Methods for stepwise deposition of silk fibroin coatings

Abstract

The invention provides a method for the controlled assembly of layered silk fibroin coatings using aqueous silk fibroin material. The methods described herein can be used to coat substrates of any material, shape, or size. Importantly, the described methods enable control of the biomaterial surface chemistry, thickness, morphology and structure using layered thin film coatings, or bulk coatings. Furthermore, the methods can be performed in all water and do not require intensive chemical processing enabling controlled entrapment of labile molecules such as, drugs, cytokines, and even cells or viruses to generate functional coatings that can be used in a variety of applications.

What is claimed is: 
     
         1 . A composition comprising a substrate coated with silk fibroin, wherein the silk fibroin coating the substrate comprises a therapeutic agent. 
     
     
         2 . The composition of  claim 1 , wherein the composition is selected from the group consisting of vascular wound repair devices, hemostatic dressings, patches, glues, and sutures. 
     
     
         3 . The composition of  claim 1 , wherein the therapeutic agent comprises an agent for enhancing wound healing. 
     
     
         4 . The composition of  claim 1 , wherein the therapeutic agent is selected from the group consisting of antiproliferatives, antineoplastics, antiinflammatories, antiplatelets, anticoagulants, antifibrins, antithrombins, antimitotics, antibiotics, antioxidans, and combinations thereof. 
     
     
         5 . The composition of  claim 1 , wherein the composition is formulated for topical administration. 
     
     
         6 . The composition of  claim 1 , wherein the therapeutic agent is present as a liquid or a finely divided solid. 
     
     
         7 . The composition of  claim 1 , wherein the therapeutic is controlled released over a period of about 2 to about 90 days. 
     
     
         8 . The composition of  claim 1 , wherein the therapeutic agent is released in an amount of about 1 ng/day to 1 mg/day. 
     
     
         9 . The composition of  claim 1 , wherein composition further comprises an excipient. 
     
     
         10 . The composition of  claim 1 , wherein the silk fibroin coating comprises an ultrathin layer of silk fibroin. 
     
     
         11 . The composition of  claim 1 , wherein the silk fibroin coating comprises a plurality of silk fibroin layers. 
     
     
         12 . The composition of  claim 1 , wherein the substrate is selected from the group consisting of plastic, wood, glass, leather, cloth, synthetic fibers, ceramic, and metal or alloy. 
     
     
         13 . The composition of  claim 1 , wherein the substrate is selected from the group consisting of sutures, meshes, plates, screws, and cements.