Device for release of chemical molecules using pressure-generated rupture of reservoirs

Abstract

Devices are provided for controlled release of chemical molecules, such as drugs or diagnostic agents. The devices comprises a substrate; a plurality of discrete reservoirs located in the substrate, wherein the reservoirs each have at least one opening at a surface of the substrate; chemical molecules, for release, disposed in the reservoirs; a rupturable barrier layer closing the at least one opening; and a pressure generating material disposed in the reservoirs, the pressure generating material being selected from the group consisting of water-swellable materials, osmotic pressure generating materials, and combinations thereof, wherein the chemical molecules can be selectively released from each reservoir by rupturing of the barrier layer, due to pressure generated by the pressure generating material.

1 . A device for controlled release of chemical molecules comprising: 
 a substrate;    a plurality of discrete reservoirs located in the substrate, wherein the reservoirs each have at least one opening at a surface of the substrate;    chemical molecules, for release, disposed in the reservoirs;    a rupturable barrier layer closing the at least one opening; and    a pressure generating material disposed in the reservoirs, the pressure generating material being selected from the group consisting of water-swellable materials, osmotic pressure generating materials; and combinations thereof,    wherein the chemical molecules can be selectively released from each reservoir by rupturing of the barrier layer, due to pressure generated by the pressure generating material.    
     
     
         2 . The device of  claim 1 , wherein each reservoir has a second opening which is closed by a second barrier layer.  
     
     
         3 . The device of  claim 2 , wherein the second barrier layer comprises a discrete reservoir cap.  
     
     
         4 . The device of  claim 3 , further comprising a power source and control circuitry for disintegrating the reservoir cap.  
     
     
         5 . The device of  claim 2 , wherein the reservoir is separated between the two openings into a first space and a second space by a fluid-tight, flexible structure that allows a change in pressure within the first space to affect the pressure in the second space while maintaining separation of the contents of the first and second spaces.  
     
     
         6 . The device of  claim 5 , wherein the first space is proximate the first opening and contains the chemical molecules for release and the second space is proximate the second opening and contains the pressure generating material.  
     
     
         7 . The device of  claim 6 , wherein the second barrier layer comprises a semi-permeable barrier layer and the pressure generating material comprises an osmotic pressure generating material, and wherein pressure generated by the osmotic pressure generating material causes the first barrier layer to rupture to release the chemical molecules while the second barrier layer remains intact.  
     
     
         8 . The device of  claim 7 , further comprising a reservoir cap covering the semi-permeable barrier layer.  
     
     
         9 . The device of  claim 8 , further comprising a power source and control circuitry for disintegrating the reservoir cap.  
     
     
         10 . The device of  claim 1 , wherein the pressure generating material and the chemical molecules are mixed together, and a semi-permeable layer is provided between the opening of the rupturable barrier layer and the mixture, and wherein pressure generated by the pressure generating material causes the semi-permeable layer and the rupturable barrier layer to both rupture to release the chemical molecules.  
     
     
         11 . The device of  claim 10 , wherein the rupturable barrier layer is a reservoir cap covering the semi-permeable barrier layer.  
     
     
         12 . The device of  claim 11 , further comprising a power source and control circuitry for disintegrating the reservoir cap.  
     
     
         13 . The device of  claim 1 , wherein the pressure generating material is a swellable polymer.  
     
     
         14 . The device of  claim 1 , wherein the chemical molecules are selected from the group consisting of proteins, nucleic acids, polysaccharides, and cells.  
     
     
         15 . The device of  claim 1 , wherein the chemical molecules comprise organic molecules.  
     
     
         16 . The device of  claim 1 , wherein the chemical molecules comprise a diagnostic agent.  
     
     
         17 . The device of  claim 1 , further comprising a microprocessor-controlled actuation means for rupturing the barrier layer.  
     
     
         18 . The device of  claim 1 , wherein the rupturable barrier layer comprises a metal film.  
     
     
         19 . The device of  claim 1 , which biocompatible and suitable for implantation into a patient.  
     
     
         20 . A method for the controlled release of chemical molecules comprising: 
 providing the device of  claim 1  at a site for release; and    generating pressure, with the pressure generating material, in at least one reservoir, effective to rupture the barrier layer covering the reservoir,    thereby opening the reservoir and permitting the release of the chemical molecules at the site.