Variable permeability bone implants, methods for their preparation and use

摘要

The present invention involves filler for treating injured tissue sites made from compositions having variable permeability to bodily fluid to reduce the flow to these fluids (bleeding) from the site of injury into the surrounding tissue. The fillers are prepared by dispersing a pore-forming agent in a polymer with agitation. Density developing a variable concentration of pore-forming agent throughout the polymer through application of an external force acting on the mixture so that a portion of the filler has a variable impermeability to bodily fluids. After agitation and/or density development, the pore-forming agent is leached from the mixture to form a polymer matrix having variable permeability. Alternatively, the compositions can be made by fixedly combining a permeable material with an impermeable material to form a filler with reduced permeability to bodily fluid flow.