i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.
INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.
Sci Rep. 2020 Nov 5;10(1):19098. doi: 10.1038/s41598-020-76063-9.
Bone graft infections are serious complications in orthopaedics and the growing resistance to antibiotics is increasing the need for antibacterial strategies. The use of magnesium oxide (MgO) is an interesting alternative since it possesses broad-spectrum antibacterial activity. Additionally, magnesium ions also play a role in bone regeneration, which makes MgO more appealing than other metal oxides. Therefore, a bone substitute composed of hydroxyapatite and MgO (HAp/MgO) spherical granules was developed using different sintering heat-treatment cycles to optimize its features. Depending on the sintering temperature, HAp/MgO spherical granules exhibited distinct surface topographies, mechanical strength and degradation profiles, that influenced the in vitro antibacterial activity and cytocompatibility. A proper balance between antibacterial activity and cytocompatibility was achieved with HAp/MgO spherical granules sintered at 1100 ºC. The presence of MgO in these granules was able to significantly reduce bacterial proliferation and simultaneously provide a suitable environment for osteoblasts growth. The angiogenic and inflammation potentials were also assessed using the in vivo chicken embryo chorioallantoic membrane (CAM) model and the spherical granules containing MgO stimulated angiogenesis without increasing inflammation. The outcomes of this study evidence a dual effect of MgO for bone regenerative applications making this material a promising antibacterial bone substitute.
骨移植感染是骨科的严重并发症，抗生素耐药性的不断增加增加了对抗菌策略的需求。氧化镁 (MgO) 的应用是一种很有前途的替代方法，因为它具有广谱的抗菌活性。此外，镁离子在骨再生中也发挥作用，这使得 MgO 比其他金属氧化物更具吸引力。因此，使用不同的烧结热处理循环开发了一种由羟基磷灰石和 MgO (HAp/MgO) 球形颗粒组成的骨替代物，以优化其特性。根据烧结温度的不同，HAp/MgO 球形颗粒表现出明显不同的表面形貌、机械强度和降解特性，这影响了体外的抗菌活性和细胞相容性。在 1100°C 烧结的 HAp/MgO 球形颗粒中实现了抗菌活性和细胞相容性之间的适当平衡。这些颗粒中 MgO 的存在能够显著抑制细菌增殖，同时为成骨细胞的生长提供适宜的环境。还使用体内鸡胚绒毛尿囊膜 (CAM) 模型评估了血管生成和炎症潜力，含有 MgO 的球形颗粒刺激了血管生成而没有增加炎症。这项研究的结果证明了 MgO 在骨再生应用中的双重作用，使这种材料成为一种有前途的抗菌骨替代物。
