In vitro and preliminary in vivo assessment of anodized Mg-based alloy as a potential material for biomedical applications

MERLO, JULIETA; KATUNAR, M.R.; SALEMME ALONSO, L.; CARRIZO, SABRINA

Mar del Plata

Congreso; LXIII Reunión Anual de la Sociedad Argentina de Investigación Clínica; 2018

SAIC ? SAI ? SAFIS

Magnesium (Mg)-based alloys are promising candidates for the development of newbiodegradable materials for fracture repair implants. However, the high degradation rate of Mg inaqueous media releases hydrogen gas, which causes pain and local swelling. Superficialtreatments, such as anodization, emerge as a potential solution to this limitation. The aims of thisstudy were to evaluate the 1) in vitro citocompatibility of anodized Mg-based material onfibroblasts, and 2) the in vivo osteoconductivity of anodized Mg-based implants after 7 days ofimplantation in a rat model. Anodization of Mg alloy (AZ91) pieces was performed at low voltagefor 40 min in potassium hydroxide solution. For the objective 1, bovine fibroblasts were seeded onthe materials (anodized or control -without anodization- AZ91 square pieces) and as cellularcontrol, cells were cultured without material (on plastic). Cellular adhesion and proliferation wereevaluated after 24 h. For objective 2, adult male rats received two implants (anodized AZ91 orcontrol ?polylactic acid, PLA; biodegradable material used clinically- pins), placed transversely onein each medial area of the femur. At 1 and 6 days after surgery, different fluorochromes wereadministered intraperitoneally, to be incorporated at mineralization sites of the new bone. Ratswere sacrificed 7 days after implantation and femurs were retrieved, cleaned, fixed and embeddedin polymethyl methacrylate (PMMA) blocks. Fluorescence and Toluidine blue staining wasobserved on thin sections (150 µm) of the implanted area of each block. In the in vitro test, anincreased adhesion and proliferation of bovine fibroblasts was observed in the anodized pieces,compared with controls. The in vivo preliminary results indicated a higher osteoinductivity of theMg-based pins, compared with PLA pins, at the site of implantation. In conclusion, anodization atlow voltage is a promising superficial treatment for the development of Mg- based biomedicalapplications