Design and Manufacturing of Multifunctional Hydroxyapatite-Coated Ti6Al4V Implants With Cissus quadrangularis

This study presents a novel approach to enhance the early-stage osseointegration of orthopedic implants through surface engineering. Lithium (Li), strontium (Sr), and silver (Ag)-doped hydroxyapatite (HA) were coated on Ti6Al4V substrates using RF induction based plasma spray coating and loaded with polydopamine (PD) and Cissus quadrangularis extract (CQE). The engineered coating integrates bioactive metal ions, drug-loaded polymer layers, and plant-derived osteogenic compounds to accelerate bone healing. Co-culture with mesenchymal stem cells and monocytes demonstrates that Li-Sr-Ag-doped HA upregulated key osteogenic markers, including alkaline phosphatase and bone gamma-carboxyglutamic acid-containing protein, while also modulating osteoclastic activity. An in vivo rat distal femur study demonstrated enhanced osteoid formation with the addition of CQE, promoting mineralized bone formation. We demonstrate that induction plasma spray can be used to design and manufacture doped HA coated implant with PD and CQE, thereby accelerating early stage osseointegration and providing a scalable, clinically translatable solution to enhance the performance of cementless orthopedic and dental implants.