Poly(ethylene glycol) cryogels as potential cell scaffolds: effect of polymerization conditions on cryogel microstructure and properties
Poly(ethylene glycol) cryogels as potential cell scaffolds: effect of polymerization conditions on cryogel microstructure and properties
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DOI：
10.1039/b917142h
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发表时间：
2010-01-01
影响因子：
--
通讯作者：
Varghese, Shyni
中科院分区：
文献类型：
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作者：
Hwang, Yongsung;Zhang, Chao;Varghese, Shyni
报道了用冷冻凝胶法合成和表征聚乙二醇大孔网络结构的方法。以单一前驱体为原料，通过控制其聚合动力学，得到了具有层状孔径梯度的新型整体网络。与冰晶成核相比，保持促进凝胶化速度的条件会导致形成传统的水凝胶状网络结构或包含水凝胶层和冷凝胶层的连续的非均相网络结构。相反，与凝胶化速度相比，促进冰晶成核速度更快的条件会导致冷冻机具有几乎均匀的相互连接的大孔网络。通过改变引发剂浓度、冻结温度和过冷度等不同参数，改变了冰晶的聚合和成核速度。与传统水凝胶相比，冷冻胶在断裂时表现出更高的应力和应变；其力学和平衡溶胀性能与网络结构有很强的相关性。细胞活性研究表明，这些支架对细胞附着及其分布没有不良影响。此外，在长期培养的冷冻机中，观察到软骨细胞增殖的时间依赖性增加。
We report the synthesis and characterization of interconnected macroporous network structures of poly(ethylene glycol) (PEG) using cryogelation techniques. Novel monolithic networks containing a gradient of pore size in a layered fashion were created from a single precursor by manipulating their polymerization kinetics. Maintaining conditions that promote the rate of gelation compared to that of the nucleation of ice crystals leads to formation of either conventional hydrogel-like network structures or continuous heterogeneous networks containing layers of hydrogel-like and cryogel-like microstructures. In contrast, conditions promoting a faster rate of the nucleation of ice crystals compared to rate of gelation result in cryogels with a nearly homogeneous interconnected macroporous network. The rates of polymerization and nucleation of ice crystals were altered using a number of different parameters such as concentration of initiator, freezing temperature, and degree of supercooling. Compared to conventional hydrogels, the cryogels exhibit higher stress and strain at break; their mechanical and equilibrium swelling properties show a strong correlation with the network microstructure. Cell viability studies suggest no detrimental effect of these scaffolds on cell attachment and their distribution. Furthermore, a time dependent increase in chondrocyte proliferation was observed in cryogels over a long period of culture.