Self-assembling peptide compositions

Abstract

The present disclosure provides peptide compositions (e.g., of self-assembling peptides) with particular attributes (e.g., peptide identity, peptide concentration, pH, ionic strength [including salt identity and/or concentration), etc that show particularly useful material properties. The present disclosure also provides technologies for selecting and/or formulating particular peptide compositions useful in specific contexts. In some embodiments, provided peptide compositions have an elevated pH within the range of about 2.5 to about 3.5 and/or an ionic strength that is above that of a corresponding composition of the same peptide, at the same concentration, in water, but is below a critical salt point for the peptide (e.g., so that the composition is not cloudy).

We claim: 
     
         1 . An IEIK13 composition comprising:
 an IEIK13 peptide at a concentration of at least 0.25%;   which composition has a pH within the range of about 2.5 to about 4.0.   
     
     
         2 . The composition of  claim 1 , which composition is a solution. 
     
     
         3 . The composition of  claim 1 , which composition is a gel. 
     
     
         4 . The composition of  claim 1 , wherein the composition has ionic strength within the range of about 0.0001 M to about 0.1 M. 
     
     
         5 . The composition of  claim 4 , wherein the ionic strength is adjusted/given by common salts, wherein the common salts are selected from the group consisting of NaCl, KCl, MgCl 2 , CaCl 2 , and CaSO 4 . 
     
     
         6 . The composition of  claim 4 , wherein the ionic strength is given by common salts, wherein the common salts are composed of one or more salt forming cations and one or more salt forming anions, wherein the salt forming cations are selected from the group consisting of ammonium, calcium, iron, magnesium, potassium, pyridinium, quaternary ammonium, and sodium, wherein the salt forming anions are selected from the group consisting of acetate, carbonate, chloride, citrate, cyanide, fluoride, nitrate, nitrite, and phosphate. 
     
     
         7 . The composition of  claim 1 , wherein the composition has storage modulus within the range of about 100 to about 10000 Pa at 1 rad/sec of frequency and 1 Pa of oscillation stress. 
     
     
         8 . The composition of  claim 1 , wherein the composition is buffered with sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium acetate, sodium sulfide, or DMEM. 
     
     
         9 . The composition of  claim 1 , wherein:
 the IEIK13 peptide is present at a concentration of less than 3% and/or   the composition has a pH within the range of about 3.0 to about 4.0.   
     
     
         10 . The composition of  claim 9 , which composition is a gel that exhibits a storage modulus of more than 500 Pa at 1 rad/sec of frequency and 1 Pa of oscillation stress. 
     
     
         11 . The composition of  claim 1 , wherein the composition is buffered with a sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium acetate, or sodium sulfide, so that the pH of the composition is regulated. 
     
     
         12 . A liquid peptide composition comprising:
 a peptide having a length within the range of about 6 to about 20 amino acids and an amino acid sequence of alternating hydrophobic amino acid and hydrophilic amino acids, which composition is characterized in that:
 it has a viscosity within the range of about 1 Pa-s to about 500,000 Pa-s at room temperature 
 it has a storage modulus at 1 rad/sec of frequency and 1 Pa of oscillation stress within the range of about 1 to about 5000 Pa 
 it forms a gel within a time period about 0 to about 30 s when exposed to/maintained under pH within the range of about 2.5 to about 4.0 or and/or ionic strength within the range of about 0.0001 M to about 1.5 M. 
   
     
     
         12 A. The composition of  claim 12 , which is an aqueous composition. 
     
     
         13 . The composition of  claim 12 , wherein the peptide comprises RADA16. 
     
     
         14 . The composition of  claim 12 , wherein the peptide comprises IEIK13 
     
     
         15 . The composition of  claim 12 , wherein the peptide comprises KLD12. 
     
     
         16 . The composition of  claim 12 , wherein the ionic strength is given by common salts, wherein the common salts are selected from the group consisting of NaCl, KCl, MgCl 2 , CaCl 2 , and CaSO 4 . 
     
     
         17 . The composition of  claim 12 , wherein the ionic strength is given by common salts, wherein the common salts are composed of one or more salt forming cations and one or more salt forming anions, wherein the salt forming cations are selected from the group consisting of ammonium, calcium, iron, magnesium, potassium, pyridinium, quaternary ammonium, and sodium, wherein the salt forming anions are selected from the group consisting of acetate, carbonate, chloride, citrate, cyanide, fluoride, nitrate, nitrite, and phosphate. 
     
     
         18 . The composition of  claim 12 , wherein the composition is buffered with a sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium acetate, or sodium sulfide, so that the pH of the composition is regulated. 
     
     
         19 . A method comprising steps of:
 selecting a peptide composition for application to a particular in vivo site, the method comprising steps of:   determining one or more parameters selected from the group consisting of storage modulus, viscosity, gelation time, shear-thinning property, and peptide nano-fiber re-assembly time for the peptide composition; and   comparing the determined one or more parameters to a set of characteristics determined to be appropriate for application to the particular in vivo site; and   choosing the peptide composition in light of the comparison; and   administering the chosen peptide composition to the site.