Riedel Stefanie, Ward Daniel, Kudláčková Radmila, Mazur Karolina, Bačáková Lucie, Kerns Jemma G, Allinson Sarah L, Ashton Lorna, Koniezcny Robert, Mayr Stefan G, Douglas Timothy E L
Leibniz Institute of Surface Engineering (IOM), Permoserstraße 15, 04318 Leipzig, Germany.
Division of Surface Physics, Faculty of Physics and Earth Science, Leipzig University, Linnéstraße 5, 04103 Leipzig, Germany.
J Funct Biomater. 2021 Oct 8;12(4):57. doi: 10.3390/jfb12040057.
Biological hydrogels are highly promising materials for bone tissue engineering (BTE) due to their high biocompatibility and biomimetic characteristics. However, for advanced and customized BTE, precise tools for material stabilization and tuning material properties are desired while optimal mineralisation must be ensured. Therefore, reagent-free crosslinking techniques such as high energy electron beam treatment promise effective material modifications without formation of cytotoxic by-products. In the case of the hydrogel gelatin, electron beam crosslinking further induces thermal stability enabling biomedical application at physiological temperatures. In the case of enzymatic mineralisation, induced by Alkaline Phosphatase (ALP) and mediated by Calcium Glycerophosphate (CaGP), it is necessary to investigate if electron beam treatment before mineralisation has an influence on the enzymatic activity and thus affects the mineralisation process. The presented study investigates electron beam-treated gelatin hydrogels with previously incorporated ALP and successive mineralisation via incubation in a medium containing CaGP. It could be shown that electron beam treatment optimally maintains enzymatic activity of ALP which allows mineralisation. Furthermore, the precise tuning of material properties such as increasing compressive modulus is possible. This study characterizes the mineralised hydrogels in terms of mineral formation and demonstrates the formation of CaP in dependence of ALP concentration and electron dose. Furthermore, investigations of uniaxial compression stability indicate increased compression moduli for mineralised electron beam-treated gelatin hydrogels. In summary, electron beam-treated mineralized gelatin hydrogels reveal good cytocompatibility for MG-63 osteoblast like cells indicating a high potential for BTE applications.
生物水凝胶因其高生物相容性和仿生特性，是骨组织工程（BTE）中极具前景的材料。然而，对于先进的定制化骨组织工程而言，在确保最佳矿化的同时，还需要精确的材料稳定化工具和调节材料性能的方法。因此，诸如高能电子束处理等无试剂交联技术有望实现有效的材料改性，且不会形成细胞毒性副产物。就水凝胶明胶而言，电子束交联进一步诱导热稳定性，使其能够在生理温度下应用于生物医学领域。在碱性磷酸酶（ALP）诱导并由甘油磷酸钙（CaGP）介导的酶促矿化情况下，有必要研究矿化前的电子束处理是否会影响酶活性，进而影响矿化过程。本研究通过在含有CaGP的培养基中孵育，对预先掺入ALP并进行连续矿化的电子束处理明胶水凝胶进行了研究。结果表明，电子束处理能最佳地维持ALP的酶活性，从而实现矿化。此外，还可以精确调节材料性能，如提高压缩模量。本研究从矿物形成方面对矿化水凝胶进行了表征，并证明了磷酸钙的形成取决于ALP浓度和电子剂量。此外，单轴压缩稳定性研究表明，矿化的电子束处理明胶水凝胶的压缩模量有所增加。总之，电子束处理的矿化明胶水凝胶对MG-63成骨样细胞具有良好的细胞相容性，表明其在骨组织工程应用中具有很高的潜力。
