NOVELTY - A hydrophobic peptide and/or peptidomimetic capable of forming a hydrogel, is new.    USE - The hydrophobic peptide and/or peptidomimetic is useful for forming a hydrogel, where the hydrogel is for use in producing a wound dressing or wound healing agent, a surgical implant, or stent, a pharmaceutical and/or cosmetic composition and/or a biomedical device and/or electronic device; for use in the in vitro or in vivo method of tissue regeneration; for the treatment of a wound and for wound healing; for use in a bioimaging device for in vitro and/or in vivo use, preferably for oral application, for injection and/or for topical application; and for producing a 2D or 3D cell culture substrate. Also, the hydrogel is used in at least one of the following: medical tool kit, a fuel cell, a solar cell, an electronic cell, regenerative medicine and tissue regeneration, implantable scaffold disease model wound healing, stem cell therapy, injectable therapies, biosensor development, high-throughput screening, biofunctionalized surfaces, biofabrication, such as bio-printing, and gene therapy (all claimed).    ADVANTAGE - The hydrophobic peptide and/or peptidomimetic is stable in aqueous solution at physiological conditions at ambient temperature for a period of 1 day to at least 6 months, preferably to at least 12 months, and stable in aqueous solution at physiological conditions, at a temperature up to 90 degrees C, for at least 1 hour. It also produces hydrogel with various uses, such as in regenerative medicine, injectable therapies, delivery of bioactive moieties, wound healing, 2D and 3D synthetic cell culture substrate, biosensor development, biofunctionalized surfaces, and biofabrication.    DETAILED DESCRIPTION - A hydrophobic peptide and/or peptidomimetic capable of forming a hydrogel, the hydrophobic peptide and/or peptidomimetic having the general formula: Z-(X)a-Z'b, is new.    Z=an N-terminal protecting group;    X=aliphatic amino acids and aliphatic amino acid derivatives, and where the overall hydrophobicity decreases from N- to C-terminus;    a=2-7, preferably 2-6;    Z'=a C-terminal group; and    b=0 or 1.    INDEPENDENT CLAIMS are:    (1) a composition or mixture comprising: (a) at least one hydrophobic peptide and/or peptidomimetic; and (b) at least one hydrophobic peptide and/or peptidomimetic capable of forming a hydro gel, the hydrophobic peptide and/or peptidomimetic having the general formula: Z-(X)a-N'b;    (2) a hydrogel comprising the hydrophobic peptide and/or peptidomimetic;    (3) a method of preparing the hydrogel, comprising dissolving a hydrophobic peptide and/or peptidomimetic in an aqueous solution;    (4) a wound dressing or wound healing agent comprising the hydrogel;    (5) a surgical implant, or stent, the surgical implant or stent comprising a peptide and/or peptidomimetic scaffold, where the peptide and/or peptidomimetic scaffold is formed by the hydrogel;    (6) a pharmaceutical and/or cosmetic composition and/or a biomedical device and/or electronic device comprising the hydrophobic peptide and/or peptidomimetic;    (7) a kit of parts, comprising a first container with the hydrophobic peptide and/or peptidomimetic and a second container with an aqueous solution;    (8) an in vitro or in vivo method of tissue regeneration, comprising: (a) providing the hydrogel; (b) exposing the hydrogel to cells which are to form regenerated tissue; and (c) allowing the cells to grow on the hydrogel;    (9) a method of treatment of a wound and for wound healing, comprising applying an effective amount of the hydrogel or the pharmaceutical composition to a wound;    (10) a bioimaging device comprising the hydrogel for in vitro and/or in vivo use, preferably for oral application, for injection and/or for topical application; and    (11) a 2D or 3D cell culture substrate comprising the hydrogel.    N'=a non-polar C-terminal group which differs from Z', and is preferably carboxylic acid, amide, alcohol, biotin, maleimide, sugars, and hydroxyacids; and    b=0 or 1.