Layered double hydroxide-8HQ/CA composite coating with spin-coated bioactive glass for bioactivity and corrosion resistance of magnesium alloy WE43

Bioactive glass (BG) was spin-coated onto Layered double hydroxide /citric acid intercalated with 8-hydroxyquinoline (LDHCA8HQ) to develop a multi-functional coating with enhanced bioactivity and corrosion resistance. Mg-Fe LDH was prepared via electrodeposition of oxidized WE43 at -1.4 VSCE for 300s in an aqueous solution with pH 3.0, adjusted using 1.0 M nitric acid HNO3. The LDH coating was modified with citric acid (CA) and intercalated with 8-hydroxyquinoline (8HQ), following a previous method. A BG (45S5) solution was prepared and spin-coated onto the LDHCA8HQ sample at 2500 rpm for 30s, followed by drying at 200 ºC for 15 minutes, repeated three times, and then annealed at 250 ºC for 2 hours to obtain the final LDHCA8HQBG sample. The XRD analysis exhibits an amorphous glass-ceramic phase, indicating BG incorporation. The nanoindentation analysis with reduced elastic modulus and hardness demonstrates values closer to that of human bone and electrochemical testing confirms BG as an effective insulating layer. The surface morphology examination revealed the supported attachment of human bone marrow-derived stromal cells (hBMSCs), which maintained its ideal spindle shape. LDHCA8HQBG induced a higher proliferation rate and osteoinduction properties, comparable with commercial bone graft, suggesting its potential application in bone tissue engineering.