Song Kedong, Yan Xinyu, Li Shixiao, Zhang Yu, Wang Hong, Wang Ling, Lim Mayasari, Liu Tianqing
a State Key Laboratory of Fine Chemicals, Dalian R&D Center for Stem Cell and Tissue Engineering, Dalian University of Technology , Dalian , China .
b Department of Orthopaedics , The First Affiliated Hospital, Dalian Medical University , Dalian , China .
J Microencapsul. 2015;32(8):811-9. doi: 10.3109/02652048.2015.1094533.
Calcium alginate microbeads have been widely used in tissue engineering application, due to their excellent biocompatibility, biodegradability, enhanced mechanical strength and toughness. Bone powder containing abundant hydroxylapatite, type I collagen and growth factors such as BMP2 and BMP4, possesses good osteoinductive activity. Herein, a hybrid calcium alginate/bone powder microbead was therefore prepared. Afterwards, different seeding density of adipose-derived stem cells (ADSCs) in these hybrid microbeads was discussed systematically for further in vitro expansion. Optimised microbeads suitable for in vitro expansion and differentiation of ADSCs were prepared using the droplet method under overall considering suitable concentrations of calcium alginate and calcium chloride as well as the density of bone powder through an orthogonal experiment. The results showed that the concentration of sodium alginate had the most influence on inside mass transfer and mechanical strength of the hybrid microbeads, secondly the calcium chloride, then the density of bone powder. The hybrid microbeads could be optimally performed while the concentrations of sodium alginate and calcium chloride were 2.5% and 4.5%, as well as 5.0 mg/mL bone powder, respectively. Live/Dead assay showed that the expanded ADSCs differentiated well with an initial embedding density of 5 × 10(6) cells/mL.
海藻酸钙微球因其优异的生物相容性、生物降解性、增强的机械强度和韧性，已被广泛应用于组织工程领域。含有丰富羟基磷灰石、I型胶原蛋白以及BMP2和BMP4等生长因子的骨粉具有良好的骨诱导活性。因此，本文制备了一种海藻酸钙/骨粉复合微球。随后，系统地探讨了这些复合微球中不同接种密度的脂肪来源干细胞（ADSCs）的体外进一步扩增情况。通过正交实验，在综合考虑海藻酸钠和氯化钙的合适浓度以及骨粉密度的情况下，采用液滴法制备了适合ADSCs体外扩增和分化的优化微球。结果表明，海藻酸钠浓度对复合微球的内部传质和机械强度影响最大，其次是氯化钙，然后是骨粉密度。当海藻酸钠和氯化钙的浓度分别为2.5%和4.5%，以及骨粉密度为5.0 mg/mL时，复合微球的性能最佳。活/死检测表明，初始接种密度为5×10(6) 个细胞/mL时，扩增后的ADSCs分化良好。
