1. A stimulus-responsive soluble PEG hydrogel containing a matrix of PEG polymers modified to contain at least one multifunctional composite protein that contains as components a substrate binding peptide (SBP), a repeating RGD binding peptide, at least one N-and / or C-terminal linker and preferably a purification label in which at least one multifunctional composite protein is covalently linked to the PEG polymer. 2. The stimulus-responsive soluble PEG hydrogel according to claim 1, wherein the PEG polymer is a multi-beam star-shaped polymer, preferably from 3 to 15-beam star-shaped PEG polymer. The stimulus-responsive soluble PEG hydrogel according to claim 1, wherein the substrate binding peptide (SBP) is selected from the N-terminal sequence of the Escherichia coli DNA gyrase B subunit (GyrB), from the N-terminal sequence of the DNA gyrase B subunit Escherichia coli according to SEQ ID NO: 2 or an amino acid sequence showing at least 80%, preferably at least 90%, more preferably at least 95% and even more preferably at least 97.5% sequence identity according to SEQ ID NO : 2, or from proteins FKBP, FM, ToxT, DHFR, Cyp, E, PIP, Te tR, ArgR, ArsR, HucR, FRB, streptavidin, avidin, neutravidin, steroid hormone receptor, steroid hormone, heparin binding protein, member of the lipocalin family, FluA, FluA according to SEQ ID NO: 55, DigA, DigA according to SEQ ID NO: 57, SABP2, SABP2 according to SEQ ID NO: 59 or 61, or FKBP42 according to SEQ ID NO: 64, or an scFv fragment according to SEQ ID NO: 69, or from a nucleic acid sequence encoding these substrate binding peptides (SBP), or following1. Реагирующий на стимул растворимый ПЭГ-гидрогель, содержащий матрицу из ПЭГ-полимеров, модифицированных таким образом, чтобы содержать по меньшей мере один многофункциональный составной белок, который содержит в качестве компонентов субстрат-связывающий пептид (SBP), повторяющийся RGD-связывающий пептид, по меньшей мере один N-и/или C-концевой линкер и предпочтительно метку оч