Institute for Multiphase Processes, Leibniz University Hannover, An der Universität 1, Building 8143, 30823 Garbsen, Germany.
Lower Saxony Centre for Biomedical Engineering, Implant Research and Development, Stadtfelddamm 34, 30625 Hannover, Germany.
Int J Mol Sci. 2021 Mar 18;22(6):3096. doi: 10.3390/ijms22063096.
Alginate as a versatile naturally occurring biomaterial has found widespread use in the biomedical field due to its unique features such as biocompatibility and biodegradability. The ability of its semipermeable hydrogels to provide a favourable microenvironment for clinically relevant cells made alginate encapsulation a leading technology for immunoisolation, 3D culture, cryopreservation as well as cell and drug delivery. The aim of this work is the evaluation of structural properties and swelling behaviour of the core-shell capsules for the encapsulation of multipotent stromal cells (MSCs), their 3D culture and cryopreservation using slow freezing. The cells were encapsulated in core-shell capsules using coaxial electrospraying, cultured for 35 days and cryopreserved. Cell viability, metabolic activity and cell-cell interactions were analysed. Cryopreservation of MSCs-laden core-shell capsules was performed according to parameters pre-selected on cell-free capsules. The results suggest that core-shell capsules produced from the low viscosity high-G alginate are superior to high-M ones in terms of stability during in vitro culture, as well as to solid beads in terms of promoting formation of viable self-assembled cellular structures and maintenance of MSCs functionality on a long-term basis. The application of 0.3 M sucrose demonstrated a beneficial effect on the integrity of capsules and viability of formed 3D cell assemblies, as compared to 10% dimethyl sulfoxide (DMSO) alone. The proposed workflow from the preparation of core-shell capsules with self-assembled cellular structures to the cryopreservation appears to be a promising strategy for their off-the-shelf availability.
海藻酸盐作为一种多功能的天然生物材料，由于其生物相容性和可生物降解性等独特特性，在生物医学领域得到了广泛的应用。其半透性水凝胶能够为临床相关细胞提供有利的微环境，这使得海藻酸盐包封成为免疫隔离、3D 培养、冷冻保存以及细胞和药物输送的主要技术。本工作的目的是评估用于封装多能基质细胞（MSCs）的核壳胶囊的结构特性和溶胀行为，以及使用慢速冷冻对其进行 3D 培养和冷冻保存。使用同轴静电纺丝将细胞封装在核壳胶囊中，培养 35 天并进行冷冻保存。分析了细胞活力、代谢活性和细胞间相互作用。根据无细胞胶囊预选的参数对载有 MSCs 的核壳胶囊进行冷冻保存。结果表明，与高粘高 G 海藻酸盐相比，低粘高 G 海藻酸盐生产的核壳胶囊在体外培养过程中的稳定性方面优于高 M 海藻酸盐，在促进活细胞自组装结构的形成和长期维持 MSCs 功能方面优于固体珠。与单独使用 10%二甲基亚砜（DMSO）相比，0.3 M 蔗糖的应用对胶囊的完整性和形成的 3D 细胞组装的活力具有有益的影响。从制备具有自组装细胞结构的核壳胶囊到冷冻保存的提出的工作流程似乎是一种有前途的策略，可实现其即拿即用。
