Preparation of Hemoglobin-Containing Microcapsules.

Abstract : Microcapsules containing stroma-free hemoglobin (SFHb) were prepared from ethyl cellulose (EC), lecithin-protein-polysaccharide complexes, and protein-polysaccharide complexes. The EC microcapsules were prepared in small-scale experiments in sizes ranging from 0.8 to 1.2 micrometer, with wall thickness of 0.02 to 0.03 micrometer. these microcapsules had good stability and showed oxygen-carrying properties comparable with those of STFHb. However, in scale-up experiments with EC, the Hb was denatured. The microcapsules made from complexes of lecthin-gelatin-gum arabic, lecithin-gelatin-chondroitin sulfate, and lecithin-gelatin-carrageenan were generally large, 10 to 15 micrometer, and had irregular shapes and thick walls. In some of the experiments with these systems the Hb was crosslinked when the capsules were hardened. The microcapsules made from gelatin-chondroitin sulfate complexes were prepared in aqueous media, and although some of the early capsules had irregular shapes, spherical capsules were made by improving the procedure. These capsules ranged from 3 to 12 micrometer and the Hb in the capsules retained its ability to reversibly combine with oxygen,