Akkineni Ashwini Rahul, Elci Bilge Sen, Lode Anja, Gelinsky Michael
Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus, Faculty of Medicine of Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany.
Gels. 2022 Mar 23;8(4):199. doi: 10.3390/gels8040199.
Long-term stability of gellan gum (GG) at physiological conditions is expected, as very low concentration of divalent ions are required for crosslinking, as compared to alginate—which is extensively used for tissue engineering (TE) applications. Hence, GG is proposed as an ideal candidate to substitute alginate for TE. Deacylated (low acyl; LA) GG forms brittle gels, thus only low concentrations were used for cell encapsulation, whereas acylated (high acyl; HA) GG forms weak/soft gels. 3D bioprinting using pure LAGG or HAGG is not possible owing to their rheological properties. Here, we report development and characterization of bioprintable blends of LAGG and HAGG. Increase in HAGG in the blends improved shear recovery and shape fidelity of printed scaffolds. Low volumetric swelling observed in cell culture conditions over 14 days indicates stability. Volumetric scaffolds were successfully printed and their mechanical properties were determined by uniaxial compressive testing. Mesenchymal stem cells bioprinted in blends of 3% LAGG and 3% HAGG survived the printing process showing >80% viability; a gradual decrease in cell numbers was observed over 21 days of culture. However, exploiting intrinsic advantages of 3D bioprinting, LAGG/HAGG blends open up numerous possibilities to improve and/or tailor various aspects required for TE.
与广泛用于组织工程（TE）应用的藻酸盐相比，结冷胶（GG）在生理条件下有望具有长期稳定性，因为其交联所需的二价离子浓度非常低。因此，GG被认为是替代藻酸盐用于TE的理想候选材料。脱酰基（低酰基；LA）GG形成脆性凝胶，因此仅使用低浓度用于细胞封装，而酰化（高酰基；HA）GG形成弱/软凝胶。由于其流变学性质，使用纯LAGG或HAGG进行3D生物打印是不可能的。在此，我们报告了LAGG和HAGG生物可打印共混物的开发和表征。共混物中HAGG的增加改善了打印支架的剪切恢复和形状保真度。在细胞培养条件下14天内观察到的低体积膨胀表明具有稳定性。成功打印了体积支架，并通过单轴压缩测试确定了其机械性能。在3% LAGG和3% HAGG的共混物中生物打印的间充质干细胞在打印过程中存活，活力>80%；在21天的培养过程中观察到细胞数量逐渐减少。然而，利用3D生物打印的固有优势，LAGG/HAGG共混物为改善和/或定制TE所需的各个方面开辟了许多可能性。
