The present invention generally relates to novel biocompatible crosslinked polysaccharide gel compositions, methods of their manufacture and use, and the novel crosslinkers used to make them. In one aspect of the invention, a novel polyethylene glycol crosslinking agent is described for crosslinking hyaluronic acid. In another aspect of the invention, novel crosslinking agents comprising more than two functional groups are described. These multifunctional crosslinking agents can be used on their own to crosslink hyaluronic acid, or they may be combined with bifunctional crosslinking agents in varying ratios to make hyaluronic acid of tunable mechanical strength and hardness. The present invention also discloses novel hyaluronic acid compositions that have been coated with polyethylene glycol and methods of their use.
