Cementos óseos acrílicos: desarrollo de nuevas formulaciones bioactivas y con actividad terapéutica

Introduction: Deficiencies associated with the classic formulations of poly(methyl methacrylate) (PMMA) bone cements and new applications in Orthopedics, Traumatology and Neurosurgery have encouraged the investigation of new formulations of bone cements with better properties. Methods: Synthesis of micrometric hydroxyapatite (MicroHA) derived from Coraline HAP-200O, nanometric hydroxyapatite (NanoHA) and bioglasses; silanization, matrix-filler coupling study; preparation of PMMA cements with ceramic fillers or drugs (single or combined); characterizations: FTIR, XRD, XPS, SEM-EDS, mechanical, bioactivity and microbiological. Results: Cements with hybrid fillers (MicroHA/NanoHA) with 30 %, 40 % and 50 % and different proportions (60:40; 55:45; 50:50) guaranteed mechanical properties, were bioactive and were non-cytotoxic in fibroblast cultures (L929) and osteoblasts (MC3T3-E1). The inclusion of silanized phosphate glass particles: 44,5 % CaO- 44,5 % P2O5-11 % Na2O and 44,5 % CaO-44,5 % P2O5 -6 % Na2O- 5 % TiO2 produced in vitro formation of a layer of hydroxycarbonate apatite precursor to direct long-term implant-bone binding. Simple antibiotic formulations (3,125 %) ciprofloxacin, cephalexin, ceftriaxone, meropenem, cefazolin and ceftazidime released therapeutic concentrations in vitro and maintained their elution for 8 months (long term). Combination of Ciprofloxacin/Meropenem and ciprofloxacin/ceftazidime in cements showed a greater antibacterial effect against Staphylococcus aureus and Pseudomonas aeruginosa than cements doped with Gentamicin (conventional antibiotic). Oleozon®, ciprofloxacin/meropenem and ciprofloxacin/meropenem/Oleozon® cements with 10 % ozonized oil reduce Pseudomonas aeruginosa cultures by 100 % for 11 days, which is an opportunistic germ that complicates orthopedic replacements and other bone injuries. Conclusions: This work proposes cements with bioactivity for a more durable bond to bone tissue and greater prosthetic durability, as well as acrylic cements with drugs with greater antibacterial effectiveness with no history in the literature.