#$%^&*AU2013273820A120140116.pdf#####TUNABLY CROSSLINKED HYALURONIC ACID COMPOSITIONS The present invention relates to biocompatible crosslinked hyaluronic acid gel compositions, methods of their manufacture and use, and the crosslinkers used to make them. In one aspect of the invention, a polyethylene glycol crosslinking agent is described for crosslinking hyaluronic acid preferably a multifunctional one like 4-Arm Star PEG. In another aspect of the invention, 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 hyaluronic acid compositions that have been coated with polyethylene glycol and methods of their use.
