| 主权项 |
1. A composite structure comprising a fibril core and a polymeric porous coat coating at least a part of said fibril core, said fibril core being a fiber characterized by a tensile strength of at least 200 MPa, said coat comprising at least one hydrophilic, amphiphilic or amphipathic bioactive agent encapsulated therein and/or applied thereon, wherein:
said coat has a microstructure of a freeze-dried water-in-oil emulsion, said emulsion comprises, prior to freeze-drying, a dispersed aqueous solution and a continuous organic solution, said organic solution containing at least one second polymer and said aqueous solution containing said at least one bioactive agent, and a ratio of said organic solution and said aqueous solution is at least 8:1 and/or a concentration of said at least one second polymer ranges from 10 weight-to-volume percentages to 25 weight-to-volume percentages; and wherein a plurality of droplets of said dispersed aqueous solution freeze-dry to form microscopic capsules encapsulating said bioactive agent in a solid form of said continuous organic solution, in a form of a plurality of discrete pores randomly dispersed within said polymeric porous coat, wherein said microstructure is characterized by said plurality of discrete pores. |
