Immobilized Metallic Nanoparticles as Unique Materials for Therapeutic and Biosensor Applications

Abstract

The present invention relates to compositions and methods by which surface modification techniques can be used to modify wide range polymeric or metal substrates using metal nanoparticles.

1 . A method for making a metal substrate comprising metallic nanoparticles, said method comprising:
 obtaining a metal substrate and optionally etching said surface;   contacting said metal substrate with a composition comprising a metal for forming metallic nanoparticles;   and optionally washing said metal substrate following said contact, thereby making a metal substrate comprising metallic nanoparticles.   
     
     
         2 . The method of  claim 1 , wherein said metal substrate comprises a metal film. 
     
     
         3 . The method of  claim 2 , wherein said metal substrate comprises titanium. 
     
     
         4 . The method of  claim 2 , wherein said metal substrate is etched. 
     
     
         5 . The method of  claim 4 , wherein said metal substrate is etched with NaOH. 
     
     
         6 . The method of  claim 2 , wherein said metal substrate is contacted with a composition comprising silver. 
     
     
         7 . The method of  claim 6 , wherein said composition comprises silver nitrate. 
     
     
         8 . The method of  claim 6 , wherein said metallic nanoparticles are silver nanoparticles. 
     
     
         9 . The method of  claim 4 , wherein said metal substrate is washed after etching. 
     
     
         10 . The method of  claim 2 , wherein said metal substrate is washed after contact with said composition. 
     
     
         11 . The method of  claim 2 , wherein the nanoparticles range in size from about 1.0 nm to about 100 nm. 
     
     
         12 . The method of  claim 11 , wherein the nanoparticles range in size from about 2.0 nm to about 75 nm. 
     
     
         13 . The method of  claim 12 , wherein the nanoparticles range in size from about 3.0 nm to about 50 nm. 
     
     
         14 . The method of  claim 13 , wherein the nanoparticles range in size from about 4.0 nm to about 25 nm. 
     
     
         15 . The method of  claim 14 , wherein the nanoparticles range in size from about 5.0 nm to about 10.0 nm. 
     
     
         16 . The method of  claim 4 , wherein said metal substrate is etched for up to 48 hours. 
     
     
         17 . The method of  claim 16 , wherein said metal substrate is etched for up to 24 hours. 
     
     
         18 . The method of  claim 2 , wherein said metal substrate is contacted with said composition for up to 48 hours. 
     
     
         19 . The method of  claim 18 , wherein said metal substrate is contacted with said composition for up to 24 hours. 
     
     
         20 . The method of  claim 2 , wherein said method immobilizes said metallic nanoparticles on said metallic substrate. 
     
     
         21 . A metal substrate comprising immobilized metallic nanoparticles made according to  claim 1 . 
     
     
         22 . The method of  claim 2 , wherein said metallic nanoparticles are useful as a therapeutic agent or as a biosensor. 
     
     
         23 . The method of  claim 22 , wherein said metal substrate comprising metallic nanoparticles comprises at least one additional therapeutic agent. 
     
     
         24 . The method of  claim 22 , wherein said metallic nanoparticle is useful as an antimicrobial. 
     
     
         25 . A method of making polymeric substrates comprising metallic nanoparticles, said method comprising;
 forming a photoactive polymer by contacting a polymer comprising a reactive group with an aromatic azide or aliphatic azide;   contacting said photoactive polymer with said polymeric substrate;   immobilizing said photoactive polymer to said polymeric substrate by irradiation;   contacting said polymeric substrate comprising immobilized photoactivated polymers with a composition comprising a metal for forming metallic nanoparticles and optionally washing said substrate after said contact;   thereby making polymeric substrates comprising metallic nanoparticles.   
     
     
         26 . The method of  claim 25 , wherein said polymeric substrate is polystyrene. 
     
     
         27 . The method of  claim 25 , wherein said polymer comprising a reactive group is selected from the group consisting of poly(acrylic acid), alginica acid, heparin, and chondroitin sulfate. 
     
     
         28 . The method of  claim 25 , wherein said azidated polymer is purified following azidation. 
     
     
         29 . The method of  claim 28 , wherein said purified azidated polymer is dried. 
     
     
         30 . The method of  claim 29 , wherein before contacting said polymeric substrate said dried purified azidated polymer is resuspended at concentrations selected from the group consisting of 10 mg/ml, 5.0 mg/ml, 1.0 mg/ml, and 0.05 mg/ml. 
     
     
         31 . The method of  claim 25 , wherein said irradiation is ultraviolet irradiation. 
     
     
         32 . The method of  claim 31 , wherein the wavelength of said ultraviolet irradiation is about 275 nm. 
     
     
         33 . The method of  claim 25 , wherein the composition comprises silver. 
     
     
         34 . The method of  claim 33 , wherein the immobilized silver is reduced from silver ion to silver metal. 
     
     
         35 . The method of  claim 33 , wherein the silver nanoparticles are made using ammoniacal polysaccharides. 
     
     
         36 . The method of  claim 25 , wherein said polymers are applied in patterns. 
     
     
         37 . A polymeric substrate comprising metallic nanoparticles made by the method of  claim 25 . 
     
     
         38 . The method of  claim 25 , wherein the nanoparticles range in size from about 1.0 nm to about 100 nm. 
     
     
         39 . The method of  claim 38 , wherein the nanoparticles range in size from about 2.0 nm to about 75 nm. 
     
