Bioactive Hydroxyapatite–Carboplatin–Quercetin Coatings for Enhanced Osteointegration and Antitumoral Protection in Hip Endoprostheses

The recurrence of bone cancer poses severe complications, particularly after orthopedic surgery, necessitating advanced biomaterials with dual functionality. This study develops nanostructured coatings composed of hydroxyapatite, carboplatin, and quercetin, designed to enhance bone regeneration while delivering localized cancer therapy. These coatings present a promising solution for hip endoprostheses, addressing osteointegration and tumor recurrence prevention simultaneously. Hydroxyapatite was synthesized and characterized using XRD, TEM, SAED, FTIR, and SEM to assess crystallinity, surface morphology, and functional groups. The coatings were obtained by MAPLE. In vitro biocompatibility tests showed that HAp@CPT and HAp@CPT/QUE coatings supported osteoblast viability and adhesion while exhibiting selective cytotoxic effects on osteosarcoma cells. The Griess assay indicated that nitric oxide (NO) levels remained unchanged in hFOB osteoblasts, confirming that neither coating induced inflammatory responses in healthy cells. In contrast, MG63 osteosarcoma cells exhibited significantly elevated NO levels (p < 0.05) in response to HAp@CPT/QUE, suggesting increased oxidative stress. MTT assay results showed a 12% and 28% reduction in osteosarcoma cell viability for HAp@CPT and HAp@CPT/QUE, respectively. Phase-contrast microscopy further confirmed strong osteoblast adhesion and reduced osteosarcoma attachment, particularly on HAp@CPT/QUE surfaces. These findings highlight the dual functionality of hydroxyapatite–carboplatin–quercetin coatings, promoting osteointegration while exerting localized anticancer effects. Their bone-regenerative and selective cytotoxic properties make them a promising material for hip endoprostheses in oncological orthopedic applications.