Siloxane polymer of the general formula I comprising a central polysiloxane polymer block B, (i) which is substituted with organofunctional radicals, (ii) the polymer block B has linear and/or branched structures with at least two difunctional siloxane units, (iii) the polymer block B has on at least two terminal silicon atoms or at least one terminal and at least one lateral silicon atom on the siloxane units of polymer block B, the organofunctional radicals -Q1 and -Q2, where the radicals are identical or different, Q2-B-Q1 where -Q1 corresponds to the general formula IIa and-Q2 corresponds to the formula IIb, -Q1 = -Q1'-A-(C=O)-D-Q1"-A'-(C=O)-D'-Q1* (IIa) -Q2 = -Q2'-A-(C=O)-D-Q2"-A'-(C=O)-D'-Q2* (IIb) - where A is -NH-, -0- or -S- and D is -NH-, in each case independently in formulae IIa and IIb, - where A' is -NH- and D' is -NH-, -0- or -S-, in each case independently in formulae IIa and IIb, where each radical Q1 and Q2 of the formulae IIa or IIb has at least one bivalent urea group and one further bivalent urea or carbamate group - with Q1' and Q2' in each case independently comprising a bivalent hydrocarbon radical with 6 to 200 carbon atoms optionally comprising at least one heteroatom selected from 0, N and S, a bivalent radical comprising aryl, arylalkyl groups optionally comprising at least one heteroatom 0, N or S or polyether radicals containing alkyl, aryl or alkyl and aryl groups, - with Q1" and Q2" in each case independently comprising a bivalent linear, branched and/or cyclic alkyl radical having 4 to 200 carbon atoms or a bivalent radical comprising an aryl and/or arylalkyl radical with 6 to 200 carbon atoms, and - with -D'-Q1* and -D'-Q2* with D', as defined above, and where -D'-Q1* and -D'-Q2* in each case independently comprise radicals which are derived from an amino acid, an amino acid derivative or salts thereof. (i) which is substituted with organofunctional radicals, (ii) the polymer block B has linear and/or branched structures with at least two difunctional siloxane units, (iii) the polymer block B has on at least two terminal silicon atoms or at least one terminal and at least one lateral silicon atom on the siloxane units of polymer block B, the organofunctional radicals -Q1 and -Q2, where the radicals are identical or different, Q2-B-Q1 where -Q1 corresponds to the general formula IIa and-Q2 corresponds to the formula IIb, -Q1 = -Q1'-A-(C=O)-D-Q1"-A'-(C=O)-D'-Q1* (IIa) -Q2 = -Q2'-A-(C=O)-D-Q2"-A'-(C=O)-D'-Q2* (IIb) - where A is -NH-, -0- or -S- and D is -NH-, in each case independently in formulae IIa and IIb, - where A' is -NH- and D' is -NH-, -0- or -S-, in each case independently in formulae IIa and IIb, where each radical Q1 and Q2 of the formulae IIa or IIb has at least one bivalent urea group and one further bivalent urea or carbamate group - with Q1' and Q2' in each case independently comprising a bivalent hydrocarbon radical with 6 to 200 carbon atoms optionally comprising at least one heteroatom selected from 0, N and S, a bivalent radical comprising aryl, arylalkyl groups optionally comprising at least one heteroatom 0, N or S or polyether radicals containing alkyl, aryl or alkyl and aryl groups, - with Q1" and Q2" in each case independently comprising a bivalent linear, branched and/or cyclic alkyl radical having 4 to 200 carbon atoms or a bivalent radical comprising an aryl and/or arylalkyl radical with 6 to 200 carbon atoms, and - with -D'-Q1* and -D'-Q2* with D', as defined above, and where -D'-Q1* and -D'-Q2* in each case independently comprise radicals which are derived from an amino acid, an amino acid derivative or salts thereof. - where A is -NH-, -0- or -S- and D is -NH-, in each case independently in formulae IIa and IIb, - where A' is -NH- and D' is -NH-, -0- or -S-, in each case independently in formulae IIa and IIb, where each radical Q1 and Q2 of the formulae IIa or IIb has at least one bivalent urea group and one further bivalent urea or carbamate group - with Q1' and Q2' in each case independently comprising a bivalent hydrocarbon radical with 6 to 200 carbon atoms optionally comprising at least one heteroatom selected from 0, N and S, a bivalent radical comprising aryl, arylalkyl groups optionally comprising at least one heteroatom 0, N or S or polyether radicals containing alkyl, aryl or alkyl and aryl groups, - with Q1" and Q2" in each case independently comprising a bivalent linear, branched and/or cyclic alkyl radical having 4 to 200 carbon atoms or a bivalent radical comprising an aryl and/or arylalkyl radical with 6 to 200 carbon atoms, and - with -D'-Q1* and -D'-Q2* with D', as defined above, and where -D'-Q1*