     
         40 . The method of  claim 39 , wherein the nanoparticles range in size from about 3.0 nm to about 50 nm. 
     
     
         41 . The method of  claim 40 , wherein the nanoparticles range in size from about 4.0 nm to about 25 nm. 
     
     
         42 . The method of  claim 41 , wherein the nanoparticles range in size from about 5.0 nm to about 10.0 nm. 
     
     
         43 . A pharmaceutical composition comprising at least on surface active copolymer and metallic nanoparticles, wherein said composition has the same transition phase characteristics as an otherwise identical pharmaceutical composition without metallic particles. 
     
     
         44 . The composition of  claim 43 , wherein said metallic nanoparticles are silver nanoparticles. 
     
     
         45 . The composition of  claim 44 , wherein said surface active copolymers are selected from the group consisting of poloxamer, meroxapol, and poloxamine. 
     
     
         46 . The method of  claim 43 , wherein said composition comprises PluroGel™. 
     
     
         47 . A pharmaceutical composition comprising PluroGel™ and metallic nanoparticles. 
     
     
         48 . The pharmaceutical composition of  claim 47  wherein said metallic nanoparticles are silver nanoparticles. 
     
     
         49 . A thermo-gelling solution comprising chitosan and an inorganic salt, wherein said thermo-gelling solution is a solution at a pH between about 6.0 and about 8.0 and at a temperature below about 20° C., further wherein said solution forms a gel within a temperature range from about 20° C. to about 50° C., further wherein said solution comprises metallic nanoparticles. 
     
     
         50 . The thermo-gelling solution of  claim 49 , wherein said metallic nanoparticles are silver nanoparticles. 
     
     
         51 . A method of making a tri-layer membrane comprising metallic nanoparticles for use as a therapeutic agent or a biosensor, said method comprising:
 preparing a chitosan solution;   preparing a carboxymethyl chitosan solution;   applying a first layer of solution to a surface and allowing said solution to dry;   applying a second layer comprising the other solution to the dried first layer and allowing said second layer to dry;   applying a third layer of the same solution as applied for the first layer over the second layer and allowing the third layer to dry;   optionally heating the dried layers;   neutralizing the dried layers;   contacting the three layers with a composition comprising a metal for forming metallic nanoparticles;   thereby making a tri-layer membrane comprising metallic nanoparticles.   
     
     
         52 . The method of  claim 51 , wherein said composition comprising a metal is silver nitrate. 
     
     
         53 . The method of  claim 51 , wherein said metal is sliver. 
     
     
         54 . The method of  claim 51 , wherein said composition comprising a metal is contacted with said three layers for at least about 48 hour. 
     
     
         55 . The method of  claim 54 , wherein said composition is contacted with said three layers for at least about 24 hours. 
     
     
         56 . The method of  claim 55 , wherein said composition is contacted with said three layers for at least about 12 hours. 
     
     
         57 . The method of  claim 56 , wherein said composition is contacted with said three layers for at least about 6 hours. 
     
     
         58 . The method of  claim 57 , wherein said composition is contacted with said three layers for at least 3 hours. 
     
     
         59 . The method of  claim 58 , wherein said composition is contacted with said three layers for at least about 1 hour. 
     
     
         60 . The method of  claim 51 , wherein said composition is contacted with said three layers for about 24 hours or less. 
     
     
         61 . The method of  claim 51 , wherein said three layers are neutralized with NaOH. 
     
     
         62 . The method of  claim 51 , wherein said second layer comprises carboxymethyl cellulose. 
     
     
         63 . The method of  claim 51 , wherein each layer is dried at about 80° C. 
     
     
         64 . The method of  claim 51 , wherein said chitosan solution comprises about 2% chitosan. 
     
     
         65 . The method of  claim 51 , wherein said carboxymethyl chitosan solution comprises about 2% carboxymethyl chitosan. 
     
     
         66 . A method for culturing mammalian cells on a metal substrate made according to  claim 1 , said method comprising contacting said metal substrate with a composition comprising at least one mammalian cell type, allowing the cells to attach, and maintaining said cells in culture. 
     
     
         67 . The method of  claim 66 , wherein said metal substrate is a titanium substrate. 
     
     
         68 . The method of  claim 67 , wherein said titanium substrate comprises metallic nanoparticles. 
     
     
         69 . The method of  claim 68 , wherein said metallic nanoparticles are silver nanoparticles. 
     
     
         70 . The method of  claim 66 , wherein said mammalian cells are selected from the group consisting of stem cells, pluripotent stem cells, committed stem cells, embryonic stem cells, adult stem cells, bone marrow stem cells, bone marrow-derived stem cells, adipose stem cells, umbilical cord stem cells, dura mater stem cells, precursor cells, differentiated cells, osteoblasts, osteoclasts, myoblasts, neuroblasts, fibroblasts, glioblasts, germ cells, hepatocytes, chondrocytes, keratinocytes, smooth muscle cells, cardiac muscle cells, connective tissue cells, glial cells, epithelial cells, endothelial cells, hormone-secreting cells, cells of the immune system, normal cells, cancer cells, Schwann cells, and neurons. 
     
     
         71 . The method of  claim 70 , wherein said cells are human cells. 
     
     
         72 . The method of  claim 71 , wherein said human cells are bone marrow-derived mesenchymal stem cells.