PDF(Pubmed)
Abstract：
Cross-linking chitosan at room and subzero temperature using a series of diglycidyl ethers of glycols (DEs)-ethylene glycol (EGDE), 1,4-butanediol (BDDE), and poly(ethylene glycol) (PEGDE) has been investigated to demonstrate that DEs can be a more powerful alternative to glutaraldehyde (GA) for fabrication of biocompatible chitosan cryogels with tunable properties. Gelation of chitosan with DEs was significantly slower than with GA, allowing formation of cryogels with larger pores and higher permeability, more suitable for flow-through applications and cell culturing. Increased hydration of the cross-links with increased DE chain length weakened intermolecular hydrogen bonding in chitosan and improved cryogel elasticity. At high cross-linking ratios (DE:chitosan 1:4), the toughness and compressive strength of the cryogels decreased in the order EGDE > BDDE > PEGDE. By varying the DE chain length and concentration, permeable chitosan cryogels with elasticity moduli from 10.4 ± 0.8 to 41 ± 3 kPa, toughness from 2.68 ± 0.5 to 8.3 ± 0.1 kJ/m3, and compressive strength at 75% strain from 11 ± 2 to 33 ± 4 kPa were fabricated. Susceptibility of cryogels to enzymatic hydrolysis was identified as the parameter most sensitive to cross-linking conditions. Weight loss of cryogels increased with increased DE chain length, and degradation rate of PEGDE-cross-linked chitosan decreased 612-fold, when the cross-linker concentration increased 20-fold.
摘要：
使用一系列二缩水甘油醚的乙二醇（DEs）-乙二醇（EGDE），在室温和零度以下的温度下交联壳聚糖，1,4-丁二醇(BDDE),和聚（乙二醇）（PEGDE）已经进行了研究，以证明DE可以是戊二醛（GA）的更强大的替代品，用于制造具有可调特性的生物相容性壳聚糖冻凝胶。壳聚糖与DEs的凝胶化明显慢于GA，允许形成具有更大孔隙和更高渗透性的冷冻凝胶，更适合流通应用和细胞培养。随着DE链长度的增加，交联的水合作用增加，削弱了壳聚糖中的分子间氢键，并改善了冷冻凝胶的弹性。在高交联比（DE：壳聚糖1：4）下，低温凝胶的韧性和抗压强度按EGDE>BDDE>PEGDE的顺序降低。通过改变DE链的长度和浓度，渗透性壳聚糖冷冻凝胶，弹性模量为10.4±0.8至41±3kPa，韧性为2.68±0.5至8.3±0.1kJ/m3，在75％应变下的抗压强度为11±2至33±4kPa。冷冻凝胶对酶促水解的敏感性被确定为对交联条件最敏感的参数。低温凝胶的重量损失随着DE链长度的增加而增加，PEGDE交联壳聚糖的降解率下降了612倍，当交联剂浓度增加20倍时。
