Melting and swelling behaviors of UV-irradiated gelatin gel microcapsules.
Melting and swelling behaviors of UV-irradiated gelatin gel microcapsules.
复制标题
紫外线照射明胶凝胶微胶囊的熔化和溶胀行为。
作者：
Takao Yamamoto;Michiru Koike;T. Dobashi
采用SPG（Shirasu porous glass）乳化法和紫外光交联法制备了用于再生治疗的窄粒径分布明胶凝胶微胶囊，并观察了微胶囊凝胶膜的熔融和溶胀行为。凝胶熔化温度与紫外光照射时间t的2/3次方成正比，当t ≤ 1 h时，凝胶熔化温度与2/3次方成正比，当t ≥ 1 h时，凝胶熔化温度与2/3次方成正比。保持不溶的微胶囊的平均横截面积通过在25 ° C下的平均横截面积标准化而随温度单调增加，持续t<或=1小时。然后在高温下持续t ≥ 1 h后，其值下降，达到最小值，然后升高。在两个温度（25和40摄氏度）之间重复淬火的凝胶微胶囊诱导可逆的尺寸变化，这是由于局部胶原分子的螺旋-卷曲转变。从凝胶颗粒的理论考虑，很好地解释了所观察到的凝胶熔融行为，并将微胶囊的标度体积表示为标度温度的函数，其中t ≤ 1 h有四个拟合参数。
Gelatin gel microcapsules with a narrow size distribution have been prepared for the use of regenerative therapy by means of SPG (Shirasu porous glass) emulsification and UV-induced cross linking, and the melting and swelling behaviors of the gel membrane of the microcapsules were observed. The gel melting temperature was proportional to the 2/3 power of UV irradiation time t for t<or=1 h and deviated from the 2/3 power behavior for t>or=1 h. The average cross-sectional area of the microcapsules that remains insoluble normalized by that at 25 degrees C monotonically increased with temperature for t<or=1 h. It then decreased, passed a minimum, and increased at high temperature for t>or=1 h. Repeated quenching of the gel microcapsules between two temperatures (25 and 40 degrees C) induced a reversible size change, which was attributed to the helix-coil transition of collagen molecules locally. From a theoretical consideration of gel particles, the observed gel melting behavior was explained well, and the scaled volume of the microcapsules was expressed as a function of scaled temperature with four fitting parameters for t<or=1 h.