Disclosed are macroscopic systems of highly concentrated, cross-linked biopolymers. The macroscopic system is created by combining a biopolymer with a cross-linking agent, submerging the resulting product in an aqueous solution which contains additional cross-linking agents, to allow the biopolymer to undergo a second cross-linking process. The resulting macroscopic biopolymer has an increased biopolymer concentration and increased longevity within the body.
