A kit comprising: a) at least one oxidized polysaccharide containing aldehyde groups, said oxidized polysaccharide having a weight-average molecular weight of 1,000 to 1,000,000 Daltons and having an equivalent weight per aldehyde group of 65 to 1500 Daltons; b) at least one water-dispersible, multi-arm polyether amine wherein at least three of the arms are terminated by at least one primary amine group, said multi-arm polyether amine having a number-average molecular weight of 450 to 200,000 Daltons; and c) at least one oligomer of the formula: R1- -R2 wherein: (i) PS is a linear polymeric segment comprising ethylene oxide monomers or a combination of ethylene oxide and propylene oxide monomers, wherein said ethylene oxide monomers comprise at least 50 weight percent of said polymeric segment; (ii) R1 is at least one nucleophilic group capable of reacting with aldehyde groups to form at least one reversible covalent bond; (iii) R2 is at least one functional group which is not capable of reacting with an aldehyde, a primary amine, a secondary amine, or R1 to form a covalent bond, such that said oligomer does not induce gelation when mixed in an aqueous medium with either (a) alone or (b) alone; (iv) said oligomer has a weight-average molecular weight of 200 to 10,000 Daltons; and (v) said oligomer is water soluble. a) at least one oxidized polysaccharide containing aldehyde groups, said oxidized polysaccharide having a weight-average molecular weight of 1,000 to 1,000,000 Daltons and having an equivalent weight per aldehyde group of 65 to 1500 Daltons; b) at least one water-dispersible, multi-arm polyether amine wherein at least three of the arms are terminated by at least one primary amine group, said multi-arm polyether amine having a number-average molecular weight of 450 to 200,000 Daltons; and c) at least one oligomer of the formula: R1- -R2 wherein: (i) PS is a linear polymeric segment comprising ethylene oxide monomers or a combination of ethylene oxide and propylene oxide monomers, wherein said ethylene oxide monomers comprise at least 50 weight percent of said polymeric segment; (ii) R1 is at least one nucleophilic group capable of reacting with aldehyde groups to form at least one reversible covalent bond; (iii) R2 is at least one functional group which is not capable of reacting with an aldehyde, a primary amine, a secondary amine, or R1 to form a covalent bond, such that said oligomer does not induce gelation when mixed in an aqueous medium with either (a) alone or (b) alone; (iv) said oligomer has a weight-average molecular weight of 200 to 10,000 Daltons; and (v) said oligomer is water soluble. (i) PS is a linear polymeric segment comprising ethylene oxide monomers or a combination of ethylene oxide and propylene oxide monomers, wherein said ethylene oxide monomers comprise at least 50 weight percent of said polymeric segment; (ii) R1 is at least one nucleophilic group capable of reacting with aldehyde groups to form at least one reversible covalent bond; (iii) R2 is at least one functional group which is not capable of reacting with an aldehyde, a primary amine, a secondary amine, or R1 to form a covalent bond, such that said oligomer does not induce gelation when mixed in an aqueous medium with either (a) alone or (b) alone; (iv) said oligomer has a weight-average molecular weight of 200 to 10,000 Daltons; and (v) said oligomer is water soluble.