Department of Industrial Engineering, Biotech Research Center, University of Trento , Trento, Italy .
European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Trento, Italy .
Tissue Eng Part C Methods. 2018 Jan;24(1):20-31. doi: 10.1089/ten.tec.2017.0258. Epub 2017 Nov 6.
Cell encapsulation in hydrogels is a technique that offers a variety of applications, ranging from drug delivery to biofabrication of three-dimensional scaffolds. The assembly of cell-laden hydrogel building blocks aims to generate complex biological constructs by manipulating microscale units. An important issue for the clinical implementation of this technique is the long-term storage of a large stock of cell/hydrogel building blocks. In this work, the impact of cryopreservation on the viability and functionality of cells encapsulated in alginate matrices is presented comparing different cryoprotective agents (CPAs). Human osteosarcoma MG63 cells were encapsulated in sodium alginate fiber constructs with wetspinning method and exposed to different formulations of cryopreservation media, containing dimethyl sulfoxide (DMSO), glycerol, and trehalose. The cell-laden fibers were subsequently slow-cooled down to -80°C and stored in liquid nitrogen. After thawing, viability and death pathway of encapsulated cells were investigated, and metabolic activity and proliferative capacity of cells released from the alginate matrix were evaluated. The viability of MG63 cells encapsulated in alginate matrix ranged from 71% ± 4% to 85% ± 2%, depending on the cryoprotective media formulation with no protracted harmful effects from the CPAs. On the other side, cells cryopreserved in encapsulated conditions and released from the hydrogel showed larger metabolic activity and proliferative capacity in tissue culture plate compared to cells cryopreserved in suspension, in particular when DMSO and glycerol were used as CPAs. Results have been correlated with the viscoelastic properties and water content changes of the alginate constructs loaded with the different CPAs.
细胞水凝胶包封是一种提供了多种应用的技术，从药物输送到三维支架的生物制造。载细胞水凝胶构建块的组装旨在通过操纵微尺度单元来生成复杂的生物结构。该技术临床实施的一个重要问题是大量细胞/水凝胶构建块的长期储存。在这项工作中，比较了不同的冷冻保护剂 (CPA)，研究了冷冻保存对包封在藻酸盐基质中的细胞活力和功能的影响。用人骨肉瘤 MG63 细胞通过湿法纺丝方法包封在海藻酸钠纤维构建体中，并暴露于含有二甲亚砜 (DMSO)、甘油和海藻糖的不同冷冻保存培养基配方中。随后将载细胞纤维缓慢冷却至-80°C 并储存在液氮中。解冻后，研究了包封细胞的活力和死亡途径，并评估了从藻酸盐基质中释放的细胞的代谢活性和增殖能力。海藻酸钠基质中包封的 MG63 细胞的活力范围为 71%±4%至 85%±2%，这取决于冷冻保护剂介质配方，CPA 没有产生长期的有害影响。另一方面，与悬浮液中冷冻保存的细胞相比，在封装条件下冷冻保存并从水凝胶中释放的细胞在组织培养板中显示出更大的代谢活性和增殖能力，特别是当 DMSO 和甘油用作 CPA 时。结果与不同 CPA 负载的藻酸盐构建体的粘弹性特性和含水量变化相关。
