Drug delivery matrices to enhance wound healing

Abstract

Bioactive molecules are entrapped within a matrix for the controlled delivery of these compounds for therapeutic healing applications. The matrix may be formed of natural or synthetic compounds. The primary method of entrapment of the bioactive molecule is through precipitation of the bioactive molecule during gelation of the matrix, either in vitro or in vivo. The bioactive molecule may be modified to reduce its effective solubility in the matrix to retain it more effectively within the matrix, such as through the deglycosylation of members within the cystine knot growth factor superfamily and particularly within the TGFβ superfamily. The matrix may be modified to include sites with binding affinity for different bioactive molecules, for example, for heparin binding.

We claim:  
     
         1 . A composition for wound healing comprising: 
 a polymeric matrix, and    a bioactive molecule, wherein the bioactive molecule is a non-glycosylated member of the cystine knot growth factor superfamily,    and wherein the molecule is physically entrapped in the polymeric matrix.    
     
     
         2 . The composition of  claim 1  wherein the bioactive molecule is a non-glycosylated member of the TGFβ superfamily.  
     
     
         3 . The composition of  claim 2 , wherein the bioactive molecule is selected from the group consisting of a non-glycosylated bone morphogenetic protein, a non-glycosylated rh-BMP-2, and a non-glycosylated platelet derived growth factor.  
     
     
         4 . The composition of  claim 1 , wherein the matrix consists essentially of natural polymers.  
     
     
         5 . The composition of  claim 4 , wherein the natural polymers are selected from the group consisting of fibrin, collagen and agarose.  
     
     
         6 . The composition of  claim 5 , wherein the matrix is fibrin.  
     
     
         7 . The composition of  claim 1 , wherein the bioactive molecule is physically entrapped by precipitation within the matrix.  
     
     
         8 . The composition of  claim 7 , wherein the matrix is fibrin and the bioactive molecule is rh-BMP-2.  
     
     
         9 . The composition of  claim 7 , wherein the matrix is fibrin and the bioactive molecule is PDGF AB.  
     
     
         10 . The composition of  claim 1  wherein the matrix consists essentially of synthetic polymers.  
     
     
         11 . The composition of  claim 10  wherein the matrix is formed of functionalized a synthetic polymer and a functionalized peptide, wherein the functionality is such that the polymer and peptide react in a Michael-type addition reaction.  
     
     
         12 . The composition of  claim 11  wherein the polymer is a polyethylenglycol comprising m conjugated unsaturated groups wherein m is at least two, 
 and the peptide comprises n thiol groups wherein n is at least two, and wherein the sum of n and m is at least five.  
 
     
     
         13 . The composition of  claim 12  wherein the conjugated unsaturated groups are selected from the group consisting of vinylsulfone and acrylate.  
     
     
         14 . The composition of  claim 11 , wherein the bioactive molecule is selected from the group consisting of rh-BMP-2 and PDGF AB.  
     
     
         15 . A kit for wound healing comprising at least a first and a second composition 
 wherein at least one of the first or second compositions comprises a biologically active molecule, wherein the biologically active molecule is a nonglycosylated member of the cystine knot growth factor superfamily, and    wherein the first and the second compositions comprise precursor components that form a three dimensional network upon mixing under conditions that allow polymerization of the precursor components.    
     
     
         16 . The kit of  claim 15  wherein the first composition comprises fibrinogen.  
     
     
         17 . The kit of  claim 15  wherein the second composition comprises thrombin.  
     
     
         18 . The kit of  claim 15  wherein the first composition comprises fibrinogen and the second composition comprises thrombin.  
     
     
         19 . The kit of  claim 15  wherein at least one of the first or second composition further comprises a calcium source.  
     
     
         20 . The kit of  claim 15  wherein the first composition comprises fibrinogen and thrombin and the second composition comprises a calcium source.  
     
     
         21 . The kit of  claim 15  wherein the first composition comprises at least one component having n nucleophilic groups wherein n is at least two, 
 and the second composition comprises at least one component having m conjugated unsaturated groups wherein m is at least two,  
 and wherein the sum of n and m is at least five.  
 
