Encapsulation Procedure to Isolate Components from Body Fluids

摘要

The program was designed to provide the fabrication and testing of impermeable-inclusion-loaded, medically-acceptable encapsulation materials. The goals of the program were to develop encapsulation materials and techniques that will effectively isolate implanted components from body fluids, while retaining other necessary properties. The technical approach is to load a standard, medically-acceptable, encapsulation material with impermeable inclusions which will partially block the diffusive path within the base material. In this way a less permeable coating material is formed while mechanical properties and surface characteristics are retained. Seventeen separate aggregate formulations were prepared from basic filler and encapsulating materials selected from strength, toughness, permeability and biological acceptability considerations. The most promising were determined to be glass bubble microspheres uniformly distributed at concentrations up to 70 per cent by volume in medical-grade RTV elastomer; samples of which were further subjected to standard strength, toughness, permeability and absorption tests. Test results are reported and discussed. The results of the permeability tests and their interpretation using predictive models, developed for diffusive penetration of the samples, indicate that significant potentials exist (up to 1000-fold improvements) for the inclusion-loading technique. The present results, however, display only marginal improvements. Recommendations are given for progressing beyond the present limitations. (Author)