Preliminary in vitro evaluation of biological responses associated with an Elumbotti-derived coating on titanium cortical screws

The biological response to coating-derived components is an important consideration in the preliminary development of functionalized titanium implants. In the present study, an Elumbotti ( Ormocarpum cochinchinense )-derived composite coating was applied to titanium cortical screws (12 mm), and its preliminary in vitro biological response was investigated using a cell-free protein-denaturation assay and MG-63 osteoblast-like cells. Uncoated titanium (T1) and Elumbotti-coated titanium cortical screw samples (ST1) were included in the experimental evaluation. Bovine serum albumin (BSA) protein-denaturation inhibition was assessed as a preliminary cell-free measure of protein-stabilizing activity, with diclofenac sodium used as the reference standard. MG-63 cellular responses were evaluated using MTT viability, scratch-wound closure, and acridine orange/ethidium bromide (AO/EtBr) fluorescence staining assays. The MTT assay evaluated concentration-dependent responses to the ST1 test preparation, whereas the scratch-wound and AO/EtBr assays evaluated cellular responses following exposure to conditioned medium obtained from ST1-coated titanium cortical screws. ST1 demonstrated greater BSA protein-denaturation inhibitory activity than T1, with calculated IC ₅₀ values of 63.032 and 118.379 µg/mL, respectively. In the MTT assay, MG-63 viability showed a concentration-dependent response to the ST1 test preparation, remaining above 70% at concentrations up to 32 µg/mL and decreasing below 70% at concentrations of 64 µg/mL and above. Scratch-wound closure following exposure to ST1-conditioned medium increased from 67.07% at 24 h to 83.45% at 48 h, compared with 27.24% and 34.50%, respectively, in untreated control cells. AO/EtBr staining demonstrated time-dependent changes in cell viability and membrane integrity following prolonged exposure to ST1-conditioned medium. Overall, the findings provide preliminary evidence of concentration- and time-dependent biological responses associated with the Elumbotti-derived coating system and its soluble components. However, the present assays do not establish direct cell–coating interactions, cellular anti-inflammatory activity, osteogenic differentiation, osseointegration, or improved orthopedic implant performance. Further batch-specific physicochemical characterization, direct cell–surface studies, coating stability and release analyses, osteogenic and inflammatory-marker evaluation, and in vivo investigation are required to establish the biological and functional relevance of the coating for orthopedic applications.