Medical implant based on nanocellulose

Abstract

Medical Implant ( 100 ), comprising—a microbial cellulose tube ( 1 ), comprising a wall ( 2 ) having an inner surface ( 3 ) and an outer surface ( 4 ), wherein the wall comprises several layers ( 5, 6, 7 ) of microbial cellulose, wherein said layers are concentric or substantially concentric to a longitudinal axis (L) of the tube,—a stent ( 9 ) which placed inside of the microbial cellulose tube ( 1 ), wherein an outer surface ( 10 ) of the stent contacts the inner surface ( 3 ) of the microbial cellulose tube ( 1 ), and method for producing such implant. The implant can be covered with newly created bile duct epithelium, thereby creating a new bile duct from body cells. The implant can be removed after completion of creation of the new bile duct. So, the implant as suitable as a temporary implant. The implant can be used for surgery, such as surgery of gall bladder, bile duct and/or liver, e.g. gall bladder removal, hepatobiliary malignancy surgery or liver transplantation. The implant can particularly be used for repairing or regeneration of bile duct. Further fields of use are the use as esophagus implant or urether implant.

1 .- 15 . (canceled) 
     
     
         16 . A medical implant comprising
 a microbial cellulose tube, said microbial cellulose tube comprising a wall having an inner surface and an outer surface, wherein the wall comprises several layers of microbial cellulose, wherein said layers are concentric or substantially concentric to a longitudinal axis (L) of the tube; and   a stent which placed inside of the microbial cellulose tube;   
       wherein the microbial cellulose tube is prepared by a process, the process comprising the steps of: 
       a) contacting the surface of a template which is a negative mold of a cavity of the microbial cellulose tube and of the inner wall of the cavity, with a stock mixture comprising a liquid culture medium and a cellulose-producing microorganism; 
       b) interrupting of the contact between the template and the stock mixture, wherein on the surface of the template, a liquid film remains comprising the liquid culture medium and the microorganism; 
       c) contacting of the liquid film with an oxygen-containing atmosphere and formation of microbial cellulose in and/or on the liquid film; 
       d) contacting the microbial cellulose obtained in step c) with the stock mixture; 
       e) interrupting the contact between the microbial cellulose and the stock mixture wherein on the surface of the microbial cellulose is a film of liquid is left, which comprises the liquid culture medium and the microorganism; 
       f) contacting the liquid film with an oxygen-containing atmosphere and formation of microbial cellulose in and/or on the liquid film; 
       wherein the sequence of steps d), e) and f) is repeated one or more times; 
       g) separating the microbial cellulose from the template. 
     
     
         17 . A medical implant according to  claim 16 , wherein the stent is a tubular stent. 
     
     
         18 . A medical implant according to  claim 16 , wherein an outer surface of the stent contacts the inner surface of the microbial cellulose tube. 
     
     
         19 . A medical implant according to  claim 16 , wherein the microbial cellulose tube is expanded by the stent in a radial direction (R). 
     
     
         20 . A medical implant according to  claim 16 , wherein the stent protrudes from the microbial cellulose tube at a first end of the microbial cellulose tube and a second end of the microbial cellulose tube. 
     
     
         21 . A medical implant according to  claim 16 , wherein the layers of microbial cellulose are made of fibers. 
     
     
         22 . A medical implant according to  claim 16 , wherein at least the outer surface or an outer layer of the microbial cellulose tube is porous. 
     
     
         23 . A medical implant according to  claim 16 , wherein the stent is a biliary stent, a urinary stent or a stent for esophagus. 
     
     
         24 . A medical implant according to  claim 16 , wherein the stent is made of a polymer. 
     
     
         25 . A method comprising performing surgery with a medical implant according to  claim 16 . 
     
     
         26 . A method according to  claim 25 , for use in surgery of gall bladder, hepatobiliary malignancy surgery, bile duct, esophagus, urether or liver. 
     
     
         27 . A method according to  claim 25 , wherein the surgery is repairing or regeneration of a bile duct, an esophagus lesion or an urether lesion. 
     
     
         28 . A method for producing a medical implant, comprising:
 producing a microbial cellulose tube, the method comprising the steps of:   
       a) contacting the surface of a template which is a negative mold of a cavity of the microbial cellulose tube and of the inner walls of the cavity, with a stock mixture comprising a liquid culture medium and a cellulose-producing microorganism; 
       b) interrupting of the contact between the template and the stock mixture, wherein on the surface of the template, a liquid film remains comprising the liquid culture medium and the microorganism; 
       c) contacting of the liquid film with an oxygen-containing atmosphere and formation of microbial cellulose in and/or on the liquid film; 
       d) contacting the microbial cellulose obtained in step c) with the stock mixture, 
       e) interrupting the contact between the microbial cellulose and the stock mixture wherein on the surface of the microbial cellulose is a film of liquid is left, which comprises the liquid culture medium and the microorganism; 
       f) contacting the liquid film with an oxygen-containing atmosphere and formation of microbial cellulose in and/or on the liquid film; 
       wherein the sequence of steps d), e) and f) is repeated one or more times; 
       g) separating the microbial cellulose from the template; and
 introducing a stent into the microbial cellulose tube. 
 
     
     
         29 . A medical implant comprising
 a microbial cellulose tube, said microbial cellulose tube comprising a wall having an inner surface and an outer surface, wherein the wall comprises at least two layers of microbial cellulose, wherein said at least two layers are concentric or substantially concentric to a longitudinal axis (L) of the tube; and   a stent which placed inside of the microbial cellulose tube.   
     
     
         30 . A medical implant according to  claim 17 , wherein an outer surface of the stent contacts the inner surface of the microbial cellulose tube. 
     
     
         31 . A medical implant according to  claim 17 , wherein the microbial cellulose tube is expanded by the stent in a radial direction (R). 
     
     
         32 . A medical implant according to  claim 17 , wherein the stent protrudes from the microbial cellulose tube at a first end of the microbial cellulose tube and a second end of the microbial cellulose tube. 
     
     
         33 . A medical implant according to  claim 17 , wherein the layers of microbial cellulose are made of fibers. 
     
     
         34 . A medical implant according to  claim 18 , wherein the stent protrudes from the microbial cellulose tube at a first end of the microbial cellulose tube and a second end of the microbial cellulose tube. 
     
     
         35 . A medical implant according to  claim 18 , wherein the layers of microbial cellulose are made of fibers.