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

MERLO, J.L; KATUNAR M.R.; SALEMME ALONSO L.; CARRIZO S.; TANO DE LA HOZ, M.F.; CANIZO J.; GOMEZ SANCHEZ A.; CERÉ, S.M.

Mar del Plata

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

SAIC

Magnesium (Mg)-based alloys are promising candidates for the development of newbiodegradable materials for fracture repair implants. However, the high Degradation rate of Mg in aqueous media releases hydrogen gas, which causes pain and local swelling. Superficial treatments, such as anodization, emerge as a potential solution to this limitation. The aims of this study 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 of implantation in a rat model. Anodization of Mg alloy (AZ91) pieces was performed at low voltage for 40 min in potassium hydroxide solution. For the objective 1, bovine fibroblasts adhesion and proliferation were evaluated after 24 h in culture on the materials (anodized or control -without anodization- AZ91 pieces). As cellular control, cells growth was evaluated inculture without material (on a plastic dish). For objective 2, bone formation stimulation of anodized AZ91 or control ?polylactic acid, PLA; a biodegradable material used clinically- was evaluated in adult male rats; two pins of the same material were placed transversely one in each femur. At 1 and 6 days after surgery, different fluorochromes were administered intraperitoneally, to be incorporated at mineralization sites of the new bone. Rats were sacrificed7 days after implantation and femurs were retrieved, cleaned, fixed and embedded in polymethyl methacrylate. Fluorescence and Toluidine blue staining were observed on thin sections (150 μm) of the implanted area. In the in vitro test, an increase in bovine fibroblasts adhesion and proliferation was detected over the anodized surfaces pieces, compared with controls. The in vivo preliminary results suggest a higher osteoinductivity of the Mg-based pins, compared with PLA pins. In conclusion, anodization at low voltage is a promising superficialtreatment for the development of Mg- based biomedical applications.