Proanthocyanins-capped biogenic TiO2 nanoparticles with enhanced penetration, antibacterial and ROS mediated inhibition of bacteria proliferation and biofilm formation: A comparative approach.

The biofunctionalized TiO2 NPs, having a size range of 18.42 ± 1.3 nm were synthesized employing single step approach employing Grape seed extract (GSE) mediated proanthocyanins (PACs) polyphenols. The present study purposes to examine the effect of PACs rich GSE corona on (i) the stability and dispersity of GSE-TiO 2 -NPs, their (ii) anti-proliferative and anti-biofilm efficacy and (iii) propensity of internalization and reactive oxygen species (ROS) generation in P. aeruginosa and  S. saprophyticus strains. The state-of-the-art techniques were used to validate NPs formation. The comparative FTIR spectral analysis demonstrated that PACs linked functional -OH groups likely played a central role in Ti 4+ reduction, nucleation, formation and stability of GSE-TiO 2 -NPs. The TEM and ICP-MS analyses confirmed there was significantly (p < 0.05) enhanced intracellular uptake of GSE-TiO 2 -NPs in tested uropathogens as compare to bare TiO 2 -NPs. Correspondingly, compared to bare NPs, GSE-TiO 2 -NPs induced intracellular ROS formation that corresponded well with dose-dependent inhibitory patterns of cell proliferation and biofilm formation in both the tested strains. Overall, this study demonstrates that -OH rich PACs of GSE corona on biogenic TiO 2 -NPs maximized the functional stability, dispersity and propensity of penetration into planktonic cells and biofilm matrices; albeit, such unique merits warranted the GSE-TiO 2 -NPs as a novel, functionally stable and efficient antibacterial nanoformulation to combat with UTIs menace in clinical settings.