Lin S Y, Duan K J, Lin T C
Department of Medical Research, Veterans General Hospital-Taipei, Taiwan, ROC.
Biomed Mater Eng. 1995;5(1):9-20.
The structural changes in the lipid of the excised skin of nude mice and the porcine stratum corneum was investigated by in vitro treatment with vitamin C, oleic acid, or DMSO. The CH2 stretching vibrational peaks of lipid near 2920 cm-1 (asymmetric) and 2850 cm-1 (symmetric) shifted to higher wavenumber due to the lipid-disorder after in vitro treatment with above enhancers. The spectral shift of the asymmetric CH2 band was more sensitive than that of the symmetric CH2 band. The higher wavenumber of CH2 stretching bands decreased gradually to the lower region after co-treatment or posttreatment with pyrrolidone carboxylate sodium (PCA Na). Such a decrease was dependent on the PCA Na concentration and the time of treatment. The higher the concentration of PCA Na used, the lower value of the permeability coefficient of vitamin C through the excised skin and the downward spectral shift of asymmetric CH2 band were obtained. When PCA Na coexisted with vitamin C in the cell donor compartment, a competitive effect between PCA Na and vitamin C was found. The oleic acid was supposed to directly insert it into the lipid structure to form a rigid structure, leading to larger spectral shift of both stretching bands but lesser restoring ability after PCA Na treatment. However, DMSO only displaces water from the lipid head groups and protein domain of skin to indirectly loosen the lipid structure, resulting in lesser spectral shift of the CH2 stretching bands to higher region, which was easier and better restoration after PCA Na application. The PCA Na enabled to restore the disordered lipid structure to order state might be attributed to PCA Na previously penetrated into skin and then absorbed water to directly or indirectly rearrange the disordered lipid bilayer structure.
通过用维生素C、油酸或二甲基亚砜（DMSO）进行体外处理，研究了裸鼠切除皮肤和猪角质层脂质的结构变化。在用上述增强剂进行体外处理后，由于脂质无序化，脂质在2920 cm-1（不对称）和2850 cm-1（对称）附近的CH2伸缩振动峰向更高波数移动。不对称CH2带的光谱位移比对称CH2带更敏感。在用吡咯烷酮羧酸钠（PCA Na）共同处理或后处理后，CH2伸缩带的较高波数逐渐降低到较低区域。这种降低取决于PCA Na的浓度和处理时间。使用的PCA Na浓度越高，维生素C通过切除皮肤的渗透系数值越低，不对称CH2带的光谱向下位移越大。当PCA Na与维生素C在细胞供体隔室中共存时，发现PCA Na与维生素C之间存在竞争效应。油酸被认为直接插入脂质结构中形成刚性结构，导致两个伸缩带的光谱位移更大，但在PCA Na处理后的恢复能力较小。然而，DMSO只是从皮肤的脂质头部基团和蛋白质结构域中置换出水，从而间接使脂质结构松弛，导致CH2伸缩带向更高区域的光谱位移较小，在应用PCA Na后更容易且更好地恢复。PCA Na能够将无序的脂质结构恢复到有序状态，这可能归因于PCA Na先前渗透到皮肤中，然后吸收水分以直接或间接重新排列无序的脂质双层结构。
