Multifunctional polydopamine - Zn²⁺-curcumin coated additively manufactured ceramic bone grafts with enhanced...

The lack of site-specific chemotherapeutic agents after osteosarcoma surgeries often induces severe side effects. We propose the utilization of curcumin as an alternative natural chemo-preventive drug for tumor-specific delivery systems with 3D printed tricalcium phosphate (TCP) based artificial bone grafts. The poor bioavailability and hydrophobic nature of curcumin restrict its clinical use. We have used polydopamine (PDA) coating with Zn²⁺ functionalization to enhance the curcumin release in the biological medium. The obtained PDA-Zn²⁺ complex is characterized by X-ray photoelectron spectroscopy (XPS). The presence of PDA-Zn²⁺ coating leads to ~2 times enhancement in curcumin release. We have computationally predicted and validated the optimized surface composition by a novel multi-objective optimization method. The experimental validation of the predicted compositions indicates that the PDA-Zn²⁺ coated curcumin immobilized delivery system leads to a ~12 folds decrease in osteosarcoma viability on day 11 as compared to only TCP. The osteoblast viability shows ~1.4 folds enhancement. The designed surface shows the highest ~90 % antibacterial efficacy against gram-positive and gram-negative bacteria. This unique strategy of curcumin delivery with PDA-Zn²⁺ coating is expected to find application in low-load bearing critical-sized tumor-resection sites.