Friess W, Lee G
Department of Pharmaceutical Technology, University of Erlangen, Germany.
Biomaterials. 1996 Dec;17(23):2289-94. doi: 10.1016/0142-9612(96)00047-6.
Insoluble collagen has been utilized as a base material for parenteral drug carrier systems. Information on its physicochemical properties was obtained by focussing on thermoanalytical methods. On the way from the raw material to the matrices, the acidic aqueous dispersion represents an important intermediate state. DSC and FTIR revealed its complete denaturation at 43 degrees C. Dense homogeneous collagen matrices were prepared by air-drying at 25 degrees C and became denatured at 103.5 degrees C, far above normal storage temperatures. Dielectrical Thermal Analysis demonstrated transitions in the dielectrical storage and loss moduli, reflecting the dissipation of electrical energy and increased molecular mobility caused by collapse of the triple helical structure. Cross-linking of the collagen dispersion with glutaraldehyde induced no alteration in the thermoanalytical properties of dry matrices. However, in the swollen state, after incubation of the devices in phosphate buffer the transition temperature increased from 50 to 70 degrees C as cross-linking was intensified. This indicated stronger interactions between the collagen fibre structures. Dissolution tests with cytochrome c-loaded matrices showed that higher amounts of the model protein were trapped inside the matrices as more glutaraldehyde was added.
不溶性胶原蛋白已被用作肠胃外给药载体系统的基础材料。通过聚焦热分析方法获得了其物理化学性质的信息。从原材料到基质的过程中，酸性水分散体代表了一个重要的中间状态。差示扫描量热法（DSC）和傅里叶变换红外光谱法（FTIR）显示其在43℃时完全变性。通过在25℃下空气干燥制备致密均匀的胶原蛋白基质，其在103.5℃时变性，远高于正常储存温度。介电热分析表明介电储能模量和损耗模量发生转变，反映了电能的耗散以及由三螺旋结构坍塌引起的分子流动性增加。胶原蛋白分散体与戊二醛交联不会改变干燥基质的热分析性质。然而，在肿胀状态下，将装置在磷酸盐缓冲液中孵育后，随着交联增强，转变温度从50℃升高到70℃。这表明胶原蛋白纤维结构之间的相互作用更强。对负载细胞色素c的基质进行的溶解试验表明，随着戊二醛添加量增加，更多的模型蛋白被困在基质内部。
