Department of Industrial Engineering, INSTM Research Unit Tor Vergata, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome, Italy.
J Mater Sci Mater Med. 2012 Oct;23(10):2553-62. doi: 10.1007/s10856-012-4714-3. Epub 2012 Jul 17.
Magnesium alloys represent a valuable option for the production of bioresorbable implantable medical devices aimed to improve the therapeutic approach and minimize the potential risks related to biostable materials. In this regard, the degradation process needs to be carefully evaluated in order to assess the effectiveness of the regenerative support and the eventual toxic effects induced by the released corrosion products. Aluminium is one of the most common alloying element that raised several safety concerns, contributing to shift the investigation toward Al-free alloys. To delve into this issue, a long-term investigation (up to 28 days) was performed using AZ91D alloy, due to its relevant Al content. Immersion tests in phosphate buffered saline (PBS) solution was performed following the ASTM standards and the corrosion behaviour was evaluated at fixed time points by means of electrochemical techniques. Cytotoxic effects were assessed by culturing human neuroblastoma cells with conditioned medium derived from immersion tests at different dilution degree. An increase in the resistance corrosion with the time was observed. In all the investigated cases the presence of Al in the conditioned media did not induce significant toxic effects directly correlated to its content. A decrease of cell viability was only observed in the case of 50 % dilution of PBS conditioned for the longest immersion period (i.e., 28 days).
镁合金是一种有价值的选择，可用于生产生物可吸收的植入式医疗器械，旨在改善治疗方法并最大程度降低与生物稳定材料相关的潜在风险。在这方面，需要仔细评估降解过程，以评估再生支持的有效性和由释放的腐蚀产物引起的潜在毒性作用。铝是最常见的合金元素之一，它引起了一些安全问题，促使人们研究不含铝的合金。为了深入研究这个问题，我们对 AZ91D 合金进行了长达 28 天的长期研究，因为它含有一定量的铝。根据 ASTM 标准，在磷酸盐缓冲盐水（PBS）溶液中进行了浸出试验，通过电化学技术在固定时间点评估了腐蚀行为。通过用浸出试验得到的条件培养基培养人神经母细胞瘤细胞，评估了细胞毒性作用。随着时间的推移，观察到腐蚀电阻的增加。在所有研究的情况下，条件培养基中铝的存在并没有因其含量而直接引起明显的毒性作用。仅在最长浸出时间（即 28 天）的 PBS 条件下稀释 50%时观察到细胞活力下降。
