Mixed charge copolymers and hydrogels

1. A non-fouling peptide, comprising:

(a) a plurality of negatively charged repeating units polymerized from amino acid monomers selected from the group consisting of aspartic acid and glutamic acid; and

(b) a plurality of positively charged repeating units polymerized from lysine, and

wherein

the non-fouling peptide comprises at least 3 pairs of repeating units, each pair formed of a negatively charged repeating unit adjacent to a positively charged repeating unit; and

the peptide is substantially electronically neutral at pH 7.4.

2. The non-fouling peptide of claim 1 , wherein the peptide is crosslinked.

3. The non-fouling peptide of claim 1 further comprising a plurality of repeating units each having a hydrophobic pendant group.

4. The non-fouling peptide of claim 1 , wherein the negatively charged repeating unit is polymerized from glutamic acid.

5. A copolymer, consisting of:

(a) a plurality of first repeating units selected from

negatively charged repeating units polymerized from monomers selected from 2-carboxyethyl acrylate, 2-carboxyethyl acrylate, 3-sulfopropyl methacrylate, lauryl methacrylate, and D-glucuronic acid, and

repeating units having latent negatively charged groups polymerized from monomers selected from isobutyl methacrylate, 2,2,2-trifluoroethyl methacrylate, and ethyl glycolate methacrylate, reactive to provide negatively charged groups; and

(b) a plurality of second repeating units selected from

positively charged repeating units polymerized from monomers selected from 2-(dimethylamino)ethyl methacrylate, 2-(diethylamino)ethyl methacrylate, [2-(methacryloyloxy)ethyl]trimethylammonium chloride, 2-aminoethyl methacrylate hydrochloride, and N-acetylglucosamine; and

repeating units having latent positively charged groups polymerized from monomers selected from a monomer comprising an imide and a monomer comprising an oxyimino group, reactive to provide positively charged groups,

wherein:

when the copolymer consists of a plurality of negatively charged repeating units and a plurality of positively charged repeating units, the copolymer is substantially electronically neutral at pH 7.4;

when the copolymer consists of a plurality of positively charged repeating units and a plurality repeating of units having latent negatively charged groups reactive to provide negatively charged groups, the copolymer is substantially electronically neutral at pH 7.4 when the latent negatively charged groups are converted to negatively charged groups;

when the copolymer consists of a plurality of negatively charged repeating units and a plurality of repeating units having latent positively charged groups reactive to provide positively charged groups, the copolymer is substantially electronically neutral at pH 7.4 when the latent positively charged groups are converted to positively charged groups; and

when the copolymer consists of a plurality of repeating units having latent negatively charged groups reactive to provide negatively charged groups and a plurality of repeating units having latent positively charged groups reactive to provide positively charged groups, the copolymer is substantially electronically neutral at pH 7.4 when the latent negatively charged groups are converted to negatively charged groups and the latent positively charged groups are converted to positively charged groups.

6. The copolymer of claim 5 , wherein the copolymer is selected from the group consisting of:

(a) a copolymer consisting of repeating units having a latent negatively charged group derived from isobutyl methacrylate, and positively charged repeating units derived from 2-(dimethylamino)ethyl methacrylate;

(b) a copolymer consisting of repeating units having a latent negatively charged group derived from 2,2,2-trifluoroethyl methacrylate, and positively charged repeating units derived from 2-(dimethylamino)ethyl methacrylate; and

(c) a copolymer consisting of repeating units having a latent negatively charged group derived from ethyl glycolate methacrylate, and positively charged repeating units derived from 2-(dimethylamino)ethyl methacrylate.

7. The copolymer of claim 5 , wherein the copolymer is selected from the group consisting of:

(a) a copolymer consisting of negatively charged repeating units derived from 2-carboxyethyl acrylate, and positively charged repeating units derived from 2-(dimethylamino)ethyl methacrylate;

(b) a copolymer consisting of negatively charged repeating units derived from 2-carboxyethyl acrylate, and positively charged repeating units derived from 2-(diethylamino)ethyl methacrylate;

(c) a copolymer consisting of negatively charged repeating units derived from 2-carboxyethyl acrylate, and positively charged repeating units derived from [2-(methacryloyloxy)ethyl]trimethylammonium chloride;

(d) a copolymer consisting of negatively charged repeating units derived from 2-carboxyethyl acrylate, and positively charged repeating units derived from 2-aminoethyl methacrylate hydrochloride;

(e) a copolymer consisting of negatively charged repeating units derived from 3-sulfopropyl methacrylate potassium salt, and positively charged repeating units are derived from 2-(dimethylamino)ethyl methacrylate;

(f) a copolymer consisting of negatively charged repeating units derived from 3-sulfopropyl methacrylate potassium salt, and positively charged repeating units are derived from [2-(methacryloyloxy)ethyl]trimethylammonium chloride;

(g) a copolymer consisting of negatively charged repeating units derived from 3-sulfopropyl methacrylate potassium salt, and positively charged repeating units are derived from 2-(diethylamino)ethyl methacrylate;

(h) a copolymer consisting of negatively charged repeating units derived from 3-sulfopropyl methacrylate potassium salt, and positively charged repeating units derived from 2-aminoethyl methacrylate hydrochloride;

(i) a copolymer consisting of negatively charged repeating units derived from 2-carboxyethyl acrylate, and positively charged repeating units derived from 2-(dimethylamino)ethyl methacrylate;

(j) a copolymer consisting of negatively charged repeating units derived from 2-carboxyethyl acrylate, and positively charged repeating units derived from 2-(diethylamino)ethyl methacrylate;

(k) a copolymer consisting of negatively charged repeating units derived from 2-carboxyethyl acrylate, and positively charged repeating units derived from [2-(methacryloyloxy)ethyl]trimethylammonium chloride;

(l) a copolymer consisting of negatively charged repeating units derived from 2-carboxyethyl acrylate, and positively charged repeating units derived from 2-aminoethyl methacrylate hydrochloride;

(m) a copolymer consisting of negatively charged repeating units derived from 3-sulfopropyl methacrylate potassium salt, and positively charged repeating units derived from 2-(dimethylamino)ethyl methacrylate;

(n) a copolymer consisting of negatively charged repeating units derived from 3-sulfopropyl methacrylate potassium salt, and positively charged repeating units derived from [2-(methacryloyloxy)ethyl ]trimethylammonium chloride;

(o) a copolymer consisting of negatively charged repeating units derived from 3-sulfopropyl methacrylate potassium salt, and positively charged repeating units derived from 2-(diethylamino)ethyl methacrylate; and

(p) a copolymer consisting of negatively charged repeating units derived from 3-sulfopropyl methacrylate potassium salt, and positively charged repeating units derived from 2-aminoethyl methacrylate hydrochloride.

8. The copolymer of claim 5 , wherein the ratio of the number of the negatively charged repeating units or the repeating units having latent negatively charged groups to the number of the positively charged repeating units or repeating units having latent positively charged groups is from about 1:1.1 to about 1:0.9.