Hybrid hydrogel scaffold compositions and methods of use

Abstract

The present invention includes new hybrid hydrogel scaffolds comprised of a polyoxyethylene-polyoxypropylene (block) copolymer (a “poloxamer”) and a self-assembling peptide, which maintain the mechanical and bioactive properties of its individual constituents (as compared to when the individual constituents are scaffolds or hydrogels by themselves). The hydrogels of the invention can include a combination of materials from different origins or with different properties that provides a hybrid material that meets the multiple needs of a scaffold for tissue engineering.

What is claimed: 
     
         1 . A hybrid hydrogel scaffold, the scaffold comprising:
 (a) a self-assembling peptide; and   (b) a poloxamer;   wherein the peptide and poloxamer are present in an amount sufficient for the scaffold to provide a microenvironment that: (i) substantially prevents the aggregation of cells, (ii) promotes cell proliferation at a rate that is improved or substantially similar to a hydrogel scaffold made from the self-assembling peptide alone, and (iii) has viscoelastic properties that are improved or substantially similar to a hydrogel scaffold made from the poloxamer alone.   
     
     
         2 . The scaffold of  claim 1 , wherein the self-assembling peptide is between about 8 to about 12 amino acids in length. 
     
     
         3 . The scaffold of  claim 1 , wherein the self-assembling peptide is about 8 amino acids in length. 
     
     
         4 . The scaffold of  claim 3 , wherein the self-assembling peptide is selected from the group consisting of: KFEFKFEF (SEQ ID NO:1); FEFKFEFK (SEQ ID NO:2); RADARADA (SEQ ID NO:3); RARADADA (SEQ ID NO:4); AEAKAEAK (SEQ ID NO:5); RAEARAEA (SEQ ID NO:6); KADAKADA (SEQ ID NO:7); AEAEAHAH (SEQ ID NO:8); LELELKLK (SEQ ID NO:9); AEAEAKAK (SEQ ID NO:10); and HEHEHKHK (SEQ ID NO:11). 
     
     
         5 . The scaffold of  claim 1 , wherein the poloxamer is a block copolymer comprising polyoxypropylene (poly(propylene oxide)) (“PPO”) flanked by two hydrophilic chains of polyoxyethylene (“PEO”). 
     
     
         6 . The scaffold of  claim 5 , wherein the poloxamer has an average molecular weight between about 11,000 g/mol and 14,000 g/mol. 
     
     
         7 . The scaffold of  claim 5 , wherein the poloxamer has a polyoxyethylene content between about 60-80%. 
     
     
         8 . The scaffold of  claim 1 , wherein the scaffold was gelled from a solution comprising:
 (a) a self-assembling peptide present in an amount less than about 2% by weight in the solution; and   (b) a poloxamer present in an amount between about 15% and about 40% by weight in the solution.   
     
     
         9 . The scaffold of  claim 1 , wherein the scaffold was gelled from a solution comprising:
 (a) a self-assembling peptide between about 8 and about 12 amino acids in length that is present in an amount less than about 1% by weight in the solution; and   (b) a poloxamer that is a block copolymer comprising polyoxypropylene (poly(propylene oxide)) (“PPO”) flanked by two hydrophilic chains of polyoxyethylene (“PEO”) that is present in an amount between about 20% and 30% by weight in solution.   
     
     
         10 . The scaffold of  claim 1 , wherein the self-assembling peptide is EFK8 and wherein the poloxamer is poloxamer 407. 
     
     
         11 . The scaffold of  claim 10 , wherein the scaffold was gelled from a solution comprising EFK8 present in an amount of about 1% by weight in the solution and poloxamer 407 present in an amount of about 20% by weight in the solution. 
     
     
         12 . The scaffold of  claim 1 , further comprising one or more of the following:
 methylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, bioactive molecules, somatic cells, stem cells, nutrients, minerals, and any combination thereof.   
     
     
         13 . A method for differentiating multipotent cells, the method comprising:
 (a) mixing together in a solution at a temperature that prevents gellation:
 (i) a poloxamer consisting of a central hydrophobic block of polypropylene glycol flanked by two hydrophilic blocks of polyethylene glycol (PEG) that is present in an amount between about 20% and 30% by weight in the solution; and 
 (ii) a self-assembling peptide that is between about 8 and about 12 amino acids in length and that is present in an amount between about 0.5% and 1.5% by weight in solution; 
 such that the poloxamer and the peptide are completely dissolved in solution; 
   (b) adding and mixing the multipotent cells into the mixture of step (a);   (c) transferring the mixture of step (b) to an appropriate tissue culture well or plate;   (d) incubating the tissue culture well or plate from step (c) in conditions sufficient to induce gel formation of the mixture thereby providing a hybrid hydrogel scaffold with encapsulated multipotent cells;   (e) adding an appropriate cell growth medium to the scaffold of step (d); and   (f) differentiating the multipotent cells present in the scaffold by incubating the scaffold with an appropriate cell differentiation medium and/or growth factors.   
     
     
         14 . The scaffold of  claim 1  for use as a matrix or scaffold:
 (a) for tissue engineering applications; 
 (b) to reduce scar formation post-injury or trauma; 
 (c) to improve the appearance of preexisting scars; 
 (d) as a tissue filler agent for volume restoration of tissue defects; 
 (e) to reverse the signs of skin aging or reduce volume loss of skin; 
 (f) as an in vivo delivery mechanism for proteins, peptides, small molecules, polynucleotides, and/or nutrients; and 
 (g) as an in vivo delivery mechanism for somatic and/or stem cells. 
 
     
     
         15 . A hydrogel scaffold comprising: (a) a poloxamer and (b) a cellulose at a concentration greater than 0% (w/v) and less than about 5% (w/v). 
     
     
         16 . The scaffold of  claim 15 , wherein the cellulose is one or more of methylcellulose, carboxymethylcellulose, and hydroxypropylmethylcellulose. 
     
     
         17 . The scaffold of  claim 15 , further comprising a self-assembling peptide. 
     
     
         18 . The scaffold of  claim 15 , wherein the hybrid hydrogel also contains bioactive molecules. 
     
     
         19 . The scaffold of  claim 15 , wherein the poloxamer comprises a PEO-PPO-PEO block copolymer. 
     
     
         20 . The scaffold of  claim 19 , wherein the block copolymer has an approximate average molecular weight between about 11,000 and 14,000 g/mol and is present at about 10-20% (w/v).