JHS Biomaterials, Rua Ouro Branco 345, Novo Alvorada, Sabará, Minas Gerais, CEP, 34650-120, Brazil; Universidade Federal de Minas Gerais, Escola de Engenharia, Departamento de Engenharia Metalúrgica e de Materiais, Bloco 2, Sala 2233, Avenida Presidente Antônio Carlos 6627, Pampulha, Belo Horizonte, Minas Gerais, CEP, 31270-901, Brazil.
JHS Biomaterials, Rua Ouro Branco 345, Novo Alvorada, Sabará, Minas Gerais, CEP, 34650-120, Brazil.
Appl Radiat Isot. 2021 Aug;174:109758. doi: 10.1016/j.apradiso.2021.109758. Epub 2021 May 1.
In this work, gamma sterilization was validated, and the impact of this sterilization process on collagen/hydroxyapatite (Col/HAp) composites was investigated. It has been already recognized that the improper sterilization of healthcare products may lead to infection and mortality/morbidity issues in patients. Gamma sterilization has emerged as a promising sterilization method because it shows advantages such as low cost, a small increase in temperature of irradiated materials, and no production of toxic residues. Moreover, gamma rays can reach the products even when contained in sealed packages. The dose of gamma radiation applied in this study ranged from 17.5 to 50 kGy. The studied samples were examined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), and differential scanning calorimetry (DSC). No apparent effect of gamma radiation on HAp was observed even when doses as high as 50 kGy were applied. On the other hand, Col was greatly affected by gamma radiation, displaying cross-linking and degradation after sterilization. These structural changes may alter Col's properties, which could, in turn, impact its medical use. As a consequence, it is strongly recommended that the irradiation dose used to sterilize the Col/HAp composites shall be kept as low as possible to mitigate the structural changes induced in Col. It was noticed that a radiation dose of 17.5 kGy was sufficient to sterilize the examined samples because a sterility assurance level (SAL) below 10 was detected. Although dramatic structural changes were observed in Col when this dose was applied, the sterilized samples showed no toxicity to human mesenchymal stem cells. Based on these results, we established a VD of 17.5 kGy for Col/HAp-based healthcare products.
在这项工作中，伽马灭菌得到了验证，并研究了该灭菌过程对胶原/羟基磷灰石（Col/HAp）复合材料的影响。已经认识到，医疗保健产品的不当灭菌可能导致患者感染和死亡/发病问题。伽马灭菌已成为一种有前途的灭菌方法，因为它具有成本低、辐照材料温度升高小、无有毒残留物产生等优点。此外，伽马射线甚至可以穿透密封包装的产品。本研究中应用的伽马辐射剂量范围为 17.5 至 50 kGy。通过 X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、热重分析（TG）和差示扫描量热法（DSC）对研究样品进行了检查。即使应用高达 50 kGy 的剂量，也没有观察到伽马辐射对 HAp 的明显影响。另一方面，Col 受到伽马辐射的极大影响，在灭菌后发生交联和降解。这些结构变化可能会改变 Col 的性质，从而影响其在医学上的应用。因此，强烈建议用于对 Col/HAp 复合材料进行灭菌的辐照剂量应尽可能低，以减轻 Col 中诱导的结构变化。人们注意到，17.5 kGy 的辐射剂量足以对检查样品进行灭菌，因为检测到的无菌保证水平（SAL）低于 10。尽管当应用此剂量时在 Col 中观察到剧烈的结构变化，但灭菌样品对人骨髓间充质干细胞没有毒性。基于这些结果，我们为基于 Col/HAp 的医疗保健产品建立了 17.5 kGy 的 VD。
