The PI3K/AKT pathway is triggered when lipopolysaccharide (LPS) binds to TLR4 on the cell membrane. This causes the NF-κB complex to get phosphorylated and IKB to degrade, allowing NF-κB to go into the nucleus. Pro-inflammatory genes including interleukin-4 (IL-4), IL-6, and tumor necrosis factor α are triggered by this. NF-κB activation is further enhanced by LPS's simultaneous induction of oxidative stress, which produces reactive oxygen species (ROS) and byproducts like MDA. By breaking down the Keap1-Nrf2 complex, ROS releases Nrf2, which moves to the nucleus and attaches to the antioxidant response element to promote the production of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This activates the Nrf2 pathway to combat oxidative. The addition of TiO₂ nanoparticles (mono- and dual-doped) and adipose tissue mesenchymal stem cell (AD-MSC)-conditioned media modulates these pathways by reducing oxidative and inflammation, with AD-MSC bioactive factors and TiO₂ nanoparticles (NPs) synergistically enhancing the anti-inflammatory and antioxidant responses to restore cellular balance.

The fundamental purpose of this work is to determine the anti-inflammatory/antioxidant activity of stem cell conditioned medium enhanced by mono- or dual-doped TiO₂ nanoparticles. The transmission electron microscope, X-ray diffraction, and energy-dispersive X-ray analyses are used to characterize the nanoparticles. Isolation/characterization of adipose tissue mesenchymal stem cells (AD-MSCs) is done. In vitro assays reveal that protein denaturation and proteinase induction are significantly increased with lipopolysaccharide (LPS) comparable to control, while treatments significantly decrease the induction compared to LPS. In vitro assays reveal decreasing in hydroxyl radical scavenging and DPPH radical scavenging activities with LPS, while treatments significantly increase the activity compared to LPS. Induction with LPS decreases in vitro catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) expression levels and enzyme activities are significantly compared to controls, while treatments significantly increase the CAT expression compared to LPS. Induction with LPS increases the in vitro interleukin 4 (IL4), IL6, IL10, and tumor necrosis factor α expression levels, and their activities significantly decline with treatment compared to controls, while treatments significantly decline expression compared to LPS. The anti-inflammatory and antioxidant properties of AD-MSC-conditioned medium enhanced with mono- or dual-doped TiO₂ nanoparticles are identified in this investigation. To sum up, the work has shown that mono- and dual-doped TiO₂ can inhibit the inflammation caused by LPS in vitro.