     
     
         22 . The kit of  claim 21  wherein the nucleophilic groups and the conjugated unsaturated groups are capable of reacting with each other in a base catalysed Michael-type addition reaction.  
     
     
         23 . The kit of  claim 22  wherein the nucleophilic group is a thiol.  
     
     
         24 . The kit of  claim 22  wherein the conjugated unsaturated group is selected from the group consisting of vinylsulfone and acrylate.  
     
     
         25 . The kit of  claim 23  wherein the component comprising the thiol group is selected from the group consisting of polyethylene glycol, enzymatically degradable peptides and enzymatically degradable proteins.  
     
     
         26 . The kit of  claim 24  wherein the component comprising the conjugated unsaturated group is a synthetic polymer.  
     
     
         27 . The kit of  claim 21  wherein at least one of the first and second compositions further comprises a base.  
     
     
         28 . The kit of  claim 15  wherein the first composition comprises at least one component having n nucleophilic groups wherein n is at least two, 
 and at least one component having m conjugated unsaturated groups wherein m is at least two,  
 and wherein the sum of m and n is at least five,  
 and wherein the second composition comprises at least one base.  
 
     
     
         29 . The system of  claim 28  wherein the nucleophilic groups and the conjugated unsaturated groups are capable of reacting with each other in a base catalyzed Michael-type addition reaction.  
     
     
         30 . The kit of  claim 29  wherein the nucleophilic group is a thiol.  
     
     
         31 . The kit of  claim 29  wherein the conjugated unsaturated group is selected from the group consisting of vinylsulfone and acrylate.  
     
     
         32 . The kit of  claim 30  wherein the component comprising the thiol groups is selected from the group consisting of polyethylene glycol, enzymatically degradable peptides and enzymatically degradable proteins.  
     
     
         33 . The kit of  claim 31  wherein the component comprising the conjugated unsaturated group is a synthetic polymer.  
     
     
         34 . The kit of  claim 15  wherein the bioactive molecule is a non-glycosylated member of the TGFβ superfamily.  
     
     
         35 . The kit of  claim 34  wherein the bioactive molecule is a non-glycosylated bone morphogenetic protein.  
     
     
         36 . The kit of  claim 35  wherein the bioactive molecule is selected from the group consisting of non-glycosylated rh-BMP 2 and PDGF AB.  
     
     
         37 . A device comprising a kit for wound healing, 
 wherein the kit comprises at least a first and a second composition wherein at least one of the first or second compositions comprises a biologically active molecule, wherein the biologically active molecule is a nonglycosylated member of the cystine knot growth factor superfamily, and    wherein the first and the second compositions comprise precursor components that form a three dimensional network upon mixing under conditions that allow polymerization of the precursor components    
     
     
         38 . The device of  claim 37  wherein the device is a syringe comprising at least a first and a second compartment wherein the first compartment comprises the first composition and the second compartment comprises the second composition.  
     
     
         39 . A method of forming a composition which improves wound healing, comprising 
 precipitating a bioactive molecule within a polymeric matrix,    wherein the bioactive molecule is a non-glycosylated member of the cystine knot growth factor superfamily.    
     
     
         40 . The method of  claim 39 , further comprising 
 coupling a second, different bioactive molecule to the composition, wherein the polymeric matrix includes sites with binding affinity for the second bioactive molecule and wherein the first bioactive molecule has binding affinity for the second bioactive molecule.    
     
     
         41 . The method of  claim 39 , wherein the bioactive molecule is selected from the group consisting of rh-BMP-2 and PDGF AB.  
     
     
         42 . The method of claim  40 , wherein the first bioactive molecule is rh-BMP-2 and the second bioactive molecule is heparin.  
     
     
         43 . A method for improving wound healing comprising 
 administering to a patient a therapeutically effective amount of a composition, comprising 
 a polymeric matrix, and  
 a bioactive molecule, wherein the bioactive molecule is a non-glycosylated member of the cystine knot growth superfamily,  
 and wherein the bioactive molecule is physically entrapped in the polymeric matrix.