Laboratory of Biophysics, Department of Agrotechnology & Food Sciences, Wageningen University, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands.
Carbohydr Polym. 2013 Jun 5;95(1):515-21. doi: 10.1016/j.carbpol.2013.03.031. Epub 2013 Mar 16.
Hydration properties of semi-diluted hyaluronan were studied by means of time domain nuclear magnetic resonance. Based on the transverse proton relaxation times T2, the plasticization of hyaluronan which was precipitated by isopropylalcohol and dried in the oven have been determined at water content 0.4 g of water per g of hyaluronan. Above this water content, the relaxation times increased and levelled off around 0.8 g of water per g of hyaluronan which agrees well with values determined earlier by differential scanning calorimetry and dielectric relaxometry. The freeze dried and oven dried samples showed differences in their physical structure such as glass transition, plasticization concentration and sample topography which influenced their kinetics and mechanisms of hydration. Results confirmed earlier hypothesis that some native biopolymer structures can be easily modified by manipulation of preparation conditions, e.g. drying, giving fractions with specific physicochemical properties without necessity of their chemical modification.
通过时域核磁共振研究了半稀释透明质酸的水合性质。基于横向质子弛豫时间 T2，确定了在水合透明质酸中的水含量为 0.4 g/ g 时，通过异丙醇沉淀和在烘箱中干燥的透明质酸的增塑作用。在这个水含量以上，弛豫时间增加并在 0.8 g/ g 左右趋于稳定，这与先前通过差示扫描量热法和介电弛豫法确定的值吻合得很好。冷冻干燥和烘箱干燥的样品在玻璃化转变、增塑浓度和样品形貌等物理结构方面表现出差异，这些差异影响了它们的水合动力学和机制。结果证实了早先的假设，即一些天然生物聚合物结构可以通过操纵制备条件（例如干燥）很容易地进行修饰，从而获得具有特定物理化学性质的组分，而无需进行化学修饰。
