocompatibility when assayed with MG 63 cells. Lastly, the nanocomposite scaffolds revealed the capability to degrade methylene blue (MB) dye by nearly 90% under the UV irradiation for 3 hours. Based on the results, nanocomposite new scaffolds are proposed as a promising candidate for the BTE applications as a replacement for the previous ones.