| 摘要 |
<p>Novel wound dressings and methods and systems for preparing them are provided herein. The wound dressing includes a substrate at least part of which is cellulosic and which has been chemically modified to have ionic-adsorbing sulfate sites thereon. A cationic form of a physiologically- or biologically-active agent is adsorbed therein. Upon contact with body exudate from wounds to which such wound dressing is applied, the physiologically- or biologically-active agent is released in a controlled manner by ion exchange with the ions in the exudate, in proportion to the amount of the exudate. This is due to the fact that the adsorption is by means of an ionic bond. The strength of such ionic bond is such that the controlled release is achieved. This controlled release thus reduces unnecessary exposure of unwounded skin surface to the physiologically-or biologically-active agent. Commercially-viable methods and systems are also provided for producing substrates for the production of such wound dressings. The method includes the steps of soaking the substrate by passing the substrate through a bath of an appropriate chemical reactant solution, and squeezing the excess solution from the soaked substrate to provide a wetted substrate. In the improved method, the following additional steps are carried out, namely, the wetted substrate is supported on a suitable backing member which substantially inhibits the escape of such solution from the environment of the wetted substrate, preferably by first cutting the wetted substrate to a selected length. The so-supported substrate is cured in a heating means to provide the derivatized substrate. The so-cured derivatized substrate is washed. Finally, the washed derivatized substrate is suitably dried.</p> |
