Laboratório de Biologia Celular, Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Rua Sarmento Leite 245, 90050-170 Porto Alegre, RS, Brazil.
Laboratório de Transformação Mecânica, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS, Brazil.
Mater Sci Eng C Mater Biol Appl. 2020 Oct;115:111129. doi: 10.1016/j.msec.2020.111129. Epub 2020 May 27.
Biodegradable metallic materials (BMMs) are expected to corrode gradually in vivo after providing the structural support to the tissue during its regeneration and healing processes. These characteristics make them promising candidates for use in stents. These endoprostheses are produced from metal alloys by casting and thermomechanical treatment. Since porous alloys and metals have less corrosion resistance than dense ones, the use of powder metallurgy becomes an option to produce them. Among the metals, iron has been proposed as a material in the manufacturing of stents because of its mechanical properties. However, even then it is unclear what toxicity threshold is safe to the body. Thus, the objective of this research was to verify the biocompatibility of sintered 99.95% and 99.5% pure iron by powder metallurgy in vitro with Adipose-derived mesenchymal stromal cells (ADSCs) and in vivo with a Wistar rat model. Herein, characterizations of iron powder samples produced by the powder metallurgy and the process parameters as compression pressure, atmosphere, sintering time and temperature were determined to evaluate the potential of production of biodegradable implants. The samples obtained from pure iron were submitted to tests of green and sintered density, porosity, microhardness, hardness and metallography. The biocompatibility study was performed by indirect and direct cell culture with iron. The effects of corrosion products of iron on morphology, viability, and proliferation of ADSCs were evaluated in vitro. Hemolysis assay was performed to verify the hemocompatibility of the samples. In vivo biocompatibility was evaluated after pure iron discs were implanted subcutaneously into the dorsal area of Wistar rats that were followed up to 6 months. The results presented in this paper validated the potential to produce biodegradable medical implants by powder metallurgy. Both iron samples were hemocompatible and biocompatible in vitro and in vivo, although the 99.95% iron had better performance in vitro than 99.5%.
可生物降解的金属材料（BMMs）有望在组织再生和愈合过程中为组织提供结构支撑后逐渐在体内腐蚀。这些特性使它们成为支架的理想候选材料。这些内假体是通过铸造和热机械处理由金属合金制成的。由于多孔合金和金属的耐腐蚀性比致密合金差，因此粉末冶金成为生产它们的一种选择。在金属中，由于其机械性能，铁已被提议用于制造支架。然而，即使在这种情况下，也不清楚对人体安全的毒性阈值是多少。因此，本研究的目的是通过体外脂肪间充质基质细胞（ADSCs）和体内 Wistar 大鼠模型来验证粉末冶金法制备的 99.95%和 99.5%纯铁的烧结体的生物相容性。在此，通过粉末冶金法确定了铁粉末样品的特性以及压缩压力、气氛、烧结时间和温度等工艺参数，以评估生产可生物降解植入物的潜力。从纯铁获得的样品进行了绿色和烧结密度、孔隙率、显微硬度、硬度和金相的测试。通过间接和直接的铁细胞培养进行了生物相容性研究。体外评估了铁腐蚀产物对 ADSCs 形态、活力和增殖的影响。进行了溶血试验以验证样品的血液相容性。将纯铁盘植入 Wistar 大鼠背部皮下后，在体内评估了生物相容性，随访时间为 6 个月。本文介绍的结果验证了通过粉末冶金生产可生物降解医疗植入物的潜力。两种铁样品在体外和体内均具有血液相容性和生物相容性，尽管 99.95%的铁在体外的性能优于 99.5%的铁。
